Search NASA⌕ Search

SEARCH · Search NASA

Results for “4H-SiC MOSFET”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

21 records · Page 2

Electric Drive Technologies Consortium (EDTC)/ Cost competitive, high-Performance, highly Reliable (CPR) Power Devices on 4H-SiC (Final Report)

4H-Silicon carbide (4H-SiC) is a wide bandgap semiconductor that offers superior material properties over silicon, including higher critical electric field, thermal conductivity, and electron saturation velocity. These advantages make 4H-SiC highly attractive for high-voltage, high-efficiency power electronics. However, realizing the full potential of SiC requires device technologies that are not only high-performing but also manufacturable and reliable under real-world operating conditions. This report summarizes the outcomes of a five-year R&D effort funded by the U.S. Department of Energy (DOE) under the Electric Drive Technologies Consortium (EDTC), focused on developing cost-competitive, high-performance, and highly reliable (CPR) power devices on 4H-SiC substrates. The program targeted scalable and manufacturable 1.2 kV-class SiC MOSFETs optimized for next-generation electric vehicles, renewable energy systems, and industrial power conversion. The project delivered transformative advancements in SiC power device performance and ruggedness. Particularly, Specific on-resistance (R on,sp ) was reduced by up to 37%, from ~4.0 m$\Omega \cdot$cm 2 in earlier designs to an industry-leading 2.40 m$\Omega \cdot$cm 2 , driven by optimized doping, refined JFET widths, and layout engineering. Breakdown voltages (BV) exceeded 1600 V, marking improvement over legacy baselines, and demonstrating the robustness of newly implemented junction profiles and edge terminations. Short-circuit withstand time (SCWT) saw a remarkable 4$\times$ increase, from ~2 $\mu$s to over 8 $\mu$s, achieved through the successful deployment of deep P-well structures (~1.8–2.0 $\mu$m) via channeling implantation. This innovative process breakthrough enabled precise junction formation without MeV-class implantation tools, reduced leakage under high field stress, and allowed even the shortest-channel devices (down to 0.3 $\mu$m) to achieve both high BV and excellent ruggedness—breaking the traditional trade-off between conduction efficiency and blocking capability. Several novel architectures pushed the performance envelope further. JBSFETs—featuring embedded Schottky portions—eliminated bipolar degradation and drastically reduced third-quadrant leakage, while Ladder MOSFETs introduced a clever orthogonal conduction path that achieved a 15.4% reduction in R on,sp over standard linear designs. Switching performance reached new benchmarks: short-channel devices showed a 31% reduction in total switching energy compared to 0.5 $\mu$m counterparts, while maintaining manageable gate drive requirements. Layout-optimized structures not only improved transconductance but also accelerated switching transitions, pointing to real-world benefits in converter-level efficiency. The devices also passed rigorous reliability validation. Stress-tested across TDDB, HTGB, HTRB, HVP, and burn-in, the devices screened under 30 V/10 hr and 43 V/1 s protocols consistently exhibited tighter lifetime distributions and long-term oxide robustness. These screening techniques proved effective in identifying latent defects and ensuring deployment-grade reliability. Meanwhile, advanced 3D TCAD simulations revealed and resolved electric field hotspots—particularly in HEXFET corners—where fields exceeding 4.8 MV/cm were mitigated through geometry-aware layout corrections. Overall, the results of this project demonstrate a manufacturable and scalable SiC power device platform that addresses key DOE performance targets for efficient, robust, and reliable 1.2kV 4H-SiC Power Devices. The developed technologies represent a meaningful step forward in the commercial readiness of high-voltage SiC solutions and provide a strong foundation for continued advancement in wide bandgap power electronics.

42 ENGINEERING↗

Switching Characteristics of a 1.2 kV, 50 mΩ SiC Monolithic Bidirectional Field Effect Transistor (BiDFET) with Integrated JBS Diodes

—The switching performance of large area (1cm x 1cm) monolithic 1.2 kV 50 mΩ 4H-SiC bidirectional field effect transistor (BiDFET) with integrated JBS diodes is reported for the first time. The devices were fabricated in a 6-inch commercial foundry and then packaged in a custom-designed four-terminal module. The switching performance of the BiDFET has been observed to be 1.4x better than that of its internal JBSFETs. Dynamic characterization was performed at 800 V with different gate resistances, current levels and case temperatures. An increase in switching losses was observed for the BiDFET with increasing gate resistance and current level as observed for SiC power MOSFETs. The BiDFET showed a 9% reduction in total switching loss from 25 °C to 150 °C with a current of 10 A.

Silicon Carbide, Monolithic, Bidirectional, FourQu↗

Stacking Faults Originating from Star-Defects in 4H-SiC

Intense efforts are currently in progress to study various sources of basal plane dislocations (BPDs) in SiC epitaxial layers. BPDs can generate Shockley-type stacking faults (SSFs) in SiC epitaxial layers, which have been shown to be associated with the degradation of power devices. This study shows that the star-shaped defect can be a source of several BPDs in the epitaxial layer. We investigate the complex microstructure of the star defect, the generation of BPDs, and expansion of SSFs using various complementary microscopy and optical techniques. We show direct evidence that star-defects can be a nucleation point of single-SSFs that can expand at the core of the defect. Newly found secondary dislocation arrays extending over a few centimeters away are found to be emanating from the primary arms of the star defect. The presence of such dislocation walls and the expansion of single-SSFs will affect the yield of numerous die on a wafer. Further understanding of the formation mechanism of stacking faults generated from star-defects as provided in this study helps understand their effect on SiC-based devices, which is crucial to assess device reliability.

36 MATERIALS SCIENCE↗