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Potentiometric Test for Metallurgy Strata

IP.com Disclosure Number: IPCOM000085180D
Original Publication Date: 1976-Mar-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Bendz, DJ: AUTHOR

Abstract

Packages designed to incorporate semiconductor devices often make use of multilayer metallurgies such as, for example, a layer for adhesion and a layer for conductivity. These metallurgies can be evaporated or plated usually as blankets and can then be photoprocessed and etched to provide the required circuitry.

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Potentiometric Test for Metallurgy Strata

Packages designed to incorporate semiconductor devices often make use of multilayer metallurgies such as, for example, a layer for adhesion and a layer for conductivity. These metallurgies can be evaporated or plated usually as blankets and can then be photoprocessed and etched to provide the required circuitry.

The present test, when performed after metal deposition, will function to determine the resistance to unwanted chemical attack by the photo-process and etch chemicals. Thus, samples which are least resistant can be screened out and treated, if possible, before time and resources are wasted on processing potential failures. In addition, other information useful during subsequent processing can be obtained.

The metallurgy 10 which, for example, may comprise chrome-copper-chrome on ceramic is attached to a potentiometer 11 as an electrode of a working cell 12 with calomel or platinum as the reference electrode 13. The solution 14 in the cell which, for illustrative purposes is 40% H Cl, is chosen to contain a specific corrosive species which may be present in normal processing chemicals. A recorder 15 is hooked up to the potentiometer 11. The changing potential of the metallurgy electrode 10 is recorded as a function of time.

Curves can then be interpreted as an indication of resistance to attack by that species. Time limits can be established from a data base and all runs falling within certain limits can be normally processed. Highly resistant lots can be recommended for repeated reworks and less resistant r...