Microwave chemical vapor deposition apparatus and feedback control method
US5069928A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 27, 1989 |
| Grant date | Dec 3, 1991 |
| Priority date | — |
| Expiry date | Jan 27, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C16/511
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A microwave plasma CVD apparatus includes a hermetically sealed vacuum vessel, a device for evacuating the vacuum vessel, and a device for introducing microwaves through a microwave transmission circuit into the vacuum vessel to produce a plasma within the vacuum vessel. The microwave transmission circuit includes a cavity resonator integrally provided with two matching circuits, one of which is a plunger for varying the length of the cavity resonator and the other of which is a pair of sliding matching irises. Feedback in the apparatus can be controlled by driving one of the matching circuits for rough matching of the microwave impedance and driving the other matching circuit for fine matching of the microwave impedance, so that the calculated ratio of the reflected power to the input power, based on a signal from a power monitor, is reduced to a minimum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.