Browse Prior Art Database

Reduction of Oxide Seam in Metal Going Over Steep Topography

IP.com Disclosure Number: IPCOM000037747D
Original Publication Date: 1989-Jun-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Dolgov, I: AUTHOR [+3]

Abstract

This method minimizes defects associated with the formation of a metal oxide seam where metal is deposited over steps in the production of semiconductor devices. This modification of the process interrupts metal deposition and employs Hf gettering to remove unwanted O2 from the metal tool.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 98% of the total text.

Page 1 of 1

Reduction of Oxide Seam in Metal Going Over Steep Topography

This method minimizes defects associated with the formation of a metal oxide seam where metal is deposited over steps in the production of semiconductor devices. This modification of the process interrupts metal deposition and employs Hf gettering to remove unwanted O2 from the metal tool.

In the processing of semiconductor devices adequate metal coverage is difficult to achieve over steps and/or topography since the thickness of the as- deposited metal tends to be thinner at such steps as compared to flat areas. Additionally, a metal oxide seam at the steps can manifest itself as an open in extreme conditions. This occurs because of the high oxide content or the etching of the oxide during subsequent processing.

Processing under very clean vacuum conditions helps to curtail development of the seam. This is difficult to insure in a manufacturing environment. Also, clean metal in proximity to the masterslice may increase susceptibility to metal penetration.

With this process, formation of the oxide seam is minimized by interruption in the metal evaporation process. Following the deposition of a thin layer of metal, evaporation is stopped and Hf gettering takes place for approximately 5 min. Evaporation is then resumed to complete the process step. This cleaning step yields a cleaner metal following interruption and hence a smaller oxide seam. Titanium gettering may also be used to achieve the same result...