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Browse Prior Art Database

Process for Etching Aluminum

IP.com Disclosure Number: IPCOM000093072D
Original Publication Date: 1967-May-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Collins, RH: AUTHOR [+2]

Abstract

A chemical reaction between the aluminum and the phosphoric-nitric acid solution, used for subetching aluminum during the fabrication of semiconductor devices, causes hydrogen bubbles to form at the aluminum surface. Due to surface and interfacial tensions, this gas is held at the water surface until the bubbles become large enough to escape. Uneven etching of the aluminum occurs because of this, resulting in either opens or shorts or both.

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Process for Etching Aluminum

A chemical reaction between the aluminum and the phosphoric-nitric acid solution, used for subetching aluminum during the fabrication of semiconductor devices, causes hydrogen bubbles to form at the aluminum surface. Due to surface and interfacial tensions, this gas is held at the water surface until the bubbles become large enough to escape. Uneven etching of the aluminum occurs because of this, resulting in either opens or shorts or both.

By having a nonionic wetting agent in a concentration of 0.01% to 2% in an etch made up of 40 parts phosphoric acid, 4 parts nitric acid. and 16 parts water, uneven etching of the aluminum does not occur.

Examples of nonionic wetting agents are polyoxyethylene, sulfonated esters and ethers. A specific nonionic wetting agent is nonyl phenoxy polyoxyethylene ethanol.

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