KR20180016906A - Semiconductor device and light emitting device package having thereof - Google Patents

Abstract

An embodiment relates to a semiconductor device and a light emitting device package having the same.
The semiconductor device according to the embodiment includes a first conductivity type semiconductor layer, an active layer having a plurality of barrier layers, a last barrier layer, a plurality of well layers and a last well layer on the first conductivity type semiconductor layer, A second conductive semiconductor layer disposed on the active layer, and a contact layer disposed on the second conductive semiconductor layer, wherein the thickness of the last well layer is different from that of the other well And the first semiconductor layer includes GaN / Al _p Ga _{1 - p} N (0.4 _{? P} ? 0.5) stacked two or more layers, and the contact layer contains the first conductive dopant to maintain the operating voltage And at the same time, the injection efficiency of the cavity can be increased and the luminous efficiency can be improved by the 2DEG effect.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a semiconductor device and a light emitting device package having the same,

Embodiments relate to semiconductor devices.

An embodiment relates to a light emitting device package.

An embodiment relates to a lighting device.

Semiconductor devices including compounds such as GaN and AlGaN have many merits such as wide and easy bandgap energy, and can be used variously as light emitting devices, light receiving devices, and various diodes.

Particularly, a light emitting device such as a light emitting diode or a laser diode using a semiconductor material of Group 3-5 or 2-6 group semiconductors can be applied to various devices such as a red, Blue, and ultraviolet rays. By using fluorescent materials or combining colors, it is possible to realize a white light beam with high efficiency. Also, compared to conventional light sources such as fluorescent lamps and incandescent lamps, low power consumption, , Safety, and environmental friendliness.

In addition, when a light-receiving element such as a photodetector or a solar cell is manufactured using a semiconductor material of Group 3-5 or Group 2-6 compound semiconductor, development of a device material absorbs light of various wavelength regions to generate a photocurrent , It is possible to use light in various wavelength ranges from the gamma ray to the radio wave region. It also has advantages of fast response speed, safety, environmental friendliness and easy control of device materials, so it can be easily used for power control or microwave circuit or communication module.

Accordingly, the semiconductor device can be replaced with a transmission module of an optical communication means, a light emitting diode backlight replacing a cold cathode fluorescent lamp (CCFL) constituting a backlight of an LCD (Liquid Crystal Display) display device, White light emitting diodes (LEDs), automotive headlights, traffic lights, and gas and fire sensors. In addition, semiconductor devices can be applied to high frequency application circuits, other power control devices, and communication modules.

Embodiments can provide a semiconductor device capable of improving carrier injection efficiency and a light emitting device package having the same.

Embodiments can provide a semiconductor device and a light emitting device package having the same that can improve the efficiency of light emission by a 2-dimensional electron gas (2DEG) effect by increasing electron injection efficiency.

Embodiments can provide a semiconductor device and a light emitting device package having the semiconductor device capable of improving the light intensity while improving the operation voltage.

Embodiments can provide a semiconductor device capable of improving current spreading and a light emitting device package having the same.

Embodiments can provide a semiconductor device and a light emitting device package having the semiconductor device capable of improving the current spreading by reducing the resistance of the ohmic contact.

The embodiment includes a first conductivity type semiconductor layer; An active layer having a plurality of barrier layers, a last barrier layer, a plurality of well layers and a last well layer on the first conductivity type semiconductor layer; A first semiconductor layer disposed between the first conductive semiconductor layer and the active layer; A second conductive semiconductor layer disposed on the active layer; And the second conductive type thickness of a contact layer, and the last well layer disposed on the semiconductor layer is different from the well thicker than the layer thickness, the first semiconductor layer is a second pair or more layers of GaN / Al _p Ga _{1 - p} N (0.4? _p ? 0.5). The contact layer includes the first conductive dopant to maintain the operating voltage and increase the cavity injection efficiency, thereby improving the luminous efficiency by the 2DEG effect.

