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由于Hg_(1-x)Cd_xTe的能带隙小而且可变,因此它已广泛用于红外探测器方面。对于这种应用其表面必须钝化。一种可能的钝化剂为光化学氧化物,已用X射线光电子谱法(XPS)结合氩离子溅射研究了Hg_(0.8)Cd_(0.2)Te和Hg_(0.7)Cd_(0.3)Te两种组分。对Hg_(1-x)Cd_xTe表面进行机械抛光,随后在溴-甲醇中腐蚀。在有氧的大气压下,使裸露的晶片表面暴露在低压汞蒸汽灯的紫外(波长1849和2537A)辐射下完成氧化物生长。在大多数情况下,氧化物生长是在形成厚100A的层后即告停止。而在有些情况下却生长了很厚的氧化物(～1000A),本文将报导这些氧化物的结果。根据氩离子溅射周期交替进行Ol_s,、Te3d_(5/2)、Cd3d_(5/2)和Hg4f光电子谱线的高分辨率测量,绘制出每个片子的XPS深度分布图。结果以表面特性图(SBD)的形式示于图1,看上去它与块体相图相似,但用图解说明了在
Hg_ (1-x) Cd_xTe has been widely used in infrared detectors due to its small bandgap and variable bandgap. The surface must be passivated for this application. One possible passivating agent is photochemical oxide. Two kinds of Hg_ (0.8) Cd_ (0.2) Te and Hg_ (0.7) Cd_ (0.3) Te have been studied by X-ray photoelectron spectroscopy (XPS) combined with argon ion sputtering Component. The Hg_ (1-x) Cd_xTe surface was mechanically polished and then etched in bromine-methanol. Oxide growth is accomplished by exposing exposed wafer surfaces to UV (wavelength 1849 and 2537A) radiation of a low pressure mercury vapor lamp at atmospheric pressure. In most cases, oxide growth stops after a 100 A thick layer is formed. In some cases, very thick oxides (~ 1000 A) were grown. The results of these oxides will be reported in this paper. The XPS depth profiles for each film were plotted by alternating high-resolution measurements of the Ol_s, Te3d_ (5/2), Cd3d_ (5/2) and Hg4f photoelectron lines according to the Argon ion sputtering cycle. The results are shown in Figure 1 in the form of a Surface Property Diagram (SBD), which looks similar to the bulk phase diagram but illustrates