Radiation-emitting semiconductor element and method for producing the same
View Patent ↗This invention describes a radiation-emitting semiconductor component based on GaN, whose semiconductor body is made up of a stack of different GaN semiconductor layers ( 1 ). The semiconductor body has a first principal surface ( 3 ) and a second principal surface ( 4 ), with the radiation produced being emitted through the first principal surface ( 3 ) and with a reflector ( 6 ) being produced on the second principal surface ( 4 ). The invention also describes a production method for a semiconductor component pursuant to the invention. An interlayer ( 9 ) is first applied to a substrate ( 8 ), and a plurality of GaN layers ( 1 ) that constitute the semiconductor body of the component are then applied to this. The substrate ( 8 ) and the interlayer ( 9 ) are then detached and a reflector ( 6 ) is produced on a principal surface of the semiconductor body.
1. Method for producing a radiation-emitting semiconductor component whose semiconductor body includes a stack of different III-V nitride semiconductor layers configured to emit radiation, wherein the semiconductor body has a first principal surface and a second principal surface, with at least a portion of the radiation being emitted through the first principal surface, the method comprising:
producing a reflecting contact layer for electrically contacting said semiconductor body on the second principal surface of the semiconductor body on the semiconductor layer stack,
wherein producing the contact layer comprises applying a first layer to the semiconductor layer stack and applying a second layer to the first layer,
wherein the first layer is transparent to the radiation emitted by the stack of different III-V nitride semiconductor layers and the second layer reflects the radiation emitted by the stack of different III-V nitride semiconductor layers,
wherein the different III-V nitride semiconductor layers are epitaxially grown on a substrate,
wherein the transparent first layer is not epitaxially grown on the substrate,
wherein the substrate is a composite substrate that has a substrate body and an interlayer, with a coefficient of thermal expansion of the substrate body being similar to or greater than a coefficient of thermal expansion of the III-V nitride layers, with the III-V nitride layers being deposited on the interlayer, and
wherein the substrate is removed.
2. Method pursuant to claim 1 , wherein an Si substrate is used as the substrate.
3. Method pursuant to claim 2 , wherein an SiC interlayer is applied.
4. Method pursuant to claim 1 , wherein the interlayer is applied by a wafer-bonding method.
5. Method pursuant to claim 1 , wherein the interlayer is applied by epitaxy.
6. Method pursuant to claim 1 , wherein the reflecting contact layer is made by applying a layer of metal, wherein the method further comprises using the applied layer of metal to provide an electrical contact to the semiconductor body.
7. Method pursuant to claim 1 , further comprising applying a mask to the interlayer before producing the stack.
8. Method pursuant to claim 1 , wherein the thickness of the interlayer is so small that the coefficient of thermal expansion of the composite substrate is determined essentially by the substrate body.
9. Method pursuant to claim 1 , wherein the substrate body comprises SiC, poly-SiC, sapphire, GaN, or AlN.
10. Method pursuant to claim 1 , wherein the interlayer comprises SiC, silicon, sapphire, MgO, GaN, or AlGaN.
11. Method pursuant to claim 1 , wherein the interlayer has a monocrystalline surface at least in subregions.
12. Method pursuant to claim 1 , wherein the III-V nitride layers are deposited on an Si(111) surface or on an SiC surface of the interlayer that is monocrystalline at least in subregions.
13. Method pursuant to claim 1 , wherein the interlayer is applied to the substrate body by a wafer-bonding method.
14. Method pursuant to claim 1 , wherein a bonding layer is produced between the substrate body and the interlayer.
15. Method pursuant to claim 14 , wherein the bonding layer contains silicon oxide.
16. Method pursuant to claim 1 , wherein a mask layer is produced with epitaxy windows on the composite substrate before applying the III-V nitride layers, with the epitaxy surface of the composite substrate remaining uncovered within the epitaxy windows.
17. Method pursuant claim 1 , wherein the III-V nitride layers are structured into individual semiconductor layer stacks after being applied to the composite substrate.