Another embodiment includes a first conductive semiconductor layer; An active layer having a plurality of barrier layers, a last barrier layer, a plurality of well layers and a last well layer on the first conductivity type semiconductor layer; A first semiconductor layer disposed between the first conductive semiconductor layer and the active layer; A second semiconductor layer having a superlattice structure on the first semiconductor layer; A second conductive semiconductor layer disposed on the active layer; And a contact layer disposed on the second conductivity type semiconductor layer, wherein the thickness of the last well layer is thicker than the thickness of the other well layer, and the first conductivity type semiconductor layer has a third and fourth semiconductor layers Wherein the fourth semiconductor layer comprises a first conductive type first layer stacked on one or more pairs and an undoped second layer, wherein the GaN thickness of the first semiconductor layer is greater than the GaN thickness of the first conductive type layer And the second contact layer has a thickness of 10% or less of the thickness of the second contact layer. The contact layer includes the first conductive dopant to maintain the operating voltage and increase the cavity injection efficiency, thereby improving the luminous efficiency by the 2DEG effect .

The embodiment can improve the luminous efficiency by increasing the hole injection efficiency by the 2DEG effect.

The embodiment can improve the efficiency of luminescence by improving the carrier injection efficiency of the last well layer.

The embodiment can improve the carrier injection efficiency of the last well layer to maintain the operating voltage and improve the light intensity.

The embodiment can improve the current spreading and improve the light intensity while maintaining the operating voltage by the superlattice structure including the semiconductor layer having the aluminum composition of 40% or more between the first conductivity type semiconductor layer and the active layer.

Embodiments can improve current spreading by reducing ohmic contact resistance.

1 is a view showing a semiconductor device according to an embodiment.
2 is a view showing a first semiconductor layer according to an embodiment.
3 is a view showing the second semiconductor layer, the active layer and the electron blocking layer in the embodiment.
4 is a diagram showing an energy bandgap diagram of a semiconductor device according to an embodiment.
5 is a graph showing the composition of aluminum of the semiconductor device according to the embodiment and the concentration of the dopant of the first conductivity type in the contact layer by SIMS (secondary-ion mass spectroscopy) analysis.
6 is a view showing an example in which electrodes are arranged in the semiconductor device of FIG.

The embodiments may be modified in other forms or various embodiments may be combined with each other, and the scope of the present invention is not limited to each embodiment described below.

Although not described in the context of another embodiment, unless otherwise described or contradicted by the description in another embodiment, the description in relation to another embodiment may be understood.

For example, if the features of configuration A are described in a particular embodiment, and the features of configuration B are described in another embodiment, even if the embodiment in which configuration A and configuration B are combined is not explicitly described, It is to be understood that they fall within the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG.

In the description of the embodiment according to the present invention, in the case of being described as being formed "on or under" of each element, the upper (upper) or lower (lower) or under are all such that two elements are in direct contact with each other or one or more other elements are indirectly formed between the two elements. Also, when expressed as "on or under", it may include not only an upward direction but also a downward direction with respect to one element.

The semiconductor device may include various electronic devices such as a light emitting device and a light receiving device. The light emitting device and the light receiving device may include the first conductivity type semiconductor layer, the active layer, and the second conductivity type semiconductor layer.

The semiconductor device according to this embodiment may be a light emitting device.

The light emitting device emits light by recombination of electrons and holes, and the wavelength of the light is determined by the energy band gap inherent to the material. Thus, the light emitted may vary depending on the composition of the material.

FIG. 1 is a view showing a semiconductor device according to an embodiment, and FIG. 2 is a view showing a first semiconductor layer according to an embodiment.

FIG. 3 is a view showing a second semiconductor layer, an active layer and an electron blocking layer in the embodiment, and FIG. 4 is an energy band gap diagram of a semiconductor device according to an embodiment.

As shown in FIGS. 1 and 2, the semiconductor device according to the embodiment is to be described as an example of a light emitting device 100 that emits ultraviolet light having a wavelength range of 200 nm to 400 nm. However, the present invention is not limited thereto. The light emitting device may have a short wavelength and a long wavelength depending on the application. The short wavelength may be used for sterilization or purification, and the long wavelength may be used for an exposure machine, a curing machine, or the like. In the embodiment, the light emitting device 100 having the wavelength of the ultraviolet ray A is described as an example.

The light emitting device 100 can improve the luminous intensity Po while maintaining the operating voltage and improve the carrier injection efficiency. To this end, the light emitting device 100 according to the embodiment includes the active layer 150, the first semiconductor layer 180, and the contact layer 190 including the last well layer 151L having a thickness greater than that of the other well layers can do.

