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Integrated Circuit Fabrication Involving Projection Exposure of Photoresist

IP.com Disclosure Number: IPCOM000082606D
Original Publication Date: 1975-Jan-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Feng, BC: AUTHOR [+2]

Abstract

In the fabrication of integrated circuits utilizing conventional photolithographic methods, KTFR* has been one of the standard photoresists in the art. In conventional practice, the KTFR coating on the substrate has been used in contact exposure, where the KTFR coating is in direct contact with a covering mask during exposure.

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Integrated Circuit Fabrication Involving Projection Exposure of Photoresist

In the fabrication of integrated circuits utilizing conventional photolithographic methods, KTFR* has been one of the standard photoresists in the art. In conventional practice, the KTFR coating on the substrate has been used in contact exposure, where the KTFR coating is in direct contact with a covering mask during exposure.

At the present time, the integrated circuit fabrication art is moving towards projection exposure in place of contact exposure. Thus, a projected image rather than a contact mask is at the KTFR surface during exposure. With such a projected image, oxygen in the air which is now in contact with the surface during exposure may affect the coating.

This affect may be avoided if prior to exposure, the KTFR layer is coated with a protective layer of plastic material such as a phenolformaldyhyde resin. Such a coating may be formed by dissolving the resin in a suitable solvent, such as cellusolve acetate or acetone, and depositing over the KTFR coating after the standard KTFR prebake.

The structure is then given an additional short bake at a temperature of from 60 to 100 degrees C to form a continuous resin film over the KTFR. Then, the photoresist is used in projection exposure in the standard manner. This protective coating protects the KTFR from the affects of oxygen in the air, and in no way adversely affects the performance of the KTFR coating. * Trademark of Eastman K...