缓冲层生长速率对GaSb薄膜二维生长的影响

Effect of buffer layer growth rate on two-dimension growth of GaSb epitaxial layer

用分子束外延(MBE)法在GaAs(100)衬底上生长GaSb薄膜,得到了GaSb薄膜的优化生长工艺条件。为了降低因晶格失配度较大所引起的位错密度,采用低温(LT)GaSb作为缓冲层,研究了缓冲层的生长速率对GaSb薄膜二维生长的影响,并以此说明缓冲层在GaSb薄膜生长中所起的作用。通过X射线双晶衍射仪和原子力显微镜测试分析,得到当低温GaSb缓冲层的生长速率为1.43μm/h时,GaSb外延层中的位错密度最小,晶体质量最好。

The heteroepitaxial growth of GaSb on GaAs（100） substrates by molecular beam epitaxy （MBE） was investigated,and the optimized growth conditions of GaSb film were obtained. In order to decrease the dislocation density,which is caused by the lattice mismatch, low temperature （LT） GaSb was used as buffer layer in these experiments, and it was studied that how the growth rate of buffer layer affected the two-dimension growth of GaSb epitaxial layer. Meanwhile, the effect of buffer layer on the growth of GaSb thin film was explained. By the means of double crystals X-ray diffraction （DCXRD） and atomic force microscope （AFM）, growth parameters of LT GaSb buffer layer were studied,and it was found that the optimum growth rate was 1.43μm/h.