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Alkaline Etch Solutions for Chromium Compatible with Positive Resists

IP.com Disclosure Number: IPCOM000079586D
Original Publication Date: 1973-Jul-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Bendz, DJ: AUTHOR [+4]

Abstract

This solution advantageously etches chromium at the rate of 200 Angstroms /min. at 50 Degrees C and is compatible with positive resists, including unbaked AZ-1350H* partially exposed or unexposed. It is capable of fine resolution with other known alkaline chrome etchants.

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Alkaline Etch Solutions for Chromium Compatible with Positive Resists

This solution advantageously etches chromium at the rate of 200 Angstroms /min. at 50 Degrees C and is compatible with positive resists, including unbaked AZ-1350H* partially exposed or unexposed. It is capable of fine resolution with other known alkaline chrome etchants.

The formulation having these characteristics for immersion etching is an aqueous solution of 65 g. KMnO(4) and 260 g. of Na(2)CO(8) per liter of etchant.

e general formulation consists of an oxidizing agent (such as KMnO(4), K(2)Fe(CN)(6), etc.) and an alkaline earth carbonate (such as Na(2)CO(3), K(2)O(3) etc.) dissolved in water. The etch rate may be adjusted by varying the concentrations of oxidizing agent and/or carbonate, by varying the etchant temperature, or by varying the means of etching (immersion, spraying, etc.)

The etchant is also effective in etching other refractory metals such as molybdenum.

The specific advantages of the solution are: compatibility with positive resists, high resolution and rate, and alkalinine compatibility to the oxidation rate of the metal being etched. * Trademark of Shipley Company, Inc.

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