Semiconductor layer structure comprising a cavity layer and method for fabricating the semiconductor layer structure
View Patent ↗Semiconductor layer structure and a method for producing a structure are provided, including a substrate made of semiconductor material, on which a layer made of a second semiconductor material is situated, furthermore a region ( 3 ) enriched with impurity atoms, which region is situated either in layer ( 2 ) or at a specific depth below the interface between layer ( 2 ) and substrate ( 1 ), additionally a layer ( 4 ) within the region ( 3 ) enriched with impurity atoms, which layer comprises cavities produced by ion implantation, furthermore at least one epitaxial layer ( 6 ) applied to layer ( 2 ) and also a defect region ( 5 ) comprising dislocations and stacking faults within the layer ( 4 ) comprising cavities, the at least one epitaxial layer ( 6 ) being largely crack-free, and a residual strain of the at least one epitaxial layer ( 6 ) being less than or equal to 1 GPa.
1. A semiconductor layer structure, comprising:
a substrate comprising (111), (100), or (110) silicon;
a first layer of ion beam synthesized silicon carbide disposed on the substrate, the first layer and the substrate defining an interface therebetween;
an impurity region enriched with impurity atoms including at least one of oxygen and nitrogen, the impurity region disposed below the interface, the impurity region including 3C—SiC precipitates;
a cavity layer within the impurity region, the cavity layer including cavities produced by ion implantation, the cavities including gas bubbles formed of gas selected from the group consisting of hydrogen gas, helium gas, neon gas, and a mixture thereof;
an epitaxial layer applied directly to the first layer, the epitaxial layer being substantially crack-free, and a residual strain of the epitaxial layer being less than or equal to 1 GPa; and
a defect region including dislocations and stacking faults within the cavity layer.
2. The semiconductor layer structure of claim 1 , wherein the residual strain of the epitaxial layer is less than or equal to 370 MPa.
3. The semiconductor layer structure of claim 1 , wherein a roughness of the epitaxial layer is between about 0.5 and about 7.0 nm root mean square (RMS).
4. The semiconductor layer structure of claim 3 , wherein the roughness of the epitaxial layer is between about 0.5 and about 2.0 nm RMS.
5. The semiconductor layer structure of claim 1 , wherein the epitaxial layer comprises a semiconductor material having a different coefficient of thermal expansion in comparison with a semiconductor material comprised in the substrate.
6. The semiconductor layer structure of claim 5 , wherein the epitaxial layer comprises a nitride compound semiconductor.
7. The semiconductor layer structure of claim 6 , further comprising a second epitaxial layer comprising a nitride compound semiconductor.
8. The semiconductor layer structure of claim 7 , wherein one of the epitaxial layers comprises aluminum nitride.
9. The semiconductor layer structure of claim 8 , wherein one of the epitaxial layers comprises gallium nitride.
10. The semiconductor layer structure of claim 1 , wherein an expansion of the lattice constant of silicon carbide in the first layer under a residual strain as measured by high-resolution X-ray diffraction is less than or equal to 0.2% relative to an unstrained value for the lattice constant.
11. The semiconductor layer structure of claim 1 , wherein the cavity layer is resistant to thermal cleavage at temperatures between about 25° C. and about 1250° C.
12. The semiconductor layer structure of claim 1 , wherein the gas bubbles are formed of gas comprising hydrogen.
13. The semiconductor layer structure of claim 1 , wherein the gas bubbles are formed of gas comprising helium.
14. The semiconductor layer structure of claim 1 , wherein the gas bubbles are formed of gas comprising neon.
15. The semiconductor layer structure of claim 1 , wherein the gas bubbles are formed of gas comprising hydrogen and helium.
16. The semiconductor layer structure of claim 1 , wherein the gas bubbles are formed of gas comprising hydrogen and neon.
17. The semiconductor layer structure of claim 1 , wherein the gas bubbles are formed of gas comprising helium and neon.
18. The semiconductor layer structure of claim 1 , wherein the gas bubbles are formed of gas comprising hydrogen, helium, and neon.
19. The semiconductor layer structure of claim 1 , wherein the substrate is a wafer having a diameter of 200 mm.
20. The semiconductor layer structure of claim 1 , wherein the substrate is a wafer having a diameter of 300 mm.
21. The semiconductor layer structure of claim 1 , wherein the cavity layer is stable at temperatures of 900 to 1250° C. for at least 2 hours,
wherein the cavity was produced by a process comprising an implantation temperature in a range of 400 to 800° C.
22. The semiconductor layer structure of claim 1 , wherein the cavity layer is stable at temperatures of 900 to 1250° C. for 2 hours,
wherein the cavity was produced by a process comprising an implantation temperature in a range of 400 to 800° C.
23. The semiconductor layer structure of claim 1 , wherein the cavity layer is stable at 1250° C. for 2 hours,
wherein the cavity was produced by a process comprising an implantation temperature in a range of 400 to 800° C.
24. The semiconductor layer structure of claim 1 , wherein the cavity layer is stable at temperatures of 1050 to 1250° C. for at least 2 hours,
wherein the cavity was produced by a process comprising an implantation temperature in a range of 400 to 800° C.
25. The semiconductor layer structure of claim 1 , wherein the cavity layer is stable at temperatures of 1050 to 1250° C. for 2 hours,
wherein the cavity was produced by a process comprising an implantation temperature in a range of 400 to 800° C.
26. The semiconductor layer structure of claim 1 , wherein the impurity atoms comprise oxygen.
27. The semiconductor layer structure of claim 1 , wherein the impurity atoms comprise nitrogen.
28. The semiconductor layer structure of claim 1 , wherein the impurity atoms comprise oxygen and nitrogen.
29. The semiconductor layer structure of claim 12 , wherein the impurity atoms further comprise oxygen.
30. The semiconductor layer structure of claim 15 , wherein the impurity atoms further comprise oxygen.
31. A light emitting diode, comprising the semiconductor layer structure of claim 1 .
32. A Schottky diode, comprising the semiconductor layer structure of claim 1 .
33. A high electron mobility transistor, comprising the semiconductor layer structure of claim 1 .