分子束外延用碲锌镉(211)B衬底表面预处理技术

Pretreatment of CdZnTe(211)B Substrates for MBE

本文主要分析了作为分子束外延碲镉汞的碲锌镉衬底的表面预处理工艺。湿化学处理工艺主要目的是去除衬底表面损伤层,0.5%溴甲醇溶液的腐蚀速率为7 nm/s,但腐蚀的同时会形成表面富Te层和氧化层,氧化层的厚度随溴甲醇的浓度增加而增加;高温热处理工艺主要是消除湿化学腐蚀形成的富Te层和氧化层,340℃的高温处理可去除表面氧化层;也可以直接通过回旋共振等离子体处理衬底表面,形成化学计量比正常的干净表面。

This article discusses the surface pretreatment processes for CdZnTe, which is used as a substrate for HgCdTe grown by molecular beam epitaxy. The main purpose of the wet chemical treatment process is to remove the surface damaged layer of the substrate. The etch rate of 0.5% Br-MeOH is approximately 7 nm/s; however, after the etch process, a Te-rich layer and an oxide layer will be formed on the surface. The thickness of the oxide layer increases with the increase in the concentration of Br-MeOH. The major purpose of the high-temperature thermal treatment process is to eliminate the Te-rich layer and the oxide layer formed by wet chemical etching. Thermal treatment at 340℃ can eliminate the oxide layer. The substrate surface can also be directly treated using cyclotron resonance plasma to form a normal stoichiometric clean surface.