Apparatus and method for uniformly polishing a wafer
AssigneeFujitsu Limited
InventorsSadahiro Kishii, Yoshihiro Arimoto
Life of this patent
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Abstract
For providing a method for polishing in which it is possible to polish a substance uniformly over a whole surface of a wafer without observing the polished surface of the wafer halfway through polishing, a wafer with current detective patterns formed of conductors directly contacted with a semiconductor substrate, and an insulating film covering the current detective patterns is held by a wafer holder with conductivity, and the insulating film is polished by a polisher in which a supporting plate with conductivity is exposed in openings through a polishing cloth while supplying a polishing slurry containing ions.
Claims8
An apparatus for polishing comprising:
- a polisher having a polishing cloth, a plurality of through-holes for passing a polishing slurry containing ions, and a pair of electrodes formed in at least two pieces of a plurality of said through-holes in such a manner as to be electrically separated from each other;
- a wafer holder having a wafer holding surface with conductivity, on which holding a substrate having conductive layers covered with an insulating film;
- a current detecting means connected to a pair of said electrodes for detecting the magnitude of a current flowing by way of said one electrode, said conductive layers, and the other electrode by the interposition of said abrasive.
A method for polishing comprising the steps of:
- holding on a wafer holding surface of a wafer holder a substrate having conductive layers covered with an insulating film;
- turning on a shaft perpendicular to said wafer holding surface at least any of said wafer holder and a polisher having a polishing cloth, a plurality of through-holes for passing a polishing slurry containing ions and a pair of electrodes in at least two pieces of a plurality of said through-holes in such a manner as to be electrically separated from each other;
- bringing said insulating film in contact with said polishing cloth, and polishing said insulating film while supplying said abrasive;
- and
- monitoring a current flowing between a pair of said electrodes through said conductive layers by the interposition of said abrasive, and in the case that a specified current has been detected, polishing said insulating film on the other portion of said substrate.
Dependencies are inferred from the claim text.