The light emitting device 100 includes a first conductive semiconductor layer 140, a first semiconductor layer 180, a second semiconductor layer 171, an active layer 150, an electron blocking layer (EBL) 173 ), A second conductive semiconductor layer 160, and a contact layer 190.

The light emitting device 100 may include at least one of the buffer layer 131 and the substrate 121 under the first conductive semiconductor layer 140.

The light emitting device 100 may include the buffer layer 131 and the substrate 121 under the first conductive semiconductor layer 140.

The light emitting device 100 includes a first semiconductor layer 180, a second semiconductor layer 171, an electron blocking layer (EBL) 173, a last well layer having a thickness greater than that of the other well layers 151L, and a contact layer 190, as shown in FIG. For example, the light emitting device 100 may include the first semiconductor layer 180, the second semiconductor layer 171, and the electron blocking layer 173. Alternatively, the light emitting device 100 includes the first semiconductor layer 180, the second semiconductor layer 171, the electron blocking layer 173, and the last well layer 151L having a thickness greater than that of the other well layers can do. The light emitting device 100 includes the first semiconductor layer 180, the second semiconductor layer 171, the electron blocking layer 173, the last well layer 151L having a thickness greater than the thickness of the other well layer 151L, Layer 190 of the present invention.

Although not shown in the figure, the light emitting device 100 may further include a semiconductor layer having a super lattice structure between the active layer 150 and the second conductive semiconductor layer 160, no.

The substrate 121 may be, for example, a translucent, conductive substrate or an insulating substrate. For example, the substrate 121 is a sapphire (Al ₂ O _3), SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge, and Ga ₂ O ₃ Or the like. A plurality of protrusions (not shown) may be formed on the top surface and / or bottom surface of the substrate 21, and each of the plurality of protrusions may include at least one of a hemispherical shape, a polygonal shape, and an elliptical shape, Or in the form of a matrix. The protrusions can improve the light extraction efficiency.

The substrate 121 may be formed of a material having excellent thermal conductivity, and may be a conductive substrate or an insulating substrate. For example, the substrate 121 is a sapphire (Al ₂ O _3), SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge, and Ga ₂ 0 ₃ May be used. The concavo-convex structure may be formed on the substrate 121, but the present invention is not limited thereto.

A plurality of compound semiconductor layers may be grown on the substrate 121. The plurality of compound semiconductor layers may be grown using an electron beam evaporator, physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma laser deposition (PLD) A dual-type thermal evaporator, sputtering, metal organic chemical vapor deposition (MOCVD), or the like. However, the present invention is not limited thereto.

The buffer layer 131 may be disposed on the substrate 121. The buffer layer 131 may be disposed between the substrate 121 and the first conductive semiconductor layer 140. The buffer layer 131 may be formed of at least one layer using Group III-V or Group II-VI compound semiconductors. The buffer layer 131 may be formed of a semiconductor material having a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + y? 1) . The buffer layer 131 may include at least one of materials such as GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP, and ZnO.

The buffer layer 131 may be formed in a superlattice structure by alternately arranging different semiconductor layers. The buffer layer 131 may be disposed to mitigate the difference in lattice constant between the substrate 121 and the nitride-based semiconductor layer, and may be defined as a defect control layer. The lattice constant of the buffer layer 131 may have a value between lattice constants between the substrate 121 and the nitride semiconductor layer. The buffer layer 131 may not be formed, but the present invention is not limited thereto.

The first conductive semiconductor layer 140 may be disposed between the active layer 150 and at least one of the substrate 121 and the buffer layer 131. The first conductive semiconductor layer 140 may be formed of at least one of Group III-V or Group II-VI compound semiconductor doped with a first conductivity type dopant.

The first conductive semiconductor layer 140 may be a semiconductor having a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + May be formed of a material. The first conductive semiconductor layer 140 may be GaN, but the present invention is not limited thereto. The first conductive semiconductor layer 140 may include at least one of GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP and AlGaInP. The first conductive semiconductor layer 140 may include a first conductive dopant. For example, the first conductive semiconductor layer 140 may be an n-type semiconductor layer doped with an n-type dopant such as Si, Ge, Sn, Se, or Te.

The first conductive semiconductor layer 140 may be a single layer or a multi-layer structure. The first conductive semiconductor layer 140 may include a third semiconductor layer 141 and a fourth semiconductor layer 143.

