TW398084B - Multilayered indium-containing nitride buffer layer for nitride epitaxy - Google Patents

Abstract

A semiconductor device includes a substrate (2) a buffer or nucleation structure, and an active structure (6) containing its circuit elements. The nucleation layer is fabricated at a relatively low temperature, and includes at least one layer made of a III-V nitride compound containing indium. In a multilayer structure (eg. F16.5). At least one of these layers, preferably the one (18) directly deposited on the substrate (2), is made of an indium-containing III-V nitride compound, and serves as a buffer layer. In subsequent AllnGaN epitaxy, the indium-containing layers relax. Reductions in stress and cracking result, allowing more flexibility in composition and doping modulation. Since the electrical and optical properties of the device depend on the stress and strain states present in its active structure, these properties can be tailored by controlling the composition and layer thickness of the nucleation layer. Indium-containing nitrides having advantageously high quality can be grown at relatively low temperatures.

Description

V. Description of the invention (1) Printed by the Consumer Cooperative of the Central Bureau of Standards of the Ministry of Economics Field of the Invention The present invention is roughly related to the field of semiconductor devices and their manufacturing. In particular, the present invention relates to a combination of thin film deposited layers on pre-existing materials and / or existing layers. The invention is particularly applicable to optoelectronic devices such as S-light diodes (LEDs). BACKGROUND OF THE INVENTION The basic idea The outline of a semiconductor manufacturing process begins with a substrate such as a silicon wafer and a doped-series patterning layer on the wafer. Each layer includes a doped semiconductor material, an insulating layer such as an oxide, and the like. The pattern is produced using photoresist, anti-corrosion, etching and other techniques. The patterning layer constitutes the active layer, which has the functions predetermined by the circuit elements and circuit designers. The pattern defines circuit devices and interconnections between devices, so the resulting semiconductor device is functional. 1. Membrane composition Shi Xi (Ge) and germanium (Ge) are from the column of the periodic table of the element 1 ¥, are common elements for semiconductor manufacturers. Particularly many substrates are made of silicon. Among them, the substrates include supervised gemstones (8, 203), gallium gallium (GaAs), and carbide carbide (SiC). The materials commonly used in the manufacture of semiconductor devices and special optoelectronic devices are the combination of elements of Periodic Table III and column V, commonly known as, ΠΙ_ν, compounds. The m element includes aluminum (A1) 'gallium (Ga) and indium (In). The v elements include arsenic (As), scale (P) and nitrogen (N). Perhaps the most commonly used m_v compound is gallium arsenide (GaAs). A group of III-V compounds are collectively called nitrides and are used to produce patterned layers. In particular, nitrides have proven useful in light-emitting diode (LED) technology. The nitride compound includes one or more III block elements together with V block nitrogen (N). This paper size applies to Chinese National Standard (CNS) A4 (210X297 mm) (Please read the precautions on the back page first) Binding Line -4-

Description of the invention (2). For example, if only gallium from column III is used, the nitride compound is gallium nitride (GaN). It is also common to include mixtures of elements from column III. Such compounds are, for example, Ii ^ Ga ^ xN or AlxGai-χN]! ’Here the value of the subscript (total 1) reflects the ratio of the various III elements used. Various materials listed above are used to deposit patterned layers that make up the active structure. One example is Takeuchi et al. US Patent No. 5,389,571, a method for manufacturing a gallium nitride-based semiconductor device using an intermediate layer containing aluminum and nitrogen, and describes a device having (Ga ^ AlA.ylnyN nitride material crystal as part of its active structure. 2 3. Thin film lattice properties Generally speaking, semiconductor materials are crystalline lattices. It means that the atomic systems that make up the material are arranged in a regular pattern such as columns, planes, and unit cells. Many different crystal structures are available. Specific lattices The formation is a characteristic of the material that composes the crystal lattice. Various factors such as the ionic semi-control of the elements that make up the material affect the type of crystal lattice configuration that a particular element or compound has. Especially when the film-bound semiconductor material is deposited on the substrate, it forms the main It is a film-substrate interface at the ear surface. In the case of nitride compounds, the most observed lattice configuration is hexagonal, or fiber, and the i-shaped hexagonal lattice unit is shown in Figure i. The simplest representative figure. The unit cell has hexagonal edges aa and y, and the plane has a hexagonal cross section (for example, called, horizontal ", And the vertical horizontal plane travels in the axial direction (labeled ,, vertical ,,). In order to describe the specific position of the hexagonal coordinate space, four axes are used. Among them, the three axes are in the horizontal plane and the angle between them is called & and ~. The fourth axis is marked as C on the vertical plane. V. Description of the invention (3) A7 B7 Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs, the coordinate system uses the labeling method (a, ia 'heart, 4), here Plane intersection and the reciprocal of the specified drawing coordinates. Yu-: The value used when the surface does not cross another axis (that is, the plane is parallel to the axis) is ^ For example, the simplest and most convenient plane—the top surface. The top surface of the intersecting early-stage cell is hexagonal. This plane is commonly known as, the base plane is parallel to all three axes. The plane of this base plane is labeled (0001). &Quot; The lattice of thin films that make up semiconductor devices is often It is described in terms of lattice parameters. The nitride film is roughly formed in a hexagonal lattice structure, the base surface is oriented parallel to the substrate surface, and the interface between the parallel substrate surface and the film is oriented. Thus, the "a_axis" indicates three directions Any of the _direction parallel film_ The material interface is 120 degrees apart from each other. "C_axis, which indicates the direction of the vertical film_substrate interface. Crystal lattices such as the film layer described in this specification are described with parameter values such as" lattice constant, And, the coefficient of thermal expansion, (detailed later). The values of these parameters are expressed by the a-axis and c-axis of the hexagonal coordinate system. However, there is no difference in the parameters of the crystal lattices in the & _ axis. Therefore, one more axis parameter is needed for description. Such a parameter value is sufficient to describe the parallel nature of the interface of the thin film lattice. In the case of a hexagonal crystal system, for example, nitride uses only a single a-axis parameter. However, usually the vertical thin film-based The properties of the thin film lattice in the direction of the interface of the material are different from the properties of the thin film lattice in the direction of the parallel interface. Therefore, the b-axis parameters usually have different values from the corresponding a-axis parameters. The a-pump and c-axis related parameters of the thin film lattice are usually related to the interval (ie, Ga-Ga or N-N separation distance) between two adjacent atoms of the same type in a lattice structure in a predetermined direction along each axis. This paper size applies to China National Standard (CNS) A4 (210X: Z97 mm) Please read the notes on the back side of the binding line -6- Printed on the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs A7 B7 5. Description of the Invention (4) One of the parameters is the lattice constant, which is a measurement of the atomic interval. The other parameter is the coefficient of thermal expansion, which is the expansion or contraction of the lattice parameter in response to a change in temperature, expressed as the change in the distance between each degree of temperature change. As mentioned above, a lattice is formed according to the properties of the specific substance that composes the lattice. In particular, the atomic half 彳 f can determine the fa1 distance, which determines the values of the a-axis and c_-axis. 〆 But when the S-sheet is newly formed on the substrate or formed on the earlier deposited film, the a-axis parameters of the new film tend to follow the a-axis parameters below it. The lower lattice forces the a_axis parameters of the new layer to be different from the & _axis parameters of the new film. Therefore, stress is applied to the new film. ^ In addition, when the a-axis parameters of the newly deposited film are affected by the underlying lattice structure, the c. Axis parameters of the film are also affected. Here again, force is applied to the new film crystal. If the crystal lattice is compatible with the crystal lattice below it, the new film layer will be called, "In other words, the atomic plane will cross the interface between the two materials continuously and will be distorted." If the lattice is lumped, the thin filaments will remain aligned due to the dry stress: in other words, the atoms that make up the thin film lattice can be squeezed closer or pulled apart further away, there will be no alignment stress. The lattice is overstressed and cannot be maintained. It tends to include heterogeneity. 'Ectopic belongs to the -type lattice structure defect between the material and the film _ said ^, when there is a large difference in parameters, the film lattice tends to By skipping the columns or inserting an additional column, the original heterogeneous stress causes a lattice atom itself to face the substrate lattice. When ectopic to some degree ^ = This paper size applies to X 2 Saki ·

