Control of Growth Facets and Dislocation Propagation Behavior in the Na-Flux Growth of GaN

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• 作者：Mamoru Imade ; Yasuhiro Hirabayashi ; Naoya Miyoshi ; Masashi Yoshimura ; Yasuo Kitaoka ; Takatomo Sasaki ; Yusuke Mori
• 刊名：Crystal Growth & Design
• 出版年：2011
• 出版时间：June 1, 2011
• 年：2011
• 卷：11
• 期：6
• 页码：2346-2350
• 全文大小：930K
• 年卷期：v.11,no.6(June 1, 2011)
• ISSN：1528-7505

文摘

We investigated changes in the growth mode and dislocation propagation behavior of Na-flux-grown GaN on GaN (0001) templates with changing flux composition (Ga/Na). Results suggested that deliberate control of the flux composition enables fast growth of thick GaN with a low dislocation density. The growth mode was evaluated by scanning electron microscopy (SEM). The distribution and density of dislocations were investigated using chemical etching. SEM observation revealed that the growth mode changed from a two-dimensional (2D) mode developing (0001) facets to a three-dimensional (3D) mode developing (0001) and {101虆1} facets as the Ga composition in the flux was increased. A reduction of dislocation density was promoted in the 3D growth mode favored at high Ga compositions, and the minimum dislocation density observed was on the order of 10³ cm^鈥? (280 渭m 脳 200 渭m) after growth for 96 h at a Ga composition of 40 mol %. On the other hand, the growth rate was higher in the 2D growth mode favored at low Ga compositions. Based on the observed changes in the growth mode, a growth sequence that is effective for the growth of thick GaN substrates with a low dislocation density is proposed.