Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Single Layer Lift-off Stencil Semiconductor Wafer Process

IP.com Disclosure Number: IPCOM000109949D
Original Publication Date: 1992-Sep-01
Included in the Prior Art Database: 2005-Mar-25
Document File: 1 page(s) / 35K

Publishing Venue

IBM

Related People

Flagello, DG: AUTHOR [+3]

Abstract

A technique is described whereby a single layer lift-off stencil is implemented in the fabrication of semiconductor wafer circuits so as to provide; a) stability at high temperatures, b) high gamma for greater process latitude and c) simpler process controls.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Single Layer Lift-off Stencil Semiconductor Wafer Process

      A technique is described whereby a single layer lift-off
stencil is implemented in the fabrication of semiconductor wafer
circuits so as to provide; a) stability at high temperatures, b) high
gamma for greater process latitude and c) simpler process controls.

      The single layer lift-off stencil is made of a mixture of
AZ5214 (Product of The American Hoechst Corporation) which can act as
a positive or negative resist (used in negative mode) and Kodak 418
dye to create a suitable lift-off profile.  The dye, which absorbs at
436 nm, creates an exposure gradient as the projected image
progresses through the resist film.

      Wafers are processed as follows:
      1)   A mixture of AZ5214 and approximately 0.5 - 1.0% (w/w)
Kodak 418 dye is spin-coated on a substrate.
      2)   The wafer is soft-baked on a vacuum hot plate at 90~C for
60 sec.
      3)   A pattern is exposed and the wafer is then given a
post-exposure bake on a vacuum hot plate at 130~C for 60 sec.  This
causes an image reversal into an extremely high gamma, negative
resist.
      4)   The wafer is then flood exposed, using an ultra-violet
source, to decrease develop end point time.
      5)   The pattern is developed in AZ327 developer.

      Disclosed anonymously.