-7- When it is unavoidable that the sun-daddy father interface of the invention description (5) is unavoidable, it is desirable to reduce the ectopic. Because there is a great mismatch between commonly used nitride materials and the substrate, the nitride film layer often appears ectopic. 2. The lattice structure form may also have spot defects with scattered locations. Point defects The lattice at the position of the atom may be a vacancy, and an impurity atom replaces one atom in the lattice mother value. Point defects must also be minimized. Clean manufacturing equipment and precisely controlled manufacturing environment conditions can help reduce point defects ... The technology commonly used to deposit layers is called, worm crystal growth. "That is, each layer is deposited by epitaxial growth." Each layer itself is called "Epitaxial growth, layer. In this technique, the material layer is mainly deposited on the surface of the substrate atomically from the surrounding environment. The material forming the telecrystalline growth layer is crystallized into a crystal lattice according to its own properties or according to the underlying properties. Examples of such techniques include organic metal vapor phase epitaxial growth, molecular beam epitaxial growth, and hydride vapor phase telemorphic growth. (In contrast, non-stratified crystal growth technology uses material pellets on the substrate. On the material, the heating device so that the pellets are melted on the surface of the substrate.) The growth of worm crystals and other types of manufacturing steps is roughly performed at a temperature hundreds of degrees higher than room temperature α), but it depends on the type of step and the type of deposition material Significant changes can be made. One of the issues in the development and manufacturing process is to order the steps, so the temperature required for the later steps is not harmful to the results of the earlier steps. To be resolved Statement of the problem The paper size is suitable for financial affairs in Guanjia County (CNS) Α4 specification⑺ (^ 297 公 ^ · 8- Printed by the Consumers 'Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs A7' ______ B7 V. Description of the invention (6) ~ Development of semiconductor In the manufacturing method, there are a number of issues that need to be resolved in order to ensure that the semiconductor device produced by the manufacturing method has the appropriate quality. Generally, quality, when used in semiconductor manufacturing, indicates that the manufactured semiconductor device has the proper function and reliability. For semiconductor manufacturing quality, the layers need to adhere to each other and to the substrate 'need to have good electrical characteristics and good mechanical structure. The quality of a semiconductor device is related to the crystal lattice conditions that make up the device. Defects in the lattice structure are detrimental to the quality of the device. Therefore, if the lattice stress is applied to the film layer as described above, it is necessary to limit or at least control the effect of the stress on the film lattice. The problem of combining the epitaxial growth of nitride is the problem of cracks. The cracks occur in the epitaxial growth film It occurs when it is pulled under tension and under the aforementioned stress. Usually the crack is the vertical film-substrate interface There are several possible reasons for such cracks: ⑴ The difference in the lattice configuration between the materials that make up the substrate and the film causes the lattice mismatch between the substrate and the film, (ii) the coefficient of thermal expansion between the material that makes up the substrate and the film Mismatches, (iii) high degree of doping of materials, and (W) intentional composition adjustments deliberately introduced during the growth of nitride devices, that is, lattice mismatches caused by chemical changes in the composition of the manufacturing materials. For example, the AlInGaN layer is typically higher than It grows at a growth temperature of 1100 ° C without a buffer layer effect, resulting in a film formed by hexagonal core mosaic assembly. Each layer has an extremely rough morphology and a high background donor concentration. As a result, it has characteristics ⑴ and (iii) and is easy The paper size is applicable to the Chinese National Standard (CNS) Α4 »(21GX297 mm) (Please read the precautions on the back first ^ write this page} Binding-Thread-❿ -9-

