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Browse Prior Art Database

Alternative Method for Stripping Dry Film Photoresists

IP.com Disclosure Number: IPCOM000108900D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 1 page(s) / 45K

Publishing Venue

IBM

Related People

Graham, T: AUTHOR [+3]

Abstract

Laminated dry film photoresists are used to define conductor patterns, plating terminal contact pads and joining metallurgies on microelectronic device and packaging applications. One of the problems associated with this class of resists is the need to use stripping solutions which have high basicity (high pH) and tend to attack the plated metal patterns and the back side of silicon wafers. Further, they are also potential sources of ionic contamination into the underlying dielectric layers. Some of the less aggressive stripping solutions used to alleviate these problems tend to leave undesirable residues on the part surface which can interfere with subsequent process steps such as seed layer etching. An alternate stripping methodology that utilizes a non-aqueous medium to strip these resists is disclosed herein.

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Alternative Method for Stripping Dry Film Photoresists

      Laminated dry film photoresists are used to define conductor
patterns, plating terminal contact pads and joining metallurgies on
microelectronic device and packaging applications.  One of the
problems associated with this class of resists is the need to use
stripping solutions which have high basicity (high pH) and tend to
attack the plated metal patterns and the back side of silicon wafers.
Further, they are also potential sources of ionic contamination into
the underlying dielectric layers.  Some of the less aggressive
stripping solutions used to alleviate these problems tend to leave
undesirable residues on the part surface which can interfere with
subsequent process steps such as seed layer etching.  An alternate
stripping methodology that utilizes a non-aqueous medium to strip
these resists is disclosed herein.  The method uses alcohols
(methanol, ethanol, isopropanol, for example) at temperatures
slightly above room temperature to achieve this end.  It appears that
these solvents get absorbed in the resist, swell it and delaminate it
from the substrate, leaving virtually no residues.  Their efficacy
can be enhanced with higher temperature/pressure operation and
spraying.  These solvents are innocuous to the commonly used
metallurgies, as well as the back surface of the silicon wafer and
are free of ionic contaminants.  Thus, all the problems associated
with the conventional alkaline aqueous dry f...