The third semiconductor layer 141 may be disposed on the substrate 121. The third semiconductor layer 141 may be disposed under the third semiconductor layer 143. The third semiconductor layer 141 may include at least one of GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, May be an n-type semiconductor layer doped with an n-type dopant.

The fourth semiconductor layer 143 may be disposed between the third semiconductor layer 141 and the first semiconductor layer 180. In the fourth semiconductor layer 143, two different layers may be alternately arranged. The fourth semiconductor layer 143 may include at least one of GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP and AlGaInP. For example, the fourth semiconductor layer 143 may include a first layer including an n-type dopant and an undoped second layer. For example, the fourth semiconductor layer 143 of the embodiment may include at least one pair of n-GaN / u-GaN. The thickness of each of the n-GaN / u-GaN may be 100 nm or more, but is not limited thereto.

The first semiconductor layer 180 may be disposed on the first conductive semiconductor layer 140. The first semiconductor layer 180 may be an n-type semiconductor layer doped with an n-type dopant such as Si, Ge, Sn, Se, or Te. The first semiconductor layer 180 may have a superlattice structure in which at least two or more different layers are alternately stacked. In the first semiconductor layer 180, a semiconductor layer having an Al composition of 40% or more and a semiconductor layer not containing Al may be alternated three or more times. For example, the first semiconductor layer 180 may include AlGaN 181 and GaN 183, but is not limited thereto. For example, the one semiconductor layer 180 may include three pairs or more of AlGaN / AlN / GaN. The first semiconductor layer 180 may include three or more pairs of AlGaN 181 and GaN 183 to improve the current spreading effect. The thickness T1 of the first semiconductor layer 140 may be less than the thickness of each of the n-GaN / u-GaN layers of the fourth semiconductor layer 143. [ For example, the thickness T1 of the first semiconductor layer 140 may be 100 nm or less. When the thickness T1 of the first semiconductor layer 140 is greater than 100 nm, the first semiconductor layer 140 and the external electrode are connected to each other to form a gap between the first conductive semiconductor layer 140 and the external electrode Leakage current may cause degradation of electrical characteristics.

The AlGaN 181 may include a semiconductor material having a composition formula of Al _p Ga _{1 - p} N (0.4 _{? P} ? 0.5). The thickness (T2) of the AlGaN 181 in the embodiment may be 10 nm or less. For example, the thickness T2 of the AlGaN 181 may be 2 nm to 6 nm. The AlGaN 181 may include n-type dopants such as Si, Ge, Sn, Se, and Te. When the thickness T2 of the AlGaN layer 181 is 2 nm or less, the current spreading effect may be deteriorated. When the thickness T3 of the GaN layer 183 is 20 nm or more, (100 nm) of the thickness (T1) of the substrate (1). That is, when the thickness T3 of the GaN layer 183 is 20 nm or more, electrical characteristics such as leakage current due to contact between the first semiconductor layer 180 and the external electrode portion may be degraded.

The GaN 183 may be an undoped semiconductor, but is not limited thereto. For example, the GaN layer 183 may include n-type dopants such as Si, Ge, Sn, Se, and Te. The thickness T3 of the GaN layer 183 in the embodiment may be 20 nm or less. The thickness T3 of the GaN layer 183 may be less than or equal to 10% of the thickness of each of the n-GaN / u-GaN layers of the third semiconductor layer 143. [ For example, the thickness T3 of the GaN layer 183 may be 2 nm to 10 nm. Specifically, the thickness T3 of the GaN layer 183 may be 6 nm to 8 nm. If the thickness T3 of the GaN layer 183 is less than 2 nm and the thickness T3 of the GaN layer 183 is greater than 20 nm, (100 nm) of the thickness (T1) of the substrate (1). That is, when the thickness T3 of the GaN layer 183 is 20 nm or more, electrical characteristics such as leakage current due to contact between the first semiconductor layer 180 and the external electrode portion may be degraded.

The first semiconductor layer 180 of the embodiment can realize a 2DEG (2-dimensional electron gas) effect by increasing the electron injection efficiency by the difference in bandgap between the AlGaN 181 and the GaN 183. The first semiconductor layer 180 for increasing the electron injection efficiency may be disposed on the first conductivity type semiconductor layer 140 to maintain the operating voltage and improve the luminous intensity Po.

