RADIO-FREQUENCY POWERED GLOW DISCHARGE DEVICE AND METHOD WITH HIGH VOLTAGE INTERFACE

摘要

A high voltage accelerating potential (102) is applied to the electrically conducting interior wall of an RF powered glow discharge cell (68) in order to be able to repel the positive ions formed in the discharge. The RF power supply (99) desirably is electrically grounded (120) and the conductor (92) carrying the RF power to the sample (62) held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. An impedance matching network (100) is used to match the impedance of the plasma inside the discharge cell to the impedance of the RF power supply circuit. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance (200) is electrically connected in series between the sample and the RF power supply and impedance matching network. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. In addition, an inductor (112) is added in the circuit in a manner that protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe are configured and disposed to prevent the probe's components from bridging within the cell between the relatively low vacuum region and, the relatively high vacuum region (403) surrounding the probe and cell. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components.