SiC MOSFET design considerations for reliable high voltage operation

Abstract

SiC MOSFETs have demonstrated continued performance improvement and maturation in the areas of Gate oxide stability and reliability over the past years. While necessary, this alone is not sufficient to achieve reliable high voltage operation. In this paper, the design constraints impacting high voltage reliability and their impact on SiC MOSFET performance at useful operating conditions are discussed. Experimental results are demonstrated with industry benchmark, reliable operation of up to T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">j</sub> =200°C with 1.2kV/25mOhm SiC MOSFETs and T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">j</sub> =175°C, 1.7kV/450A all-SiC MOSFET Dual-Switch modules. Avalanche ruggedness of the high-performance devices is also demonstrated with single-pulse energy densities of 9-15J/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> recorded with Drain currents as high as ID= 90A for 0.2cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> die.