AN ION-SOURCE WITH GOOD BEAM CURRENT-DENSITY UNIFORMITY FOR ASSISTED DEPOSITION

Recently, broad beam ion sources have been widely used for industrial applications. In order to obtain high quality thin films and process l arge workpieces, more uniform beam current density is needed. This art icle introduces a 10-cm-diam cusped ion source with good beam current density uniformity for assisted deposition. Its design characteristics and performance are described. The effects of operation parameters of ion source, the magnetic flux density and its distribution, the catho de shape and its location in the discharge chamber, and the configurat ion of grids on the uniformity of ion beam current density were experi mentally investigated. For screen grid voltage of 300 V and beam curre nt of 100 mA, a 0.93 beam current flatness parameter within a beam spo t of 200 mm diameter at a distance of 300 mm downstream from the sourc e was obtained.