Printed by the Consumers' Cooperative of the Central Standards Bureau of the Ministry of Economics. Lattice and thermal expansion coefficients do not match. The characteristics of wind semiconductor materials are the lattice constants and the mathematical characteristics of the material's crystal structure. As with any other material, a semiconductor material has a coefficient of thermal expansion that changes with temperature. The coefficient of thermal expansion is a measure of how the material expands or contracts. Adjacent layers have the same or compatible lattice form, and good adhesion is obtained. The incompatibility of the lattice forms leads to poor adhesion, which separates the layers and thus deteriorates the electrical properties. The thermal expansion coefficients of the adjacent layers must be as similar as possible, so when one layer expands more than the other layer, the temperature change will not cause the layers to separate. This point is important, because the semiconductor device is manufactured at a much higher temperature than the temperature at which it is stored and used. Considerable thermal shrinkage occurs when the finished device is cooled to room temperature. Known LED structures; buffer layers. Nitride-based LEDs typically include a plutonium substrate, (ii) a nuclei or buffer structure, and (iii) an active structure. The present invention relates to a buffer structure. The attached picture shows the device structure, the full picture shows that the buffer structure is a single layer, and one, the magnifying lens is centered on the single layer buffer structure, providing an enlarged detail view of the structural composition of the buffer structure. The prior art and drawings of the present invention provide representative layer thicknesses in Angstrom units. These values or other values known to those skilled in the art can be used. Also in the following discussion, the layers are "stacked" on top of each other ^, stacked ,, 1-1 is by no means intended to limit the structure to a structure that is manufactured or placed on top of another layer. The term broadly includes the use of any manufacturing technology to produce the structure. The paper size applies to the Chinese National Standard (CNS) A4 specification (210X297 mm).

(Please read the precautions on the back H-installation—I Γ This page} Order—line Φ -10- Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs A7 — " " ~ ------ B7 V. DESCRIPTION OF THE INVENTION (^ '~-日' ^ Based on this description, it is known to the industry or is an appropriate structure. The only limitation, explicit or implied, in this book is related to buffer layer manufacturing and active layer epitaxy. The relatively low temperature and high temperature of growth, etc., are described. As the present invention can be applied to LED technology, a slightly detailed description of the active LED structure is given as an example. The LED active structure includes a ^ -type layer and a P-type layer. Active layer and contacts. However, it should be understood that these components are not necessary for the present invention and are provided for illustration purposes only. Figure 2: Known devices. Known semiconductor devices are commonly referred to as nitride LEDs. Figure t is shown. The substrate is shown as 2, and the nucleation or buffer structure is shown as 4. The substrate 2 is Sapphire (ΑΙΑ), carbonized stone (Sic), etc. The active structure is shown as 6 circuit elements, interconnects, etc. Inside the active structure 6. The specifications of the active structure are not the original As necessary, the active structure will not be discussed in detail. 'This is only illustrated here. The active structure 6 of a typical LED shown in this example includes an active area 8 between the type layer 10 and the n-type layer 12. Layer 1G and 12 includes circuit elements, interconnects, etc. and contains contacts 14 and 16. The term active area is commonly used in the field of LEDs. Here, the term active structure covers the layers 8, 10, and 12, And contacts 14 and 16 and other devices included in other buffer layers include conventional buffer layers or circuit elements and structures of the buffer layer of the present invention as described herein. Used to control cracking, morphology, and background carriers. An effective method for the conductivity is to insert a buffer structure 4. The buffer structure 4 contains a layer called a buffer layer or a nucleation layer, and the two nouns are synonymous. This paper scale applies to the Chinese national standard (2 丨 ox297 公 5 I ---, ------ ΜII (Please read the precautions on the back before this page) Order—line- -11- A7 B7 V. Description of the invention (9) For devices manufactured on sapphire substrates, the buffer layer Typically deposited at 400-900 ° C. If the substrate is silicon carbide (SiC), the buffer layer is deposited It is performed at a higher temperature (for example, higher than 900 ° C). However, this temperature is usually lower than other types of deposition steps, such as epitaxial growth, but it does not need to be excluded from higher temperatures used in other deposition steps The core layer or the buffer layer is deposited before the growth of additional layers such as the active structure 6. The layers constituting the active structure 6 are usually deposited at a higher temperature than the buffer layer. The additional layers such as epitaxial growth nitride film quality The buffer layer is greatly improved when the buffer layer has been manufactured under the additional layers. It is known that the buffer layer includes one of the binary compounds A1N and GaN, or an AlGaN composition between the two binary compounds. In essence, the middle component is not labeled A1 xG a 1 _XN ′ where X is a value between 0 and 1. The insertion of such a low temperature layer can overcome the huge differences between: ⑴ lattice parameters, (ii) thermal expansion, (iii) surface energy, and (iv) crystallography between the sapphire substrate and the nitride epitaxial growth layer. However, the conventional buffer layer has its limitations, which will be described in detail later. Doping and Composition Adjustment In typical nitride-based devices, the film is heavily doped. The dopant concentration in typical optoelectronic devices often exceeds 1018-1019cm-3. Typical nitride-based devices also have several heterogeneous epitaxial growth interfaces. Almost all electronic and optoelectronic devices consist of layers having different compositions deposited on each other. A heterogeneous interface is an interface between two layers with different compositions. For example, GaN, AlGaN, and InGaN with different compositions, conductivity types, and thicknesses are directly deposited on the boundary of each other. The paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm) -12-

