A semiconductor device is manufactured in a silicon-on-insulator (SOI) wafer having an silicon active layer, a buried oxide layer, and a supporting substrate layer. Before the wafer is diced into chips along scribe lines, the silicon active layer is selectively etched to form trenches surrounding the scribe lines. The wafer is then diced using a dicing apparatus having a blade width smaller than the width of the trenches. The dicing blade accordingly does not make contact with the silicon active layer, which is particularly vulnerable to chipping.