Method and apparatus for detecting particles in ion implantation machines
US5047648A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 26, 1990 |
| Grant date | Sep 10, 1991 |
| Priority date | — |
| Expiry date | Nov 26, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/31701
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method for detecting particles in an ion implantation characterized by the steps of placing a particle sensor within the vacuum chamber of the ion implantation machine, exposing the substrate to an ion beam, thereby dislodging a stream of free particles, and detecting a portion of the free particle sensor. The particle sensor is preferably shielded from radiation to prevent false readings, and is positioned substantially along the plane of rotation of a substrate support wheel. By positioning the particle counter both along the plane of rotation and tangential to the rotation of the wheel at the point of ion impact, the particle counter intercepts the particle stream at the point of maximum particle flux. The apparatus includes a laser beam, a photodetector responsive to a portion of the laser beam scattered off of particles in the particle stream and a lead shield to shield the photodetector from x-rays generated within the vacuum chamber of the ion implantation machine.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.