Demonstration of High-Performance 0.17-mΩ⋅cm²/800-V 4H-SiC Super-Junction Schottky Diodes via Multiepitaxial Growth and Channeled Implantation Techniques

Abstract

This article demonstrates the fabrication of high-performance 4H-silicon carbide (SiC) super-junction (SJ) Schottky diodes utilizing channeled implantation and double epitaxial growth. The diodes, featuring a $4.5-\mu $ m-thick drift region and a $4-\mu $ m-thick SJ structure, underwent characterization encompassing both material and electrical attributes. After double epitaxial growth, the epitaxial layer showcased a maximum stress of 25.9 MPa. The full-width at half-maximum (FWHM) analysis underscored the exceptional quality of the 4H-SiC crystals across the entire wafer surface (FWHM < 25 arcsec), paralleled by atomic force microscopy (AFM) outcomes revealing an epitaxial layer with excellent smoothness ( ${R}_{\text {q}} \lt 0.35$ nm). Devices fabricated on these high-quality wafers exhibited consistent performance and superior yield. Electrical property distributions revealed a breakdown voltage (BV) of 800 V alongside a specific on-resistance ( ${R}_{\text {on},\text {sp}})$ of 0.17 m $\Omega \cdot $ cm2 and a record Baliga figure of merit (BFOM) value of 3.76 GW/cm2 (800 V), subtracting the substrate resistance, exceeding the 1-D theoretical limit of 4H-SiC successfully. Moreover, it is inferred that the channeled implantation technology is an attractive process for fabricating SiC SJ devices.