Browse Prior Art Database

Embedded Etch Mask Process

IP.com Disclosure Number: IPCOM000101320D
Original Publication Date: 1990-Jul-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 45K

Publishing Venue

IBM

Related People

Guthrie, WH: AUTHOR [+3]

Abstract

To create an embedded mask without creating problems with an underlying organic film, photoresist used to define the mask is stripped before any of the underlying organic film is exposed by the mask etching process.

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This is the abbreviated version, containing approximately 92% of the total text.

Embedded Etch Mask Process

       To create an embedded mask without creating problems with
an underlying organic film, photoresist used to define the mask is
stripped before any of the underlying organic film is exposed by the
mask etching process.

      Referring to Fig. 1, to define a mask eventually to be used for
etching a via hole to substrate 2 through polyimide 4, oxide (SiO2)
film 6 and nitride (Si3N4) film 8 are deposited, and photoresist 10
is then used to define the hole.  A selective etching process is used
to remove the exposed portion of nitride 8.  Photoresist 10 is then
stripped and the region of oxide film 6 not protected by nitride is
then selectively etched away without attacking or otherwise causing
deterioration of polyimide 4.

      Referring to Fig. 2, polyimide 12 is applied and a final oxide
masking layer 14 is deposited.  Photoresist (not shown) is used to
define a wiring pattern in polyimide 12 by first etching away exposed
oxide 14.  Then an oxygen reactive ion etching process is used to
etch away polyimide 12 not protected by oxide 14 and continuing to
etch exposed polyimide 4 through to substrate 2 as shown.  All of the
photoresist used to define the upper wiring pattern is removed in the
etching process.  Conventional processing is then resumed to create
the stud connection to substate 2 and conductive wiring in the upper
level.

      Though it is possible to use a thicker single material for the
buried masking layer...