| US 7,598,175 B2 | ||
| Apparatus and method for confined area planarization | ||
| John M. Boyd, Hillsboro, Oreg. (US); Fritz C. Redeker, Fremont, Calif. (US); Yezdi Dordi, Palo Alto, Calif. (US); Michael Ravkin, Sunnyvale, Calif. (US); and John de Larios, Palo Alto, Calif. (US) | ||
| Assigned to Lam Research Corporation, Fremont, Calif. (US) | ||
| Filed on May 29, 2008, as Appl. No. 12/129,612. | ||
| Application 12/129612 is a division of application No. 11/395881, filed on Mar. 31, 2006, granted, now 7,396,430. | ||
| Prior Publication US 2008/0227369 A1, Sep. 18, 2008 | ||
| Int. Cl. H01L 21/302 (2006.01) | ||
| U.S. Cl. 438—691 [438/692; 204/250; 204/251] | 15 Claims |
| 1. A method for confined area planarization of a semiconductor wafer, comprising:
disposing a proximity head over and proximate to a top surface of a semiconductor wafer such that a cation exchange membrane
of the proximity head faces the top surface of the semiconductor wafer;
disposing an electrolyte solution between a top surface of the cation exchange membrane and a cathode;
flowing deionized water between a bottom surface of the cation exchange membrane and the top surface of the semiconductor
wafer;
controlling a flow rate of the deionized water such that the cation exchange membrane flexes toward the top surface of the
semiconductor wafer under the influence of a Bernoulli force without contacting the top surface of the semiconductor wafer
and such that a substantially uniform separation distance is maintained between the cation exchange membrane and the top surface
of the semiconductor wafer; and
applying a bias voltage between the top surface of the semiconductor wafer and the cathode such that cations liberated from
the top surface of the semiconductor wafer are influenced to travel through the deionized water through the cation exchange
membrane through the electrolyte solution to the cathode.
|