Browse Prior Art Database

Method for Reducing Aspect Ratio of Open Geometries

IP.com Disclosure Number: IPCOM000122686D
Original Publication Date: 1991-Dec-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 2 page(s) / 73K

Publishing Venue

IBM

Related People

Brophy, DJ: AUTHOR [+4]

Abstract

This article describes a process which will uniformly reduce the horizontal dimensions of holes or other geometries etched in conductive substrates has become a high demand in areas that process stencils such as screening and evaporation masks. In such processes, future requirements for denser patterns with smaller image sizes is demanding a technology which can produce opened images with width dimensions which are less than the thickness of the substrate. This is impossible with a wet etch process commonly used in making masks, thus the need for a process such as the one proposed in this report.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 67% of the total text.

Method for Reducing Aspect Ratio of Open Geometries

      This article describes a process which will uniformly
reduce the horizontal dimensions of holes or other geometries etched
in conductive substrates has become a high demand in areas that
process stencils such as screening and evaporation masks.  In such
processes, future requirements for denser patterns with smaller image
sizes is demanding a technology which can produce opened images with
width dimensions which are less than the thickness of the substrate.
This is impossible with a wet etch process commonly used in making
masks, thus the need for a process such as the one proposed in this
report.

      As can be seen in Fig. 1, a two-sided photolithographic process
is used to form aligned resist images on both sides of a metallic or
otherwise conductive substrate.  The open areas in the resist, which
will become the images in the stencil, expose the surface of the
substrate to the etchant which attacks from both sides.  As noted in
Fig.  2, when the wet etching is complete, the resist images are
undercut, causing the substrate openings to be larger than the resist
openings.

      In the proposed process, the resist would not be removed just
yet.  First, a plating process (electro- or electro-less) would be
performed to fill in the undercut vertical walls of the substrate
images until they match the dimensions of the resist images.  This
can be seen in Fig. 3.  The plated material could be simila...