Very-long-wave mercury cadmium telluride infrared focal plane detector antireflective membrane and its preparing method

The antireflection coating is placed on photosensitive element array, area of signal extraction electrode, and common electrode area. The antireflection coating placed on the photosensitive element array is ZnS material with thickness 0.8-1.5 micros. The antireflection coating placed on the area of signal extraction electrode, and common electrode area is indium film with thickness 150 - 200 micros. Characters of the preparation method are that after indium film of antireflection coating is formed, oxygen plasma process is carried out for indium film. Thus, surface of the indium film becomes more smoothing and compact, and grey indium becomes grayer so that reflection coefficient reaches low limit of the material. Advantages are: receiving signal of incident light in maximum so as to raise photoelectric efficiency of apparatus. The invention is suitable to apparatus with large coverage of electrode area.