Semiconductor device and manufacturing method thereof
A high quality silicon carbide (SiC) layer being substantially lower in threading dislocation density than a prior layer is formed on silicon (Si) substrate. A semiconductor device is fabricated in such a way that a semiconductor buffer layer containing Si in part and being higher in defect density than a Si substrate is formed on the Si substrate on the upper portion of which are formed a plurality of pairs of facets being mirror-symmetrical to the surface orientation of a semiconductor substrate, further on the top of the layer a SiC layer is sequentially formed.
1. A semiconductor device comprising:
a semiconductor substrate on the upper portion of which a plurality of pairs of opposing facets are arranged;
a semiconductor buffer layer provided on the semiconductor substrate and being higher in defect density than the semiconductor substrate; and
a first semiconductor layer provided on the semiconductor buffer layer, being different from the semiconductor substrate in lattice constant, and containing constituent elements different from the semiconductor substrate, wherein the facets are different from the semiconductor substrate in surface orientation and respective pairs of facets each comprised of opposing two facets are mirror-symmetrical to the surface orientation of the semiconductor substrate.
2. The semiconductor device according to claim 1 , wherein a plurality of pairs of defects being mirror-symmetrical to the surface orientation of the semiconductor substrate exist in the semiconductor buffer layer and the first semiconductor layer, and defects in each the layer gradually decrease in number toward the surface of the first semiconductor layer.
3. The semiconductor device according to claim 1 , wherein the semiconductor buffer layer is lower than the first semiconductor layer in mechanical strength or interatomic bonding energy.
4. The semiconductor device according to claim 1 , wherein the semiconductor buffer layer is comprised of a plurality of layers each being different from one another in element composition, and the element composition therein gradually gets close to that in the first semiconductor layer as the composition in the semiconductor substrate gets close to that in the first semiconductor layer.
5. The semiconductor device according to claim 1 , wherein the semiconductor buffer layer has a multiple layered structure in which a first semiconductor buffer layer being lower than the first semiconductor layer in mechanical strength or interatomic bonding energy and a second semiconductor buffer layer being higher than the first semiconductor buffer layer in mechanical strength or interatomic bonding energy are repeated alternately.
6. The semiconductor device according to claim 1 , wherein an electronic device or light emitting element is provided on the first semiconductor layer.
7. The semiconductor device according to claim 1 , wherein a second semiconductor layer comprised of a plurality of nitrogen-containing III-V semiconductor layers is provided on the first semiconductor layer, and an electronic device or light emitting element is provided on the second semiconductor layer and/or the first semiconductor layer and/or the semiconductor substrate.
8. The semiconductor device according to claim 1 , wherein the semiconductor substrate comprises silicon, the semiconductor buffer layer comprises a material containing silicon, germanium, and carbon, and the first semiconductor layer comprises a compound semiconductor containing silicon-carbon coupling.
9. A semiconductor device comprising:
a semiconductor substrate on the upper portion of which a plurality of pairs of opposing facets are arranged along the perpendicular directions respectively;
a semiconductor buffer layer provided on the semiconductor substrate and being higher in defect density than the semiconductor substrate; and
a first semiconductor layer provided on the semiconductor buffer layer, being different from the semiconductor substrate in lattice constant, and containing constituent elements different from the semiconductor substrate, wherein the facets are different from the semiconductor substrate in surface orientation and respective pairs of facets each comprised of opposing two facets are mirror-symmetrical to the surface orientation of the semiconductor substrate.
10. The semiconductor device according to claim 9 , wherein the respective perpendicular directions along which the opposing facets are arranged are [−110] and [110], and [1-12] and [110].
11. The semiconductor device according to claim 9 , wherein the semiconductor substrate has a surface orientation of (001), the respective opposing facets comprise (111) and (−1-11), and (−111) and (1-11) planes, an area surrounded by the facets forms a rectangular pattern on the surface of the semiconductor substrate, and the semiconductor buffer layer is formed throughout the semiconductor substrate.
12. The semiconductor device according to claim 9 , wherein the semiconductor substrate has a surface orientation of (111), the respective opposing facets comprise (1-10) and (−110), and (11-2) and (−1-12) planes, an area surrounded by the facets forms a rectangular pattern on the surface of the semiconductor substrate, and the semiconductor buffer layer is formed throughout the semiconductor substrate.
13. The semiconductor device according to claim 9 , wherein a plurality of pairs of defects being mirror-symmetrical to the surface orientation of the semiconductor substrate exist in the semiconductor buffer layer and the first semiconductor layer, and defects in each the layer gradually decrease in number toward the surface of the first semiconductor layer.
14. The semiconductor device according to claim 9 , wherein the semiconductor buffer layer is lower than the first semiconductor layer in mechanical strength or interatomic bonding energy.
15. The semiconductor device according to claim 9 , wherein the semiconductor buffer layer is comprised of a plurality of layers each being different from one another in element composition, and the element composition therein gradually gets close to that in the first semiconductor layer as the composition in the semiconductor substrate gets close to that in the first semiconductor layer.
16. The semiconductor device according to claim 9 , wherein the semiconductor buffer layer has a multiple layered structure in which a first semiconductor buffer layer being lower than the first semiconductor layer in mechanical strength or interatomic bonding energy and a second semiconductor buffer layer being higher than the first semiconductor buffer layer in mechanical strength or interatomic bonding energy are repeated alternately.
17. The semiconductor device according to claim 9 , wherein an electronic device or light emitting element is provided on the first semiconductor layer.
18. The semiconductor device according to claim 9 , wherein a second semiconductor layer comprised of a plurality of nitrogen-containing III-V semiconductor layers is provided on the first semiconductor layer, and an electronic device or light emitting element is provided on the second semiconductor layer and/or the first semiconductor layer and/or the semiconductor substrate.
19. The semiconductor device according to claim 9 , wherein the semiconductor substrate comprises silicon, the semiconductor buffer layer comprises a material containing silicon, germanium, and carbon, and the first semiconductor layer comprises a compound semiconductor containing silicon-carbon coupling.
20. A semiconductor device, wherein a semiconductor buffer layer containing Si in part and being higher in defect density than a Si substrate is formed on the Si substrate on the upper portion of which a plurality of pairs of facets being mirror-symmetrical to the surface orientation of a semiconductor substrate are formed, and a SiC layer is sequentially formed on the semiconductor buffer layer.
21. A semiconductor device comprising:
a semiconductor substrate on the upper portion of which a plurality of pairs of opposing facets are arranged;
a semiconductor buffer layer provided on the semiconductor substrate and having a larger number of defects than the semiconductor substrate; and
a first semiconductor layer provided on the semiconductor buffer layer, being different from the semiconductor substrate in lattice constant, and containing constituent elements different from the semiconductor substrate, wherein the facets are different from the semiconductor substrate in surface orientation and respective pairs of facets each comprised of opposing two facets are mirror-symmetrical to the surface orientation of the semiconductor substrate.