ABSTRACT
This chapter discusses the plasma sources most widely used for industrial plasma processing under vacuum or which hold promise for industrial applications. A majority of industrial applications of glow discharge plasmas are conducted under vacuum, at pressures below 1.3 kPa. The direct current (DC), radiofrequency (RF), and flat-coil inductive plasma sources have electron number densities proportional not only to the RF power, but also to background pressure. For microelectronic plasma etching, the wafers are usually mounted on the cathode in order to take advantage of energetic ion bombardment, which promotes directional etching. The independent variables used to control plasma-processing operations include the type of working gas, the neutral gas pressure, the gas flow rate, and the DC or RF power input. A variety of independent operating parameters are used to control the processing of workpieces by inductive continuous-flow plasma sources. The type of gas used in the Kaufman electron bombardment plasma source depends on the application.