18. Method pursuant to claim 17 , wherein the method further comprises:
application of a carrier to the semiconductor layer stack,
detachment of the composite substrate.
19. Method pursuant to claim 17 , wherein the method further comprises:
application of an interlayer on the semiconductor layer stack,
detachment of the composite substrate,
application of a carrier to the side of the semiconductor layer stack from which the composite substrate has been detached,
detachment of the interlayer.
20. Method pursuant to claim 17 , wherein the reflecting contact layer is produced by applying a metallic layer.
21. Method pursuant to claim 17 , wherein the metallic layer comprises silver, aluminum or a silver or aluminum alloy.
22. Method pursuant to claim 17 , further comprising using the reflecting contact layer serves as a contact surface for an electrical connection to the semiconductor layer stack.
23. Method pursuant to claim 6 wherein said metal layer comprises both the transparent first layer and the reflecting second layer.
24. Method for producing a radiation-emitting semiconductor component whose semiconductor body includes a stack of different III-V nitride semiconductor layers configured to emit radiation, wherein the semiconductor body has a first principal surface and a second principal surface, with at least a portion of the radiation being emitted through the first principal surface, the method comprising:
applying the III-V nitride layers to a composite substrate that has a substrate body and an interlayer, with the coefficient of thermal expansion of the substrate body being similar to or greater than the coefficient of thermal expansion of the III-V nitride layers, with the III-V nitride layers being deposited on the interlayer, wherein the III-V nitride layers are deposited on an Si(111) surface or on an SiC surface of the interlayer that is monocrystalline at least in subregions; and
producing a reflector on the second principal surface of the semiconductor body on the semiconductor layer stack, wherein producing the reflector comprises applying a first layer to the semiconductor layer stack and applying a reflecting second layer to the first layer, wherein the first layer is transparent to the radiation emitted by the stack of different III-V nitride semiconductor layers.
25. Method for producing a radiation-emitting semiconductor component whose semiconductor body includes a stack of different III-V nitride semiconductor layers configured to emit radiation, wherein the semiconductor body has a first principal surface and a second principal surface, with at least a portion of the radiation being emitted through the first principal surface, the method comprising:
applying the III-V nitride layers to a composite substrate that has a substrate body and an interlayer, with the coefficient of thermal expansion of the substrate body being similar to or greater than the coefficient of thermal expansion of the III-V nitride layers, with the III-V nitride layers being deposited on the interlayer, wherein the interlayer is applied to the substrate body by a wafer-bonding method; and
producing a reflector on the second principal surface of the semiconductor body on the semiconductor layer stack, wherein producing the reflector comprises applying a first layer to the semiconductor layer stack and applying a reflecting second layer to the first layer, wherein the first layer is transparent to the radiation emitted by the stack of different III-V nitride semiconductor layers.
26. Method for producing a radiation-emitting semiconductor component whose semiconductor body includes a stack of different III-V nitride semiconductor layers configured to emit radiation, wherein the semiconductor body has a first principal surface and a second principal surface, with at least a portion of the radiation being emitted through the first principal surface, the method comprising:
applying the III-V nitride layers to a composite substrate that has a substrate body and an interlayer, with the coefficient of thermal expansion of the substrate body being similar to or greater than the coefficient of thermal expansion of the III-V nitride layers, with the III-V nitride layers being deposited on the interlayer, wherein the III-V nitride layers are structured into individual semiconductor layer stacks after being applied to the composite substrate; and
producing a reflector on the second principal surface of the semiconductor body on the semiconductor layer stack, wherein producing the reflector comprises applying a first layer to the semiconductor layer stack and applying a reflecting second layer to the first layer, wherein the first layer is transparent to the radiation emitted by the stack of different III-V nitride semiconductor layers;
wherein applying the III-V nitride layers to the composite substrate comprises:
applying the interlayer on the semiconductor layer stack,
detaching the composite substrate,
applying a carrier to the side of the semiconductor layer stack from which the composite substrate has been detached, and
detaching the interlayer.
