Abstract: The roughness of material surfaces has a significant impact on the quality of passivation films and the lithography and etching of contact holes. Therefore, studying the influence of the surface roughness of materials on the performance of HgCdTe infrared focal plane devices' is important. In this study, we separately evaluated the influence of the facet morphology and step morphology of mercury cadmium telluride on the performance of the device and the influence of mercury cadmium telluride materials with different surface roughness on the preparation process and final performance of the device. Studies have shown that as the surface roughness of the materials increases, the quality of the passivation layers decreases, uniformity of the contact holes decreases, morphology of the contact holes deteriorates, and I-V performance is degraded, eventually leading to an increase in the non-uniformity of the device responses and an increase in the blind pixel rate.