Trench Formation using Rounded Hard Mask

摘要

A method embodiment includes forming a hard mask over a dielectric layer, patterning the hard mask to form an opening, forming a passivation layer on sidewalls of the opening, and forming a trench in the dielectric layer by extending the opening into the dielectric layer using an etching process. The sidewalls of the opening are etched to form a rounded profile in the hard mask and a substantially perpendicular profile in the dielectric layer.

主权项

1. A method comprising:
forming a hard mask over a dielectric layer; patterning an opening in the hard mask; extending the opening into the dielectric layer using a first etching process, wherein the first etching process forms a passivation layer on sidewalls of the opening; and after the first etching process, forming a trench in the dielectric layer by extending the opening further into the dielectric layer using a second etching process.