Improved Inversion Channel Mobility in 4H-SiC MOSFETs on Si Face Utilizing Phosphorus-Doped Gate Oxide

Abstract

We propose a new technique for fabricating 4H-SiC metal-oxide-semiconductor field-effect transistors (MOSFETs) with high inversion channel mobility. P atoms were incorporated into the SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /4H-SiC (0001) interface by postoxidation annealing using phosphoryl chloride (POCl <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ). The interface state density near the conduction band edge of 4H-SiC was reduced significantly, and the peak field-effect mobility of lateral 4H-SiC MOSFETs on (0001) Si face was improved to 89 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /V · s by POCl <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> annealing at 1000°C.