Employees of the Cooperative Bureau of the Ministry of Economic Affairs print the surface of consumer cooperatives and produce optoelectronic devices such as LEDs. Both doped and heterogeneous interfaces affect the lattice parameters. a-axis and c_axis lattice parameter data ’and nitride and common substrate back-cut and sapphire): The expansion coefficients are shown in Table 1 (Figure 3). … When the GaN layer is of the n_ type doped with Shi Xi, cracks cause significant problems. Shi Xi atoms occupy Ga atom positions in the lattice. The ionic radius of Si is 30 ° / smaller than the ion radius of tritium. the above. As a result, the si atom is "too small" for the space it occupies in the crystal lattice. The extra space around the Si atom weakens the crystal lattice due to the stress and strain fields generated by the crystal. ~ When layers with different compositions are deposited on each other It also caused the problem of cracks when cracking. Cracks growing on top of this layer have a smaller & _axis lattice parameter than that of the layer below which is particularly troublesome because the elastic constants of inferior nitrides are extremely rigid. In addition, nitrogen The heterogeneous structure of the compound layer is usually aligned along the mandrel, and the a-axis is the parallel axis of the substrate-film interface. So when the associated axis parameter of a layer is smaller than the a_axis parameter of the layer below, The layer induces tensile stress and keeps the interface aligned. CONCLUSION Although the problems associated with lattice and thermal mismatch can be fully solved using existing core layer technology and by controlling the heating and cooling conditions associated with growth, the The cracks caused by the composition fluctuations cannot be solved by such methods. Therefore, there is still a need for a layer of semiconductor devices and a method of manufacturing such devices. The composition of the rift caused by fluctuations asked this paper applies China national scale quasi-breasted (CNS) A4 size (210X297 mm)

-13-Printed by the Consumers 'Cooperatives of the Shiyang Municipal Prospective Bureau of the Ministry of Economic Affairs ~~~ ---- ~~ ------------ 67 V. Description of Invention (11)' --- Summary of Invention Therefore, this invention- The purpose is to provide a type of III_V nitride semiconductor device, which can be formulated to achieve high-quality layers and devices, and to overcome the problems of cracks caused by doping and fluctuations in the composition of these layers and devices. Another object of the present invention is to provide a semiconductor device which is configured to overcome all the aforementioned problems of cracks. In order to achieve these and other objects, a semiconductor device according to the present invention is provided with a substrate, and an active structure and a buffer structure are interposed between the active layers of the substrate. The buffer structure includes one or more layers. Especially for multi-layer structures, at least one layer is preferably deposited directly on the substrate. The layer is made of m_v nitride compound, wherein the content of Ill is completely or partially composed of indium. The indium-containing layer according to the present invention serves as a buffer layer. It was found that the indium-containing inferior nitride buffer layer according to the present invention has the advantage of reducing cracks due to the adjustment of the strain occurring in the active structure. The invention can be used for A1InGaN vermiculite growth. By nucleating the nitride film on the buffer layer ', the stress and cracks are reduced by loosening the layer containing InN, resulting in more elastic changes in composition and doping adjustment. Because the electrical and optical properties of nitrides are determined based on the stress and strain states, these properties can be modified by controlling the composition and thickness of the nuclei layer. The material of 111 is completely indium, so that the buffer layer compound becomes InN. In the broad sense of D, the buffer layer can be any suitable aluminum gallium indium nitride intermediate. This intermediate is schematically shown here as Ogxgi and θj. This paper ruler) A4 size (21 OX 297 mm) ~ '~~~

