Method of making nitride-based compound semiconductor crystal and substrate
View Patent ↗A method of making a nitride-based compound semiconductor crystal has the step of growing a nitride-based compound semiconductor crystal with a predetermined thickness by using a nitride-based compound semiconductor substrate as a seed crystal. The nitride-based compound semiconductor substrate as the seed crystal is polished at both surfaces thereof.
1. A method of making a nitride-based compound semiconductor crystal, comprising:
growing a nitride-based compound semiconductor crystal with a predetermined thickness by using a nitride-based compound semiconductor substrate as a seed crystal,
wherein said nitride-based compound semiconductor substrate as the seed crystal is polished at both surfaces thereof; and
wherein said nitride-based compound semiconductor substrate as the seed crystal has a dispersion in crystal axis of 0.5 degrees or less.
2. The method according to claim 1 , wherein:
said nitride-based compound semiconductor substrate as the seed crystal has a threading dislocation density of 1 ×10 7 cm −2 or less.
3. The method according to claim 1 , wherein:
said nitride-based compound semiconductor substrate as the seed crystal is mechanically remedied in warp.
4. The method according to claim 1 , wherein:
said nitride-based compound semiconductor substrate as the seed crystal has a residual stress of 100 MPa or less.
5. The method according to claim 1 , wherein:
said grown nitride-based compound semiconductor crystal comprises a diameter greater than the seed crystal.
6. The method according to claim 1 , wherein:
said grown nitride-based compound semiconductor crystal comprises a diameter two times or more greater than the seed crystal.
7. The method according to claim 1 , wherein:
said growing of the nitride-based compound semiconductor crystal is conducted by a vapor-phase growth method.
8. The method according to claim 1 , wherein:
said growing of the nitride-based compound semiconductor crystal is conducted by HVPE.
9. The method according to claim 1 , wherein:
said grown nitride-based compound semiconductor crystal is kept at a same position in growth surface thereof by drawing back said nitride-based compound semiconductor crystal at a same speed as a growth speed of said nitride-based compound semiconductor crystal.
10. The method according to claim 9 , wherein:
said growth speed of said nitride-based compound semiconductor crystal is 350 μm/h or more.
11. A method of making a nitride-based compound semiconductor substrate, comprising:
growing a nitride-based compound semiconductor crystal with a predetermined thickness by using a nitride-based compound semiconductor substrate as a seed crystal; and
slicing said grown nitride-based compound semiconductor crystal,
wherein said nitride-based compound semiconductor substrate as the seed crystal is polished at both surfaces thereof; and
wherein said nitride-based compound semiconductor substrate as the seed crystal has a dispersion in crystal axis of 0.5 degrees or less.
12. A method of making a nitride-based compound semiconductor substrate, comprising:
growing a nitride-based compound semiconductor crystal with a predetermined thickness by using a nitride-based compound semiconductor substrate as a seed crystal;
forming said grown nitride-based compound semiconductor crystal into a cylindrical column;
forming an orientation flat on said formed nitride-based compound semiconductor crystal; and
slicing said grown nitride-based compound semiconductor crystal,
wherein said nitride-based compound semiconductor substrate as the seed crystal is polished at both surfaces thereof; and
wherein said nitride-based compound semiconductor substrate as the seed crystal has a dispersion in crystal axis of 0.5 degrees or less.
13. The method according to claim 12 , wherein:
said orientation flat comprises two or more orientation flats.