Browse Prior Art Database

Tdb 11-83 P.2688-2689 Resist Process Mask

IP.com Disclosure Number: IPCOM000047326D
Original Publication Date: 1983-Nov-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 27K

Publishing Venue

IBM

Related People

Gillespie, SJ: AUTHOR

Abstract

This article describes a technique for making a single layer resist mask which is insensitive to the topography of the underlying material. It uses two resist layers which have different etching characteristics. After the top layer is exposed and developed, the bottom layer is totally etched away, leaving the top imaging layer directly on the surface of the substrate. While double-layer resists have been used before to fabricate undercut profiles for lift-off processes, they have not been used in a process which requires that the lower resist layer be completely removed after imaging to make a dimensionally controlled mask in contact with the substrate. Figs. 1 and 2 illustrate two important steps of the described technique. In Fig.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 71% of the total text.

Page 1 of 2

Tdb 11-83 P.2688-2689 Resist Process Mask

This article describes a technique for making a single layer resist mask which is insensitive to the topography of the underlying material. It uses two resist layers which have different etching characteristics. After the top layer is exposed and developed, the bottom layer is totally etched away, leaving the top imaging layer directly on the surface of the substrate. While double-layer resists have been used before to fabricate undercut profiles for lift-off processes, they have not been used in a process which requires that the lower resist layer be completely removed after imaging to make a dimensionally controlled mask in contact with the substrate. Figs. 1 and 2 illustrate two important steps of the described technique. In Fig. 1, there is shown a substrate 10 which is characterized by a nonplanar surface which needs to be masked. A layer of PBS (polybutene-1 sulfone) 12, or an equivalent low-etch resistant material, is spin-coated on the substrate to planarize it. A layer of another resist, such as positive diazo novolak or any other material that is compatible with PBS and has a high contrast and high-etch resistance, is spin-coated on the PBS layer. This upper layer is then exposed and developed followed by the usual hardening and post baking process steps. Thus, imaged upper layer 14 is formed on a planar surface. Fig. 2 shows the structure of Fig. 1 after the PBS layer was completely etched away. This can be don...