Diamond based substrate for electronic devices
View Patent ↗The invention relates to a method of manufacture of a substrate for fabrication of semiconductor layers or devices, comprising the steps of providing a wafer of silicon including at least one first surface suitable for use as a substrate for CVD diamond synthesis, growing a layer of CVD diamond of predetermined thickness and having a growth face onto the first surface of the silicon wafer, reducing the thickness of the silicon wafer to a predetermined level, and providing a second surface on the silicon wafer that is suitable for further synthesis of at least one semiconductor layer suitable for use in electronic devices or synthesis of electronic devices on the second surface itself and to a substrate suitable for GaN device growth consisting of a CVD diamond layer intimately attached to a silicon surface.
1. A method of manufacture of a GaN material, the method comprising:
providing a wafer of silicon including at least one first surface suitable for use as a substrate for CVD diamond synthesis,
growing a layer of CVD diamond of a thickness greater than 300 μm and having a growth face onto the first surface of the silicon wafer,
reducing the thickness of the silicon wafer to a predetermined level,
providing a second surface on the silicon wafer that is suitable for further synthesis of at least one semiconductor layer suitable for use in electronic devices or synthesis of electronic devices on the second surface itself, and
growing GaN on the second surface of the silicon wafer.
2. The method as claimed in claim 1 , wherein the silicon is monocrystalline silicon.
3. The method as claimed in claim 2 , wherein the monocrystalline silicon wafer is a {111} monocrystalline silicon wafer.
4. The method as claimed in claim 1 , wherein the silicon wafer is processed such that at least the opposed large surfaces are substantially parallel.
5. The method as claimed in claim 1 , wherein the growth face of the CVD diamond layer is processed to become substantially flat and parallel to the first surface of the silicon wafer.
6. The method as claimed in claim 1 , wherein the second surface of the silicon wafer is opposed to- the first surface of the wafer.
7. The method as claimed in claim 1 , wherein an AlGaN buffer layer is used.
8. The method according to claim 1 , wherein reduction of the silicon wafer is accomplished by using lapidary techniques.
9. The method according to claim 1 , wherein the silicon wafer is reduced until less than 50 μm thick.
10. The method according to claim 9 , wherein the silicon wafer is reduced until less than 20 μm thick.
11. The method according to claim 9 , wherein the silicon wafer is reduced until less than 10 μm thick.
12. The method according to claim 9 , wherein the silicon wafer is reduced until less than 5 μm thick.
13. The method according to claim 1 , further comprising polishing the silicon surface to a smooth surface suitable for the growth of GaN.
14. The method according to claim 1 , wherein the GaN layer is preceded or combined with an AlGaN buffer layer.
15. A method of producing GaN material, the method comprising:
providing a wafer of monocrystalline silicon which has been processed so that the large {111} surfaces are parallel and at least a first surface is in a condition suitable for use as a substrate for CVD diamond synthesis,
growing a layer of CVD diamond of a thickness greater than 300 μm and having a growth face onto the first surface of the monocrystalline silicon wafer,
reducing the thickness of the silicon wafer to a predetermined level,
providing a second surface on the silicon wafer suitable for synthesis of semiconductor layers suitable for use in electronic devices, and
growing GaN on the second surface of the silicon wafer.
16. The method as claimed in claim 15 , further comprising processing the growth face of the CVD diamond layer to become substantially flat and parallel to the first surface of the silicon wafer.
17. The method as claimed in claim 16 , further comprising mounting the processed diamond face against a substantially planar reference plate.
18. The method according to claim 15 , wherein the layer of CVD diamond on the monocrystalline silicon wafer is greater than 400 μm.
19. The method according to claim 15 , wherein the layer of CVD diamond on the monocrystalline silicon wafer is greater than 500 μm.
20. The method according to claim 15 , wherein the layer of CVD diamond on the monocrystalline silicon wafer is greater than 550 μm.