US Patent 7759216 Method for forming trench isolation

A method for forming a trench isolation in a semiconductor device is provided. This is a novel method for rounding the top corners of trench isolations. The method ensures that rounded corner portions with a uniform shape are consistently formed regardless of the pattern densities of active areas. The method increases the reliability of semiconductor integrated circuit devices, without degrading electrical characteristics, and making it easier to achieve high integration and performance in semiconductor integrated circuit devices.