27. Method for producing a radiation-emitting semiconductor component whose semiconductor body includes a stack of different III-V nitride semiconductor layers configured to emit radiation, wherein the semiconductor body has a first principal surface and a second principal surface, with at least a portion of the radiation being emitted through the first principal surface, the method comprising:
producing a reflecting contact layer for electrically contacting said semiconductor body on the second principal surface of the semiconductor body on the semiconductor layer stack,
wherein producing the contact layer comprises applying a first layer to the semiconductor layer stack and applying a second layer to the first layer,
wherein the first layer is transparent to the radiation emitted by the stack of different III-V nitride semiconductor layers and the second layer reflects the radiation emitted by the stack of different III-V nitride semiconductor layers,
wherein the different III-V nitride semiconductor layers are epitaxially grown on a substrate,
wherein the transparent first layer is not epitaxially grown on the substrate,
wherein the substrate is a composite substrate that has a substrate body and an interlayer, with a coefficient of thermal expansion of the substrate body being similar to or greater than a coefficient of thermal expansion of the III-V nitride layers, with the III-V nitride layers being deposited on the interlayer, and
wherein the interlayer is applied to the substrate body by a wafer-bonding method.
28. Method for producing a radiation-emitting semiconductor component whose semiconductor body includes a stack of different III-V nitride semiconductor layers configured to emit radiation, wherein the semiconductor body has a first principal surface and a second principal surface, with at least a portion of the radiation being emitted through the first principal surface, the method comprising:
producing a reflecting contact layer for electrically contacting said semiconductor body on the second principal surface of the semiconductor body on the semiconductor layer stack,
wherein producing the contact layer comprises applying a first layer to the semiconductor layer stack and applying a second layer to the first layer,
wherein the first layer is transparent to the radiation emitted by the stack of different III-V nitride semiconductor layers and the second layer reflects the radiation emitted by the stack of different III-V nitride semiconductor layers,
wherein the different III-V nitride semiconductor layers are epitaxially grown on a substrate,
wherein the transparent first layer is not epitaxially grown on the substrate,
wherein the substrate is a composite substrate that has a substrate body and an interlayer, with a coefficient of thermal expansion of the substrate body being similar to or greater than a coefficient of thermal expansion of the III-V nitride layers, with the III-V nitride layers being deposited on the interlayer and structured into individual semiconductor layer stacks after being deposited, and
wherein the method further comprises applying a carrier to the semiconductor layer stack, and detachment of the composite substrate.
29. Method for producing a radiation-emitting semiconductor component whose semiconductor body includes a stack of different III-V nitride semiconductor layers configured to emit radiation, wherein the semiconductor body has a first principal surface and a second principal surface, with at least a portion of the radiation being emitted through the first principal surface, the method comprising:
producing a reflecting contact layer for electrically contacting said semiconductor body on the second principal surface of the semiconductor body on the semiconductor layer stack,
wherein producing the contact layer comprises applying a first layer to the semiconductor layer stack and applying a second layer to the first layer,
wherein the first layer is transparent to the radiation emitted by the stack of different III-V nitride semiconductor layers and the second layer reflects the radiation emitted by the stack of different III-V nitride semiconductor layers,
wherein the different III-V nitride semiconductor layers are epitaxially grown on a substrate,
wherein the transparent first layer is not epitaxially grown on the substrate,
wherein the substrate is a composite substrate that has a substrate body and an interlayer, with a coefficient of thermal expansion of the substrate body being similar to or greater than a coefficient of thermal expansion of the III-V nitride layers, with the III-V nitride layers being deposited on the interlayer and structured into individual semiconductor layer stacks after being deposited, and
wherein the method further comprises:
application of an interlayer on the semiconductor layer stack,
detachment of the composite substrate,
application of a carrier to the side of the semiconductor layer stack from which the composite substrate has been detached; and
detachment of the interlayer.