Browse Prior Art Database

Pressurized Wafer Holder for Uniform Polishing

IP.com Disclosure Number: IPCOM000119744D
Original Publication Date: 1991-Feb-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 1 page(s) / 31K

Publishing Venue

IBM

Related People

Cote, WJ: AUTHOR [+2]

Abstract

By applying gas pressure through holes normally used to apply vacuum to pick up and hold semiconductor wafers in a polishing operation, greater uniformity of removal rate of materials on the surface of the wafer is achieved.

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Pressurized Wafer Holder for Uniform Polishing

      By applying gas pressure through holes normally used to apply
vacuum to pick up and hold semiconductor wafers in a polishing
operation, greater uniformity of removal rate of materials on the
surface of the wafer is  achieved.

      Referring to the figure, wafer carrier 2 has holes 4 normally
used for application of a vacuum to pick up and hold wafer 6 during
polishing.  When wafer 6 is in position for polishing, i.e., in
contact with polishing pad 8 on polisher spindle plate 10, vacuum is
valved off and gas pressure is applied through holes 4.  Gas leaks
out of the cavity between wafer 6 and carrier 2 through the opening
between wafer 6 and retainer ring 12, thus gas flow must be supplied
to maintain a desired gas pressure on the back of wafer 6.

      Appropriate gas pressure and flow for best polishing uniformity
is determined by measuring rate of polish removal of a coating at
several points on a wafer at various gas pressure levels.

      Disclosed anonymously.