The second semiconductor layer 171 may be disposed on the first semiconductor layer 180. The second semiconductor layer 171 may have a superlattice structure in which different layers are alternately stacked. For example, the second semiconductor layer 171 may be alternated by 10 pairs or more. For example, the second semiconductor layer 171 may include InGaN / GaN alternating fifteen or more pairs. The second semiconductor layer 171 may control electron movement to the active layer 150 to provide stable electron injection.

The active layer 150 may be disposed on the second semiconductor layer 171. The active layer 150 may be formed of at least one of a single well, a single quantum well, a multi-well, a multi quantum well (MQW), a quantum-wire structure, or a quantum dot structure .

Electrons (or holes) injected through the second semiconductor layer 171 and holes (or electrons) injected through the second conductive type semiconductor layer 160 meet with each other in the active layer 150, 150 is a layer which emits light due to a band gap difference of an energy band according to a forming material of the light emitting device. The active layer 150 may emit at least one peak wavelength of ultraviolet light, blue light, green light, and red light.

The active layer 150 may be formed of a compound semiconductor. The active layer 150 may be formed of at least one of Group 3-Group-5 or Group-6-Group compound semiconductors. When the active layer 150 is implemented as a multi-well structure, the active layer 150 includes a plurality of alternately disposed well layers 151, a well layer 151L, a plurality of barrier layers 153, (153L).

The plurality of well layers 151 and the last well layer 151L may be formed of, for example, In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + Of the semiconductor material. The plurality of well layers 151 and the last well layer 151L may be formed of In _x Al _y Ga _{1 -xy} N (0? X? 1, 0? _Y? 1, 0? _X + As shown in FIG.

InGaN / AlGaN, InGaN / AlGaN, InGaN / InGaN, AlGaAs / GaAs, InGaAs / GaAs, InGaP / GaP, AlInGaP / InGaP, InP / GaN, AlGaN / AlGaN, 0.0 > GaAs < / RTI > pair.

For example, the plurality of well layers 151 and the last well layer 151L may be InGaN, and the plurality of barrier layers 153 and the last barrier layer 153L may be GaN-based semiconductors. The band gaps of the plurality of barrier layers 153 and the last barrier layer 153L may be larger than the band gaps of the plurality of well layers 151 and the last well layer 151L.

The thickness of each of the plurality of barrier layers 153 may be greater than the thickness of each of the plurality of well layers 151. When the thickness of each of the plurality of well layers 151 is thinner than the thickness of each of the plurality of barrier layers 153, the carrier blocking efficiency is lowered. When the thickness is larger than the above range, the carrier is excessively confined.

The last well layer 151L may be disposed closer to the second conductivity type semiconductor layer 160 than the plurality of well layers 151. [ The last well layer 151L can improve electron injection efficiency. For example, the thickness of the last well layer 151L may be thicker than the thickness of the plurality of well layers 151. [ The last well layer 151L can improve the luminous efficiency by increasing the confinement of electrons in the region where the hole and the recombination contribution are high in the active layer 150. [ The thickness of the last well layer 151L may correspond to the thickness of the last barrier layer 153L. For example, the thickness of the last well layer 151L may be 150% or less of the thickness of each of the plurality of well layers 151. [ If the thickness of the last well layer 151L exceeds 150% of the thickness of each of the plurality of well layers 151, the crystallinity may be lowered by indium.

The last well layer 151L and the plurality of well layers 151 may include an indium composition of 3% to 5%. The last well layer 151L may include an indium composition higher than the plurality of well layers 151 within the indium composition range. For example, the last well layer 151L may comprise an indium composition of 5% and the plurality of well layers 151 may comprise an indium composition of 4%.

The embodiment includes a last well layer 151L having a thicker thickness and a higher indium composition than the plurality of well layers 151 to increase the confinement of electrons in the region where the hole and the recombination contribution are high to maintain the operating voltage, Po) can be improved.

The electron blocking layer 173 may be disposed on the active layer 150. The electron blocking layer 173 can improve the carrier injection efficiency and improve the external quantum efficiency (EQE) reduction. The electron blocking layer 173 may include a semiconductor and a semiconductor having a second conductivity type dopant, but is not limited thereto. The electron blocking layer 173 may have a single-layer structure or a multi-layer structure. The electron blocking layer 173 may have a band gap higher than that of the active layer 150. The electron blocking layer 173. For this purpose, the Al _q Ga _{1 -} may include a semiconductor material having a compositional formula of _q N (0.2≤q≤0.3). The electron blocking layer 173 may block electrons from the active layer 150 and confine holes to increase carrier injection in the active layer 150.

