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Avoidance of Sputtering Redeposition, Especially in Tapered Via Holes

IP.com Disclosure Number: IPCOM000103087D
Original Publication Date: 1990-Jun-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 31K

Publishing Venue

IBM

Related People

Daubenspeck, TH: AUTHOR [+4]

Abstract

Whenever inert ion bombardment (sputtering) is used to reshape or clean a silicon dioxide (SiO2) surface of an integrated circuit and redeposition of sputtered SiO2 must be avoided, a fluorinated gas, e.g., NF3, is added to the usual inert sputtering gas. Thus, redeposition of SiO2, e.g., from tapered via hole walls onto exposed conductive surfaces at the bottom of the holes, is avoided.

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Avoidance of Sputtering Redeposition, Especially in Tapered Via Holes

      Whenever inert ion bombardment (sputtering) is used to reshape
or clean a silicon dioxide (SiO2) surface of an integrated circuit
and redeposition of sputtered SiO2 must be avoided, a fluorinated
gas, e.g., NF3, is added to the usual inert sputtering gas.  Thus,
redeposition of SiO2, e.g., from tapered via hole walls onto exposed
conductive surfaces at the bottom of the holes, is avoided.

      Referring to the figure, a tapered via hole in an insulating
material 2, e.g., silicon dioxide (SiO2), exposing a region d of
conductor 4 on substrate 6 exists at a time when sputtering is to be
used for a reshaping or cleaning process.  To avoid redeposition of
material 2, especially from the tapered sidewalls of the via hole,
onto metal 4 in region d, a fluorinated gas, e.g., NF3, is added to
the usual inert sputtering gas.

      Disclosed anonymously.