Version 1
: Received: 19 August 2024 / Approved: 20 August 2024 / Online: 20 August 2024 (14:30:16 CEST)
How to cite:
HAMDAOUI, Y.; Vandenbroucke, S.; Michler, S.; Ziouche, K.; Minjauw, M.; Detavernier, C.; Medjdoub, F. Optimization of Non-alloyed Backside Ohmic Contacts to N-face GaN for Fully Vertical GaN-on-Silicon Based Power Devices. Preprints2024, 2024081457. https://doi.org/10.20944/preprints202408.1457.v1
HAMDAOUI, Y.; Vandenbroucke, S.; Michler, S.; Ziouche, K.; Minjauw, M.; Detavernier, C.; Medjdoub, F. Optimization of Non-alloyed Backside Ohmic Contacts to N-face GaN for Fully Vertical GaN-on-Silicon Based Power Devices. Preprints 2024, 2024081457. https://doi.org/10.20944/preprints202408.1457.v1
HAMDAOUI, Y.; Vandenbroucke, S.; Michler, S.; Ziouche, K.; Minjauw, M.; Detavernier, C.; Medjdoub, F. Optimization of Non-alloyed Backside Ohmic Contacts to N-face GaN for Fully Vertical GaN-on-Silicon Based Power Devices. Preprints2024, 2024081457. https://doi.org/10.20944/preprints202408.1457.v1
APA Style
HAMDAOUI, Y., Vandenbroucke, S., Michler, S., Ziouche, K., Minjauw, M., Detavernier, C., & Medjdoub, F. (2024). Optimization of Non-alloyed Backside Ohmic Contacts to N-face GaN for Fully Vertical GaN-on-Silicon Based Power Devices. Preprints. https://doi.org/10.20944/preprints202408.1457.v1
Chicago/Turabian Style
HAMDAOUI, Y., Christophe Detavernier and Farid Medjdoub. 2024 "Optimization of Non-alloyed Backside Ohmic Contacts to N-face GaN for Fully Vertical GaN-on-Silicon Based Power Devices" Preprints. https://doi.org/10.20944/preprints202408.1457.v1
Abstract
In the framework of fully vertical GaN-on-Silicon device technology development, we report on the optimization of non-alloyed ohmic contacts on the N-polar n+ doped GaN face backside layer. This evaluation is made possible by using patterned TLMs (Transmission Line Model) through direct laser writing lithography after locally removing the substrate and buffer layers in order to access the n+ doped backside layer. As deposited non-alloyed metal stack on top of N-polar orientation GaN layer after buffer layers removal results in poor ohmic contact quality. To significantly reduce the related contact resistances, an HCl treatment is applied prior to metallization under various time and temperature conditions. A 3-minutes HCl treatment at 70°C is found to be the optimum condition to achieve thermally stable high ohmic contact quality. To further understand the impact of the wet treatment, SEM (Scanning Electron Microscopy) and XPS (X-ray Photoelectron Spectroscopy) analysis were performed. XPS revealed a decrease in Ga-O concentration after applying the treatment, reflecting the higher oxidation susceptibility of the N-polar face compared to the Ga-polar face, which was used as a reference. SEM images of the treated samples show the formation of pyramids on the N-face after HCl treatment, suggesting specific wet etching planes of the GaN crystal from the N-face. The size of the pyramids is time-dependent; thus, increasing the treatment duration results in larger pyramids, explaining the degradation of ohmic contact quality after prolonged high temperature HCl treatment.
Engineering, Electrical and Electronic Engineering
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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