The contact layer 190 may include a first conductive type dopant. For example, the contact layer 190 may be an n-type semiconductor layer doped with an n-type dopant such as Si, Ge, Sn, Se, or Te. The contact layer 190 may include a lower doping concentration than the fourth semiconductor layer 143. The contact layer 190 may include a doping concentration corresponding to the third semiconductor layer 141. For example, the doping concentration of the contact layer 190 may be between 7E18 and 1E19. The contact layer 190 can reduce the contact resistance. The contact layer 190 may reduce the ohmic contact resistance with an electrode (not shown) for ohmic contact to maintain the operating voltage of the light emitting device 100 and improve the current spreading to improve the luminous efficiency.

The thickness of the contact layer 190 may be 2 nm to 5 nm. If the thickness of the contact layer 190 is less than 2 nm, the function of the contact layer 190 may deteriorate. When the thickness of the contact layer 190 is more than 5 nm, the crystallinity may be lowered.

The np junction structure from the first conductivity type semiconductor layer 140 to the second conductivity type semiconductor layer 160 has been described in the embodiment, but the present invention is not limited thereto, and any one of the pn junction structure, the npn junction structure, and the pnp junction structure Structure.

The embodiment includes a first semiconductor layer 180 having a superlattice structure including an Al composition of 40% or more and capable of realizing a 2DEG effect on the first conductivity type semiconductor layer 140 to maintain an operating voltage, Can be improved, and the luminous intensity Po can be improved.

The embodiment includes a last well layer 151L having a thicker thickness and a higher indium composition than the plurality of well layers 151 to increase the confinement of electrons in the region where the hole and the recombination contribution are high to maintain the operating voltage, Po) can be improved.

A contact layer 190 having a first conductivity type dopant different from the second conductivity type semiconductor layer 160 is disposed on the second conductivity type semiconductor layer 160 to form an ohmic contact with an external electrode The resistance can be reduced to maintain the operating voltage of the light emitting device 100, and the current spreading can be improved to improve the luminous efficiency.

6 is a view showing an example in which electrodes are arranged in the semiconductor device of FIG.

1 are denoted by the same reference numerals, and technical features can be employed in Fig. 1.

As shown in FIG. 6, the light emitting device includes a first electrode 210 and a second electrode 220. The first electrode 210 may be disposed on the first conductive semiconductor layer 140. The second electrode 220 may be disposed on the second conductive semiconductor layer 160. The first electrode 210 may be connected to the first conductive semiconductor layer 140 and the second electrode 220 may be connected to the second conductive semiconductor layer 160.

The second electrode 220 may include a contact electrode 221, a reflective layer 223, a bonding layer 225, and a support member 227.

The support member 227 may be a conductive substrate. For example, the support member 227 may be a metal such as copper (Cu), gold (Au), nickel (Ni), molybdenum (Mo), copper-tungsten , GaAs, ZnO, SiC).

The bonding layer 225 may be disposed on the support member 227. The bonding layer 225 may be used as a barrier metal or a bonding metal and the material may be selected from the group consisting of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, And may include at least one.

The reflective layer 223 may be disposed on the bonding layer 225. The reflective layer 223 is formed of a structure including at least one layer made of a material selected from the group consisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, .

The contact electrode 221 may be disposed on the reflective layer 223. The contact electrode 221 may be in direct contact with the contact layer 190 under the semiconductor layer, for example, the second conductive semiconductor layer 160. The contact electrode 221 may be a low conductive material such as ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, or may be a metal of Ni or Ag.

In an embodiment, a channel layer 250 and a current blocking layer 230 are disposed between the contact layer 190 and the second electrode 220.

The channel layer 250 may be disposed along the bottom edge of the contact layer 190. The channel layer 250 may be a ring shape, a loop shape, or a frame shape, but is not limited thereto. The channel layer 250 comprises a transparent conductive material or an insulating material, such as ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, SiO _2, SiO _x, SiO _x N _y, Si ₃ N _4, Al ₂ O ₃ , and TiO ₂ . A portion of the channel layer 250 may be vertically overlapped with an edge of the contact layer 190. Another portion of the channel layer 250 may be disposed further outward than the outer side of the contact layer 190. Other portions of the channel layer 250 may include an exposed top region.

