RF bias control in plasma deposition and etch systems with multiple RF power sources
US6537421B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 24, 2001 |
| Grant date | Mar 25, 2003 |
| Priority date | — |
| Expiry date | Jul 24, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/32706
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus are provided by which the effects of the plasma power RF source and substrate bias are decoupled to reduce the effect of plasma power on the wafer bias and to improve process control. A technique is provided that includes establishing a high density plasma adjacent to a semiconductor wafer, such as by inductive coupling, at some RF plasma excitation frequency, preferably at a frequency between 50 kHz and 50 MHz. RF power from a bias power source is applied to a chuck on which a wafer is supported which exhibits high capacitance between the RF feed of the bias power source and the wafer. The RF power to the substrate support is applied through a matching unit at a frequency that is identical to or close to that of the frequency of the primary power to the plasma. Series resonant filters are connected between the RF bias power source connection to the substrate support and ground, the resonant frequencies preferably being set to harmonics of the primary power source frequency to suppress voltage components on the substrate support at these frequencies.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.