氫氣處理對氮化鎵表面影響之研究

Abstract

本論文研究了在不同的蝕刻環境中經氫氣蝕刻後的氮化鎵表面及氫氣蝕刻機制。氫氣為一種對氮化鎵具蝕刻能力之氣體, 因而氮化鎵在不同的環境中會因氫氣蝕刻而出現不同的表面, 這些表面對後續氮化鎵磊晶成長可視為圖樣氮化鎵(pattern GaN), 具有釋放應力及降低線差排的效果。氫氣自氮化鎵表面最脆弱處開始蝕刻, 氫原子促使氮化鎵中的氮原子脫離而留下鎵原子, 由反應活化能的大小可判斷脫離的氮原子最終形成氮氣脫離。

The effects of hydrogen treatment on GaN surface and the etching mechanism are studied in this work. Hydrogen is a kind of gases with the ability to etch GaN, so different GaN surfaces appear under different etching conditions in hydrogen. These surfaces can be used as pattern GaN with the advantages of defect reducing and strain releasing in epitaxy process afterwards. The weaker points on GaN surface are etched by hydrogen first; the hydrogen atoms make the nitrogen atoms in GaN dissociated and Ga atoms left. Judging from the activation energy, the nitrogen atoms generated after GaN dissociation form into nitrogen and desorb from GaN surface.