Browse Prior Art Database

Improved Cleaning Method to Remove Sputter Byproducts

IP.com Disclosure Number: IPCOM000037546D
Original Publication Date: 1989-Mar-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Sperlazza, JA: AUTHOR

Abstract

Prior to the deposition of terminal metallurgy, an energetic pre-clean is needed to remove metal oxides and residual organics from the underlying aluminum device interconnection metallurgy. This insures low contact resistance between the terminal metallurgy and the aluminum. The pre-clean process is an argon sputter clean under an RF power supply. As this sputter process is indiscriminate as to the atoms removed, the sputter tool gradually accumulates complex byproducts in its chamber. In particular, metal residues from the terminal metallurgy tooling fixtures and carbon residues from the organic passivation on the wafer. Once the accumulated byproducts reach a certain level, the pre-clean process conditions are altered and the required contact resistance cannot be maintained. At this point, the tool must be cleaned.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Improved Cleaning Method to Remove Sputter Byproducts

Prior to the deposition of terminal metallurgy, an energetic pre-clean is needed to remove metal oxides and residual organics from the underlying aluminum device interconnection metallurgy. This insures low contact resistance between the terminal metallurgy and the aluminum. The pre-clean process is an argon sputter clean under an RF power supply. As this sputter process is indiscriminate as to the atoms removed, the sputter tool gradually accumulates complex byproducts in its chamber. In particular, metal residues from the terminal metallurgy tooling fixtures and carbon residues from the organic passivation on the wafer. Once the accumulated byproducts reach a certain level, the pre-clean process conditions are altered and the required contact resistance cannot be maintained. At this point, the tool must be cleaned. In the past, this was done by disassembling the tool and manually scrubbing to remove the accumulated metal/ carbon buildup.

This article discloses an improved cleaning method which eliminates the manual scrubbing for cleaning the chamber. By operating the tool with a gas mixture of argon (flow rate = 140/sccm) and carbon tetrafluoride (20 sccm) at a power level of 800 - 1000 watts for 20 to 30 minutes, the sputter byproducts are removed. The method not only saves time (1/2 hour versus 8 hours), but also eliminates the need to disassemble the tool to clean it.

Disclosed anonymously.

1