GaSb薄膜生长的RHEED研究

RHEED Research on GaSb Film Growth by MBE

采用分子束外延技术,在GaAs衬底上生长GaSb薄膜时,利用反射式高能电子衍射仪(RHEED)对衬底表面清洁状况、外延层厚度等进行在线监控。通过RHEED讨论低温缓冲层对GaSb薄膜表面结构和生长机制的作用,可以估算衬底温度,并能计算出薄膜的生长速率。实验测量GaSb的生长周期为1.96 s,每秒沉积0.51单分子层。低温缓冲层提高了在GaAs衬底上外延GaSb薄膜的生长质量。

The use of reflection high-energy electron diffraction （RHEED） has been proven to be a powerful tool to understand growth mechanisms of GaSb by molecular beam epitaxy （MBE）. The cleaned surface of wafer and the thickness of film can be monitored with RHEED. RHEED may be used to study the GaSb surface structure with low temperature （LT） GaSb buffer layer and this in turn may be used to approximate the substrate temperature. Oscillations in the intensity of certain features of the RHEED pattern may be observed under suitable conditions, and there is a close relationship between the RHEED intensity oscillations and the growth rate of film. One RHEED oscillation of GaSb takes 1.96s, therefore 0.51 monolayers is deposited per second. The LT GaSb buffer layer is important to improve the quality of the GaSb epitaxial film on the GaAs substrates.