US RE40,008 E1 | ||
Method and apparatus for controlling ion implantation during vacuum fluctuation | ||
Steven R. Walther, Andover, Mass. (US) | ||
Assigned to Varian Semiconductor Equipment Associates, Inc., Gloucester, Mass. (US) | ||
Filed on Jun. 24, 2003, as Appl. No. 10/602,795. | ||
Application 10/602795 is a reissue of application No. 09/586492, filed on Jun. 02, 2000, now 6,323,497, filed on Nov. 27, 2001. | ||
Int. Cl. G21G 5/10 (2006.01) |
U.S. Cl. 250—492.21 [250/492.1] | 43 Claims |
2. An ion implantation system comprising:
a beam generator that generates an energetic ion beam and directs the beam [ along an ion beam path ] toward a semiconductor wafer;
a detector that detects an ion beam current;
a wafer drive that moves the semiconductor wafer in a direction transverse to the ion beam path; and
a controller that receives signals from the detector representative of a detected ion beam current, detects a vacuum fluctuation
based on
|