Browse Prior Art Database

Metallic Mask Fabrication

IP.com Disclosure Number: IPCOM000075675D
Original Publication Date: 1971-Oct-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Kleinfelder, WJ: AUTHOR [+2]

Abstract

Metallic mask fabrication is improved by ion bombardment of the metal in discrete areas, to permit differential etching of the metal with good edge definition of the remaining metal.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 68% of the total text.

Page 1 of 1

Metallic Mask Fabrication

Metallic mask fabrication is improved by ion bombardment of the metal in discrete areas, to permit differential etching of the metal with good edge definition of the remaining metal.

Metal film photolithographic masks are fabricated by sputtering, evaporating, or pyrolytically depositing a metal, typically molybdenum, aluminum, chrome, or the like, on a transparent substrate, typically glass plates or other transparent material. When molybdenum, as an example, is deposited on the substrate, the deposited film has a relatively high-residual stress. As a result, the film of molybdenum is more vulnerable to an attack by an etching agent. When the molybdenum field is bombarded by high-energy ions, typically no lighter than helium and no heavier than argon, although ions of a lighter or heavier mass could conceivably be employed, the residual stress of the deposited molybdenum film is reduced. The substantial decrease in the residual stress improves the resistance of the molybdenum to the etching agent.

In one example, molybdenum is deposited on a silicon dioxide covered wafer to a thickness of 3000 to 7000 Angstroms. An ion beam stopping plate is disposed between an ion beam source and the metallized substrate. The stopping plate is of appropriate material, typically molybdenum, suitable for stopping the ion beam employed. The stopping plate is also formed in the shape of a desired mask pattern . The molybdenum exposed through the stopping p...