ICP刻蚀HgCdTe表面的微区XPS分析

XPS Analysis of the HgCdTe Surface Etched by ICP

文章将ICP刻蚀技术应用于刻蚀HgCdTe,使用微区X射线光电子光谱学(XPS)、扫描电子显微镜(SEM)等表面分析技术研究了ICP各工艺参数,包括ICP功率、气体成分与配比、腔体压力等对刻蚀表面形貌、刻蚀后表面成分、聚合物形成的影响。XPS分析结果发现,使用光刻胶作掩模时,刻蚀气体CH4会与光刻胶发生反应,生成物可能为C6H5(CH3)。如果腔体压力较高,生成物不能及时被带走,就会附着在样品表面上,使样品表面发黑;当腔体压力较低时,生成物被及时带走,则样品表面光亮,无聚合物残留。光刻胶也会与H2发生反应,生成多种含C有机物。SiO2作掩模时,在一定的条件下,CH4会与SiO2或者真空硅脂发生反应,生成聚脂薄膜。

ICP （Inductively Coupled Plasma） etching technique has been applied to HgCdTe providing significant benefits such as high uniformity, low damage and anisotropic profile, etc. We have studied the dependence of surface profile, post-etch composition, formation of polymer on the effect of ICP parameters （ ICP power, gas ratio, chamber pressure） by using micro regional XPS and SEM （scanning electron microscopy）. We have found that methane can react with photoresist （PR） which is used as mask, the product may be C6H5 （CH3）. The product can＇t be pumped out if the chamber pressure is high, then it will be left on the sample surface forming so-called polymer. Otherwise if the chamber pressure is low, the product is pumped away the chamber in time, and there is no polymer on the surface. H2 can react with PR, and the products are several organic compounds with carbon. Under certain condition, methane can reacts with SiO2 or high vacuum grease, generating Mylar Polyster.