In order to obtain an optimized method for low etch damage,the different etch gas for extended wavelength In0.83Ga0.17As detector materials by Cl2/N2 ICP etching and Cl2/CH4 ICP etching was studied in this paper.The quality of the sample before and after etching was investigated using photoluminescence(PL)technology.The etch damage of InGaAs sample in our work were characterized by Transmission Line Model(TLM)and current voltage(Ⅳ)technology.The results indicate that the sample with etch gas Cl2/CH4 has lower PL intensity than the Cl2/N2 sample.The square resistance of the Cl2/CH4 sample is larger than the Cl2/N2 sample.The dark current of the Cl2/CH4 sample has lower than the Cl2/N2 sample.The research shown that the sample with Cl2/CH4 etch gas has some advantages than the Cl2/N2 etch gas sample.The reason leaded the lower dark current and larger square resistance and lower PL intensity may attribute to the hydrogen decomposed by CH4 which is created the non-radiative recombination centers in inner material and passivated the dangling bond of the surface of material.The non-radiative recombination centers would make the PL intensity lower and the dangling bond passivated by hydrogen would reduce the dark current of the extended wavelength In0.83Ga0.17As detectors.