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Method for Making Vertical Electroplating Masks

IP.com Disclosure Number: IPCOM000061908D
Original Publication Date: 1986-Jul-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Cisneroz, PE: AUTHOR [+3]

Abstract

A method is described for producing a vertical electroplating mask which is suitable for applications in which high aspect ratio depositions are required.

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This is the abbreviated version, containing approximately 85% of the total text.

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Method for Making Vertical Electroplating Masks

A method is described for producing a vertical electroplating mask which is suitable for applications in which high aspect ratio depositions are required.

The method comprises the steps of depositing a relatively thick layer of a deep ultraviolet sensitive resist on a suitable substrate, forming a layer of polymerized fluorocarbon on the deep ultraviolet photoresist layer, and depositing a relatively thin positive type photoresist layer on the polymerized fluorocarbon layer so that the polymerized layer forms a barrier l between the photoresist layers whereby uniform illumination of the deep ultraviolet photoresist layer can be obtained.

In a specific embodiment the deep ultraviolet photoresist layer comprises an alkyl methoacrylate polymer (PMMA) and the positive type photoresist comprises an AZ resist.

The desired pattern is produced by exposing the AZ resist through a mask. The AZ resist is then developed by using a developer comprising AZ developer and H20 at 1:1 ratio. This developer attacks neither the polymerized fluorocarbon layer nor the PMMA layer. Once the image of the positive photoresist is obtained, it can be used as an opaque mask during a deep ultraviolet flood exposure.

After exposure, the thick PMMA layer is developed in a solvent mixture comprising 40% by volume of acetone, 40% by volume of isopropyl alcohol, and 20% by volume of H20. This developer mixture prevents the thick PMMA layer from crack...