Patent ID: 6239025
Filing Date: 2001-05-29
Classification: H01L

Abstract:
A method for making contact structures in an integrated circuit comprising the steps of:a) providing at least a portion of a first horizontal conductive or semiconductive layer;b) providing a first electrically insulating layer over the first horizontal conductive or semiconductive layer;c) in a location chosen for the formation of a contact structure:isotropically etching the first electrically insulating layer in order to provide an excavation of a first diameter penetrating only an upper portion of the first electrically insulating layer; andanisotropically etching, concentrically with the excavation, a substantially vertical hole of a second diameter through the first electrically insulating layer to expose a part of the first horizontal conductive or semiconductive layer; the second diameter being inferior to the first diameter;d) filling the contact hole with a conductive material in order to provide a first conductive member in electrical contact with the part of the first horizontal conductive or semiconductive layer, and having an upper surface substantially coplanar with an upper surface of the first electrically insulating layer;e) applying a second electrically insulating layer over the upper surfaces of the first conductive member and the first electrically insulating layer;g) anisotropically etching an opening through the second electrically insulating layer in order to expose a portion of the upper surface of the first conductive member;h) filling the opening through the second electrically insulating layer with a conductive material in order to form a second conductive member therein; andi) providing a portion of a second horizontal electrically conductive layer in electrical contact with an upper surface of the second conductive member.