Ulta-wide bandgap semiconductors based on β-Ga2O3 offer the potential to achieve higher power switching performance, efficiency, and lower manufacturing cost than today's wide bandgap power semiconductors. However, the most critical challenge to the commercialization of Ga2O3 electronics is overheating, which impacts the device's performance and reliability. We fabricated a Ga2O3/4H-SiC composite wafer using a fusion-bonding method. A low temperature (≤ 600 ∘C) epitaxy and device processing approach based on low-temperature (LT) metalorganic vapor phase epitaxy is developed to grow a Ga2O3 epitaxial channel layer on the composite wafer and subsequently fabricate into Ga2O3 power MOSFETs. This LT approach is essential to preserve the structural integrity of the composite wafer. These LT-grown epitaxial Ga2O3 MOSFETs deliver high thermal performance (56% reduction in channel temperature), high voltage blocking capabilities up to 2.45 kV, and power figures of merit of ∼ 300 MW/cm2, which is a record high for any heterogeneously integrated Ga2O3 devices reported to date. This work is the first realization of multi-kilovolt homoepitaxial Ga2O3 power MOSFETs fabricated on a composite substrate with high heat transfer performance which delivers state-of-the-art power density values while running much cooler than those on native substrates. Thermal characterization and modeling results reveal that a Ga2O3/diamond composite wafer with a reduced Ga2O3 thickness (∼ 1 μm) and thinner bonding interlayer (< 10 nm) can reduce the device thermal impedance to a level lower than today's GaN-on-SiC power switches.
@article{arxiv.2210.07417,
title = {Ultra-Wide Bandgap Ga$_2$O$_3$-on-SiC MOSFETs},
author = {Yiwen Song and Arkka Bhattacharyya and Anwarul Karim and Daniel Shoemaker and Hsien-Lien Huang and Saurav Roy and Craig McGray and Jacob H. Leach and Jinwoo Hwang and Sriram Krishnamoorthy and Sukwon Choi},
journal= {arXiv preprint arXiv:2210.07417},
year = {2023}
}