Anisotropic Diffusion of In Atoms from an In Droplet and Formation of Elliptically Shaped InAs Quantum Dot Clusters on (100) GaAs

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• 作者：Takeshi Noda ; Takaaki Mano ; Hiroyuki Sakaki
• 刊名：Crystal Growth & Design
• 出版年：2011
• 出版时间：March 2, 2011
• 年：2011
• 卷：11
• 期：3
• 页码：726-728
• 全文大小：672K
• 年卷期：v.11,no.3(March 2, 2011)
• ISSN：1528-7505

文摘

The surface diffusion of In atoms from an In droplet and their subsequent reaction with As₄ molecules lead to the formation of InAs quantum dots elliptically distributed around the initially formed droplet. The size of this elliptic dot cluster depends sensitively on the growth conditions. For instance, as the substrate temperature T_s is raised from 220 to 350 掳C, the shorter and longer diameters of the elliptic clusters, elongated in the [011] direction, increase exponentially with T_s, expanding from the range of 0.8鈭?.6 渭m to 2鈭? 渭m. When the pressure P_As of As₄ is increased from 0.7 to 10 脳 10^鈭? Torr at T_s = 300 掳C, the cluster diameters shrink from 3鈭? 渭m to 1鈭? 渭m in inverse proportion to P_As^0.3鈭?.4. These findings are interpreted in terms of anisotropic diffusion of In atoms from the droplet.