Method for shallow trench isolation with removal of strained island edges

摘要

A method of isolation of active islands on a silicon-on-insulator semiconductor device, including steps of (1) providing a silicon-on-insulator semiconductor wafer having a silicon active layer, a dielectric insulation layer and a silicon substrate; (2) etching through the silicon active layer to form an isolation trench, the isolation trench defining an active island in the silicon active layer, the active island having at least one upper sharp corner; (3) rounding the at least one upper sharp corner of the active island, whereby at least one strained edge portion of the active island is formed; (4) removing at least a part of the at least one strained edge portion; and (5) at least partially filling the isolation trench with a dielectric trench isolation material to form a shallow trench isolation structure. An SOI wafer semiconductor device having a STI isolation structure free from a strained edge portion and a bird's beak.