长波碲镉汞材料阳极氧化膜/ZnS界面的电学特性参数

Electrical properties of a MIS structure consisting of AOF/ZnS and LWIR HgCdTe film

通过碲镉汞阳极氧化膜和磁控溅射ZnS膜,结合HgCdTe器件工艺,成功制备了以阳极氧化膜和磁控溅射ZnS双层钝化膜为绝缘层的"长波弱P"型HgCdTe MIS器件.通过对器件的C-V特性实验分析,获得了长波HgCdTe材料的阳极氧化膜/ZnS界面电学特性参数.并通过获得的界面参数,计算了阳极氧化和ZnS的双层钝化膜的表面复合速度.并对MIS器件的变温C-V特性进行了实验和分析.

The semiconductor-passivating layer interface, as well as the dielectric properties of the passivator, plays an important role in HgCdTe based photoelectric detectors. Anodization is commonly used as a surface passivator for HgCdTe. ZnS is deposited on the AOF （ anodic-oxide film） as antireflecfing layer. The electrical properties of the interface between AOF/ZnS and LWIR bulk HgCdTe materials were determined by capacitance-voltage （C-V） measurements in the frequency range of 10 KHz-10 MHz in the metal insulator semiconductor （ MIS ） structures. The results showed that the MIS detector could not reach the high frequency level even at frequencies up to 10 MHz in the case where the interfacial state densities were 3.4 × 10H cm^2q^-1 V^-1. The fixed charges were 1.1 × 1012cm^-2. The surface recombination velocity at the interface of AOF/ZnS and LWlR HgCdTe was 700cm/s. The variation of C-V properties with temperature has been obtained and analyzed.