DE102008039790A1 - Optoelectronic component i.e. LED, for use as headlight in motor vehicle, has connecting terminals provided for supplying charge carriers to partial layers of layer sequence, where terminals are arranged at main side of layer sequence - Google Patents

Abstract

The component (1) has an epitaxially produced layer sequence (10) with a main side that is turned towards a main radiation direction and another main side that is turned away from the direction. A carrier substrate (40) is transparent for light emitted in the direction and mechanically stabilizes the layer sequence. The carrier substrate is arranged on the former main side and connected with the sequence layer. Two connecting terminals (20, 21) are provided for supplying charge carriers to partial layers (11, 12) of the layer sequence and arranged on the latter main side. An independent claim is also included for a method for producing an optoelectronic component.

Description

The The invention relates to an optoelectronic component and to a method for producing such.

Optoelectronic Components, often and also referred to as light-emitting diodes possess a variety of different applications in the Field of light generation. This is how optoelectronic components are characterized among other things, that they also light different Can emit wavelengths. By additional Combine optoelectronic components with dyes in a simple way mixed colors and especially white Realize light. The manifold design and manipulation possibilities allow applications as bulbs in the automotive sector as well in industrial and domestic areas. About that In addition, optoelectronic components can also be used as projection light sources be used. Their low power consumption, the long service life as well as an industrial production in large quantities is increasing the demand for such components increase.

For the production of highly efficient optoelectronic components However, a complex production is required. So will for example, for the production of a growth substrate used, which after a production of the optoelectronic component or applying light-emitting layers of the optoelectronic Component replaced mechanically in subsequent processes becomes. For further processing then subcarrier come used on which the light-emitting layers with the growth substrate be applied to the growth substrate subsequently to remove.

The In addition, light-emitting layers must be provided with electrical Contacts for feeding the necessary charge carriers be provided. This is done, for example, from the top of the optoelectronic component or its back ago. While training electrical contacts on the front, that is on the light-emitting Page is particularly simple, this arrangement has the disadvantage to reduce the luminous efficacy due to shading effects. Corresponding are increasingly contacts on the back of the optoelectronic Component executed to the light-emitting layers to contact electrically.

rear However, connections require the formation of via contacts in the subcarrier. This is an elaborate and error-prone process. For example, a high one Level of planarity needed, otherwise after a connection of the auxiliary carrier with the light-emitting layers Cavities remain, the starting points of a reinforced Chip holder can be. Moreover, in relation to a lateral positioning of the two elements to be connected sufficiently accurate adjustment required, for example, existing Align through contacts in the submount exactly.

It Therefore, there is a need for a cost-effective optoelectronic component and on the other hand according to a manufacturing method, which is inexpensive for the production of optoelectronic Components is suitable.

this Need is through the objects of the independent Claims taken into account. Trainings and Embodiments of the invention will become apparent from the dependent claims.

The Invention proposes a mechanically stabilizing and at the same time transparent submitter not on the the main emission direction facing away, but on the decoupling side to arrange a layer sequence suitable for light emission. For this a manufacturing process for the layer sequence is carried out, in which the layer sequence is applied to the growth substrate, for example, epitaxially deposited or grown. Before the detachment of the growth substrate becomes a transient Subcarrier on the back side attached, which allows the growth substrate detached can be. Subsequently, a usual surface texturing the exposed and over the entire wafer related Layer to maximize the light extraction done. On this Page is now the actual, the layer sequence mechanically stabilizing and transparent carrier substrate applied and the temporary Subcarrier removed again. Then you can a contact on the back and a separation respectively.

Under The term "carrier substrate" is hereafter understood a carrier, with those in the previous Manufacturing steps generated layer sequence is connected, so that this against other mechanical loads is stabilized. The element thus carries the layer sequence, both in subsequent process steps and after Completion. The carrier substrate comprises a transparent material, since the carrier substrate is arranged on the outcoupling side of the layer sequence is.

In one embodiment of the invention, an optoelectronic component has an epitaxially grown layer sequence with one to the light Emission suitable sub-layer. The layer sequence has a first main side which faces the first main emission direction of emitted light and a second main side facing away from the main emission direction. The first main page is called the outcoupling page. The optoelectronic component furthermore comprises a carrier substrate which is transparent to the light emitted in the main emission direction and designed for mechanical stabilization of the epitaxially grown layer sequence. This is arranged on the first main side and thus the main emission direction facing side and connected to the epitaxially grown layer sequence.

