Dual cathode ion source

US9978554B1 · kind B1 · utility

Assignee

• Varian Semiconductor Equipment Associates, Inc. · US

Inventors

• Bon-Woong Koo · Andover, US
• Jun Lu · Shanghai, CN
• Frank Sinclair · Quincy, US
• Eric D. Hermanson · Tewksbury, US
• Joseph E. Pierro · Danvers, US
• Michael D. Johnson · Houston, US
• Michael S. DeLucia · Gloucester, US
• Antonella Cucchetti · Beverly, US

Key dates

• Filing date: Jan 26, 2017
• Grant date: May 22, 2018
• Expiry date: Jan 26, 2037

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01J2237/31701
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

An ion source having dual indirectly heated cathodes is disclosed. Each of the cathodes may be independently biased relative to its respective filament so as to vary the profile of the beam current that is extracted from the ion source. In certain embodiments, the ion source is used in conjunction with an ion implanter. The ion implanter comprises a beam profiler to measure the current of the ribbon ion beam as a function of beam position. A controller uses this information to independently control the bias voltages of the two indirectly heated cathodes so as to vary the uniformity of the ribbon ion beam. In certain embodiments, the current passing through each filament may also be independently controlled by the controller.