InGaAs薄膜表面的粗糙化过程

Roughening and pre-roughening processes on InGaAs surface

采用STM分析InGaAs表面形貌演变研究InGaAs表面的粗糙化和预粗糙化等相变过程,特别针对In(0.15)Ga(0.85)As薄膜表面预粗糙化过程进行了深入研究.发现In(0.15)Ga(0.85)As薄膜在不同的衬底温度和As等效束流压强下表现出不同的预粗糙化过程.在低温低As等效束流压强下,薄膜表面将经历从有序平坦到预粗糙并演变成粗糙的过程,起初坑的形成是表面形貌演变的主要形式,随着退火时间的延长,大量坑和岛的共同形成促使表面进入粗糙状态;在高温高As等效束流压强下薄膜表面将率先形成小岛,退火时间延长后小岛逐渐增加并最终达到平衡态,表面形貌将长期处于预粗糙状态.

Roughening and pre-roughening processes on InGaAs surface are studied using scanning tunneling microscopy. There are differ-ent roughening and pre-roughening processes for InGaAs films at different substrate temperatures and As beam equivalent pressure. Under low temperature and low As beam equivalent pressure, pits is main mechanism in the beginning of InGaAs morphology evolu-tion, with the increase of annealing time, a great number of pits and islands are observed which make the surface rough. Small islands should play a leading role during the InGaAs morphology evolution at high temperature and high As beam equivalent pressure, and the number of islands will increase gradually with the increase of annealing time till it reaches an equilibrium state.