Features of a high‐current implanter and a medium‐current implanter

Abstract

In contrast to the majority of MOS circuit applications, the use of ion implantation for bipolar devices involves doping levels from 5×1013–1016 ions cm−2. This requires implantation systems with milliampere beam current capability. Some problems associated with high power beams are discussed and two contrasting systems are described. The first uses conventional electrostatic scanning techniques for beam currents up to 0.5 mA. The second operates at beam currents up to 3 mA and incorporates a fully mechanical scanning technique. In this way the high beam powers are distributed over a large effective area corresponding to 26 3‐in.‐diam wafers per batch.