Development of 4H-SiC LJFET-Based Power IC

Abstract

A novel lateral junction field-effect transistor (JFET)-based power IC technology in 4H-SiC is presented in detail covering device and circuit design, fabrication, and characterization. The optimal reduced surface field design for the lateral power JFET has been carried out and implemented in the IC fabrication. Since this technology has great promise at high temperatures, the temperature dependences (from room temperature to 300degC) of the threshold voltage, transconductance, resistance, and electron mobility have been fully characterized. Advantages of the SiC vertical-channel lateral JFET (VC-LJFET) technology, such as lower output capacitance (C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">oss</sub> ) for lateral power JFETs and adjustable threshold voltages at mask design level, are also discussed. Finally, a monolithic power IC chip integrating a power lateral JFET with its low-voltage buffers is presented, which demonstrated megahertz switching at a power level of 270 W. The successful development of the VC-LJFET technology should hasten the introduction of SiC smart power ICs and eventually the system-on-a-chip applications in harsh environments.