-14- Printed by the Consumer Cooperatives of the Central Bureau of Standards of the Ministry of Economic Affairs A7 B7 V. Description of the Invention (12) The specific properties of the various elements in column III will be enumerated below for a discussion of various specific examples of the invention. Experiments have verified that these specific ratios can produce a buffer structure with good results. However, the present invention broadly includes other compositions and thicknesses. In addition, high-quality InGaN layers can be grown at temperatures much lower than the temperatures used by GaN, A1N, and AlGaN (below 800 ° C vs. 1000 ° C), so the buffer layer containing InN and InGaN is excellent. High structural quality, which is impossible to achieve by previous industry manufacturing technology. Further according to the present invention, the buffer structure includes a cover layer on top. The capping layer may be GaN, A1N or a suitable AlInGaN interlayer. Generally speaking, a III-V nitride buffer layer containing a specific amount of indium can be covered by a III-V nitride capping layer containing a smaller amount of indium. Here, each component is an appropriate choice for the temperature of the subsequent epitaxial growth step. An additional advantage provided by the capping layer is that during the manufacturing process, after the buffer structure is deposited, followed by a high-temperature active structure deposition step, the cap can maintain the positioning of the remaining buffer structures and protect the buffer structure from the harmful effects of high temperatures. It is also believed that the change in strain state caused by the use of a multi-step nuclei layer also has a beneficial effect on electrical properties and the performance of the LED device of the present invention. Brief Description of the Drawings Figure 1 is an unintended perspective view of the lattice and its associated axes. Figures 2A and 2B are schematic diagrams showing the manufacturing of a conventional nitride LED. Figure 3 is a table also labeled "Table I", which lists the parameter values of nitrides and substrate materials. Figures 4A and 4B are schematic views showing the manufacture of a nitride LED according to the first basic specific example of the present invention. This paper size is in accordance with Chinese National Standard (CNS) A4 (210 X 297 mm) I. Knitwear Thread (please read the precautions on the back before V " this page) Printed by A7, Consumers Cooperative of Central Bureau of Standards, Ministry of Economic Affairs B7 V. Description of the invention (13) Figures 5A, 5B, 6A, and 6B are schematic diagrams showing the manufacture of the first type of nitride LED according to the present invention. These specific examples have multiple buffer layers. 7A, 7B, 8A, 8B, 9A, 9B, 10A, and 10B are schematic diagrams showing the manufacture of nitride LEDs according to the second specific example of the present invention, which has a cover layer. Figure 11 is a line diagram called "SIMS Depth Profile" showing the device characteristics of Figure 9. Figure 12 is a table also marked as "Table Π", enumerating the measured values of the device of Figure 9. 13A, 13B, 14A, 14B, 15A, and 15B are schematic diagrams showing the manufacture of nitride LEDs according to the third specific example of the present invention, which has a repeating (or nearly repeating) secondary structure inside the buffer structure. 16 The figure is a table, labeled "Table III" lists performance data of several devices according to the present invention. Figure 17 is a table, also labeled "Table IV", showing further performance information. 〇 Detailed description of the preferred specific examples According to the present invention, the low-temperature core layer is composed of several discrete layers with different compositions. In particular, at least one of the multilayer structures is preferably directly deposited on the substrate. This layer is composed of an indium-containing nitride as a buffer layer for AlInGaN epitaxial growth. Generally, the present invention can be embodied in two ways. A buffer layer containing an indium nitride compound is usually disposed directly on the substrate. In contrast, conventional buffer layer compounds contain only aluminum or gallium from column III. Specific performance of the two aspects of the present invention I --------- batch clothes ^^-^ 11 ------ # (Please read the precautions on the back before writing this page) Paper size applies Chinese National Standard (CNS) A4 specification (210X297 mm) -16- Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs. A7 B7 V. Description of the invention (14) The difference between the methods is that the buffer layer is on the one hand InN (including only indium from column III), and other aspects thereof include compounds containing indium and another III element, which are preferably married. This compound can be formulated, for example, as GajjIrikN, where 0 < x < 1. InN melts at about 1100 ° C, which is close to the GaN epitaxial growth temperature. However, because the bonding of indium and nitrogen atoms is relatively fragile, the InN lattice may decompose at this temperature or even slightly lower. For example, consider a case where after the InN buffer layer is deposited, a subsequent GaN epitaxial growth step is performed to form an active structure layer. Because the temperature of the GaN vermicular growth step is quite high, the underlying InN layer melts or "relaxes". This relaxation of the underlying InN buffer layer can reduce the tendency to crack by providing a conformation between the substrate and the film. Because the melting points of InN and other indium compounds used in the present invention are relatively low, it is found that it is necessary to provide a capping layer, preferably a GaN layer, just above the indium-containing buffer layer. When the copper-containing layer relaxes and relaxes during the high-temperature worm crystal growth step, the InN layer is constrained by the capping layer of the material, which remains solid in this temperature range. For the sake of brevity, this specification will describe the InGaN / GaN buffer layer. It should be understood that the structure is actually an InGaN buffer layer under the GaN cap layer. Both the buffer layer and the cap layer are part of the total buffer structure between the substrate and the active structure. Specific examples There are countless possible specific examples of the invention. Multiple specific cases can be classified into multiple types of specific cases. The first basic specific example of the present invention will be described, and then other types of specific examples will be described as variations or extensions of the basic specific examples. First specific example: single buffer layer (Figure 4) Figure 4 illustrates the simplest and specific example of the present invention with a single buffer layer 16, the same as Figure 2, but according to the present invention, the buffer layer 4 is made of indium-containing Nitride compounds (please read the notes on the back page first) Binding and binding The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) -17- A7 B7 5. Composition of the invention (15). Formula The indium-containing III-V nitride usually used in accordance with the present invention has the following shape I ---; ----- batch coating-(Please read the precautions on the back before this page)

