Planarized gate conductor on substrates with above-surface isolation

摘要

Stringers and depth of focus problems in substrates having above-surface isolation schemes are avoided by applying a first portion of a gate conductor over the entire surface having above-surface isolation, selectively removing the gate conductor from above the isolation features of the above-surface isolation, and overcoating the entire surface with a second portion of gate conductor. The process has particular application to substrates that employ regions having field-shield isolation. An important feature of the invention is drawn to creating structures wherein gate conductor is applied to a substrate including both above-surface and below-surface isolation regions in a manner which leaves the gate conductor planarized over both the above-surface and below-surface regions.