Semiconductor device and the method of manufacturing the same
View Patent ↗The present application discloses a semiconductor device comprising a crystalline substrate having a first region and a second region, a nuclei structure on the first region, a first crystalline buffer layer on the nuclei structure, a void between the second region and the first crystalline buffer layer, a second crystalline buffer layer on the first crystalline buffer layer, an intermediate layer located between the first crystalline buffer layer and the second crystalline buffer layer, and a semiconductor device layer on the second crystalline buffer layer.
1. A semiconductor device, comprising:
a substrate having a first region as single crystalline structure and a second region as polycrystalline structure or amorphous structure, and the second region of the substrate comprises an impurity absent in the first region, wherein the substrate comprises a top surface and a bottom surface opposite to the top surface;
a nuclei structure on the first region of the substrate and located on the top surface, and the nuclei structure is absent on the second region of the substrate;
a first crystalline buffer layer on the nuclei structure, lattice-mismatched with the substrate, and the first crystalline buffer layer physically contacts with a portion of the second region, wherein the nuclei structure comprises a top closer to the first crystalline buffer layer, and the second region comprises a surface closer to the first crystalline buffer layer, wherein the surface is closer to the bottom surface of the substrate than the top is;
a second crystalline buffer layer on the first crystalline buffer layer;
an intermediate layer located between the first crystalline buffer layer and the second crystalline buffer layer; and
a semiconductor device layer on the second crystalline buffer layer.
2. A semiconductor device according to claim 1 , wherein the first crystalline buffer layer and the second crystalline buffer layer comprise a first nitride material having a first element, and the intermediate layer comprises a second nitride material having a second element which is different from the first element.
3. A semiconductor device according to claim 1 , wherein the semiconductor device layer comprises a two-dimensional electron gas or a light-emitting layer.
4. A semiconductor device according to claim 1 , wherein the intermediate layer comprises a first portion having a first composition ratio of a first element and located on the first crystalline buffer layer, a second portion having a second composition ratio of the first element and located on the first portion, and a third portion having a third composition ratio of the first element and located between the second portion and the second crystalline buffer layer, wherein the first composition ratio, the second composition ratio, and the third composition ratio are different.
5. A semiconductor device according to claim 1 , wherein the first region is continuous and the second region is discontinuous.
6. A semiconductor device according to claim 1 , further comprising multiple voids formed on the second region and separated from each other.
7. A semiconductor device according to claim 1 , further comprising multiple thread dislocation lines above the first region and bending toward the second region.
8. A semiconductor device according to claim 1 , wherein the first crystalline buffer layer comprises a surface roughness larger than that of the intermediate layer.
9. A semiconductor device according to claim 1 , wherein the nuclei structure comprises an inclined sidewall.
10. A semiconductor device according to claim 4 ,
wherein the second composition ratio is greater than the first composition ratio and the third composition ratio.
11. A semiconductor device according to claim 1 , wherein the nuclei structure has a bottom which is wider than the top, and the bottom connects with the first region of the substrate.
12. A semiconductor device according to claim 1 , wherein the substrate comprises silicon and the semiconductor device layer comprises gallium nitride (GaN).
13. A semiconductor device according to claim 12 , wherein the first crystalline buffer layer and the second crystalline buffer layer comprise GaN, and the intermediate layer comprises AlGaN.
14. A semiconductor device according to claim 12 , wherein the nuclei structure comprises aluminum nitride (AlN).
15. A semiconductor device according to claim 1 , wherein a void is located between the second region of the substrate and the first crystalline buffer layer.
16. A semiconductor device according to claim 15 , wherein the void is absent between the first region of the substrate and the first crystalline buffer layer.
17. A semiconductor device according to claim 1 , wherein a pattern interface is formed between the first crystalline buffer layer and the intermediate layer.
18. A semiconductor device according to claim 17 , wherein the pattern interface comprises several recesses, and each of the recesses comprises a vertex portion.
19. A semiconductor device according to claim 18 , wherein the vertex portion is formed on and aligned with the second region of the substrate.
20. A semiconductor device according to claim 1 , wherein the second region extends from the surface to a depth in the substrate.