Accession Number : ADD018448

Title :   Sidewall Passivation by Oxidation during Refractory-Metal Plasma Etching.

Descriptive Note : Patent, Filed 14 Apr 95, patented 19 Nov 96,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Kosakowski, John ; Chu, William ; Foster, Kelly W ; Marrian, Christie R ; Peckerar, Martin C

Report Date : 19 Nov 1996

Pagination or Media Count : 7

Abstract : Sidewalls in a pattern of a refractory metal on a substrate are passivated during plasma etching by introducing water vapor into the etching chamber. This process obtains nearly vertical sidewalls. In one exemplified embodiment, a pattern of tungsten on a chromium etch step layer was reactive ion etched. In that embodiment, the reactive ion etching was intermittently paused. After each pause, the workpiece was warmed from below about 20 deg C. to about room temperature. Then, water vapor was introduced into the etching chamber housing the workpiece. After the water vapor was introduced, the workpiece was cooled to below about 20 deg C. and reactive ion etching was resumed. Alternatively. water vapor can be introduced into the etching chamber continuously during plasma etching.

Descriptors :   *REFRACTORY METALS, *PRINTED CIRCUITS, *PATENTS, PLASMAS(PHYSICS), SUBSTRATES, ETCHING, CIRCUIT INTERCONNECTIONS, CHROMIUM, TUNGSTEN, CHAMBERS, WATER VAPOR, PASSIVITY

Subject Categories : Electrical and Electronic Equipment
      Metallurgy and Metallography
      Mfg & Industrial Eng & Control of Product Sys

Distribution Statement : APPROVED FOR PUBLIC RELEASE