AlxInyGai-x-yN, among which 0 < ySl and OSxSl. That is, the compound contains, in addition to indium, gallium and / or gallium. In addition to such a basic buffer structure, countless specific examples of the present invention have a buffer structure including a plurality of layers, some or all of which serve as buffer layers. Several specific examples can be divided into multiple categories' The following examples discuss these specific examples;. Right The first specific example: multilayer Figure 5 shows a buffer structure, in which the first buffer layer is directly disposed on the substrate, and the second buffer layer 20 is disposed on the first buffer layer ^. As for the chemical formula shown in Figure 5, both layers are steel-containing gaseous compounds, but the element ratio of the element II is different from that of the two layers. The first-layer 18 is _ not containing 仏 仙. However, the second layer 2Q column 111 is not pure indium, but can be pure inscription or pure gallium. All in all, the second layer 20 contains fewer marriages than the first layer 18. FIG. 6 shows a buffer structure similar to the first one, but the third buffer layer is cut on the second buffer layer 20. In accordance with the chemical formula listed in Figure 6, the buffer layer 18 printed by the Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs contains some indium, the second buffer layer 20 contains less indium than the first layer 20 and the third buffer layer 22 and less. The specific examples of FIGS. 5 and 6 are believed to belong to the first type of specific examples of the present invention. A first type of example is a multilayer indium-containing buffer layer. Although two- and three-layer buffer structures are shown, additional buffer layers may be used. The common point of such specific examples is that the layers are formulated so that they are used as buffer layers by relaxing the temperature in subsequent manufacturing steps such as the worm crystal growth step. The following other M's Zhang scales are suitable for wealth_ 家 县 (CNS) AW (210 ^ 1 ^ 7 -18- Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs A7 —-------—_ B7_ V. Invention Explanation " — ~ Specific examples include other types of buffer layers in the buffer structure. Specific examples of the second type: cover layer: Figures 7, 8, 9 and 10 Figure 7, 8, 9, and 10 examples The second specific example of the present invention will be described. In these specific examples, the buffer structure includes a cap layer disposed above the buffer layer. The buffer structures in Figs. 7 and 8 are represented by a large class of chemical composition. Figs. 9 and} 〇 Corresponding to the structures in Figures 7 and 8, respectively, but Figures 9 and 10 provide specific examples of devices that are manufactured and used. ~ It is better to provide a cover layer, where the overall manufacturing process includes high-temperature steps such as ia buffering, structure The next step is the growth of insect crystals. The indium-containing buffer layer that has been deposited is relaxed under the same fox. The cover layer is preferably positioned about the indium-containing material (refer to Figures 7 and 8). So the cover layer is more bearable It is made of high-temperature II-V gaseous material in the later manufacturing steps. Gallium nitride (No. 1 and No. 1) is the preferred capping material; bucket 4 is based on daily growth steps. Depending on the temperature, the capping layer may contain indium or other out-of-class elements. Referring now to Figure 7, the first specific example of the type of capping layer is shown. The buffer layer 24 is covered by a rhenium layer 26, and the formulation of the capping layer can be listed as The general formula of the III V nitride used above. The indium-containing buffer layer has any of the chemical formulae listed above. Generally, f, the cap layer 26 contains a smaller amount of material, which is selected to reduce the tendency to relax at a later manufacturing step temperature. However, in the specific example of Fig. 9, a relatively small amount of indium accounts for only 20% of indium, and the difference is that gallium is provided for the buffer layer 24. This thickness is successfully used, but the precise thickness is not particularly limited to the present invention, so it can be Use other thicknesses. The following thickness materials are used to describe the structural properties of this method. This formula is suitable for a state of the article, and its active structure will be manufactured at a high temperature. Therefore, it is suitable for China-(Please read first Note on the back page) fe® -Package. Order-19- Printed by the Consumers Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs A7 B7 V. Description of Invention (Π) The punching layer 24 remains loose even with a moderate amount of indium. Figure 8 shows another capping tool By way of example, two buffer layers 28 and 30 are disposed below the cover layer 32. Again, the buffer layers 28 and 30 and the cover layer 32 are indicated by the general formula of the chemical composition. The first buffer layer 28 (directly above the substrate) High indium content can achieve good relaxation. The second buffer layer 30 contains a mixture of III column elements with less indium content. Again, Figure 10 shows a more specific structure. A pure InN layer 28 is provided for maximum relaxation and stress relief Provides an intermediate layer 30 containing a small amount of indium for better stability at high temperatures, and provides a GaN cap layer 32 to constrain the lower two layers 28 and 30 at high temperatures. The GaN cap layer can tolerate such high temperature manufacturing steps. In the specific case shown, the middle layer 30 is indium gallium nitride, where the indium content is again at most only 20% and provides a good balance between relaxation and structural stability at high temperatures during active structure manufacturing. Figure 11 presents the experimental data of the specific example in Figure 9 in the form of "SIMS depth profile". The initial word SIMS stands for secondary ion mass spectrometry. The number of secondary ions in the SIMS plot is a function of the depth below the device surface. SIMS depth side The profile is a line graph showing the N and In trajectories from the SIMS profile of a single-layer n-type (silicon-doped) GaN layer grown on the nuclei layer as illustrated in Figure 9. InGaN buffer layer and sapphire The depth of the interface of the substrate is about 0.8 microns. The number of ions is provided for the two elements nitrogen and indium. The nitrogen curve is constant in most areas of the line graph. This is reasonable because most of the areas correspond to the nitride layer. The film contains Approximately 50% nitrogen, the substrate is substantially free of nitrogen. Therefore, the number of nitrogen drops sharply at a depth of about 0.8 microns, which is the substrate-film interface. (Please read the precautions on the back first

