The fabrication of type-II superlattice infrared detectors with a dual color single indium column structure is difficult and prone to damage during the mesa forming process, which affects the performance of the device. In order to solve this problem, the mesa etching technology for type-II superlattice materials with low damage and high aspect ratio was studied. Firstly, a damage judgment mechanism is established to determine whether the material has inversion after etching in the existing process. By optimizing the photoresist thickness and variable power step etching, the mesa etching of type-II superlattice materials with low damage and high aspect ratio is realized, while effectively solving the process problems such as easy accumulation of products and excessively steep sidewalls in single etching of deep mesas. The distance between centers of mesa is 20 μm. Etching depth exceeds 8 μm. The gap depth to width ratio can reach 2. The devices subsequently fabricated on this mesa have significant dual impedance characteristics, with a peak long wave impedance of 100 MΩ, and a flat region on the long wave side of the I-V curve exceeding 100 mV. From the perspective of electricity, it is preliminarily judged that the detector has the ability of dual color detection, and the feasibility of this process is verified.