Method of fabricating transistors, including ambient oxidizing after etchings into barrier layers and anti-reflecting coatings

Abstract

A method to fabricate a transistor comprises: forming a first dielectric layer on a semiconductor substrate; depositing a barrier layer on the first dielectric layer; depositing an anti-reflective coating on the barrier layer; depositing and exposing a pattern in a photoresist layer to radiation followed by etching to provide an opening; etching a portion of the anti-reflective coating below the opening; etching a portion of the barrier layer below the opening to expose a portion of the first dielectric layer; providing an ambient oxidizing agent to grow an oxide region followed by removing the barrier layer; implanting dopants into the semiconductor substrate after removing the barrier layer; removing the first dielectric layer after implanting dopants into the semiconductor substrate; and forming a second dielectric layer after removing the first dielectric layer, wherein the oxide region is grown to be thicker than the second dielectric layer.