Ultrafast Pulsed I-V and Charge Pumping Interface Characterization of Low-Voltage n-Channel SiC MOSFETs

Control of defects at or near the MOS interface is paramount for device performance optimization. The SiC MOS system is known to exhibit two types of MOS defects, defects at the SiO2/SiC interface and defects inside of the gate oxide that can trap channel charge carriers. Differentiating these two types can be challenging. In this work, we use several electrical measurement techniques to extract and separate these two types of defects. The charge pumping method and the ultrafast pulsed I-V method are given focus, as they are independent methods for extracting the defects inside the gate oxide. Defects are extracted from low voltage n-channel MOSFETs with differently processed gate oxides: steam-treatment, dry oxidation and nitridation. Ultrafast pulsed I-V and charge pumping gives comparable results. The presented analysis of the electrical characterization methods is of use for SiC MOSFET process development.