用MOCVD方法生长的GaAs/GaAsP量子线及其特性

本实验采用普通的光刻和湿法腐蚀技术,将GaAs基片刻蚀成具有W形沟槽样的非平面结构,基片表面为(100)面,沟槽的侧斜面为(111)B面.在此基片上用低压MOCVD设备外延生长了GaAs/GaAsP多层膜,通过扫描电镜和微区拉曼光谱,研究它们的生长特性,发现GaAs和GaAsP的生长速率与基片的晶向及基片上的生长位置有关.根据这一生长特性,选择合适的W形沟道形状,用常规的量子阱外延方式,在W形沟道中央顶部突起的线条状平面上形成宝塔形生长,从而在尖端长出量子线.低温荧光光谱中观察到相应的能量峰,从而证实量子线的存在.

THE GROWTH OF GaAs/GaAsP QUANTUM WIRES BY MOCVD

rown by MOCVD, the GaAs/GaAsP quantum wires were obtained on a GaAs (100) non-planar substrate with W-groove profile patterns, which were etched by common UV lithograph and solution etching.It is found in term of SEM and micro area Raman spectrum that the growth rates both of GaAs and GaAsP were different at the different locations on these substrates.The growth rate at the middle top of the W-groove was faster than thatat theplanarsurfece and at the bevel of the W-groove,the(111)surface.Then the epitaxial layers of GaAs/GaAsP become triangel at these middle tops ofthew-grooves.So that the quan-tum wires would be grown on them when the width of the middle tops of the W-grooves was etched to be verynarrow bychoosing suitable mask and etching conditions.Thequantum effect of these quantum wires has been viewed In the lumlnescence spectrum atlow temperature.