Methods for improved encapsulation of thick metal features in integrated circuit fabrication

Abstract

The present invention provides a method of manufacturing an integrated circuit having a capping layer over a thick metal feature. In one embodiment, the method comprises forming first and second oxide layers over the thick metal feature, forming a composite oxide layer including an oxide spacer by etching the first and second oxide layers, and forming a capping layer over the composite oxide layer. More specifically, forming the first oxide layer involves using a high density plasma (HDP) process, forming the second oxide layer involves using a plasma enhanced chemical vapor deposition (PECVD) process, and forming the composite oxide layer preferably involves etching with a reactive ion etch.

Dependencies are inferred from the claim text.