At least two connection contacts for the supply of charge carriers on partial layers of the epitaxially grown layer sequence. The at least two connection contacts are on the second main page and thus the main emission direction facing away from arranged.

The applied on the first main page or the decoupling page transparent carrier substrate causes a complete and sufficient mechanical stabilization of the epitaxially grown Layer sequence. This allows subsequent manufacturing process steps very easy to perform at wafer level level. simultaneously the carrier substrate remains even after completion of the component on the layer sequence, so will not be back decreased.

The Rear side arranged connection contacts allow one good heat connection of the optoelectronic component to a board, since only thin solder pads between the epitaxially grown layer sequence or the connection contacts and the board are present.

It is possible on the side opposite the decoupling side to arrange the layer sequence a mirror layer. In this way is light that radiates to the back of the device is reflected by the mirror layer towards the outcoupling side. The mirror layer may be, for example, silver or another material containing a high reflection coefficient. In addition, the mirror layer can also take over other functional tasks, for example serve as a current spreading layer.

In An embodiment of the invention is the epitaxially grown Layer sequence on the first main page to increase the Lichtauskopplung structured. In one embodiment are on the first main side of the epitaxially grown layer sequence one or more functional layers to increase light extraction applied.

In In another embodiment, the transparent carrier substrate a variety of additional functional layers for improvement the light extraction of the epitaxially grown layer sequence on the main page.

In In another embodiment, the functional Layers also conversion layers with a light conversion material include. This serves to operate in an optoelectronic Component that of the sub-layer of the epitaxially grown Layer sequence emitted light in terms of its wavelength to change. In this way, mixed colors can be easily created become. In one embodiment, a conversion material is provided, which consists of light with a wavelength in the blue area light in one wavelength in the yellow area generated so that the optoelectronic device in an operation a produces white light.

to Connection of the first main side of the epitaxially grown layer sequence, or functional layers on the epitaxially grown Layer sequence and the carrier substrate may be a transparent Adhesive layer provided between the carrier substrate and the layer sequence be. Preferably, the adhesive layer in a cured State a refractive index substantially equal to a refractive index the carrier substrate or a refractive index corresponds to a layer connected to the adhesive. This will the decoupling further improved because between the individual layers reduces reflection due to different refractive indices becomes.

ever after desired application, the preferred light emission be different in an operation of the optoelectronic component. For this purpose, it is provided in one embodiment of the invention, the carrier substrate with different geometric Form dimensions with respect to its two main pages. Thus, the carrier substrate in the form of a polyhedron with formed two substantially parallel main pages be one of the two main pages with the decoupling of the epitaxially grown layer sequence is connected. The two Main sides of the carrier substrate may be different Dimensions have. As a result, the side surfaces of the Support substrate ge, so that a wedge, an obelisk, a tetrahedron, a truncated pyramid or another geometric one Form results. In a further embodiment, the carrier substrate have the shape of a lens to the light emission of the optoelectronic To form component.

The connection contacts of the optoelectronic component are mounted on the side facing away from the main emission direction. This is called the back of the optoelectronic device mentes.

In In one embodiment, the rear side comprises an insulating layer, which is arranged on the epitaxially grown layer sequence and the underlying conductive layers are electrically isolated. The Insulating layer can be made of a material with a high reflection coefficient consist. In the insulating layer are now first and second trenches formed so that areas of an underlying first sub-layer the layer sequence are exposed by the first trench. areas a second sub-layer of the layer sequence are through the second trench exposed by the first sub-layer and the light emission suitable sub-layer for epitaxially grown layer sequence passes. By the second with an electrically conductive material filled trench becomes the sub-layer of the layer sequence contacted, which faces the decoupling side. Between the first and second sub-layer is suitable for light emission Sublayer. This is usually formed by a pn junction.

The optoelectronic component according to the proposed principle in which a layer sequence is formed on a growth substrate epitaxially grown, one suitable for light emission Partial layer comprises. For this purpose, an embodiment is provided, differently doped semiconductor layers one above the other to arrange, so that at the interface of the two Semiconductor layers forms a pn junction. This represents the suitable for light emission partial layer of the epitaxially grown Layer sequence dar. The layer sequence has a first main page on, which faces the main emission of an emitted light is. Furthermore, it comprises one of the main emission direction facing away second main page, which are called the back can.

