CdGeAs_2单晶体的腐蚀研究

Studies of Etching on CdGeAs_2 Crystals

报道了一种新型的CdGeAs2晶体择优腐蚀剂,配方为:H2O2(30%)∶NH4OH(含NH325%-28%)∶NH4Cl(5mol/L)∶H2O=1 mL∶1.5 mL∶1.5 mL∶2 mL。将经机械研磨、物理抛光和溴甲醇化学抛光处理后的表面平整无划痕的CdGeAs2晶片,在40℃下超声振荡腐蚀数分钟,采用金相显微镜和SEM进行蚀坑观察。结果表明,新型腐蚀剂对CdGeAs2晶体(204)和(112)晶面择优腐蚀效果显著,蚀坑取向一致,具有很强的立体感;(204)晶面蚀坑呈三角锥形,(112)晶面蚀坑呈五边形,从晶体结构上对蚀坑形成机理进行了分析讨论。

A novel preferential etching solution of H2O2（30%） ∶NH4OH（25~28%）∶NH4Cl（5 mol/L） ∶H2O in the ratio of 1 mL∶1.5 mL∶1.5 mL∶2 mL（Vol） for CdGeAs2 crystals was reported in this paper.The CdGeAs2 wafer with flat smooth surfaces was prepared through mechanical grinding,physical polishing and chemical polishing in 3% BM solution respectively.The wafer was etched in the etching solution for a few minutes at 40 ℃ with ultrasonic vibration.Then the wafer after being cleaned was observed by metallurgical microscope and SEM.It is found that the pattern of etching pits of（204） faces are pyramid and that of（112） faces are pentagon,the preferential etching effect is very obvious,orientations of etching pits are consistence and have strong stereoscopic impression,the etching pits density（EDP） is less than 105 cm-2.Final,the formation mechanism of the two kinds of etch pits is theoretically analyzed from the crystal structure.