Browse Prior Art Database

Etched Thick Metal Structure

IP.com Disclosure Number: IPCOM000112962D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

Bausmith, RC: AUTHOR [+5]

Abstract

Disclosed is an interconnection structure for Si devices which may be produced with near micron-sized definition. The structure is fabricated (process described below) to cover a via or vias defined by openings in the passivation over the top wiring level (usually aluminum) of the circuit device. The vertical structure, from the bottom up, consists of a layer or layers of evaporated metals such as chromium, copper, or aluminum to form a thick metal layer (about 5 to 30 microns), covered by a thin layer of gold.

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

Etched Thick Metal Structure

      Disclosed is an interconnection structure for Si devices which
may be produced with near micron-sized definition.  The structure is
fabricated (process described below) to cover a via or vias defined
by openings in the passivation over the top wiring level (usually
aluminum) of the circuit device.  The vertical structure, from the
bottom up, consists of a layer or layers of evaporated metals such as
chromium, copper, or aluminum to form a thick metal layer (about 5 to
30 microns), covered by a thin layer of gold.

Process

1.  Clean surface

2.  Blanket evaporate metals

3.  Spin on, pattern photoresist

4.  Etch through gold layer with ion beam

5.  Etch through remaining metals with anisotropic RIE

6.  Strip resist

Applications:

1.  Bonding structure for package/silicon interconnection

2.  Power supply busbar on device

3.  Engineering change on device, e.g. conversion of an area array
    pattern to peripheral pattern, or rerouting of an interconnection

      The Figure shows a Power Supply Busbar.  For some devices,
internal rows of I/Os are provided for power and ground.  A center
line busbar may be used to connect these internal pads to a
peripheral pad.  The busbar is made of the etched thick metal
structure.