Method of manufacturing nitride semiconductor device
View Patent ↗A method of manufacturing a nitride semiconductor device includes the step of forming a second nitride semiconductor layer having an inclined facet by metal-organic chemical vapor deposition, in which a molar flow ratio of a group V element gas to a group III element gas that are supplied to a growth chamber of a metal-organic chemical vapor deposition growth apparatus is set at 240 or less.
1. A method of manufacturing a nitride semiconductor device, comprising the steps of:
forming a first nitride semiconductor layer by metal-organic chemical vapor deposition;
forming a silicon nitride layer on said first nitride semiconductor layer;
forming a second nitride semiconductor layer having an inclined facet by metal-organic chemical vapor deposition to cover said first nitride semiconductor layer and said silicon nitride layer; and
forming a third nitride semiconductor layer having a flat upper surface by metal-organic chemical vapor deposition to bury said inclined facet of said second nitride semiconductor layer,
in said step of forming a second nitride semiconductor layer by metal-organic chemical vapor deposition, a molar flow ratio of a group V element gas to a group III element gas that are supplied to a growth chamber of a metal-organic chemical vapor deposition growth apparatus being set at 240 or less.
2. The method of manufacturing a nitride semiconductor device according to claim 1 , wherein
a sapphire substrate is provided,
said method further comprises the step of forming a buffer layer on a surface of said substrate before said step of forming a first nitride semiconductor layer by metal-organic chemical vapor deposition, and
said step of forming a first nitride semiconductor layer by metal-organic chemical vapor deposition includes the step of forming said first nitride semiconductor layer on said buffer layer.
3. The method of manufacturing a nitride semiconductor device according to claim 2 , wherein
said buffer layer is aluminum nitride.
4. The method of manufacturing a nitride semiconductor device according to claim 2 , wherein
said surface of said substrate has concave and convex portions.
5. The method of manufacturing a nitride semiconductor device according to claim 1 , wherein
said first nitride semiconductor layer includes an inclined facet layer and a flat layer.
6. The method of manufacturing a nitride semiconductor device according to claim 1 , wherein
said inclined facet of said second nitride semiconductor layer is inclined at an angle of 45° or more relative to a growth surface of said second nitride semiconductor layer.
7. The method of manufacturing a nitride semiconductor device according to claim 1 , wherein
said second nitride semiconductor layer has a thickness of 2 μm or more.