A NOVEL DISTRIBUTED SYSTEM FOR PLASMA IMMERSION ION IMPLANTER CONTROLAND AUTOMATION

The high voltage and electromagnetic field environment poses a big cha llenge to a control system for plasma immersion ion implantation (PIII ). The automation process must be immune to electric field interferenc e produced by the high voltage power supply, modulator, radio-frequenc y or microwave plasma generator, MEVVA plasma sources, and so oil. We have recently designed and installed a distributed control system, PII IDCS, to automate the operation of our PIII facility. Programmable log ic controllers are used as the held control stations because of their good anti-interference ability and good real time response. A DH-485 n etwork is used as the communication link between the field controllers and the management station in order to improve the robustness and rel iability of the system. The newly developed interface is designed to w ork in a graphic mode in Microsoft Windows 95. Test runs have shown th at the system is reliable, flexible, and easy to operate. The developm ent of this novel control system will expedite the development of comm ercial PIII instrumentation. (C) 1998 American Institute of Physics.