表面处理对CdZnTe晶片漏电流的影响  

Effect of Surface Processing on the Leakage Current of CdZnTe Wafer

作　　者：邱春丽[1] 赵北君[1] 朱世富[1] 丁群[1] 何知宇[1] 陈宝军[1] 

机构地区：[1]四川大学材料科学系,成都610064

出　　处：《人工晶体学报》2010年第B06期100-104,共5页Journal of Synthetic Crystals

基　　金：国家自然科学基金(No.60276030);教育部博士点基金(No.20020610023)

摘　　要：采用EDS、XPS、I-V等方法研究了Cd1-xZnxTe(CZT)表面处理工艺与晶片漏电流之间的相互关系。结果表明,机械抛光后的CZT晶片存在损伤层,采用5%BM溶液腐蚀可有效去除损伤层,得到光滑无划痕的表面,但腐蚀后晶片表面组成偏离化学计量配比,随腐蚀时间的延长表面呈现富Te现象,晶体表面漏电流随之增大1～2个数量级;采用KOH溶液对BM抛光后的晶片进一步腐蚀10min,可消除多余的Te得到接近于化学计量比的表面;采用NH4F/H2O2溶液对晶片表面进行钝化,XPS分析表明样品表面的Te0或Te2-被氧化成Te4+,形成高阻氧化层。I-V测试结果表明晶片经KOH+NH4F/H2O2溶液两步钝化后,表面漏电流相对于BM抛光后降低2～3个数量级,具有较好的钝化效果。The paper analyzed the correlation between the surface and the performances of CZT semiconductor devices after chemical polishing, etching and passivation for the wafer. The results showed that CZT wafer surface has the damage layer after mechanical polishing, which could been removed effectively and gained the smooth surface without scratches though using 5% BM solution to corrosion. But Energy dispersive analyzer of X-ray showed the CZT surface was Te-rich after the BM etching, which resulted in surface leakage current increasing. However, though KOH solution further etching 10 min, the sample surface decreased Te-rich layers and the composition was close to the stoichiometry. In the subsequent passivation, the X-ray photoemission spectroscopy （XPS） analysis showed that the Te-rich layer of sample had been oxidated a TeO2 （CdTeO3 ）oxide layer by NH4F/H2O2 solution. Current-voltage measurement showed that the KOH ＋ NH4F/H2O2 solution treatment had significantly passivation effect to decrease the surface leakage current.

关 键 词：Cd1-xZnx Te晶片 表面处理 钝化 XPS分析 漏电流 

分 类 号：TL816[核科学技术—核技术及应用]