(BB page). Binding and binding. The paper size is applicable to Chinese National Standard (CNS) A4 (210X297 mm). -20- Printed by A7 B7, Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs. 5. Illustration of the invention (18). The plot is based on a logarithmic scale, so the peak in the depth of the indium curve from 0.0 microns to about 0.7 microns is only about one-thousandth of the peak amplitude of the indium with a noise of about 0.8 microns. The indium peak at 0.8 microns corresponds to the buffer layer, indicating that indium is incorporated into the structure and retained therein. Because indium only grows thin films in the surrounding environment during the growth of the InGaN portion of the InGaN / GaN buffer structure, the indium signal indicates the presence of the InGaN portion and its location in the multilayer buffer layer. Additional confirmation that indium is present at the film-substrate interface can be confirmed by the fact that the peak of the indium signal is located at the same depth as the nitrogen signal. The peak of indium at the substrate-film interface also indicates that the cap layer (GaN in this example) can maintain the positioning of the InGaN buffer layer. Figure 16 is a table of Van der Pauw Hall measurement values (labeled as "Table II"), which is the measured value of the conductive characteristics of the device layer relative to the operation of the semiconductor device. The devices each have an active layer GaN: Si (that is, a doped Si-doped GaN layer) on the nuclei layer of similar thickness and doping degree. Two sets of values are obtained. The other group is the value of the device according to the present invention with an InGaN / GaN layer as shown in Figure 9. The notable difference is the electron mobility, preferably as high as possible to achieve the highest conductivity and lowest input drive current of each layer, Electron mobility is about 5% higher for the InGaN / GaN device of Figure 9 of the present invention than the sample (Figure 2) grown conventionally on a GaN buffer layer. The total resistivity is preferably as small as possible for the device of the present invention Smaller than conventional devices. This excellent difference is believed to be due to favorable changes in the strain state, or come (please read the precautions on the back page first). Binding. --- r This paper size applies Chinese national standards ( CNS) A4 size (210X297 mm)- 21-A7 ____B7 V. Description of the invention (19) Since the ectopic and / or point defect density of the GaN: Si top layer is reduced, and it is the effect obtained by using the InGaN / GaN composite nuclei layer according to the present invention. The third specific example: Cushioning secondary structure: The second type of concrete examples in Figures 13, 14, and 15 are broadly characterized as having a series of buffering secondary structures. Each secondary structure is the same or similar to each other. The buffering structure of the foregoing specific example can be used as An example of a repetitive secondary structure is shown in Figure 13. Figure 13 shows a buffer structure including secondary secondary structures 34 and 36, each of which includes an indium nitride buffer layer (38 and 40) and a gallium nitride cap layer ( 42 and 44). In other words, if the capping buffer structure of FIG. 9 is repeated twice, the result is the structure of FIG. 13 ”Such specific examples will describe the invention and apply for a patent on the buffer secondary structure. In the figure, 'the buffer secondary structures 34 and 36 are shown as two double-layer secondary structures. Each layer is described as a secondary structure layer in a secondary structure and a patent is applied. Referring again to Figure 13, the two-layer indium nitride Buffer layers 38 and 40 are called secondary structure buffer layers And two layers of gallium nitride capping layers 42 and 44 are called secondary structure capping layers. Referring next to FIG. 14, a buffer structure including three secondary structures 46, 48, and 50 is shown. Each of the three secondary structures is the first Figure 9: This type of cover hierarchy includes indium gallium nitride buffer layers (52, 54, and 56) and gallium nitride cover layers (58, 60, and 62). The buffer layers are shown to be exactly the same (i.e. thickness and layers The composition X values are exactly the same), but the composition can be changed with each buffer layer. Finally, Figure 15 shows a buffer structure with an infinite secondary structure. The bottom secondary structure 64 and the top secondary structure 66 are shown. Bottom and top sub-structures 64 and 66. The standard "CNS" 8 4 Na (210X297 mm) " ~~-(Please read the precautions on the back page first). 5T Printed by the Consumer Standards Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs-22- V. Description of the Invention (20 The gap 68 printed by the members of the Economic Standards Bureau of the Cooperatives indicates a secondary structure of any number of materials. Secondary structure slow yarn. The chemical composition of the secondary structure buffer layer-Maoming Chong layer-human-level enumeration. Systematic ^ describes the secondary structure bottom layer (? 〇 and called package) of each secondary structure of the general formula containing fine -V nitride. The bottom layer of a structure is directly adjacent to the base material.) It contains the grade ^. The quantity is related to the subscript center value. The quantity can be as high as ^, that is, the material is nitrided steel. The columns are structured. The layers (74 and 76) contain a smaller amount of 锢. The -secondary and y :: T chemical formulas use the same-and force parameters for the bottom layer of each secondary structure, but this special formula can also be the top layer for different secondary structures. True. M Other Specific Examples From the discussion of these specific examples of the present invention, it will be clear that a variety of other configurations are possible. For example, you can use several three-layer secondary structures, each of which is based on the three-layer buffer structure of Figure 8. You can also use the secondary structure similar to Figure 8 but the chemical formula of the buffer layer of various secondary structures can be formulated with the chemical The thickness can also be changed. Generally speaking, a layer with a specific chemical composition can be used as a buffer layer or a cover layer depending on its chemical composition. If the material is generally solid and rigid at the south temperature of the later manufacturing temperature, This layer can be used as a capping layer. Of course, it is assumed that the specific layer below the layer has a higher relaxation tendency of a material layer that can relax or melt at such a high temperature, and it is better as a buffer layer. The final high temperature temperature can be determined; t has Is it possible to use the -layer as a mitigation item? It is also applicable to the Chinese paper standard (CNS) 8 and 4 (210x297 public fantasy -23-printed by the Central Bureau of Standards of the Ministry of Economic Affairs, Consumer Consumption Cooperative, A7, B7). (21) Cap layer. In most cases, the temperature at which the buffer layer starts to grow is much lower than the temperature at which the buffer layer is grown directly on the sapphire substrate for nitride films. Typical blue The buffer layer deposited on the stone is deposited at 400-900 ° C, and the rest of the structure is deposited at 700-1200 ° C. The composite nuclei layer is capped to protect it from increasing to higher temperatures during the growth process. The nuclei layer The total thickness can be any value deemed appropriate by the industry. However, the preferred thickness is about 250-300 angstroms. General description of manufacturing technology The buffer layer and cover layer are at 200 to 1000 ° C, preferably 400-600 ° C Growth at a range of temperatures. Discrete layers do not need to grow at the same temperature. Other conditions can also be changed. For example, the surrounding conditions can be changed, such as the strength of the growth atmosphere. The surrounding growth atmosphere usually includes the surrounding gas, which is not reactive or participates in the layer formation process . These gases include argon, helium, hydrogen, nitrogen, a mixed gas of hydrogen and nitrogen, and the like. The surrounding gas and others can be used in various proportions, combinations, etc. in a manner known to those skilled in the art. Finally, if the elements of column III (and column V) to be deposited are provided in the surrounding atmosphere, their proportions and quantities can also be changed, including the ratio of column V to column III. The experimental data also grows LED devices for special cases of the buffer structures shown and discussed above. The LED performance data obtained from each structure are shown in Table 111 (Figure 16). The light output value is provided as a percentage gain of a normalized round using a photovoltaic device of the prior art such as the device of FIG. 2. Standardized rounds grown at the same time frame have an external quantum efficiency of 5-7% and emit light in the 485-505 nm wavelength range. I want to produce an LED device that can deliver the highest possible light output (please read the caution page on the back first). Packing. The size of the paper is applicable to China National Standard (CNS) A4 (210X297 mm) -24- A7 ___B7__ 5. Description of the invention (22), so the advantages of using the invention described herein are obvious. Note that different specific examples can produce light wavelengths that vary in the range of about 15 nm (compared to the wavelength difference between the adjacent two colors in the visible spectrum of about 50 nm). The manufacturing technology understood by the LED industry can be applied to the present invention to adjust the light wavelength to the correct predetermined value. Previous studies have shown that the presence of strains in the device structure can change the composition of the active or light-emitting area of the structure. Since the composition of the active layer determines the emission wavelength, the change in the strain state of the wavelength migration indicator structure is observed here. The light output and efficiency of the 'devices in each case are comparable to or even higher than the light output and light efficiency of LED devices grown on the GaN nuclei layer during the same period. In the special case shown in Figure 9, the InN Moire component adjusted in the InGaN portion of the nuclei layer can also affect device performance. Β Table IV data (Figure π) shows that the light output of the LED device of the present invention is higher than that of the prior art device (Molar content of 〇〇〇〇N) increased. The wavelength of the light generated by the 100 Angstrom InGaN portion of the X-buffer layer is affected by composition changes (Figure 9). The column labeled "0 · 00" indicates the performance of the prior art device in Fig. 2. As shown in Fig. 16-the material, the data in Fig. 7 also shows that performance improvements and strain state changes can be achieved according to the present invention. When the thickness of this InGaN layer is changed, similar light output and wavelength migration can be seen. As the previous example measures the power transmission properties, these results are related to the state of strain or microstructure brought about by using the core layer of the present invention. The improvement is directly related. -25-A7 A7 38-40 ... Indium nitride buffer layer 42-4 ... Gallium nitride cap layer 46-50 ... Substructure 52-6 ... Indium gallium nitride buffer Layers 58-62 ... gallium nitride capping layer 64 ... bottom secondary structure 66 ... top secondary structure 6 8 ... gap 70-6 ... secondary structure layer B. V. Description of the invention (23) Component number comparison 2. .. substrate 32 ... cover layer 4 .. nuclei structure, buffer structure 34-6 ... secondary structure 6. active structure 8. active area 10 .. .P-type layer 12. .η-type layer 14-6 ... contact 18-22 ... buffer layer 24..buffer layer 26..cap 28-30 ... slow Punch (please read the precautions on the back first and then this page)