The current blocking layer 230 may be disposed under the second conductive semiconductor layer 160. The current blocking layer 230 may be disposed between the contact layer 190 and the reflective layer 223. The current blocking layer 230 includes an insulating material such as SiO ₂ , SiO _x , SiO _x N _y , Si ₃ N ₄ , Al ₂ O ₃ , TiO ₂ As shown in FIG. As another example, the current blocking layer 230 may also be formed of a metal for Schottky contact.

The current blocking layer 230 may be vertically overlapped with the first electrode 210. The current blocking layer 230 may cut off current supplied from the second electrode 220 and diffuse the current blocking layer 230 to another path. Specifically, the current blocking layer 230 may block a current concentrated in the short-distance direction between the first electrode 210 and the second electrode 220.

The above-described light emitting device is constituted by a light emitting device package and can be used as a light source of an illumination system, for example, as a light source of an image display device or a light source of an illumination device.

When used as a backlight unit of a video display device, it can be used as an edge type backlight unit or as a direct-type backlight unit. When used as a light source of a lighting device, it can be used as a regulator or a bulb type. It is possible.

The light emitting element includes a laser diode in addition to the light emitting diode described above.

The laser diode may include the first conductivity type semiconductor layer, the active layer and the second conductivity type semiconductor layer having the above-described structure, like the light emitting element. Then, electro-luminescence (electroluminescence) phenomenon in which light is emitted when an electric current is applied after bonding the p-type first conductivity type semiconductor and the n-type second conductivity type semiconductor is used, And phase. That is, the laser diode can emit light having one specific wavelength (monochromatic beam) with the same phase and in the same direction by using a phenomenon called stimulated emission and a constructive interference phenomenon. It can be used for optical communication, medical equipment and semiconductor processing equipment.

As the light receiving element, a photodetector, which is a kind of transducer that detects light and converts the intensity of the light into an electric signal, is exemplified. As such a photodetector, a photodiode (e.g., a PD with a peak wavelength in a visible blind spectral region or a true blind spectral region), a photodiode (e.g., a photodiode such as a photodiode (silicon, selenium), a photoconductive element (cadmium sulfide, cadmium selenide) , Photomultiplier tube, phototube (vacuum, gas-filled), IR (Infra-Red) detector, and the like.

In addition, a semiconductor device such as a photodetector may be fabricated using a direct bandgap semiconductor, which is generally excellent in photo-conversion efficiency. Alternatively, the photodetector has a variety of structures, and the most general structure includes a pinned photodetector using a pn junction, a Schottky photodetector using a Schottky junction, and a metal-semiconductor metal (MSM) photodetector have.

The photodiode, like the light emitting device, may include the first conductivity type semiconductor layer having the structure described above, the active layer, and the second conductivity type semiconductor layer, and may have a pn junction or a pin structure. The photodiode operates by applying reverse bias or zero bias. When light is incident on the photodiode, electrons and holes are generated and a current flows. At this time, the magnitude of the current may be approximately proportional to the intensity of the light incident on the photodiode.

A photovoltaic cell or a solar cell is a type of photodiode that can convert light into current. The solar cell, like the light emitting device, may include the first conductivity type semiconductor layer, the active layer and the second conductivity type semiconductor layer having the above-described structure.

In addition, it can be used as a rectifier of an electronic circuit through a rectifying characteristic of a general diode using a p-n junction, and can be applied to an oscillation circuit or the like by being applied to a microwave circuit.

In addition, the above-described semiconductor element is not necessarily implemented as a semiconductor, and may further include a metal material as the case may be. For example, a semiconductor device such as a light receiving element may be implemented using at least one of Ag, Al, Au, In, Ga, N, Zn, Se, P, or As, Or may be implemented using a doped semiconductor material or an intrinsic semiconductor material. While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

121: substrate
131: buffer layer
140: a first conductive semiconductor layer
141: third semiconductor layer
143: fourth semiconductor layer
150: active layer
151: a plurality of well layers
151L: Last well layer
153: a plurality of barrier layers
153L: Last barrier layer
160: second conductive type semiconductor layer
180: first semiconductor layer
190: contact layer

Claims (16)

