Taking the deep table etching of medium-length two-color InAs/GaSb class II superlattice infrared detectors as the research background, we study the relationship between the photolithographic solid-film process and the deep table etching molding. The effects of different solid film temperatures on the graphic transfer effect of the countertop and the quality of countertop etching are analyzed, and the best solid film process is optimized. The smooth countertop superlattice chip prepared by this process was interconnected with a two-color readout circuit, then encapsulated into a Dewar and cooled down to 77 K by liquid nitrogen for component testing. The experimental results show that the two-color superlattice material was prepared with AZ4620 photoresist for mask patterning, and after a gradient temperature increase to 140 °C for firming the film, it was formed by dry etching to obtain a deep countertop structure with smooth sidewalls. The module test results illustrate that the smooth sidewall can effectively reduce the NETD, blind element rate and non-uniformity of the module.