Here is the abstract you requested from the HiTEN_2009 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|250°C Voltage Compliant SOI MESFETs for High Power PWM Drive Circuits|
|Keywords: silicon-on-insulator, MESFETs, SiC driver circuits|
|Silicon Carbide (SiC) junction gate field effect transistors (JFETs) are ideal for switching high current, high voltage loads in high temperature environments. These devices require external drive circuits to generate pulse width modulated (PWM) signals switching from 0 to approximately 10V. Advanced CMOS microcontrollers are ideal for generating PWM signals but are limited in output voltage due to their low breakdown. As a result an intermediate buffer stage is required between the CMOS circuitry and the JFET. A discrete silicon-on-insulator (SOI) metal semiconductor field effect transistor (MESFET) was used to drive the gate of a SiC Power JFET switching a 120V RMS AC supply into a 55 Ohm load. The wide operating temperature range and high breakdown voltage of up to 50V make the SOI MESFET optimum for power electronics in extreme environments. Characteristic curves for the MESFET were measured up to 250C using an Agilent 4156B Semiconductor Parameter Analyzer. To drive the JFET, the MESFET was DC biased and then driven by a 1.2V square wave PWM signal to switch the JFET gate from 0 to 10V at frequencies up to 20 kHz. This switching topology was tested up to 250C by placing the JFET and MESFET in a convection oven. Due to the easy integration of MESFETs into SOI CMOS processes, MESFETs can be fabricated alongside MOSFETs without any changes in the process flow. This work demonstrates the feasibility of integrating a MESFET with CMOS PWM circuitry for a completely integrated SiC driver thus eliminating the need for the intermediate buffer stage.|
|Nicholas Summers, Research Associate
Arizona State University