**Figure 2.**

*The ASM 220 ion implanter in which a beam is scanned horizontally, then collimated by a dipole lens magnet, to generate a parallel uniform scanned beam.*

maximizing the beam size within the analyzing magnet, to keep the ion density low enough that Ωpi remained below Ωc, at beam currents of 5 mA at 5 keV or less.

The resulting design was the SHC-80 ion implanter [11] from which the VIISta-80 and other descendants under the VIISta tradename have manufactured and sold by Varian, and after acquisition by Applied Materials are still being produced and sold. The key design decision was to use a horizontally oriented *convex* ribbon beam ion source, and to produce a horizontally divergent ribbon beam to enter an analyzing magnet and be sharply refocused at a resolving aperture. This was loosely based on the design of the Applied/Lintott PI9000 ion implanter (See pages 241 and 242 of [1]). Then this analyzed beam was allowed to diverge again and was shaped by a 70-degree magnet into a parallel beam greater than 300 mm in width. This beam then implanted single 300 mm wafers which were mechanically vertically translated through it (**Figure 3**) [12].
