Nitride semiconductor component and process for its production
A process for the production of a layer structure of a nitride semiconductor component on a silicon surface, comprising: provision of a substrate having a silicon surface; deposition of an aluminium-containing nitride nucleation layer on the silicon surface of the substrate; optional: deposition of an aluminium-containing nitride buffer layer on the nitride nucleation layer; deposition of a masking layer on the nitride nucleation layer or, if present, on the first nitride buffer layer; deposition of a gallium-containing first nitride semiconductor layer on the masking layer, wherein the masking layer is deposited in such a way that, in the deposition step of the first nitride semiconductor layer, initially separate crystallites grow that coalesce above a coalescence layer thickness and occupy an average surface area of at least 0.16 μm 2 in a layer plane of the coalesced nitride semiconductor layer that is perpendicular to the growth direction.
1. A nitride semiconductor component comprising:
a substrate with a silicon surface;
an aluminum-containing nitride nucleation layer on the silicon surface of the substrate;
an aluminum-containing nitride buffer layer on the aluminum-containing nitride nucleation layer;
a first SiN masking layer directly on the aluminum-containing nitride buffer layer;
a gallium-containing first nitride semiconductor layer on the first masking layer, the gallium-containing first nitride semiconductor layer having a structure of coalesced crystallite islands, wherein layer planes of the gallium-containing first nitride semiconductor layer above a coalescence layer of the gallium-containing first nitride semiconductor layer have crystallite islands;
a portion of the nitride semiconductor component on and adjoining the gallium-containing first nitride semiconductor layer, the portion including (i) a nitride intermediate layer formed by an aluminum-containing nitride intermediate layer that has a thickness of up to 30 nanometers and (ii) a gallium-containing second nitride semiconductor layer over the aluminum-containing nitride intermediate layer; and
a multi-quantum-well structure on the portion,
wherein the first masking layer is made of silicon nitride, and
wherein the gallium-containing second nitride semiconductor layer has a thickness in a range of 800 nanometers to 1600 nanometers.
2. The nitride semiconductor component according to claim 1 , wherein the crystallite islands in the layer planes above a coalescence distance of at least 600 nm from the first masking layer have an average size of at least 400×400 nm 2 per crystallite such that a layer surface that is at least 80% closed is formed.
3. The nitride semiconductor component according to claim 1 , wherein the gallium-containing first nitride semiconductor layer has a layer thickness of between 800 nm and 1600 nm.
4. The nitride semiconductor component according to claim 1 , wherein the portion further comprises:
a second masking layer over the gallium-containing second nitride semiconductor layer; and
a gallium-containing third nitride semiconductor layer over the second masking layer, and
wherein the multi-quantum-well structure includes nitride semiconductor material and is deposited over the gallium-containing third nitride semiconductor layer.
5. The nitride semiconductor component according to claim 4 , wherein the second masking layer is deposited immediately before a deposition of the third gallium-containing nitride semiconductor layer.
6. The nitride semiconductor component according to claim 1 , further comprising a doped semiconductor cover layer on the multi-quantum-well structure.
7. The nitride semiconductor component according to claim 6 , further comprising a carrier that is bonded to the doped semiconductor cover layer.
8. The nitride semiconductor component according to claim 7 , wherein the carrier and the doped semiconductor cover layer are bonded to one another via a metal layer.
9. The nitride semiconductor component according to claim 7 , wherein the carrier comprises primarily copper, aluminium, silicon, aluminum nitride, or Al/Si.
10. The nitride semiconductor component according to claim 7 , further comprising an electrically conducting contact layer arranged between the carrier and the doped semiconductor cover layer.
11. The nitride semiconductor component according to claim 10 , wherein the contact layer has a higher refractive index than the doped semiconductor cover layer.
12. The nitride semiconductor component according to claim 6 , wherein the doped semiconductor cover layer is deposited in a thickness of
m
·
λ
2
·
n
nitride
+
λ
4
·
n
nitride
-
d
MQW
2
,
where m=0, 1, 2, 3, . . . ; λ is a wavelength of a light emission of the multi-quantum-well structure during operation of the nitride semiconductor component, n nitride is a refractive index of a nitride semiconductor material, which forms the doped semiconductor cover layer at the wavelength λ, and d MQW denotes a thickness of the multi-quantum-well structure.
13. The nitride semiconductor component according to claim 1 , further comprising an n-side and a p-side electrical contact element.
14. The nitride semiconductor component according to claim 1 , wherein the nitride intermediate layer has a thickness in a range between 8 and 15 nanometers.
15. The nitride semiconductor component according to claim 1 , wherein an average surface area of the crystallite islands ranges from 0.16 μm 2 to 0.36 μm 2 .
16. The nitride semiconductor component according to claim 1 , wherein the silicon surface of the substrate is a (111) silicon surface.
17. The nitride semiconductor component according to claim 6 , wherein the doped semiconductor cover layer is a p-doped gallium-containing nitride semiconductor cover.