摘要We investigate epitaxy of AlN layers on sapphire substrates by molecular beam epitaxy. It is found that an atomically flat surface can be obtained under Al-rich conditions at growth temperature of 780 °C. However, the growth window to obtain an Al−droplet-free surface is too narrow to be well-controlled. However, the growth window can be greatly broadened by increasing the growth temperature up to 950 °C, where an Al-droplet-free surface with a step-flow feature is obtained due to the enhanced re-evaporization rate and migration ability of Al adatoms. The samples grown at the higher temperature also show a higher crystalline quality than those grown at lower temperatures.
Abstract:We investigate epitaxy of AlN layers on sapphire substrates by molecular beam epitaxy. It is found that an atomically flat surface can be obtained under Al-rich conditions at growth temperature of 780 °C. However, the growth window to obtain an Al−droplet-free surface is too narrow to be well-controlled. However, the growth window can be greatly broadened by increasing the growth temperature up to 950 °C, where an Al-droplet-free surface with a step-flow feature is obtained due to the enhanced re-evaporization rate and migration ability of Al adatoms. The samples grown at the higher temperature also show a higher crystalline quality than those grown at lower temperatures.
PAN Jian-Hai;WANG Xin-Qiang**;CHEN Guang;LIU Shi-Tao;FENG Li;XU Fu-Jun;TANG Ning;SHEN Bo***
. Epitaxy of an Al-Droplet-Free AlN Layer with Step-Flow Features by Molecular Beam Epitaxy[J]. 中国物理快报, 2011, 28(6): 68102-068102.
PAN Jian-Hai, WANG Xin-Qiang**, CHEN Guang, LIU Shi-Tao, FENG Li, XU Fu-Jun, TANG Ning, SHEN Bo***
. Epitaxy of an Al-Droplet-Free AlN Layer with Step-Flow Features by Molecular Beam Epitaxy. Chin. Phys. Lett., 2011, 28(6): 68102-068102.
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