Reduction of mechanical stress in shallow trench isolation process

摘要

A method of minimizing mechanical stress generated during the trench-forming/trench-filling process steps in a standard shallow trench isolation (STI) process is provided. This is achieved by forming trenches with a more sloped and smoother profile, and/or limiting the trench depth to be less than 0.4 mum, and/or reducing or increasing the trench densification temperature, and/or performing the densification step after the chemical-mechanical polishing step. In addition, a furnace TEOS oxide film is used as the trench-filling material.