表面处理工艺对于N型HgCdTe材料和光导器件的影响

工程应用的HgCdTe光导探测器厚度一般在10μm左右,因此表面对于HgCdTe器件至关重要。报导了采用溴腐蚀和溴抛光两种表面处理工艺对于HgCdTe材料表面的影响,测试了材料的迁移率谱和迁移率变温曲线,将材料制成光导器件后测试了器件的电阻变温曲线,比较了溴腐蚀和溴抛光所得器件电阻变温曲线最大电阻值所对应的温度。上述实验均表明,采用溴腐蚀的材料,表面电子较多,电离杂质散射较为严重,所制得器件性能较差,而采用溴抛光的材料,表面电子较少,以晶格散射为主,所制得器件性能良好。

The difference between etching bromine and polishing on HgCdTe material and photoconductive detector

Bromine etching and bromine polishing are two different surface treatment reported. Mobility spectrum and mobility-temperature character are used to compare the influence between bromine etching and polishing. After that, the material treated with two different methods is fabricated into detector. Resistivity as a function of temperature is measured. All the experiments indicated that there is more surface electron and ionized impurity scattering counted more in the material treated by bromine etching, however, for the material polished by bromine, the surface electron concentration is much less and lattice scattering plays a major role, in result the performance of the final detector is much better.Etching and polishing with bromine are two different surface treatments for HgCdTe material. To evaluate the effectiveness of the surface treatment, both the mobility dependence of carrier concentration and temperature dependence of the mobility were investigated. Then, the material treated with the two different methods was fabricated into detectors. Resistivity as a function of temperature was measured. The experiments indicated that there are more surface electrons and ionized impurity scattering in the material treated by bromine etching than that treated by polishing, wherein lattice scattering plays a major role. Thus the performance of the final detector made of material treated by polishing is much better.