In situ real time particle monitor for a sputter coater chamber
US5347138A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 1, 1993 |
| Grant date | Sep 13, 1994 |
| Priority date | — |
| Expiry date | Apr 1, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/4792
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A structure and a method use a non-invasive particle monitor to detect particles in a process chamber for a "down sputtering" metal deposition process. In one embodiment, only non-spherical particles are detected using a single laser beam of a predetermined polarization is used, and the phase shift in the polarization due to the passing of a particle through the laser beam is measured. In another embodiment, two closely spaced orthogonally polarized laser beams are used, and the differential intensity of the laser beams is measured when a particle passes through one of the laser beams. In another embodiment, shield tubes for housing optical components are used to prevent coating of the optical components and to prevent deposition to take place outside the shielded area. Internal electric and magnetic fields are used to drive particles through the laser beams for particle detection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.