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Image Reversal of Positive Photoresist Without Additives

IP.com Disclosure Number: IPCOM000060086D
Original Publication Date: 1986-Feb-01
Included in the Prior Art Database: 2005-Mar-08
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Feinberg, GM: AUTHOR [+4]

Abstract

A unique set of processing conditions is used to obtain a negative resist image from a positive resist without the use of resist additives.

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Image Reversal of Positive Photoresist Without Additives

A unique set of processing conditions is used to obtain a negative resist image from a positive resist without the use of resist additives.

Image reversal is obtained by exposing the resist to an image in a warm (70 to 90 degrees Celsius), dry (<1% relative humidity) environment. After image exposure, the resist is blanket exposed at room temperature in an ambient having >30% relative humidity and developed in the conventional manner using a dilute aqueous alkali developer.

The following is a specific process sequence from which good reversal images are obtained : 1. Apply and dry positive resist on a silicon wafer at 75 degrees Celsius for 5 minutes. 2. While maintaining the temperature at 75 degrees in a dry nitrogen (N2) atmosphere, image expose the resist. 3. Change the environment of the wafer to room temperature air having relative humidity of 30% or greater and blanket expose the resist. 4. Develop the resist using an aqueous solution of 15 grams/ liter sodium metasilicate pentahydrate.

Disclosed anonymously.

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