Browse Prior Art Database

Method to Control Dishing in Chemical-Mechanical Polishing

IP.com Disclosure Number: IPCOM000101870D
Original Publication Date: 1990-Sep-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Chu, SF: AUTHOR [+4]

Abstract

By means of strategically placed etch stop layers, dishing in large area features during chemical-mechanical polishing (CMP) is prevented. Forming conductive line patterns by etching channels in an insulating substrate, conformally depositing a relatively soft conductor, polishing and, thus removing, upper level conductor is the process used as an example.

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Method to Control Dishing in Chemical-Mechanical Polishing

       By means of strategically placed etch stop layers,
dishing in large area features during chemical-mechanical polishing
(CMP) is prevented.  Forming conductive line patterns by etching
channels in an insulating substrate, conformally depositing a
relatively soft conductor, polishing and, thus removing, upper level
conductor is the process used as an example.

      Referring to Fig. 1, insulating substrate 2 is first etched to
form channels in a pattern desired for wiring. Nucleation layer 4 is
deposited on all horizontal features by a directional process, e.g.,
ion beam deposition. Conductive layer 6 is then conformally
deposited.  Etch stop layer 8 is next deposited on horizontal
features by a directional process.

      Referring next to Fig. 2, a material, such as photoresist 10,
is applied and then removed from elevated topography by an
anisotropic etch to expose the etch stop material 8 on the elevated
regions.  Exposed etch stop material 8 is then selectively removed
and remaining photoresist 10 is stripped away.  CMP is used to remove
conductor 6 from all regions except in the channels etched in
substrate 2.  The cross section shown in Fig. 3 is thus formed
without dishing the top surface of conductor 6 (as indicated by the
dashed line) as is normally experienced in large areas.  Remaining
etch stop material 8 and nucleation material 4 may be removed by
selective etching if not desir...