GATE ALIGNMENT PROCEDURE IN FABRICATING SEMICONDUCTOR DEVICES

摘要

A self-aligned metal gate is formed on a semiconductor substrate surface between a source region and a drain region of the substrate. Precise alignment of the boundaries of the gate with the bou ndaries of the source and drain regions is obtained by shadowing a photoresist coating over metal deposited onto the substrate surface, while photochemically dissociating the photoresist over metal deposited onto an oxide layer formed over the source and drain regions of the substrate. The developed photoresist is removed, and the undeveloped photoresist is hard-baked to serve as a protective coating for the metal between the source and drain regions. The metal over the source and drain regions is etched away, leaving the metal between the source and drain regions to function as an electronic gate.