Browse Prior Art Database

Very High Temperature Lift-Off Stencil

IP.com Disclosure Number: IPCOM000101863D
Original Publication Date: 1990-Sep-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Baratte, H: AUTHOR [+7]

Abstract

The use of organic/photoresist lift-off stencils has typically limited to processing temperatures less than 150oC. In organic systems taken over 250oC, the thermal crosslinking renders the polymer almost completely unstrippable by solvents.

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

Very High Temperature Lift-Off Stencil

       The use of organic/photoresist lift-off stencils has
typically limited to processing temperatures less than 150oC.  In
organic systems taken over 250oC, the thermal crosslinking renders
the polymer almost completely unstrippable by solvents.

      This invention describes an inorganic lift-off stencil
comprised of two layers deposited upon a GaAs wafer.  The bottom
layer is gallium oxide (Ga2O3) reactively deposited, and the top
layer is Plasma Enhanced Chemical Vapor Deposited (PECVD) silicon
nitride (Si3N4).  The Si3N4 is etched through to the Ga2O3, using the
photoresist as a mask, in a Reactive Ion Etching (RIE) system.  The
Ga2O3 acts as an etch stop.  The patterned nitride acts as a mask for
the etching of the underlying Ga2O3 .  The overetch produces an
undercut profile which is suitable for lift-off. The wafer is then
stripped of all organics and sent for lift-off (see the figure).