Abstract: A filamentless (without a heated cathode) ion source for thin film processing and surface modification. The ion source comprises a plasma chamber which includes a wall defining an evacuable chamber having a first end and a second end, with a dielectric member extending across the first end of the evacuable chamber. A gas inlet admits a plasma forming gas into the chamber. An RF emitter is positioned adjacent to the dielectric member for inductively generating a plasma in the gas in the plasma chamber during use of the ion source. A control grid structure is provided for extracting ions from plasma in the plasma chamber, and include a first grid connected to a positive voltage source and a second grid connected to a negative voltage source, to produce an acceleration field for accelerating ions towards and through the second grid of the control grid structure. An ion beam processing apparatus and an ion beam neutralizer incorporating such an ion source are also described.

Abstract: An electrode assembly is described for use in plasma processes, such as reactive dry etching and plasma deposition. This includes a primary electrode which is electrically insulated from the vacuum chamber in which it is mounted in use. The primary electrode may be connected to an r.f. or d.c. power source and has a cylindrical hole with an insulated subsidiary electrode at the bottom of the hole which can be earthed or allowed to adopt a floating voltage in use. Magnets are used to trap electrons adjacent the walls of the hole. These may consist of a plurality of elongate magnets positioned around an annular pole plate with their largest dimension arranged longitudinally with respect to the pole plate and the hole, with their magnetic axes arranged radially, and with alternating polarity around the inner periphery of the pole plate. In use an r.f. frequency (e.g. 13.56 MHz) may be applied to the primary electrode while a reactant gas (e.g. C.sub.2 F.sub.6 or a C.sub.2 F.sub.6 /CHF.sub.