A first conductive semiconductor layer;
An active layer having a plurality of barrier layers, a last barrier layer, a plurality of well layers and a last well layer on the first conductivity type semiconductor layer;
A first semiconductor layer disposed between the first conductive semiconductor layer and the active layer;
A second conductive semiconductor layer disposed on the active layer; And
And a contact layer disposed on the second conductive type semiconductor layer,
The thickness of the last well layer is thicker than the thickness of the other well layer,
Wherein the first semiconductor layer comprises GaN / Al _p Ga _{1 - p} N (0.4 _{? P} ? 0.5) laminated two or more layers,
Wherein the contact layer includes a first conductivity type dopant.
The method according to claim 1,
And a second semiconductor layer of a superlattice structure on the first semiconductor layer,
Wherein the first conductive semiconductor layer includes third and fourth semiconductor layers having different doping concentrations,
Wherein the fourth semiconductor layer includes a first conductive type first layer and a second conductive type layer stacked one on top of the other,
Wherein the GaN thickness of the first semiconductor layer is 10% or less of the thickness of each of the first conductive type first layer and the undoped second layer.
3. The method of claim 2,
The GaN thickness of the first semiconductor layer is 2 nm to 10 nm,
And the AlGaN thickness of the first semiconductor layer is 2 nm to 6 nm.
3. The method of claim 2,
Wherein a thickness of the first semiconductor layer is thinner than a thickness of the fourth semiconductor layer.
The method according to claim 1,
The thickness of the last well layer corresponds to the thickness of the last barrier layer,
Wherein a thickness of each of the plurality of well layers is thinner than a thickness of each of the plurality of barrier layers.
6. The method of claim 5,
And the thickness of the last well layer is 150% or less of the thickness of each of the plurality of well layers.
6. The method of claim 5,
Wherein the last well layer and the plurality of well layers comprise an indium composition and the indium composition of the last well layer is higher than the indium composition of each of the plurality of well layers.
3. The method of claim 2,
The doping concentration of the contact layer corresponds to the doping concentration of the third semiconductor layer and is lower than the doping concentration of the fourth semiconductor layer.
9. The method of claim 8,
And the thickness of the contact layer is 2 nm to 5 nm.
A first conductive semiconductor layer;
An active layer having a plurality of barrier layers, a last barrier layer, a plurality of well layers and a last well layer on the first conductivity type semiconductor layer;
A first semiconductor layer disposed between the first conductive semiconductor layer and the active layer;
A second semiconductor layer having a superlattice structure on the first semiconductor layer;
A second conductive semiconductor layer disposed on the active layer; And
And a contact layer disposed on the second conductive type semiconductor layer,
The thickness of the last well layer is thicker than the thickness of the other well layer,
Wherein the first conductive semiconductor layer includes third and fourth semiconductor layers having different doping concentrations,
Wherein the fourth semiconductor layer includes a first conductive type first layer and a second conductive type layer stacked one on top of the other,
The GaN thickness of the first semiconductor layer is 10% or less of the thickness of each of the first conductive type first layer and the undoped second layer,
Wherein the contact layer includes a first conductivity type dopant.
11. The method of claim 10,
Wherein the first semiconductor layer comprises GaN / Al _p Ga _{1 - p} N (0.4 _{? P} ? 0.5) laminated two or more layers.
12. The method of claim 11,
The GaN thickness of the first semiconductor layer is 2 nm to 10 nm,
And the AlGaN thickness of the first semiconductor layer is 2 nm to 6 nm.
11. The method of claim 10,
Wherein a thickness of the first semiconductor layer is thinner than a thickness of the fourth semiconductor layer.
11. The method of claim 10,
The thickness of the last well layer corresponds to the thickness of the last barrier layer,
Wherein a thickness of each of the plurality of well layers is thinner than a thickness of each of the plurality of barrier layers,
And the thickness of the last well layer is 150% or less of the thickness of each of the plurality of well layers.
15. The method of claim 14,
Wherein the last well layer and the plurality of well layers comprise an indium composition and the indium composition of the last well layer is higher than the indium composition of each of the plurality of well layers.
11. The method of claim 10,
The doping concentration of the contact layer corresponds to the doping concentration of the third semiconductor layer, is lower than the doping concentration of the fourth semiconductor layer,
And the thickness of the contact layer is 2 nm to 5 nm.

Images