This work presents the study results of using inductively coupled plasma (ICP)-reactive ion etching (RIE) for fabricating InSb mesa with CH4/H2/Ar plasma.With optimized ICP etching parameters,good etching results have been obtained. Etch rates is about 70 to 90 nanometers per minute,sidewall angles of etched mesa is about 80°,and the etched surface is as smooth as that before the RIE process and with low damage.The lateral etching effect commonly encountered in wet etching has been reduced distinctly.320×256 InSb detective array with the mesa fabricated with the ICP-RIE have been developed also.The current-voltage characteristic of this detector measured at 77 K is as good as that of the devices fabricated by wet etching.