Thermal annealing effect on low temperature molecular beam epitaxy grown GaAs: Arsenic precipitation and the change of resistivity
Thermal annealing effect on low temperature molecular beam epitaxy grown GaAs: Arsenic precipitation and the change of resistivity
复制标题
热退火对低温分子束外延生长GaAs的影响：砷沉淀和电阻率的变化
DOI：
10.1063/1.111216
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发表时间：
1994
影响因子：
4
通讯作者：
D. Westwood
中科院分区：
文献类型：
--
作者：
Jikui Luo;H. Thomas;D. Morgan;D. Westwood
研究了后处理对分子束外延低温(LT-)GaAs电学性质的影响。结果表明，LT-GaAs层的电阻率随退火温度TA呈指数增加，激活能为2.1 eV。该活化能与砷沉淀的活化能有关。根据跳跃电导理论，由LT-GaAs层的电阻率估算了As团簇密度Nt。砷原子团簇密度随TA的变化形式为NT=Nt0 EXP(−T/T0)，与电子显微镜测量结果一致。当TA增加到650 °C时，LT-GaAs层的击穿电压基本不变，但击穿特性变得软化。As团簇的形成是LT-GaAs层在退火后软击穿的主要原因。
The post‐growth annealing effects on the electrical properties of low temperature (LT‐) GaAs grown by molecular beam epitaxy have been investigated. It was found that the resistivity of the LT‐GaAs layer increased exponentially with annealing temperature TA, resulting in an activation energy of 2.1 eV. This activation energy is related to the activation energy of arsenic precipitation. Based on hopping conduction theory, an As cluster density NT, has been estimated from the resistivities of the LT‐GaAs layers. The change of density of arsenic clusters with TA, was found to be of the form NT=NT0 exp(−T/T0), in agreement with values obtained by transmission electron microscopy measurements. The breakdown voltage of the LT‐GaAs layer remained almost unchanged as TA was increased up to 650 °C, but the breakdown characteristic became soft. The formation of As clusters is held responsible for the soft breakdown of the LT‐GaAs layer after annealing.