Method of reducing particle contamination for ion implanters
US7566887B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 3, 2007 |
| Grant date | Jul 28, 2009 |
| Priority date | — |
| Expiry date | Sep 30, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/08
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.