A pulse transformer for plasma immersion ion implantation applications

Abstract

Summary form only given, as follows. Plasma Immersion Ion Implantation (PIII) applies a series of negative high-voltage pulses to a sample (target) immersed in plasma. PIII is a technology used to modify the material surface properties of a variety of products, e.g. for the manufacturing of semiconductor junctions and oxides, and for the production of high-strength, light-weight corrosion-resistant aerospace components. The pulse transformers become an essential part of the discharging circuit in a low impedance high-voltage pulser used with high impedance load such as PIII reactor. Summary form only given. The design and construction of high-voltage pulse transformer using metglas core are described and the analysis of a simplified lumped circuit model is used. It is found that a fast rise time requires low leakage inductance and low distributed capacitance and can be realized by reducing the number of secondary turns, but it produces larger pulse droop and requires a large core size. After careful choice of these parameters, a conventional pulse transformer with rise time less than 1 microsecond, and pulse droop of 1.5% has been built. The transmission characteristics and pulse time-response were measured. The agreement with the model was good when the measured values were used in the model simulation. The results of the high voltage test using PIII reactor as a load are also presented.