Optimisation of a power 4H-SiC SIT device for RF heating applications

In this paper, the optimisation procedure for a static induction transistor (SIT) in silicon carbide is described and its application in a typical RF heating circuit is presented. A field plate edge termination is optimised f or a 10 mu m thick epitaxial layer with doping in the range 10(15) cm(-3) t o 10(16) cm(-3). Results show a breakdown voltage of 1280 V, corresponding to 68% of the theoretical value. For the chosen application an epitaxial la yer doping level of 5 x 10(15) cm(-3) is revealed to offer the best comprom ise. This allows pinch off of drain voltages exceeding 600 V from a 20 V ga te drive whilst achieving a current density of 250 A cm(-2) at an on-state voltage of less than 1 V. Transient simulations are performed for a series load resonant converter with a switching frequency of 27.12 MHz. The result s emphasise the suitability of the device for RF heating applications. (C) 1999 Elsevier Science S.A. All rights reserved.