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Claims (1)

Nano 2201s A8 B8 C8 D8 Printed and patented by the Consumers' Cooperative of the Central Government Standards Bureau of the Ministry of Economic Affairs. A semiconductor device comprising: a substrate (2); a buffer structure (4) provided on the substrate (2 ), The buffer structure includes a first buffer layer (16) directly disposed on the substrate (2), the first buffer layer (16) is made of the first indium nitride-containing compound; and an active structure (6 ) Is provided on the buffer structure (4). 2. The semiconductor device as claimed in claim 1, wherein the first buffer layer (16) is made of the first indium nitride compound selected from the group consisting of: AlJnyGa ^ yN, where 0 < y $ i and 3. The semiconductor device according to item 1 of the patent application scope, wherein the buffer structure further includes a second buffer layer (20) disposed on the first buffer layer (18), and the second buffer layer (20) is composed of Made of a second indium nitride-containing compound. 4. The semiconductor device according to the scope of the patent application, wherein the buffer structure further includes a cap layer (26), and the second layer (26) is provided by the second indium nitride-containing compound on the first buffer layer (24) Made from above. 5. The semiconductor device according to item 4 of the application, wherein the capping layer (26) is made of gallium nitride. 6. The semiconductor device according to claim W, wherein the buffer structure further includes a first buffer layered secondary structure (34). 7. A semiconductor device as claimed in item 6 of Shen Qing's patent, wherein the first buffer layered secondary structure (34) includes a secondary structure buffer layer (38) made of an indium nitride-containing compound; and the first The buffer layer is included in the first buffer layered secondary structure of the second f paper scale applicable national national standard (CNS) Eighty-fourth secret (I-^ 1 1-.. ^ 1 1-1 I —1-— In I # (Please read the notes on the back before filling out this page) Order-27 Patent Application Scope Inside the level structure buffer layer. 8. According to the sixth patent application of the patent application scope, wherein the first buffer layered secondary structure (34) includes:, and ,. The structure buffer layer (38) is made of an indium-containing nitride compound; and above and ". The structure cap layer (42) is provided on the secondary structure buffer layer. Only a thousand-conductor device, in which the secondary structure cap layer (42) is made of gallium nitride. 10. As described in the patent application No. Xiao Gongwu conductor, the first buffer layered secondary structure (64) It includes: a first-secondary structure buffer layer (7G) is made of the first-indium-containing nitride compound; and a second secondary-structure buffer layer (74) is made of the second-indium-nitride-containing compound at the first time Grade structure buffer layer (70) is made on top. 11. For the semiconductor device with the scope of patent application No. 6, among which the buffer structure please read the precautions before reading i printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs The further step includes the second buffer layered secondary structure (36) disposed above the first punched layered secondary structure (34). The two buffer layered secondary structures each include: a primary structure buffer layer (3 8.40) is made of indium-containing nitride compound; and one-human-level structure cover layer (42, 44) is arranged above the indium-containing nitride layer. This paper size applies to Chinese National Standard (CNS) A4 specifications (21〇χ297 public envy) -28- AS B8 C8 '^' ~ -____ D8 Patent Application Park 'One'] 3. As the semiconductor device in the scope of the patent application, which is in the first and the first buffer layer The individual secondary structure cap layers (42, 44) of the shape-like secondary structure (34, 36) are made of gallium nitride. For example, the semiconductor device of the scope of application for item 11 of the patent, wherein: the first buffer layer is shaped like The secondary structure (64) includes a first secondary structure buffer layer (70) made of a first indium nitride-containing compound; and the second buffer layered secondary structure (66) includes a second buffer-containing nitride A second secondary structure buffer layer (72) made of a compound. 15. The semiconductor device according to item 丨 丨 in the patent application scope, wherein the first and second buffer layered secondary structures (64, 66) each include : A first secondary structure buffer layer (74, 76) is made of the first first indium nitride-containing compound; and The second secondary structure buffer layer is made by Dike You. The first indium nitride-containing compound is placed above the first secondary structure buffer layer. (Please read the precautions on the back before this page) m Fill in this order Printed by the Consumer Cooperatives of the Central Bureau of Standards of the Ministry of Economic Affairs 29-