| US 7,476,877 B2 | ||
| Wafer charge monitoring | ||
| Russell J. Low, Rowley, Mass. (US); George M. Gammel, Marblehead, Mass. (US); Peter F. Kurunczi, Somerville, Mass. (US); and Eric Cobb, Danvers, Mass. (US) | ||
| Assigned to Varian Semiconductor Equipment Associates, Inc., Gloucester, Mass. (US) | ||
| Filed on Feb. 14, 2006, as Appl. No. 11/353,820. | ||
| Prior Publication US 2007/0187615 A1, Aug. 16, 2007 | ||
| Int. Cl. H01J 37/30 (2006.01) | ||
| U.S. Cl. 250—492.21 [250/397] | 20 Claims |
| 1. A charge monitoring system comprising:
a platen having a surface configured to accept a wafer thereon; and
a charge monitor disposed relative to said platen so that an ion beam simultaneously strikes a portion of said charge monitor
and a portion of said wafer, said charge monitor configured to provide a charge monitor signal representative of a charge
on a surface of said wafer when said ion beam simultaneously strikes said portion of said charge monitor and said portion
of said wafer.
|