大面积、高质量碲锌镉单晶是制备碲镉汞红外焦平面器件的理想衬底材料,而腐蚀法是常用的揭示碲锌镉晶体缺陷和评价晶体质量的方法之一。对碲锌镉晶体常用的Nakagawa、Everson、EAg1和EAg2四种腐蚀剂在碲锌镉材料(111)晶面上的腐蚀坑坑形进行了研究,结果发现,EAg2腐蚀剂在(111)B面上的腐蚀坑为平底坑,Everson腐蚀剂在 (111)B面上产生的腐蚀坑包括平底坑和带有不同倾斜方向坑底的三角锥形坑,进一步的研究还表明,三角锥形坑并未沿着坑底的倾斜方向向下延伸。实验中也首次观察到了EAg腐蚀剂的黑白平底坑。对常用腐蚀剂的坑形特性研究,将有助于更好地利用腐蚀剂开展碲锌镉材料缺陷研究和晶体质量评价工作。
CdZnTe single crystals with large area and high quality are perfect substrate material for HgCdTe IRFPA Device. The morphologies of the CdZnTe etch pits developed by four etchants including Nakagawa, Everson, EAg1 and EAg2 solutions are studied. The results show that the etch pits of EAg2 etchant on the (111) B surface are flat-bottomed. And the etch pits of Everson etchant on (111) B include flat-bottomed pits and pyramidal pits with different slant directions, while the positions of pyramidal pits don′t move as the surface layer is continuously removed. The black and white pits developed by EAg etchants on (111) B surface are observed. The characteristic study of etch pits is beneficial to the study of defects in CdZnTe materials further.