US 7,491,947 B2
	Technique for improving performance and extending lifetime of indirectly heated cathode ion source
Eric R. Cobb, Danvers, Mass. (US); Russell J. Low, Rowley, Mass. (US); Craig R. Chaney, Rockport, Mass. (US); and Leo V. Klos, Newburyport, Mass. (US)
Assigned to Varian Semiconductor Equipment Associates, Inc., Gloucester, Mass. (US)
Filed on Aug. 16, 2006, as Appl. No. 11/505,168.
Claims priority of provisional application 60/708783, filed on Aug. 17, 2005.
Prior Publication US 2007/0085021 A1, Apr. 19, 2007
Int. Cl. H01J 27/08 (2006.01)

U.S. Cl. 250—426  [250/423 R; 250/424; 250/492.2; 250/492.21]

14 Claims

1. A method for improving performance and lifetime of an indirectly heated cathode (IHC) ion source in an ion implanter, the method comprising the steps of: maintaining an arc chamber of the IHC ion source under vacuum during a maintenance of the ion implanter, wherein no gas is supplied to the arc chamber; heating a cathode of the IHC ion source by supplying a filament with a current; biasing the cathode with respect to the filament at a current level of 0.5-5 A without biasing the arc chamber with respect to the cathode; and keeping a source magnet from producing a magnetic field inside the arc chamber.