不同厚度对分子束外延生长GaSb薄膜的影响

Effect of thickness on GaSb thin film deposited by MBE

采用分子束外延(MBE)在GaAs衬底上生长GaSb薄膜,为了减小因晶格失配度较大所引起的位错密度,采用低温GaSb作为缓冲层。通过X射线双晶衍射仪和原子力显微镜分析得出,当低温GaSb缓冲层的厚度为20nm时,GaSb外延层中的位错密度最小,晶体质量最好。此外,缓冲层和外延层的厚度共同对GaSb薄膜晶体质量和表面形貌产生影响。

Heteroepitaxial growth of GaSb on GaAs ted. In order to decrease the dislocation density, substrates by molecular beam epitaxy （MBE） was investigawhich is caused by the lattice mismatch, low temperature （LT） GaSb was used as buffer layer. By the means of double crystals X-ray diffraction （DCXRD） and atomic force microscope （AFM）, it was found that the optimum thickness of LT GaSb buffer layer was 20nm, furthermore, the thicknesses of LT GaSb buffer layer and GaSb epilayer affect crystal quality together.