On the second main side of the epitaxially grown layer sequence Now a temporary subcarrier is applied. This is designed, the growth substrate then to be able to replace, and yet a sufficient mechanical stability of the epitaxially grown layer sequence to ensure. After detachment of the growth substrate becomes the first main page to increase light extraction structured. Then one for by the sub-layer emitted light transparent carrier applied on the first main page and with the first main page attached. This forms the carrier substrate, with a sufficient ensures mechanical stability of the component is. The temporary submitter on the second Main page can now be replaced easily. After all electrical connection contacts are formed on the second main page.

at The method proposed here can be after the Applying the transparent substrate support on the first Main page due to the great mechanical stability the back of the epitaxially grown layer sequence structure and process in further process steps. For example can now easily electrical connection contacts be formed on the second main page. These allow one good thermal connection to a board and thus a sufficient Cooling in one operation of the device.

alternative It is also possible after the production of the epitaxial Grown layer sequence on the electrical connection contacts the second main page and then afterwards the temporary subcarrier on the electrical connection contacts applied. In this context, it is conceivable that a part the material of the terminal contacts forms a sacrificial layer to the facilitate later detachment of the subcarrier.

To the detachment of the growth substrate but before applying of the transparent substrate carrier on the first main side This can be structured or further processed. For example, the surface of the first main page or a sub-layer forming the first main page epitaxially grown layer sequence be roughened to the Improve light extraction. Also possible is the application various functional layers to improve the light extraction or for converting the emitted light to another wavelength.

In In these cases, after the structuring of the second Main side applied an adhesive layer on the textured main page and then the substrate carrier disposed thereon. Then the adhesive layer is cured to an intimate connection the substrate carrier with the structured second main page and thus to achieve the epitaxially grown layer sequence. Preferably, the adhesive layer in a cured State a refractive index substantially equal to the refractive index the carrier substrate corresponds. This reduces if necessary a light reflection between the carrier substrate and the Adhesive layer.

Alternatively, the carrier substrate is implemented with additional functional layers which may correspond to those mentioned above. For example, dielectric mirror layers, Bragg mirrors but also conversion layers can form part of the substrate carrier. This allows a separate production. In addition, the layer sequence can be measured in terms of their radiation characteristics to then depending on the additional functional layers to vary.

in the The invention will be described below with reference to various embodiments explained in detail with reference to the drawings.

It demonstrate:

1 a first embodiment of the invention,

2 a diagram for illustrating the dependence of the coupling-out efficiency to the refractive index of the carrier substrate,

3 A second embodiment of the invention,

4 A third embodiment of the invention,

5 a representation for comparing optoelectronic components with differently structured surfaces,

6 A fourth embodiment of the invention,

7 A fifth embodiment of the invention,

8th a sixth embodiment of the invention,

9A to 9K An embodiment of a method for producing a component according to the proposed principle.

In The embodiments and figures are the same or the same acting components provided with the same reference numerals. The Figures and the proportions of the Elements shown in the figures are basically not to be considered as true to scale. For clarification and for better understanding as well as representability single elements, such as layers exaggeratedly large respectively be shown thick. Individual aspects of the various embodiments can be easily combined with each other and in the frame replace the technology used.

Of Furthermore, it is often referred to below that a Layer "on" or "over" one second layer is arranged. This includes both a direct adjacent arrangement of the two layers, but also includes additional intermediate layers, which are arranged between the first and the second layer. In addition, the terms "over" or "under" merely serve the representation in relation to the corresponding figure, however, stand not for a specific indication of direction. In the embodiments In addition, reference is made to individual connections or material systems. This is not a limitation, but may be dependent of the technology used among other external Framework conditions other material systems and materials are used.

1 shows an embodiment of an optoelectronic component 1 according to the proposed principle, in which an epitaxially grown layer sequence 10 with its light extraction side over an adhesive layer 30 with a carrier substrate 40 is attached. In other words, it is provided in the optoelectronic component to arrange the carrier substrate on the outcoupling side of the epitaxially grown layer sequence.

The epitaxially grown layer sequence 10 contains a first sub-layer 12 doped with a first charge carrier type and a second sub-layer disposed thereon 11 doped with a second charge carrier type. At the interface of the two partial layers, a pn junction forms 13 out. Over the second sub-layer 11 is an additional sub-layer 11a arranged of the same material forming a patterning or sacrificial layer. This can, as explained below, be manufactured in the same manufacturing process as the sub-layer and comprise the same material. Often the sub-layer indicates 11a one with respect to the sub-layer 11 lower doping concentration.

