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HgCdTe(mercury cadmium telluride)has excellent optical and electrical properties which make it an ideal material for fabricating infrared detectors.However,the main disadvantages of this material is a weak Hg-Te bond which lead to instabilities of surface and interface and became the potential problems for reliability of infrared detectors.The stability of electrical properties of Sn/p-HeCdTe contacts were investigated using transmission line model(TLM)structures and Ⅰ-Ⅴ measurements under the long time baking.The structures were fabricated on the mid-wave Hg1-xCdxTe(x=0.301)thin film which grown by liquid phase epitaxy and metal layers of Sn and Au were deposited in succession using ion beam sputtering.The rest of the sample surface was coated with thermally evaporated CdTe/ZnS complex passivation layer.The chips were baking for 624 hours at 90oC and Ⅰ-Ⅴ characteristics were measured at the liquid nitrogen temperature.The results indicate that the nonlinear property of Sn/p-HgCdTe contact gradually changes into linear property under the baking process,and the specific contact resistance decreases from the order of 10-3Ω·[cm]^2 to 10-4Ω·[cm]^2 which demonstrated good stability of this metal-semiconductor system.And,an insight into the mechanisms of current transport through the contact was investigated by temperature dependence Ⅰ-Ⅴ characteristics.In temperature range 87-175K,the specific contact resistance increases with temperature which disagrees with mechanisms associated with thermionic emission,field emission and thermionic-field emission.Therefore,it is assumed that the electrical properties of Sn/PHeCdTe contact is metallic conduction like which is possibly due to the intermixing between the contact metal and the alloy constituents.