A 16 CM BROAD-BEAM ION-SOURCE FOR ION-BEAM ETCHING OF QUARTZ WAFERS

A broad-beam ion source is developed for ion-beam etching of quartz wa fers, which are used in resonators with a high basic frequency of the order of magnitude of 1 GHz. The improvement of uniformity of the extr acted ion beam is investigated. The double-grid multiple-aperture ion optics is adopted, in which perveance is matched by varying both the a perture diameters and spaces between grids. The configuration of the m agnetic field is optimized. Measured at the target of 12 cm from the g rids, the area of uniform region (nonuniformity <5%) is approximately equal to the area of the bored region of the grids (12 cm diam) and 1/ 1.78 of the cross-section area of the anode (16 cm diam). A broad beam of 100-1000 eV and 0.1-2.0 mA/cm(2) is extracted from the source to f ulfill the requirement of the etching process. Without any cooling sys tem, the ion source is installed in vacuum chamber. (C) 1996 American Institute of Physics.