采用有机金属化学气相沉积方法在单晶硅(111)衬底上生长GaN薄膜,并利用X射线衍射分析确定了GaN主要为以〈0001〉方向取向生长的纤锌矿结构。对样品进行自由和压力荷载状态下的拉曼光谱测试,结果表明,自由状态下,GaN处于张应力状态,最大应力为342.272 MPa,同时Si衬底为压应力,但由于缓冲层的存在及影响,GaN中的张应力和Si中的压应力数值不完全相同。在对样品施加平行于(0002)面的外加压力后,随着加压的增大,GaN和Si的拉曼峰都发生蓝移,说明外加压力在材料内部造成了压应力。

GaN thin films have been grown on Si(111) substrates by metal-organic chemical-vapour deposition. The analyses of X-ray diffraction indicate that GaN is of wurtzite structure with the 〈0001〉 crystal orientation. Raman spectroscopy is used to study the sample under different pressures. The results of Raman spectroscopy,show that when the sample is under relaxation,GaN flims are in tensile stress the maximum of which is 342.272 MPa and Si substrates are in compressive stress. But due to the existence of a buffer layer between GaN flims and Si substrates,the values of tensile and compressive stress are not identical. After applying different pressures parallel to the (0002) plane of GaN,the peaks of GaN and Si are both blue shit as the pressures increasing,which supports that applied pressures lead to compressive stress in the interior of the sample.