Sidewall-Implanted Trench Termination for 4H-SiC Devices With High Breakdown Voltage and Low Leakage Current

Abstract

In this letter, a sidewall-implanted trench termination for SiC devices is proposed and experimentally demonstrated. With the p-type sidewall region implemented by tilted ion implantation, the electric field crowding at the edge of the main junction can be alleviated. Compared with the conventional trench termination, devices with the fabricated sidewall-implanted trench termination exhibits a higher breakdown voltage ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">BV</i> ) exceeding 1800V, as well as lower leakage current. Moreover, the minimum trench width for over 1800V blocking is significantly reduced from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$14~\mu \text{m}$ </tex-math></inline-formula> to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5~\mu \text{m}$ </tex-math></inline-formula> . In addition, the sidewall-implanted trench termination shows stronger robustness as the dominant current path is relocated from the trench sidewall to the whole active region.