本文通过测量ＳＩ－ＧａＡｓ抛光晶片及其本体（腐蚀了晶片的亚表面损伤层）的Ｘ射线回摆曲线ＦＷＨＭ，与抛光晶片的ＴＥＭ观测相结合，作出晶片回摆曲线ＦＷＨＭ的比率Ｒ与ＴＥＭ观测的晶片亚表面损伤层厚度Ｄ的关系曲线，建立了一种定量检测ＳＩ－ＧａＡｓ抛光晶片的亚表面损伤层厚度技术，文中将对这种技术进行描述并作讨论． In this paper, by measuring the X-ray gyration curve FWHM of SI-GaAs polished wafer and its bulk (etched wafer sub-surface damage layer), combined with the TEM observation of the polished wafer, the ratio R and TEM of the wafer swing curve FWHM The thickness of the subsurface damage layer of the wafer D is established, and a technique for quantitatively detecting the thickness of the subsurface damage layer of the SI-GaAs wafer is set forth. The technique will be described and discussed in the text.