• – an einer der gewünschten Abstrahlseite der strahlungserzeugenden Halbleiterschichtenfolge, bei der es sich insbesondere um eine strahlungserzeugende Epitaxie-Schichtenfolge handeln kann, ist eine reflektierende Schicht aufgebracht oder ausgebildet, die zumindest einen Teil der in der Halbleiterschichtenfolge erzeugten elektromagnetischen Strahlung in diese zurückreflektiert;
• – der Dünnfilm-Leuchtdiodenchip weist ein Trägerelement auf, bei dem es sich nicht um das Wachstumssubstrat handelt, auf dem die Halbleiterschichtenfolge epitaktisch gewachsen wurde, sondern um ein separates Trägerelement, das nachträglich an der Halbleiterschichtenfolge befestigt wurde;
• – die Halbleiterschichtenfolge weist eine Dicke im Bereich von 20 μm oder weniger, insbesondere im Bereich von 10 μm oder weniger auf;
• – die Halbleiterschichtenfolge ist frei von einem Aufwachssubstrat. Vorliegend bedeutet ”frei von einem Aufwachssubstrat, dass ein gegebenenfalls zum Aufwachsen benutztes Aufwachssubstrat von der Halbleiterschichtenfolge entfernt oder zumindest stark gedünnt ist. Insbesondere ist es derart gedünnt, dass es für sich oder zusammen mit der Epitaxie-Schichtenfolge alleine nicht freitragend ist. Der verbleibende Rest des stark gedünnten Aufwachssubstrats ist insbesondere als solches für die Funktion eines Aufwachssubstrates ungeeignet; und
• – die Halbleiterschichtenfolge enthält mindestens eine Halbleiterschicht mit zumindest einer Fläche, die eine Durchmischungsstruktur aufweist, die im Idealfall zu einer annähernd ergodischen Verteilung des Lichtes in der Halbleiterschichtenfolge führt, das heißt, sie weist ein möglichst ergodisch stochastisches Streuverhalten auf.

In this embodiment, the optoelectronic component is implemented in thin-film technology. Such a "thin-film light-emitting diode chip" is characterized by at least one of the following characteristic features:

• - On one of the desired emission side of the radiation-generating semiconductor layer sequence, which may be in particular a radiation-generating epitaxial layer sequence, a reflective layer is applied or formed, which reflects at least a portion of the electromagnetic radiation generated in the semiconductor layer sequence in this back;
• The thin-film light-emitting diode chip has a carrier element, which is not the growth substrate on which the semiconductor layer sequence has been epitaxially grown, but a separate carrier element which has subsequently been attached to the semiconductor layer sequence;
• The semiconductor layer sequence has a thickness in the range of 20 μm or less, in particular in the range of 10 μm or less;
• - The semiconductor layer sequence is free of a growth substrate. In the present context, "free from a growth substrate means that a growth substrate which may be used for growth is removed from the semiconductor layer sequence or at least heavily thinned. In particular, it is thinned so that it alone or together with the epitaxial layer sequence is not self-supporting. The remainder of the highly thinned growth substrate is in particular unsuitable as such for the function of a growth substrate; and
• - The semiconductor layer sequence contains at least one semiconductor layer having at least one surface having a mixing structure, which leads in the ideal case to an approximately ergodic distribution of light in the semiconductor layer sequence, that is, it has the most ergodisch stochastic scattering behavior.

A basic principle of a thin-film light-emitting diode chip is, for example, in of the publication I. Schnitzer et al., Appl. Phys. Lett. 63 (16) 18 October 1993, pages 2174-2176 described, the disclosure of which is hereby incorporated by reference. Examples of thin-film light-emitting diode chips are in the documents EP 0905797 A2 and WO 02/13281 A1 described, whose disclosure content is hereby also included by reference. A thin-film light-emitting diode chip is, to a good approximation, a Lambertian surface radiator and is therefore suitable, for example, well for use in a headlight, for example a motor vehicle headlight.

As the material system in the present case, a III / V compound semiconductor material, namely gallium nitride is used, wherein the first sub-layer 12 p-doped and the transparent carrier substrate 40 facing partial layers 11 . 11a n-doped. In addition, other material systems can be used.

One III / V compound semiconductor material has at least one element from the third main group, such as B, Al, Ga, In, and an element of the fifth main group, such as N, P, ace, up. In particular, the term "III / V compound semiconductor material" includes the Group of binary, ternary or quaternary Compounds containing at least one element from the third main group and at least one element of the fifth main group contain, for example, nitride and phosphide compound semiconductors. Such a binary, ternary or quaternary For example, compound may also include one or more dopants and have additional constituents.

