A new high-efficiency and low-damage polishing process of HgCdTe wafer

HgCdTe crystals have been accepted as a very important material of infrared detectors, and due to their soft-brittle nature, machining HgCdTe wafers is a challenge in the field of ultraprecision manufacture. In this article, the new polishing slurry is developed, and the new polishing process is employed to polish HgCdTe wafers; the polishing results showed that the polished surface roughness Ra is as small as 0.32nm, the polished surface is smooth and flat, and the subsurface damage only contains thin amorphous layer with depth of 3nm. The material removal mechanism during polishing HgCdTe wafers is that HgCdTe react with oxidant and acid in the polishing slurry, and at last, the polished surfaces are covered with HgCdTe and TeO ₂.