GaMnAs grown on (0 0 1), (3 1 1) A and (1 1 0) GAaS substrates: Comparison of growth conditions and post-growth annealing behaviour

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• 作者：Ursula Wurstbauer ; Matthias Sperl ; Dieter Schuh ; Gü ; nther Bayreuther ; Janusz Sadowski ; Werner Wegscheider
• 关键词：A3. Molecular beam epitaxy ; B1. GaMnAs ; B2. Semiconducting III– ; IV materials ; B3. Spintronic devices
• 刊名：Journal of Crystal Growth
• 出版年：2007
• 出版时间：April 2007
• 年：2007
• 卷：301-302
• 期：Complete
• 页码：260-263
• 全文大小：204 K

文摘

Thin GaMnAs layers were grown by low temperature molecular beam epitaxy on (0 0 1), (3 1 1) A and (1 1 0) GaAs substrates. In an effort to increase the ferromagnetic transition temperature T_C, we studied growth conditions and the effectiveness of post-growth annealing under an arsenic capping layer and in air. Avoiding As antisite defects with a small As to Ga flux ratio during MBE growth and reducing Mn interstitials by annealing the GaMnAs films in air for very long time at temperatures far below growth temperature allows us to obtain (0 0 1) samples with T_C up to 150 K, (3 1 1) A samples with T_C about of 110 K and (1 1 0) samples with T_C of 89 K.