研究了以金属有机化学气相沉积方法生长在SiNx掩模层的GaN的应力状态, 以及应力对光学性质的影响。通过微区拉曼光谱对应力进行了表征, 结果显示, 随着SiNx掩模淀积时间的增加, 其上生长的GaN应力会相应地, 释放。相应地,低温光致发光测试显示, 施主束缚激子发光峰峰位出现明显的红移。我们认为, 随着SiNx掩模淀积时间的增加, 掩模覆盖度的增大, 促进了侧向外延的生长, 释放了压应力, 进而影响了材料的光学性质。

The stress state and its effect on optical properties of GaN films grown on porous SiNx interlayers by using metal organic chemical vapor deposition (MOCVD)method are investigated. The stress is characterized by the frequency shift based on micro-Raman spectroscopy measurement. It shows that more residual stress in GaN film grown on the SiNx interlayers is relaxed when the time of in situ SiNx deposition is increased. Accordingly, the donor bound extion(DBE) peak shows red shift in low temperature photoluminescence(PL) measurement. We assume that the increasing time of in situ SiNx deposition enlarging the lateral overgrowth area is the main reason to reduce the residual stress and influence corresponding optical properties.