The　residual　stress　in　ground　wafers　will　induce　wafer　warpage　and　reduce　the　strength　of　thinned　wafers.　The　residual　stress　distribution　in　ground　wafers　are　investigated　by　Raman　micro-spectroscopy　in　this　paper.　The　results　show　that　there　is　compressive　stress　in　ground　wafers　and　the　stress　distribution　is　not　uniform.　In　addition,　the　residual　tensile　stress　exists　on　rough　ground　wafer　surface.　The　scanning　electron　microscopy　images　of　ground　wafers　indicate　that　wafer　surface　materials　are　removed　mainly　by　the　brittle　fracture　mode　during　rough　grinding　process　but　by　the　ductile　mode　during　fine　grinding　process.