Corresponding For example, an II / VI compound semiconductor material comprises at least one element the second main group such as Be, Mg, Ca, Sr, and a member of the sixth main group, such as O, S, Se, up. In particular, an II / VI compound semiconductor material comprises a binary, ternary or quaternary compound, the at least one element from the second main group and at least comprises an element from the sixth main group. Such a binary, ternary or quaternary connection can also for example, one or more dopants and additional Have constituents. For example, the II / VI compound semiconductor materials include: ZnO, ZnMgO, CdS, ZnCdS, MgBeO.

The optoelectronic component 1 according to 1 further comprises an insulating layer 14 that are on the sublayer 12 the epitaxially grown layer sequence 10 is arranged. The insulating layer 14 protects the partial layer 12 from damage or contamination and isolates it electrically. For contacting the two partial layers 12 and 11 are two connection contacts 20 and 21 on the back of the layer sequence 10 arranged. A first contact 20 is in a trench of the insulating layer 14 formed and contacted the p-doped sub-layer 12 electric.

A second contact 21 is on the insulating sublayer 14 applied. There are also trenches 22 provided by the insulating layer 14 , the sub-layer 12 , the pn junction 13 into the sub-layer 11 pass. The trenches 22 are with an insulating layer 23 and filled with an electrically conductive material. Through the insulating layer 23 becomes a short circuit of the connection contact 21 with the p-doped sublayer 12 avoided. Via the two rear connection contacts 20 and 21 In an operation of the optoelectronic component, charge carriers are injected which are exposed to light in the pn junction 13 recombine with each other. The direct contacting of the connection contacts 20 and 21 With highly conductive materials causes a good heat dissipation in an operation of the optoelectronic device to the back.

The adhesive layer 30 on the textured surface 11b the sub-layer 11a is also like the carrier substrate 40 transparent and has a refractive index which substantially corresponds to the refractive index of the carrier substrate. The structuring of the surface 11b the sub-layer 11a improves the light extraction in the adhesive layer 30 and the carrier substrate 40 ,

When transparent carrier substrate is particularly suitable Glass with a refractive index in the range of 1.4.

2 shows in this regard the coupling-out efficiency with respect to the refractive index. Significantly too The maximum of the coupling-out efficiency is approximately 1.19 with a refractive index in the range of 1.4 to 1.43. This refractive index essentially corresponds to the refractive index of glass, so that the coupling-out efficiency is maximal in the case of a carrier substrate made of glass.

3 shows a further embodiment of the invention. In this embodiment, the carrier substrate is in the form of a pyramid 41 formed their side surfaces in the in 3 shown sectional view have the shape of an isosceles triangle. Also in this embodiment, the carrier substrate is formed of a transparent material such as glass or sapphire, and a transparent adhesive layer 30 with a roughened upper surface 11b the n-doped gallium nitride layer 11a connected. The shape of the carrier substrate influences the efficiency of the light extraction and the radiation characteristic. In the illustrated embodiment according to 3 a bundling of the emitted light in the forward direction is achieved.

In particular in connection with additional converter layers, not shown here, between the surface 11b the sub-layer 11a and the carrier substrate 41 , this type of "angular filtering" is well suited to produce a directional radiation characteristic.

A similar embodiment shows 7 in which the carrier substrate 45 Having in the emission direction converging inclined edges. This structure, called ATON-like cut, enables a high level of efficiency in light extraction.

An alternative embodiment shows 4 , In this embodiment, the carrier substrate becomes "upside down", that is, with the major side having a smaller area over the adhesive layer 30 at the roughened surface 11b the sub-layer 11a attached. The at the sub-layer 11a attached bottom 42a of the carrier substrate 42 has a smaller geometric dimension than the corresponding top of the carrier substrate 42 , Accordingly, the side edges are inclined away from each other. Additional adhesive layers 43 in the resulting space between the surface 42a and the obliquely running side edges 42b of the carrier substrate 42 cause a light extraction to the side. This makes it possible to realize an optoelectronic component for the backlight, in which the component with the carrier substrate is placed on the object to be illuminated.

In addition, there is the possibility of the carrier substrate prior to application to the surface of the sub-layer 11a with additional functional layers. Alternatively, it is of course possible, after detachment of the growth substrate to the surface of the sub-layer 11a In addition to the adhesive layer to grow additional functional layers and then connect them to the carrier substrate.

