**6. Ribbon beam flat-panel display implanters**

Diamond Semiconductor Group then developed an implanter beamline with a ribbon beam width of >620 mm, for use in flat-panel display implanters made by Mitsui Zosen [13]. Subsequently White developed methods of changing the ion source orientation and achieving higher resolving power, by orienting the ribbon vertically, and bending it horizontally [14] with a magnet using 'bedstead' coils. This concept was used by Mitsui Zosen for producing a 1300 mm tall ribbon beam (**Figures 4** and **5**).

To operate an HC PIG ion source with a 150 mm long slot, and produce a uniform but expanding ion beam, the ion source magnet had to generate a substantially uniform field down the length of the ion source, the y-direction—yet the overall yoke height was only 500 mm, as it was in **Figure 2**. Usually this creates a minimum field at the center, and substantially greater field near the poles. But here the poles were shaped to cause a rapid increase in a direction transverse to the beam direction and normal to its breadth, which I label x, which improves the uniformity along the
