Minimizing particle contamination in high current ion implanters

Many issues contribute to the particle contamination of implanters. High current systems incur added microdischarging in the post accel system and accelerated erosion of beam defining stops and slits. The Varian VIISion implanter has been designed to include a number of fundamental improvements, which greatly reduce these additional particle contributions. Microdischarging adds negligible additional particles. A novel design mass slit reduces erosion at this point almost 400-fold. Overall particle performance is typically <0.1 cm^-2⩾0.2 μm even at full beam current