Influence of Diverse Post-Trench Processes on the Electrical Performance of 4H-SiC MOS Structures

Christian T. Banzhaf; Michael Grieb; Achim Trautmann; Anton J. Bauer; Lothar Frey

doi:10.4028/www.scientific.net/MSF.778-780.595

Paper Titles

Conduction Mechanism of Leakage Current in Thermal Oxide on 4H-SiC
p.579

Systematic Analysis of the High- and Low-Field Channel Mobility in Lateral 4H-SiC MOSFETs
p.583

Experimental Studies on Water Vapor Plasma Oxidation and Thermal Oxidation of 4H-SiC (0001) for Clarification of the Atomic-Scale Flattening Mechanism in Plasma Assisted Polishing
p.587

Rapid Thermal Oxidation of Si-Face N and P-Type On-Axis 4H-SiC
p.591

Influence of Diverse Post-Trench Processes on the Electrical Performance of 4H-SiC MOS Structures
p.595

Impact of the Oxidation Temperature on the Interface Trap Density in 4H-SiC MOS Capacitors
p.599

Deep Traps in 4H-SiC MOS Capacitors Investigated by Deep Level Transient Spectroscopy
p.603

4H-SiC MOS Capacitors and MOSFET Fabrication with Gate Oxidation at 1400°C
p.607

Step-Bunching Dependence of the Lifetime of MOS Capacitor on 4^o Off-Axis Si-Face 4H-SiC Epitaxial Wafers
p.611

HomeMaterials Science ForumMaterials Science Forum Vols. 778-780Influence of Diverse Post-Trench Processes on the...

Influence of Diverse Post-Trench Processes on the Electrical Performance of 4H-SiC MOS Structures

Abstract:

This paper focuses on the evaluation of subsequent process steps (post-trench processes, PTPs) after 4H silicon carbide (4H-SiC) trench etching with respect to the electrical performance of trenched gate metal oxide semiconductor field effect transistors (Trench-MOSFETs). Two different types of PTP were applied after 4H-SiC trench formation, a high temperature post-trench anneal (PTA) [1] and a sacrificial oxidation (SacOx) [2]. We found significantly improved electrical properties of Planar-MOS structures using a SacOx as PTP, prior to gate oxide deposition. Besides excellent quasi-static capacitance-voltage (QSCV) behavior even at T = 250 °C, charge-to-breakdown (QBD) results up to 8.8 C/cm2 at T = 200 °C are shown to be similar on trenched surfaces as well as on untrenched surfaces of SacOx-treated Planar-MOS structures. Moreover, dielectric breakdown field strengths up to 12 MV/cm have been measured on Planar-MOS structures. However, thick bottom oxide Trench-MOS structures indicate best dielectric breakdown field strengths of 9.5 MV/cm when using a trench shape rounding PTA as the PTP.