摘要
采用分子束外延方法在GaAs（001）衬底上生长了InSb外延薄膜,其中采用＂二步法＂制备了不同厚度的低温InSb缓冲层结构。利用Mullins扩散模型对缓冲层的生长过程进行了具体演化。结合扩散模型的计算结果,通过原子力显微镜以及透射电子显微镜研究了InSb缓冲层表面的波纹结构对后续InSb薄膜生长的影响规律。研究表明,适当的缓冲层厚度有利于InSb薄膜的外延生长,缓冲层厚度超过60 nm后,InSb薄膜表面的粗糙度明显增加,引人了大量位错导致外延薄膜的电性能下降,采用＂二步法＂生长30~50 nm厚的InSb缓冲层比较合适。
InSb epilayers on GaAs（001） substrates with different thicknesses of InSb buffer layers were grown by two-step method using molecular beam epitaxy（MBE）.The Mullins′ diffusion equation based on the continuum model was employed to investigate the evolution of the undulating surface during the initial stage of the InSb epilayer growth.Combined with the calculation results,the effects of undulation structure of InSb buffer layer on the following growth of InSb epilayer were illustrated by means of the atomic force microscope（AFM） data and the transmission electron microscopy（TEM）.The results show that the InSb buffer layer with appropriate thickness could facilitate the InSb homoepitaxial growth,whereas InSb buffer layer beyond about 60 nm would increase the surface roughness and induce a lot of dislocations,which degrade the electrical properties of InSb epilayer.The InSb buffer layer with thickness of 30-50 nm grown by two-step method is suitable for high quality devices.
出处
《红外与激光工程》
EI
CSCD
北大核心
2011年第3期480-483,共4页
Infrared and Laser Engineering
基金
国家自然科学基金资助项目(50972032)
国家高技术研究发展计划资助项目(2009AA03Z407)
