A high voltage pulse generator for PIII processing in toroidal and cylindrical geometry vacuum vessels

摘要

The design and construction of a high voltage pulse generator intended to implant ions in plasma immersed materials (PIII process) are presented. The generator characteristics are: 100-2000 Hz pulses, 1-70 kV high and 1-100 mu s long. Two vacuum vessels have been adapted for the purpose, one with a cylindrical structure and another with a toroidal one. Both vessels are capable enough to allow the formation of a dynamic sheath sufficiently dense for the PIII process. Early results from the nitruration of a 304 stainless steel plates substrata are presented. Such results indicate a clear increase in the implanted nitrogen, showing that, under identical work conditions, the hardness Vickers increases from 260 HV to 546 HV in the cylindrical vessel, and from 260 HV to 740 RV in the toroidal vessel. The system developed here enables to operate in the comparatively high pressure range 10~(-1) to 10~(-3) Torr, at an economical cost due to, among other reasons, the plasma being generated by an 1kV/1A CD power supply.