A hard tube type pulse generator for plasma immersion ion implantation

Abstract

This paper describes a high voltage pulsed power system for a plasma immersion ion implantation (PIII) experiment. The pulsed power supply consists of a high voltage pulse generator that uses a hard tube switch. The reason for using this type of circuit category in the PIII facility rather than a previously used pulse-forming network (PFN) circuit configuration is stated. The experimental results of the application of this device to a glow discharge PIII are also discussed. In order to assess these results, a simple electrical model describes the plasma as a resistive load in parallel. With a capacitance taking into account the pulse rise-time distortion caused by a long coaxial feeding cable. Plasma parameters for PIII processing, such as implantation ion average current and plasma sheath thickness, are calculated from the experimental results.