| US 7,453,059 B2 | ||
| Technique for monitoring and controlling a plasma process | ||
| Bon-Woong Koo, Andover, Mass. (US); Ziwei Fang, Beverly, Mass. (US); Ludovic Godet, North Reading, Mass. (US); Vikram Singh, North Andover, Mass. (US); Vassilis Panayotis Vourloumis, Peabody, Mass. (US); and Bernard G. Lindsay, Danvers, Mass. (US) | ||
| Assigned to Varian Semiconductor Equipment Associates, Inc., Gloucester, Mass. (US) | ||
| Filed on Feb. 23, 2007, as Appl. No. 11/678,524. | ||
| Application 11/678524 is a continuation in part of application No. 11/371907, filed on Mar. 10, 2006. | ||
| Prior Publication US 2007/0227231 A1, Oct. 04, 2007 | ||
| This patent is subject to a terminal disclaimer. | ||
| Int. Cl. G01N 27/26 (2006.01); G01N 33/00 (2006.01); H01J 49/40 (2006.01) | ||
| U.S. Cl. 250—287 [250/286; 250/423 R; 250/492.2; 315/111.31; 315/111.81] | 31 Claims |
| 1. A time-of-flight ion sensor for monitoring ion species in a plasma used for processing a substrate, the time-of-flight
ion sensor comprising:
a housing;
a drift tube that is positioned in the housing the drift tube being configured as an energy analyzer;
an extractor electrode positioned in the housing at a first end of the drift tube, the extractor electrode being configured
to perform at least one of attraction and repulsion of ions from a plasma;
a plurality of electrodes that are positioned at a first end of the drift tube proximate to the extractor electrode, the plurality
of electrodes being biased so as to cause at least a portion of the attracted ions to enter the drift tube and to drift towards
a second end of the drift tube; and
an ion detector that is positioned proximate to the second end of the drift tube, the ion detector detecting arrival times
associated with the at least a portion of the attracted ions.
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