Fifty centimeter ion beam source

A 50-cm-diam ion source and its industrial applications are described. This is the largest commercial ion source presently available for ion beam etching and deposition over a full 20 in. diam. It has been used to generate beams of argon ions at 300-900 eV of ion energy and beam currents of 1-5 A with standard filament-type cathodes. Operation at even higher current levels is possible with high emissivity hollow cathodes. A presentation of general performance characteristics of the ion source is given and some of the special considerations required for reliable and cost-effective operation of large scale ion beam systems are discussed. To illustrate the application of this source, a brief description of a fully automatic production ion beam etching system developed around this ion source is given along with a description of the etch results. This system can simultaneously etch a batch of five B-in.-diam wafers with etch rates of nickel-iron exceeding 500 A/min. The etch uniformity is excellent. (C) 1996 American Institute of Physics.