Browse Prior Art Database

Dual-Image Resist for Single-Exposure Self-Aligned Processing

IP.com Disclosure Number: IPCOM000101311D
Original Publication Date: 1990-Jul-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 3 page(s) / 98K

Publishing Venue

IBM

Related People

Greco, SE: AUTHOR [+2]

Abstract

This article describes a resist system having a wet developable first image and a dry developable second image (based on silicon incorporation through a silylation step). A novel material/process approach is described which simplifies device fabrication through self-aligned dual-image lithography.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Dual-Image Resist for Single-Exposure Self-Aligned Processing

       This article describes a resist system having a wet
developable first image and a dry developable second image (based on
silicon incorporation through a silylation step). A novel
material/process approach is described which simplifies device
fabrication through self-aligned dual-image lithography.

      Dual-tone resists (positive or negative working depending upon
the choice of wavelength and developer) are useful to a degree for
self- aligned processes where elements of two separate patterns are
to be placed on a substrate in a single masking step and developed
out separately.  They are limited in use, however, since the resist
must survive the first process unaffected in order to allow the
subsequent development of the second latent image and completion of
the second process.  Where the first process is a harsh one, such as
metal RIE (reactive ion etch), the effects of ion and electron
bombardment, UV radiation, heat, polymer deposition, etc., act to
prevent proper delineation of the second image, i.e., development of
the second latent image.  The technique here disclosed is capable of
high resolution imaging, successfully overcoming the prior noted
difficulties while achieving the objective of sequentially
delineating, on a wafer, two separate self-aligned patterns from a
single mask exposure.

      The material used for resist is one which, when exposed to
radiation of wavelength g1, acts as a positive working, wet
developing resist and, when exposed to radiation of wavelength g2,
acts as a positive working, dry developing (developed by oxygen
plasma) resist.  One mask containing the elements of two patterns is
used, where a first pattern (p1) is defined by areas which transmit
the wavelength g1, and the second, (p2), is defined by areas which
transmit the wavelength 2, or some combination of g1 and g2.  The
disclosed dual-imaging technique is illustrated by Figs. 1 - 5, wh...