Next Article in Journal
Enhanced Thermal Conductivity and Dielectric Properties of h-BN/LDPE Composites
Previous Article in Journal
Corrosion-Resistant Steel–MgO Composites as Refractory Materials for Molten Aluminum Alloys
Previous Article in Special Issue
Comparative Research of GaN Growth Mechanisms on Patterned Sapphire Substrates with Sputtered AlON Nucleation Layers
Open AccessFeature PaperEditor’s ChoiceArticle

Use of Bilayer Gate Insulator in GaN-on-Si Vertical Trench MOSFETs: Impact on Performance and Reliability

1
Department of Information Engineering, University of Padua, 35131 Padua, Italy
2
IMEC, Kapeldreef 75, 3001 Leuven, Belgium
3
CMST imec/UGent, 9052 Ghent, Belgium
*
Author to whom correspondence should be addressed.
Materials 2020, 13(21), 4740; https://doi.org/10.3390/ma13214740
Received: 27 September 2020 / Revised: 19 October 2020 / Accepted: 21 October 2020 / Published: 23 October 2020
(This article belongs to the Special Issue Wide-Bandgap Materials and Applications)
We propose to use a bilayer insulator (2.5 nm Al2O3 + 35 nm SiO2) as an alternative to a conventional uni-layer Al2O3 (35 nm), for improving the performance and the reliability of GaN-on-Si semi vertical trench MOSFETs. This analysis has been performed on a test vehicle structure for module development, which has a limited OFF-state performance. We demonstrate that devices with the bilayer dielectric present superior reliability characteristics than those with the uni-layer, including: (i) gate leakage two-orders of magnitude lower; (ii) 11 V higher off-state drain breakdown voltage; and (iii) 18 V higher gate-source breakdown voltage. From Weibull slope extractions, the uni-layer shows an extrinsic failure, while the bilayer presents a wear-out mechanism. Extended reliability tests investigate the degradation process, and hot-spots are identified through electroluminescence microscopy. TCAD simulations, in good agreement with measurements, reflect electric field distribution near breakdown for gate and drain stresses, demonstrating a higher electric field during positive gate stress. Furthermore, DC capability of the bilayer and unilayer insulators are found to be comparable for same bias points. Finally, comparison of trapping processes through double pulsed and Vth transient methods confirms that the Vth shifts are similar, despite the additional interface present in the bilayer devices. View Full-Text
Keywords: GaN; vertical GaN; trench MOS; gate dielectric; breakdown; trapping; reliability GaN; vertical GaN; trench MOS; gate dielectric; breakdown; trapping; reliability
Show Figures

Figure 1

MDPI and ACS Style

Mukherjee, K.; De Santi, C.; Borga, M.; You, S.; Geens, K.; Bakeroot, B.; Decoutere, S.; Meneghesso, G.; Zanoni, E.; Meneghini, M. Use of Bilayer Gate Insulator in GaN-on-Si Vertical Trench MOSFETs: Impact on Performance and Reliability. Materials 2020, 13, 4740. https://doi.org/10.3390/ma13214740

AMA Style

Mukherjee K, De Santi C, Borga M, You S, Geens K, Bakeroot B, Decoutere S, Meneghesso G, Zanoni E, Meneghini M. Use of Bilayer Gate Insulator in GaN-on-Si Vertical Trench MOSFETs: Impact on Performance and Reliability. Materials. 2020; 13(21):4740. https://doi.org/10.3390/ma13214740

Chicago/Turabian Style

Mukherjee, Kalparupa; De Santi, Carlo; Borga, Matteo; You, Shuzhen; Geens, Karen; Bakeroot, Benoit; Decoutere, Stefaan; Meneghesso, Gaudenzio; Zanoni, Enrico; Meneghini, Matteo. 2020. "Use of Bilayer Gate Insulator in GaN-on-Si Vertical Trench MOSFETs: Impact on Performance and Reliability" Materials 13, no. 21: 4740. https://doi.org/10.3390/ma13214740

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Search more from Scilit
 
Search
Back to TopTop