Group III nitride semiconductor substrate and method for cleaning the same
View Patent ↗A Group-III nitride semiconductor substrate having a flat surface with a dangling bond density of higher than 14.0 nm −2 is produced by cleaning the surface having a dangling bond density of higher than 14.0 nm −2 with a cleaning agent containing an ammonium salt.
1. A cleaning method for a Group-III nitride semiconductor substrate, comprising cleaning a surface of a Group-III nitride semiconductor substrate that has a dangling bond density of higher than 14.0 nm −2 , with a cleaning agent containing an ammonium salt.
2. The cleaning method for a Group-III nitride semiconductor substrate according to claim 1 , wherein the surface having a dangling bond density of higher than 14.0 nm −2 is the broadest surface of the Group-III nitride semiconductor substrate.
3. The cleaning method for a Group-III nitride semiconductor substrate according to claim 1 , wherein particles having a particle size of at most 200 nm adhere to the surface of the Group-III nitride semiconductor substrate before being cleaned.
4. The cleaning method for a Group-III nitride semiconductor substrate according to claim 1 , wherein the surface having a dangling bond density of higher than 14.0 nm −2 is polished with an abrasive agent containing abrasive particles having a particle size of at most 200 nm, before being cleaned.
5. The cleaning method for a Group-III nitride semiconductor substrate according to claim 4 , wherein the abrasive particles are colloidal silica.
6. The cleaning method for a Group-III nitride semiconductor substrate according to claim 1 , wherein the ammonium salt is NH 4 F or NH 4 Cl.
7. The cleaning method for a Group-III nitride semiconductor substrate according to claim 1 , wherein the pH of the cleaning agent is from 6.5 to 8.0.
8. The cleaning method for a Group-III nitride semiconductor substrate according to claim 1 , wherein the Group-III nitride semiconductor substrate is cleaned by dipping it in the cleaning agent.
9. A Group-III nitride semiconductor substrate containing a surface that has a dangling bond density of higher than 14.0 nm −2 and has a surface roughness (RMS) of at most 0.1 nm.
10. The Group-III nitride semiconductor substrate according to claim 9 , wherein the surface having a dangling bond density of higher than 14.0 nm −2 and having a surface roughness (RMS) of at most 0.1 nm is a (11-22) plane.
11. The Group-III nitride semiconductor substrate according to claim 9 , wherein the surface having a dangling bond density of higher than 14.0 nm −2 and having a surface roughness (RMS) of at most 0.1 nm is a (10-1-1) plane.
12. The Group-III nitride semiconductor substrate according to claim 9 , wherein the surface having a dangling bond density of higher than 14.0 nm −2 and having a surface roughness (RMS) of at most 0.1 nm is a (000-1) plane.
13. The Group-III nitride semiconductor substrate according to claim 9 , wherein the surface having a dangling bond density of higher than 14.0 nm −2 and having a surface roughness (RMS) of at most 0.1 nm is a (1-101) plane.
14. The Group-III nitride semiconductor substrate according to claim 9 , wherein the surface having a dangling bond density of higher than 14.0 nm −2 and having a surface roughness (RMS) of at most 0.1 nm is a (10-12) plane.
15. The Group-III nitride semiconductor substrate according to claim 9 , wherein the Group-III nitride semiconductor substrate is a GaN substrate.