6 shows a related embodiment, in which between a carrier substrate layer 43 and the n-doped sub-layer 11a several functional layers 53 . 51 . 52 are arranged.

In the present embodiment, the functional layers form 51 to 53 and the carrier substrate layer 43 and the additional coupling-out layer 44 together the carrier substrate. The carrier substrate is produced in separate process steps. This allows the functional layers 50 with the individual partial layers 51 to 53 on the carrier substrate layer 43 in various deposition processes at temperatures above 300 degrees. A conversion layer 52 with a conversion material is used for the conversion of the layer sequence 10 emitted light in a different wavelength. By the separate production of the carrier substrate with the functional layers 50 can the converter layer 52 be significantly reduced in thickness.

Alternatively or additionally, it is also possible in the adhesive layer 30 To introduce converter particles. Conversion particles or layers may also be disposed on top of the carrier substrate layer.

In addition to the converter layer 52 the carrier substrate has an additional functional layer 51 in the form of a Bragg mirror. This includes a plurality of laterally structured sublayers arranged one above the other to improve the light outcoupling and to reduce the reflection of light emitted by the epitaxial layer sequence in the outcoupling direction.

The separate application of the carrier substrate with the converter layers on the already produced layer sequence 10 allows a pre-characterization of the epitaxial layer sequence to depending on the thickness of the converter layer 52 for the carrier substrate. In this way, individual epitaxial layers can be selected 10 conversion layers 52 on the carrier substrate layer 43 to produce a desired mixed color.

Finally shows 8th an embodiment in which the carrier substrate 46 is formed in the form of a lens and the adhesive layer with the layer sequence 10 connected is. This allows one Bundling and directional radiation of the epitaxial layer sequence 10 generated and emitted light. In addition, on the carrier layer 46 a lenticular silicone layer 47 be upset. This improves the stability and at the same time protects the lenticular carrier substrate 46 ,

5 shows a comparison of Auskoppeleffizienz for different embodiments of optoelectronic devices, in which rear side connection contacts are provided. A light emission thus takes place in the direction of the roughened structured surface. The components are connected with their back to electrical connections, which also form heat sinks for cooling the component during operation. A decoupling of light on the outcoupling side directly to air shows a normalized decoupling efficiency of 1. By contrast, in the case of the component according to the invention 1 applied over an adhesive layer, a 0.4 mm thick carrier substrate made of glass. This points opposite to the component 1a an improved coupling-out efficiency in the range of 1.19. For comparison herewith is an optoelectronic device 1B shown, which is completely enclosed by a silicone lens. Although this shows a slightly improved coupling-out efficiency of 1.23, silicone is susceptible to aging processes, so that the coupling-out efficiency tends to worsen over a longer period of time. In addition, the silicone lens has significantly larger dimensions than the device according to the invention 1 ,

The 9A to 9K show an embodiment of a manufacturing method for an optoelectronic device according to the proposed principle.

According to 9A becomes a growth substrate in first steps 90 provided. This will be a first sub-layer 110 deposited, which is doped with a first type of charge carrier. The sub-layer 110 corresponds to the partial layers 11a and 11 the previous embodiments. A small area is thus intended to be later chemically or physically structured or roughened in order to improve the light extraction. Accordingly, the sub-layer should 110 have a sufficient thickness. Above the sub-layer 110 becomes a second sublayer 12 epitaxially deposited with respect to the sub-layer 110 different charge carrier type is doped. This forms at the interface between the two sublayers 12 and 110 a pn junction 13 out.

The two sublayers partially shown here 110 and 12 may comprise additional sublayers such as charge carrier injection layers or charge carrier transport layers. Their doping concentration can vary in individual partial layers. In one embodiment, for example, provided between the growth substrate 90 and the first sub-layer 110 additionally to arrange a lightly doped sub-layer of the same charge carrier type. This can serve as a sacrificial layer for the subsequent detachment of the growth substrate 90 serve. At the same time it is also suitable for the surface of the growth substrate 90 to planarize. Alternatively, also the partial layer 110 be provided with a Dotiergradienten so that the doping concentration changes across the thickness of the layer away.

On the epitaxially grown layer sequence according to 9B still a sub-layer 14 deposited. This can be an insulating layer, which protects the underlying sub-layers of the epitaxial layer sequence. between the sub-layer 14 and the sub-layer 12 In addition, a reflective and highly conductive layer is arranged.

