The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 28, 2009
Filed:
Jan. 03, 2007
Yongzhang Huang, Hamilton, MA (US);
Que Weiguo, Melrose, MA (US);
Zhang Jincheng, Brighton, MA (US);
Yongzhang Huang, Hamilton, MA (US);
Que Weiguo, Melrose, MA (US);
Zhang Jincheng, Brighton, MA (US);
Axcelis Technologies Inc., Beverly, MA (US);
Abstract
The present invention is directed to a beam control circuit and method used to minimize particle contamination in an ion implantation system by reducing the duty factor of the ion beam. In one embodiment the beam control circuit comprises a high voltage switch connected in series with a power supply and an ion source portion of the ion implantation system, wherein the switch is operable to interrupt or reestablish a connection between the power supply and an electrode of the ion source including electrodes for plasma production. The beam control circuit also comprises a switch controller operable to control the duty factor of the ion beam by controlling the switch to close before a start of ion implantation and to open after a completion of implantation or at other times when the beam is not needed, thereby minimizing beam duty and particle contamination. The beam control technique may be applied to wafer doping implantation and duty factor reduction. Protection circuits for the high voltage switch absorb energy from reactive components and clamp any overvoltages.