| AVS 65th International Symposium & Exhibition | |
| Electronic Materials and Photonics Division | Wednesday Sessions |
| Session EM+2D+SS-WeA |
| Session: | Wide and Ultra-Wide Bandgap Materials for Electronic Devices: Growth, Modeling and Properties |
| Presenter: | Jiancheng Yang, University of Florida |
| Authors: | J.C. Yang, University of Florida F.R. Ren, University of Florida M.J. Tadjer, U.S. Naval Research Laboratory S.J. Pearton, University of Florida A. Kuramata, Tamura Corporation and Novel Crystal Technology, Inc., Japan |
| Correspondent: | Click to Email |
A reverse breakdown voltage of 2300 V with corresponding breakdown field of 1.15 MV/cm was demonstrated for 20 µm epi-β-Ga2O3 edge-terminated vertical Schottky rectifiers. This breakdown voltage is the highest ever reported for Ga2O3 rectifiers. Ga2O3 has an energy band gap of range 4.5 – 4.9 eV, which correlates to the theoretical breakdown electric field of ~8 MV/cm. The theoretical Baliga figure of merit (defined as VB2/RON, where VB is the reverse breakdown voltage and RON is the on-state resistance) of Ga2O3 estimated to be 400% higher than GaN.[1] Previously reported, an unterminated Ga2O3 rectifier shown a breakdown voltage of 1600 V, and a field-plated Schottky diode has a breakdown voltage of 1076 V with the epi thickness 7 µm [2,3] This work has shown the improvement of the Ga2O3 vertical rectifiers breakdown voltage using a field-plate terminated approach with a lightly doped 20 µm Ga2O3 epitaxial layer . The edge-terminated Schottky rectifiers of various dimensions (circular geometry with diameter of 50-200 µm and square diodes with areas 4 × 10-3- 10-2 cm2) fabricated on 20µm lightly doped (n=2.10 × 1015 cm -3) β-Ga2O3 epitaxial layers grown by hydride vapor phase epitaxy on conducting (n=3.6 × 1018 cm-3) Ga2O3 substrates grown by edge-defined, film-fed growth. The RON for these devices was 0.25 Ω-cm2, leading to a figure of merit (VB2/RON) of 21.2 MW/cm2. The Schottky barrier height with the Ni/Au based metallization was 1.03 eV, with an ideality factor of 1.1 at room temperature. The Richardson’s constant of 43.35 A/cm-K2 was extracted from the temperature dependent forward IV. The breakdown voltages for the different size devices ranged from 1400-2300V, with a general, but not a linear trend of decreasing breakdown voltage for larger area rectifiers. The diode reverse recovery time of ~22 ns was measured by switching the diode from +2V to -2V.
1. J. Green, K. D. Chabak, E. R. Heller, R. C. Fitch, M. Baldini, A. Fiedler, K. Irmscher, G. Wagner, Z. Galazka, S. E. Tetlak, A. Crespo, K. Leedy, and G. H. Jessen, IEEE Electron Device Lett., vol. 37, no. 7, pp. 902–905, Jul. (2016)
2. J. Yang, S. Ahn, F. Ren, S. J. Pearton, S. Jang, and A. Kuramata, IEEE Electron Device Lett,. 38(7), 906 (2017).
3. K. Konishi, K. Goto, H. Murakami, Y. Kumagai, A. Kuramata, S. Yamakoshi, and M. Higashiwaki, Appl. Phys. Lett. 110, 103506 (2017).