To 9C will now be on the insulating layer 14 a thin adhesive layer 93 applied and then a temporary subcarrier 92 attached, z. By a special 3M process. This is only for short-term mechanical stabilization and should therefore on the adhesive layer 93 reversible with the insulating layer 14 be connected. The adhesive layer is removed in a chemical, mechanical or physi cal way in later process steps to the temporary subcarrier 92 to replace again.

The temporarily applied subcarrier 92 stabilizes the epitaxially grown layer sequence so that the growth substrate 90 as in 9D can be removed. This is done for example by a so-called laser lift-off process. The exposed surface of the sub-layer 110 is in a subsequent process step according to 9E roughened to increase the light extraction. Subsequently, a transparent in the cured state adhesive layer 30a Applied to the roughened surface and evenly distributed. The adhesive used may, for example, be liquid and spun or spin-coated so that it spreads as evenly as possible over the roughened surface 11b distributed. It also ensures that there are no air pockets between the adhesive layer 30a and the roughened surface 11b the sub-layer 110 available.

According to 9F Now becomes a structured and if necessary provided with additional functional layers carrier substrate 47 on the not yet cured adhesive layer 30a applied and then the adhesive layer 30a hardened. There through connects the carrier substrate 47 intimate with the epitaxial layer sequence 10 and leads to a sufficiently large mechanical stabilization. The adhesive layer 30 in the cured state has a refractive index, which is substantially the subsequent region of the carrier substrate 47 ' equivalent. Thereby, reflection becomes due to a difference in the refractive indices between the adhesive layer 30 and the carrier substrate 47 ' reduced or avoided.

According to 9G can the carrier substrate 47 ' be additionally structured, for example by grinding or removal as shown side edges.

The temporary subcarrier 92 will now be as shown in 9H removed and the underlying insulating layer 14 exposed. For contacting the p- or n-doped partial layers 12 and 110 are now ditches 80 ' respectively 80 Etched in different areas on the back of the device. The trenches 80 ' pass through the insulating layer 14 as well as between the insulating layer 14 and the sub-layer 12 arranged mirror layer through and are thus areas within the sub-layer 12 free. Accordingly, the trenches break through 80 the insulating layer 14 , the mirror layer, the sublayer 12 as well as the pn junction 13 and end in the sublayer 110 ,

To prevent short circuits now especially the trenches 80 on its side walls with an insulation layer 23 Mistake. The bottom of the trenches 80 remains, however, remains free, so that a conductive material in the sub-layer 110 electrically conductive contacted.

Then the trenches 80 ' and 80 according to 9K filled with an electrically conductive material and the back contacts 20 respectively 21 educated. The mirror layer between the insulating layer 14 and the sub-layer 12 gets through the material in the trenches 80 ' contacts and also serves as a current distribution layer for improving the lateral charge carrier injection into the sub-layer 12 , Accordingly, the trenches 80 in an area of the sub-layer 110 end, which has a low late ral resistance and thus is also well suited for power distribution.

In addition to the method shown here, in which the rear connection contacts and in particular the trenches after the application of the carrier substrate 46 It is also possible to make trenches 80 ' and 80 to train in previous procedural steps. For example, the trenches may be etched into the individual sublayers and filled with electrically conductive material before the temporary subcarrier is applied and the growth substrate 90 is replaced. In this embodiment, the temporary submount would be applied and secured to the already structured and trenched rear.

Likewise, it is possible after forming and filling the trenches 80 ' and 80 to completely provide the back with a thin layer of metal and place the temporary submount thereon. After the subsequent structuring of the coupling-out side and the application of the carrier substrate, the temporary auxiliary carrier is detached again, and then the metallic layer applied to the insulating layer is patterned to form the rear-side connection contacts.

The The present invention allows a thin film LED chip with both electrical connections on the from the emission surface to realize the opposite side, without sacrificing the mechanical To have stability of the chip. In addition, the manufacturing process according to the proposed Realize principle at wafer level including training the connection contacts. This is achieved in which the mechanical Stabilization of the epitaxial layer sequence serving carrier substrate transparent with the decoupling side of the epitaxially grown layer sequence is connected. This allows the back of the epitaxial Layer sequence completely including the Terminal contacts are formed without additional vias through To form the carrier substrate. The chip can so processed as a single-die without need for bonding wires and no additional package is needed. If a casting is still desired, this can by an adaptation of its refractive index to the refractive index of the substrate carrier contribute to an optimization of the light extraction.

