A novel simple shallow trench isolation (SSTI) technology using high selective CeO/sub 2/ slurry and liner SiN as a CMP stopper

A novel simple shallow trench isolation technology, SSTI, has been developed. SSTI consists of direct trench etching masked only with the photoresist, trench oxidation, liner SiN deposition, CVD oxide trench fill, densification, and high selectivity CMP. CMP stops at the liner SiN with a residual SiN thickness range of less than 2 nm and without micro-scratching. High selectivity CMP eliminates the field recess variation which is one of the drawbacks of conventional STI. SSTI is a promising candidate for future isolation technology.