Ultra-Wide Bandgap Ga\(_2\)O\(_3\)-on-SiC MOSFETs

• Published in: arXiv.org
• Main Authors: Song, Yiwen, Bhattacharyya, Arkka, Karim, Anwarul, Shoemaker, Daniel, Hsien-Lien Huang, Roy, Saurav, McGray, Craig, Leach, Jacob H, Hwang, Jinwoo, Krishnamoorthy, Sriram, Choi, Sukwon
• Format: Paper
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 21.02.2023
• Subjects: Bonding; Commercialization; Diamonds; Epitaxial growth; Interlayers; Low temperature; Metalorganic chemical vapor deposition; MOSFETs; Overheating; Production costs; Semiconductors; Silicon carbide; Structural integrity; Substrates; Switches; Thermodynamic properties; Vapor phase epitaxy; Vapor phases; Wide bandgap semiconductors
• ISSN: 2331-8422

Ulta-wide bandgap semiconductors based on \(\beta\)-Ga\(_2\)O\(_3\) 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 Ga\(_2\)O\(_3\) electronics is overheating, which impacts the device's performance and reliability. We fabricated a Ga\(_2\)O\(_3\)/4H-SiC composite wafer using a fusion-bonding method. A low temperature (\(\le\) 600 \(^{\circ}\)C) epitaxy and device processing approach based on low-temperature (LT) metalorganic vapor phase epitaxy is developed to grow a Ga\(_2\)O\(_3\) epitaxial channel layer on the composite wafer and subsequently fabricate into Ga\(_2\)O\(_3\) power MOSFETs. This LT approach is essential to preserve the structural integrity of the composite wafer. These LT-grown epitaxial Ga\(_2\)O\(_3\) 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 \(\sim\) 300 MW/cm\(^2\), which is a record high for any heterogeneously integrated Ga\(_2\)O\(_3\) devices reported to date. This work is the first realization of multi-kilovolt homoepitaxial Ga\(_2\)O\(_3\) 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 Ga\(_2\)O\(_3\)/diamond composite wafer with a reduced Ga\(_2\)O\(_3\) thickness (\(\sim\) 1 \(\mu\)m) and thinner bonding interlayer (\(<\) 10 nm) can reduce the device thermal impedance to a level lower than today's GaN-on-SiC power switches.