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Thin Film Sandwich Memory Array

IP.com Disclosure Number: IPCOM000097421D
Original Publication Date: 1962-Nov-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Stevens, RG: AUTHOR

Abstract

This process is for the electrochemical preparation of a thin film sandwich memory array. Previously, the photo resist process removed all the evaporated nickel conductive layer on a memory board, leaving only the dots which made up the array. In order to build up the thickness of these dots or make a sandwich type film, the deposition of an additional evaporated nickel layer was necessary before another layer could be plated on it.

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Thin Film Sandwich Memory Array

This process is for the electrochemical preparation of a thin film sandwich memory array. Previously, the photo resist process removed all the evaporated nickel conductive layer on a memory board, leaving only the dots which made up the array. In order to build up the thickness of these dots or make a sandwich type film, the deposition of an additional evaporated nickel layer was necessary before another layer could be plated on it.

In this process, electrolessly deposited nickel is used as a conductive layer instead of evaporated nickel. Since the electroless nickel is not removed by standard photo resist techniques, any number of additional layers can be plated until a desired dot thickness is formed. Thus, it is possible either to tailor individual dots to a specific switching time or to prepare layers of different types of magnetic material for sandwich type films.

The specific procedure used is as follows:
1. Electrolessly deposit a nickel film of desired thickness on a

glass plate.
2. Electroplate an iron nickel film onto the substrate with the

electrolessly deposited nickel film.
3. Photo-etch the desired array pattern using ferric chloride

1 FeCl(3). 6H(2)O to 1 H(2)O) to remove the excess nickel iron

film. Thus, a pattern of nickel iron dots and a background

of conductive electroless nickel remains. This is possible

because the electroless nickel is not affected by the ferric

chloride etch.
4. The substrate can then be sub...