Next Article in Journal
Mechanical Behavior Investigation of 4H-SiC Single Crystal at the Micro–Nano Scale
Next Article in Special Issue
Design and Implementation of a GaN-Based Three-Phase Active Power Filter
Previous Article in Journal
Dye-Doped ZnO Microcapsules for High Throughput and Sensitive Optofluidic Micro-Thermometry
Previous Article in Special Issue
Physical-Based Simulation of the GaN-Based Grooved-Anode Planar Gunn Diode
Open AccessArticle

Vertical Leakage in GaN-on-Si Stacks Investigated by a Buffer Decomposition Experiment

1
Department of Information Engineering, University of Padova, 35151 Padova, Italy
2
Fraunhofer Institute for Integrated Systems and Device Technology IISB, 91058 Erlangen, Germany
3
EpiGaN, 3500 Hasselt, Belgium
4
IEMN-CNRS, 59652 Villeneuve d’Ascq, France
*
Authors to whom correspondence should be addressed.
Micromachines 2020, 11(1), 101; https://doi.org/10.3390/mi11010101
Received: 19 December 2019 / Revised: 10 January 2020 / Accepted: 12 January 2020 / Published: 17 January 2020
(This article belongs to the Special Issue Wide Bandgap Based Devices: Design, Fabrication and Applications)
We investigated the origin of vertical leakage and breakdown in GaN-on-Si epitaxial structures. In order to understand the role of the nucleation layer, AlGaN buffer, and C-doped GaN, we designed a sequential growth experiment. Specifically, we analyzed three different structures grown on silicon substrates: AlN/Si, AlGaN/AlN/Si, C:GaN/AlGaN/AlN/Si. The results demonstrate that: (i) the AlN layer grown on silicon has a breakdown field of 3.25 MV/cm, which further decreases with temperature. This value is much lower than that of highly-crystalline AlN, and the difference can be ascribed to the high density of vertical leakage paths like V-pits or threading dislocations. (ii) the AlN/Si structures show negative charge trapping, due to the injection of electrons from silicon to deep traps in AlN. (iii) adding AlGaN on top of AlN significantly reduces the defect density, thus resulting in a more uniform sample-to-sample leakage. (iv) a substantial increase in breakdown voltage is obtained only in the C:GaN/AlGaN/AlN/Si structure, that allows it to reach VBD > 800 V. (v) remarkably, during a vertical I–V sweep, the C:GaN/AlGaN/AlN/Si stack shows evidence for positive charge trapping. Holes from C:GaN are trapped at the GaN/AlGaN interface, thus bringing a positive charge storage in the buffer. For the first time, the results summarized in this paper clarify the contribution of each buffer layer to vertical leakage and breakdown. View Full-Text
Keywords: Gallium nitride (GaN) high-electron-mobility transistors (HEMTs); vertical breakdown voltage; buffer trapping effect Gallium nitride (GaN) high-electron-mobility transistors (HEMTs); vertical breakdown voltage; buffer trapping effect
Show Figures

Figure 1

MDPI and ACS Style

Tajalli, A.; Borga, M.; Meneghini, M.; De Santi, C.; Benazzi, D.; Besendörfer, S.; Püsche, R.; Derluyn, J.; Degroote, S.; Germain, M.; Kabouche, R.; Abid, I.; Meissner, E.; Zanoni, E.; Medjdoub, F.; Meneghesso, G. Vertical Leakage in GaN-on-Si Stacks Investigated by a Buffer Decomposition Experiment. Micromachines 2020, 11, 101. https://doi.org/10.3390/mi11010101

AMA Style

Tajalli A, Borga M, Meneghini M, De Santi C, Benazzi D, Besendörfer S, Püsche R, Derluyn J, Degroote S, Germain M, Kabouche R, Abid I, Meissner E, Zanoni E, Medjdoub F, Meneghesso G. Vertical Leakage in GaN-on-Si Stacks Investigated by a Buffer Decomposition Experiment. Micromachines. 2020; 11(1):101. https://doi.org/10.3390/mi11010101

Chicago/Turabian Style

Tajalli, Alaleh; Borga, Matteo; Meneghini, Matteo; De Santi, Carlo; Benazzi, Davide; Besendörfer, Sven; Püsche, Roland; Derluyn, Joff; Degroote, Stefan; Germain, Marianne; Kabouche, Riad; Abid, Idriss; Meissner, Elke; Zanoni, Enrico; Medjdoub, Farid; Meneghesso, Gaudenzio. 2020. "Vertical Leakage in GaN-on-Si Stacks Investigated by a Buffer Decomposition Experiment" Micromachines 11, no. 1: 101. https://doi.org/10.3390/mi11010101

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