论文部分内容阅读
利用能量为2 MeV的高能电子束对金属有机物化学气相沉积方法(MOCVD)生长的非故意掺杂氮化镓(GaN)异质结在室温下进行辐照,辐照剂量分别为1×1015/cm2和5×1015/cm2。经垂直于样品表面的电子辐照后,GaN外延层的(0004)和(10ī2)高分辨X射线衍射峰分别向高角和低角发生移动,表明电子辐照使GaN外延层发生了部分应变弛豫。利用电子背散射衍射(EBSD)对应变弛豫进行了表征。EBSD结果显示,剂量为5×1015/cm2的电子辐照相对于1×1015/cm2的电子辐照可诱导GaN外延层发生更为显著的应变弛豫。卢瑟福背散射/沟道(RBS/C)实验结果表明,5×1015/cm2的电子辐照对GaN外延层引入更为严重的辐照损伤。上述实验结果表明,GaN外延层的应变弛豫与2 MeV的电子辐照引入的缺陷如弗伦克尔对有关。运用弹性原子链模型(EACM)对电子辐照诱导GaN外延层应变弛豫机制进行了讨论。
The unintentionally doped GaN heterojunction grown by metal organic chemical vapor deposition (MOCVD) was irradiated by high energy electron beam with an energy of 2 MeV at room temperature with irradiation doses of 1 × 10 15 / cm2 and 5 × 1015 / cm2. After (0004) and (10ī2) high-resolution X-ray diffraction peaks of the GaN epitaxial layer were irradiated by the electrons perpendicular to the sample surface, the high-and low-angle X-ray diffraction peaks shifted to high and low angles, respectively, indicating that partial relaxation of the GaN epitaxial layer Yu. Strain relaxation was characterized by electron backscatter diffraction (EBSD). The results of EBSD show that the electron irradiation at a dose of 5 × 10 15 / cm 2 can induce more pronounced strain relaxation of the GaN epitaxial layer than the electron irradiation at 1 × 10 15 / cm 2. Rutherford backscatter / channel (RBS / C) experimental results show that 5 × 10 15 / cm 2 electron irradiation introduces more serious damage to the GaN epitaxial layer. The above experimental results show that the strain relaxation of the GaN epitaxial layer is related to defects introduced by 2 MeV electron irradiation such as the Friedel’s pair. The mechanism of electron-induced GaN induced strain relaxation was discussed using elastic atomic chain model (EACM).