中文摘要：

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。

英文摘要：

The unintentional doped GaN epitaxial layers grown by metal organic chemical vapor deposition（MOCVD） were irradiated by 2 MeV electron beam perpendicular to the surfaces with the doses of 1×1015/cm2 and 5×1015/cm2 at room temperature.The high resolution X-ray diffraction（HRXRD） data presented that the（0004） and（10 12） diffraction peaks shifted to high-angle and low-angle side respectively.It was indicated that the high energy electron irradiation could induce the strain of GaN epitaxial layers relaxed partially.In addition,the electron back scattering diffraction（EBSD） was employed to characterize the strain relaxation.The visible strain relaxation was recognized in the GaN epitaxial layer by the 5×1015/cm2 electron irradiation other than the 1×1015/cm2 electron irradiation.Rutherford backscattering spectroscopy in channeling geometry（RBS/C） proved that the 5×1015/cm2 electron irradiation resulted in more serious radiation damage in the GaN epitaxial layer.The results from EBSD and RBS/C suggested that strain relaxation of the GaN epitaxial layer was related with the introduction of irradiation defects such as Frenkel pairs by 2 MeV electron irradiation.The strain relaxation mechanism was proposed on the basis of the elastic atom-chain model（EACM）.