Browse Prior Art Database

In Situ Metal Lift-Off Structure

IP.com Disclosure Number: IPCOM000042536D
Original Publication Date: 1984-May-01
Included in the Prior Art Database: 2005-Feb-04
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Bergeron, RJ: AUTHOR [+4]

Abstract

A metal lift-off structure is disclosed having a profile in the form of an inverted trapezoid with sharp top edges. The structure is used to deposit metal films of a thickness greater than the resist structure thickness. Standard lift-off processes form a resist structure which is wide at the top, thereby developing an overhang lip of resist material. During metal evaporation, the deposited film will be discontinuous due to this overhang, and the metal on top of the resist structure may be lifted away by dissolving the underlying resist material. This type of structure, primarily due to the rounded top edges, will not permit the deposition of metal films thicker than the resist film thickness.

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 100% of the total text.

Page 1 of 2

In Situ Metal Lift-Off Structure

A metal lift-off structure is disclosed having a profile in the form of an inverted trapezoid with sharp top edges. The structure is used to deposit metal films of a thickness greater than the resist structure thickness. Standard lift-off processes form a resist structure which is wide at the top, thereby developing an overhang lip of resist material. During metal evaporation, the deposited film will be discontinuous due to this overhang, and the metal on top of the resist structure may be lifted away by dissolving the underlying resist material. This type of structure, primarily due to the rounded top edges, will not permit the deposition of metal films thicker than the resist film thickness. Referring to the figure, metal lift-off structures in the form of inverted trapezoids with sharp top edges can be formed, for example, by the modified image reversal process (MIRP). With the inverted tapezoid structure, the sidewall angle of the deposited metal at the substrate surface R1 is substantially equal to the angle at the top of the resist structure R2 . This inverted trapezoid resist structure allows the deposition of metal films greater than the thickness of the lift-off structure. This allows the use of thinner resist film, thereby conserving resist and developer material and allowing the printing of smaller lines and spaces with existing equipment and techniques.

1

Page 2 of 2

2

[This page contains 4 pictures or other non-text o...