磨抛工艺中HgCdTe晶片的表面损伤

Surface Damage of HgCdTe Wafers in Lapping and Polishing

用Ｘ射线反射形貌术研究了磨抛工艺在用Ｔｅ溶剂法和布里奇曼法生长的碲镉汞晶片表面引入的损伤，发现精磨精抛的ＨｇＣｄＴｅ晶片表面的损伤结构与切割、粗磨造成的损伤结构明显不同。根据实验结果分析，认为机械划痕是精磨精抛过程中的主要损伤结构，并提出一个新的表面损伤模型──表面不完全损伤模型。用Ｘ射线形貌相测出了精磨精抛ＨｇＣｄＴｅ晶片表面的平均损伤和最大损伤深度。结合压痕实验，确定了机械划痕周围的晶格应变区是高密度位错增殖区；在特定条件下，测出两者之间的比值约为５。最后讨论了最大损伤深度和平均损伤深度对探测器性能的影响。

Surface damages of Te solvent and Bridgman grown HgCdTe wafers have beenstudied with X-ray reflection topography. The different surface damages between variousprocessing methods are compared. Experiments show that mechanical scratches on waferswith carefully lapping and polishing are the main damages. An incomplete surface damagemodel is Suggested. Surface damage depths of well lapped and polished HgCdTe wafersare measured by X-ray topography. Expandments show that there is a high dislocationdensity in the lattice strain area around mechanical scratchs. The ratio of the highdislocation density area to the observable damage area is about five under certainconditions. Finally, effects of the damage death on detector properties are diSscussed.