Browse Prior Art Database

End Point Detection of Chemical/Mechanical Polishing of Circuitized Multilayer Substrates

IP.com Disclosure Number: IPCOM000121760D
Original Publication Date: 1991-Sep-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 2 page(s) / 69K

Publishing Venue

IBM

Related People

Carr, JW: AUTHOR [+2]

Abstract

Described is a technique for detecting the end-points of chemical- mechanical (chem-mech) polishing of circuitized multilayer substrates, as used in the fabrication of circuit boards and thin film structures. The technique involves primarily glass-ceramic or silicon substrates and is designed to resolve problems of under or over etching in the polishing operation.

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This is the abbreviated version, containing approximately 58% of the total text.

End Point Detection of Chemical/Mechanical Polishing of Circuitized
Multilayer Substrates

      Described is a technique for detecting the end-points of
chemical- mechanical (chem-mech) polishing of circuitized multilayer
substrates, as used in the fabrication of circuit boards and thin
film structures.  The technique involves primarily glass-ceramic or
silicon substrates and is designed to resolve problems of under or
over etching in the polishing operation.

      The concept described herein makes use of the ability of
transition metal ions to catalyze the oxidation of luminal in
buffered alkaline solutions [*].  The technique is applicable to
polishing multilayer structures with transition metal layers, any of
which can be used as an indicator.  Chromium often is used as an
adhesion layer or copper in thin films, as an example.  The
selectivity of various metal ions is achieved by taking advantage of
the difference in their rate of complexing with a given reagent. Fig.
1 shows a schematic of the chemiluminescence end-point detection
technique as applied to Damascene polishing of copper-plated
glass-ceramic subsrates.  A 200 Ao Cr layer is used to signal the
end-point of the polishing process.  The presence of CrCIII in the
solution catalyzes luminal decomposition.  The chemiluminescence
signal associated with Cr(III) can then be detected photometrically
and used to monitor the analyte concentration. Selection between
Cr(III) and Cu(II) is accomplished thr...