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Profile Improvement in E-Beam Exposed Resist Patterns

IP.com Disclosure Number: IPCOM000048963D
Original Publication Date: 1982-Apr-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Henderson, GE: AUTHOR [+3]

Abstract

Approximately vertical profiles in electron (E)-beam-exposed resist layers are achieved with a small blanket optical exposure following the patterned E-beam exposure.

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Profile Improvement in E-Beam Exposed Resist Patterns

Approximately vertical profiles in electron (E)-beam-exposed resist layers are achieved with a small blanket optical exposure following the patterned E- beam exposure.

A resist composition, which is a mixture of a phenol-formaldehyde novolak resin and 2-diazo quinone sensitizer such as the 2-diazo-1-oxonaphthalene-5- sulfuric acid ester of dihydroxybenzophenone, is coated on a substrate and exposed in selected areas with a scanning electron beam. The resist layer is then given a low dose UV blanket exposure of about 15 mJ/cm/2/. The resist layer is then partially developed in aqueous alkaline developer, rinsed, and the development completed in the alkaline developer. A positive slope results. The degree of slope and thinning of the unexposed resist layer is controlled by varying the UV exposure dosage.

Extensions to this method, to improve profile control, are:

1. Divide the blanket exposure so that there is some

exposure after each development

interrupt. This will allow more uniform exposure

as a function of depth instead of merely having

extra exposure in the top region.

2. In situ exposure as development occurs. The integral

exposure would have to be kept

suitably low to prevent thinning but could be

time-varied within this restriction to completely

tailor the profile.

In summary, a blanket, low level UV exposure after the patterned E beam exposures is used to partially or totally cancel out the effect of s...