Browse Prior Art Database

In Situ Evaporation of Chrome, Copper Doped Aluminum and Silicon

IP.com Disclosure Number: IPCOM000087087D
Original Publication Date: 1976-Dec-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Dahlke, GP: AUTHOR [+4]

Abstract

Cr-Al/Cu-Si may be evaporated atop a semiconductor substrate through an underlay stencil consisting of a composite of photoresist, and a thin layer of organosilicate glass. The glass has a slight overhang which prevents the evaporant from building up against the photoresist patterns. Evaporant build-up tends to form spikes on the metal land causing interlevel shorts, and tunnelling in through quartz during subsequent opening of via holes. When using a two-step process, the thermal cycling and the intrinsic stress of the Cr film cause the underlay glass to curl and crack, which eliminates the protective overhang. This causes the Al/Cu-Si to build up on the side of the photoresist stencil.

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

Page 1 of 1

In Situ Evaporation of Chrome, Copper Doped Aluminum and Silicon

Cr-Al/Cu-Si may be evaporated atop a semiconductor substrate through an underlay stencil consisting of a composite of photoresist, and a thin layer of organosilicate glass. The glass has a slight overhang which prevents the evaporant from building up against the photoresist patterns. Evaporant build-up tends to form spikes on the metal land causing interlevel shorts, and tunnelling in through quartz during subsequent opening of via holes. When using a two-step process, the thermal cycling and the intrinsic stress of the Cr film cause the underlay glass to curl and crack, which eliminates the protective overhang. This causes the Al/Cu-Si to build up on the side of the photoresist stencil.

This problem is eliminated when the three films Cr, Al/Cu, Si are deposited in a single pump-down by the use of an evaporation beam turret source. By depositing the three layers at a constant temperature, the thermal cycling is eliminated and the intrinsic stress is reduced considerably.

A pure Cr slug, which is heliarc-melted and then machined to the E-gun heart dimensions, is used. By using a beam sweep and the machined slug, pinhole- and particle-free Cr is formed.

1