Browse Prior Art Database

L1 And V1 Stud Metal Rework Procedure (Filament Fail)

IP.com Disclosure Number: IPCOM000103290D
Original Publication Date: 1990-Sep-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 63K

Publishing Venue

IBM

Related People

Anzivina, N: AUTHOR [+5]

Abstract

Disclosed is a method for reworking metal studs when a system fails during stud metal evaporation.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 59% of the total text.

L1 And V1 Stud Metal Rework Procedure (Filament Fail)

      Disclosed is a method for reworking metal studs when a system
fails during stud metal evaporation.

      A number of VLSI chip sets use metal studs to form
interconnects through the insulator between wiring levels. The studs
are deposited using evaporated Al/Cu and defined using lift-off
resist technology.  An in-situ rf sputter clean is done prior to the
stud deposition to clean off any native oxide on the underlying
metal.  Resistance data from stud interconnects and physical analysis
show the process is repeatable and free of any continuous interfacial
film between the stud and the underlying metal land.

      If a system fail occurred during stud metal evaporation, the
previous approach was to vent the system and transfer the wafers to a
working tool.  An in-situ sputter clean was then performed to remove
any native oxide grown during the transfer, and deposition was
completed. This process often resulted in a continuous resistive
interfacial film of aluminum oxide at the rework point. This was
particularly evident on isolated studs, the most sensitive.  The
cause for this interface is believed to be resist outgassing driven
by the heat generated during sputter clean.  Due to the impermeable
metal coating, gases are vented only through the stud openings in the
resist. This is opposed to the situation prior to any metal
deposition where gasses can evolve over the entire resist/wafer
surface. ...