Patent ID: 6218314
Filing Date: 2001-04-17
Classification: H01L

Abstract:
A method of fabrication of a silicon oxide-oxynitride passivation film as a passivation film for a semiconductor device; comprising:forming metal layer over a dielectric layer over a semiconductor structure; said metal layer composed of an Al alloy;forming a silicon oxide-oxynitride passivation film composed of three layers of (1) a silicon oxide layer, (2) an oxide/oxynitride transition layer and (3) a silicon oxynitride layer; said oxide/oxynitride transition layer has a bottom surface at the side of said semiconductor structure and a top surface opposite said bottom surface; a compositional ratio between nitrogen and oxygen increases from said bottom surface to said top surface;loading said substrate into a plasma enhanced chemical vapor deposition chamber;said silicon oxide-oxynitride passivation film formed in a three step in-situ PECVD deposition process as follows:a) performing a first step for a first time period to form a silicon oxide layer; said first step is performed at the following conditions: using a PECVD process and flowing a gas source of silicon and a gas source of oxygen to form said silicon oxide layer;b) performing a second step performed for a second time period to form an oxide/oxynitride transition layer at the following conditions: using a PECVD process and flowing a silicon gas source, an oxygen gas source and a nitrogen gas source of where said nitrogen gas source is gradually increased during said second step;c) performing a third step for a third time period to form a oxynitride layer at the following conditions: using a PECVD process and flowing a silicon gas source and an oxygen gas source and a nitrogen gas source; so that said oxynitride layer has a molar composition of Nitrogen between 30 and 36%, oxygen between 30 and 36%; and Si between 30 and 36%; andremoving said substrate from said plasma enhanced chemical vapor deposition (PECVD) chamber.