Patent ID: 6455403
Filing Date: 2002-09-24
Classification: H01L

Abstract:
A method of fabricating a Schottky diode in an integrated circuit device comprising:providing a thermal oxide layer overlying a silicon substrate; depositing an insulating layer overlying said thermal oxide layer; etching a contact opening through said insulating layer and said thermal oxide layer to said silicon substrate; overetching said contact opening for between 45 and 50 seconds after an endpoint etching signal is received whereby a shallow trench is formed within said silicon substrate underlying said contact opening wherein said shallow trench has a bottom and sidewalls comprising said silicon substrate and wherein said shallow trench has a depth of between 300 and 500 Angstroms into said silicon substrate; thereafter reflowing said insulating layer thereby forming curved sidewalls of said contact opening; depositing a first metal layer over said insulating layer and within said contact opening and within said shallow trench; sintering said first metal layer whereby said first metal layer is transformed to a silicide layer where said silicide layer contacts said silicon substrate at said bottom and said sidewalls of said shallow trench and wherein said first metal layer contacting said insulating layer and said thermal oxide layer is not transformed; removing said first metal layer that is not transformed to a silicide layer; thereafter removing native oxide on said silicide layer whereby a portion of said thermal oxide layer is removed and wherein contact is not broken between said thermal oxide layer and said silicide layer at said sidewalls of said trench thereby preventing leakage; thereafter depositing a barrier metal layer overlying said insulating layer and said silicide layer within said shallow trench wherein said barrier metal layer contacts said silicide layer at bottom and sidewall surfaces of said shallow trench; and depositing a second metal layer overlying said barrier metal layer to complete fabrication of said Schottky diode in said integrated circuit device.