Browse Prior Art Database

Fabrication of an Evaporation Mask

IP.com Disclosure Number: IPCOM000074525D
Original Publication Date: 1971-May-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Koste, WW: AUTHOR [+2]

Abstract

A stepped hole evaporation mask is formed using an electron beam cutter and chemical milling.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Fabrication of an Evaporation Mask

A stepped hole evaporation mask is formed using an electron beam cutter and chemical milling.

A 1 mil layer of chromium is plated on one side of a 3 mil thick molybdenum sheet. An electron beam cutter is used to cut 3 mil diameter holes through the chromium-molybdenum composite. A potassium ferricyanide solution comprising 300 g/liter potassium ferricyanide K(3)F(e)(CN)(6); and 100 g/liter potassium hydroxide @ 150 degrees F to 180 degrees F is used to selectively etch the molybdenum layer at the holes. For example, the molybdenum holes 1 can be opened to 6 mil diameter while reducing the thickness of the molybdenum layer 2 by only 0.2 mil and leaving the chromium layer 3 and the holes 4 unaffected.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]