the isolation and mesa formation have particular significance.In this work we have studied the chemical etching technique and mesa formation with alkaline K
3
Fe(CN)
6
etchant which provides higher etching rate and a perfect surface is excellent for GaP. For GaP material and have examined the dependence of etching depth and appearance on etching time and etching temperature.We have found that the alkaline K
3
Fe(CN)
6
etchant which providss higher etching rate and a perfect surface is excellent for GaP