Performance of a large-volume, unmmagnetized Microwave Plasma Facility (MPF) for industrial plasma processing applications

Summary form only given, as follows. We are currently upgrading and testing the UTK Microwave Plasma Facility (MPF). This facility is intended for plasma ion implantation studies, but may be useful for other plasma processing applications because of its volumetric uniformity, large dimensions, and the use of familiar 2.45 GHz microwave technology to generate the plasma. The MPF consists of a cylindrical vacuum tank approximately one meter high and 50 em in diameter, which serves as a multimode cavity for 2.45 GHz radiation. A schematic diagram of the operating configuration is shown. Standard microwave components are used to connect the Varian Model PPS 2.5 AS, 2500 watt 2.45 GHz power source to the vacuum window and antenna network. The low pressures and high power of this application have made it necessary to develop several specialized components. These include a 3 kW, CW vacuum window, a launching structure in the cavity which is designed to avoid breakdown in the waveguide at high power, and a RF choke designed to prevent the plasma ion implantation sample holder from acting as a microwave radiator. In an earlier paper we reported on the MPF operating characteristics and plasma parameters at the 800 Watt power level. This paper will extend those results by providing mformation on the performance of the specialized components required for higher power operation, as well as data on the plasma parameters and uniformity at the 2.5 kW operating level.