The separate production of the carrier substrate with functional Layer and the subsequent application of the same on the decoupling side the epitaxial layer sequence still allows it in an intermediate step during process production the epitaxial layer sequence to characterize in terms of their radiation characteristics and dependent on it for the production of the parameters to adjust functional layers.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• EP 0905797 A2 [0045]
• WO 02/13281 A1 [0045]

Cited non-patent literature

• - The publication I. Schnitzer et al., Appl. Phys. Lett. 63 (16) 18 October 1993, pages 2174-2176 [0045]

Claims (15)

Optoelectronic component comprising: - one epitaxially grown layer sequence, the one for light emission includes suitable sub-layer, wherein the layer sequence is a first Main side facing the main emission direction of emitted light is and the Hauptabstrahlrichtung remote second main page having; - one for the in the main direction of radiation emitted light transparent carrier substrate, for mechanical Stabilization of the epitaxially grown layer sequence on the first main page arranged and with the epitaxially grown Layer sequence is connected; - at least two connection contacts for the supply of charge carriers to partial layers the epitaxially grown layer sequence, both connection contacts arranged on the second main page. The device of claim 1, wherein the epitaxially Grown layer sequence on the first main page to increase the light extraction is structured. The component according to one of the claims 1 to 2, in which between the epitaxially grown layer sequence and the carrier substrate, a transparent adhesive layer for Connecting the carrier substrate arranged with the layer sequence is. The device of claim 3, wherein a refractive index of the adhesive substantially a refractive index of the carrier substrate equivalent. The component according to one of the claims 1 to 4, in which between the carrier substrate and the epitaxial grown layer sequence at least one of the following layers is arranged: - A light conversion layer with a conversion dye; A Bragg reflection layer. The component according to one of the claims 1 to 4, wherein the carrier substrate at least one of following layers facing the first main page is: A light conversion layer with a conversion dye; - one Bragg reflection layer. The component according to one of the claims 1 to 6, wherein the carrier substrate is a first of the epitaxial grown layer sequence facing the main page and a second opposite main page, wherein first and second main page have different dimensions. The component according to one of the claims 1 to 7, further comprising: - one on the second Main side of the epitaxially grown layer sequence arranged insulating layer; A first trench in the insulating layer, a portion of an underlying first sublayer of the Layer sequence uncovered; - a second ditch in the insulating layer, in the first sub-layer and in the light emission suitable sub-layer, which is a region of a second sub-layer the layer sequence exposes; - a conductive Material in the first and second trench which each one of the contacted at least two terminals. Process for producing an optoelectronic Component comprising: - Deploy one a growth substrate epitaxially grown layer sequence, the a sub-layer suitable for light emission comprises the layer sequence comprising a first main side, the main emission direction emitted light and one of the main emission direction facing away from the second main page; - applying a Subcarrier on the second main page; - detachment the growth substrate; - Structure the first Main page to increase the light extraction; - Apply transparent to a light emitted by the sub-layer Substrate carrier on the first main page; - detachment the subcarrier on the second main page; - Training of electrical connection contacts on the second main page. The method of claim 9, wherein forming of electrical connection contacts on the second main page the step of applying a subcarrier on the second main page. Method according to one of claims 9 to 10, in which the structuring of the first main page at least one the following steps include: - roughening the surface a sub-layer forming the first main page; - Apply a light conversion layer; - applying a Bragg reflection layer. Method according to one of claims 9 to 11, wherein the carrier substrate is a mechanically stabilizing transparent carrier, in particular a glass carrier and at least one of the following layers, that of the first Main page is adjacent: A light conversion layer having a conversion dye; A Bragg reflection layer. Method according to one of claims 9 to 12, in which the application of a substrate carrier comprises: - Apply a transparent adhesive layer on the first main side; - Apply the substrate carrier on the adhesive layer; - Harden the transparent adhesive layer. Method according to one of claims 9 to 13, in which the formation of electrical connection contacts comprises: - Training an insulating layer on the second main side of the epitaxial grown layer sequence; - Forming a first Trench in the insulating layer, one area below one lying first sub-layer of the layer sequence exposed; - Training a second trench in the insulating layer, in the first sub-layer and in the sub-layer suitable for light emission, which is a region a second sub-layer of the layer sequence exposed; - Fill up of the first and second trenches with a conductive material. The method of claim 14, wherein forming followed by electrical connection contacts the subcarrier on the connection contacts thus formed is applied.