Effects of surface traps on breakdown voltage and switching speed of GaN power switching HEMTs

Zhang, N.-Q.; Moran, B.; DenBaars, Steven P.; Mishra, Umesh K.; Wang, X.W.; Ma, T.P.

doi:10.1109/iedm.2001.979575

Cited by 75 publications

(32 citation statements)

References 5 publications

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“…SiO 2 passivation of GaN devices results in similar effects. This suppressed leakage current and increased the breakdown voltage, indicative of deep surface traps and enhanced vertical depletion [20]. Fig.…”

Section: Resultsmentioning

confidence: 99%

Contact Resistance and Leakage Current of GaN Devices with Annealed Ti/Al/Mo/Au Ohmic Contacts

Ha¹,

Kang-Min²,

Jo³

et al. 2016

JSTS:Journal of Semiconductor Technology and Science

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Abstract-In recent years, the on-resistance, power loss and cell density of Si power devices have not exhibited significant improvements, and performance is approaching the material limits. GaN is considered an attractive material for future high-power applications because of the wide band-gap, large breakdown field, high electron mobility, high switching speed and low on-resistance. Here we report on the Ohmic contact resistance and reversebias characteristics of AlGaN/GaN Schottky barrier diodes with and without annealing. Annealing in oxygen at 500℃ resulted in an increase in the breakdown voltage from 641 to 1,172 V for devices with an anode-cathode separation of 20 μm. However, these annealing conditions also resulted in an increase in the contact resistance of 0.183 Ω-mm, which is attributed to oxidation of the metal contacts. Auger electron spectroscopy revealed diffusion of oxygen and Au into the AlGaN and GaN layers following annealing. The improved reverse-bias characteristics following annealing in oxygen are attributed to passivation of dangling bonds and plasma damage due to interactions between oxygen and GaN/AlGaN. Thermal annealing is therefore useful during the fabrication of high-voltage GaN devices, but the effects on the Ohmic contact resistance should be considered.

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Section: Resultsmentioning

confidence: 99%

Contact Resistance and Leakage Current of GaN Devices with Annealed Ti/Al/Mo/Au Ohmic Contacts

Ha¹,

Kang-Min²,

Jo³

et al. 2016

JSTS:Journal of Semiconductor Technology and Science

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“…The reaction process of Ni and O in the AlGaN barrier may be related to the formation of deep states. It has been reported that the deep states suppress the leakage current due to their low emission rate [9,10]. We also measured test samples oxidized at 300 and other samples oxidized at 700 °C.…”

Section: Resultsmentioning

confidence: 99%

“…The proposed device sustained a low leakage current until breakdown. The oxidation process can form deep states which suppress the gate leakage current [9,10]. The deep states as a result of the oxidation process are explained by the subsequent pulsed I-V.…”

Section: Resultsmentioning

confidence: 99%

“…Si 3 N 4 passivation [6,7] has widely used to suppress the RF dispersion in microwave applications. SiO 2 passivation [8,9] reportedly improves the blocking characteristics of high-voltage switches. Post-annealing [10] or oxidation [11] methods have also been proposed to improve the breakdown voltage and gate leakage current.…”

Section: Introductionmentioning

confidence: 99%

“…In an effort to address these surface problems, various passivation methods [6][7][8][9] and surface treatments [9][10][11][12] have been studied. Si 3 N 4 passivation [6,7] has widely used to suppress the RF dispersion in microwave applications.…”

Section: Introductionmentioning

confidence: 99%

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High-Voltage AlGaN/GaN High-Electron-Mobility Transistors Using Thermal Oxidation for NiO_xPassivation

Kim¹,

Seok²,

Han³

et al. 2013

Journal of Electrical Engineering and Technology

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-We proposed AlGaN/GaN high-electron-mobility transistors (HEMTs) using thermal oxidation for NiOx passivation. Auger electron spectroscopy, secondary ion mass spectroscopy, and pulsed I-V were used to study oxidation features. The oxidation process diffused Ni and O into the AlGaN barrier and formed NiOx on the surface. The breakdown voltage of the proposed device was 1520 V while that of the conventional device was 300 V. The gate leakage current of the proposed device was 3.5 µA/mm and that of the conventional device was 1116.7 µA/mm. The conventional device exhibited similar current in the gate-and-drain-pulsed I-V and its drain-pulsed counterpart. The gate-and-drain-pulsed current of the proposed device was about 56 % of the drain-pulsed current. This indicated that the oxidation process may form deep states having a low emission current, which then suppresses the leakage current. Our results suggest that the proposed process is suitable for achieving high breakdown voltages in the GaN-based devices.

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Effect of SiO₂ Surface Passivation on the Performance of GaN Polarization Superjunction Heterojunction Field Effect Transistors

Du,

Madathil,

Kawai

et al. 2023

Physica Status Solidi (a)

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In this article, the effects of the SiO2 surface passivation layer are reported on normally‐on 1.2 kV GaN polarization superjunction (PSJ) heterojunction field effect transistors (HFETs) by comparing the electrical performances of PSJ HFETs with and without SiO2 surface passivation. A slight recovery of the 2D electron gas sheet density is observed in the slight negative shift of Vth after SiO2 surface passivation. Passivation also increases the breakdown voltage. This improvement may result from removing positive surface charges in defects along the P‐GaN gate sidewall and top u‐GaN layer after the specifically designed SiO2 surface passivation. Furthermore, the SiO2 surface passivation can also effectively suppress the surface gate leakage currents in the PSJ HFETs by eliminating the conductive channel created by the positive surface charges in defects.

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Effects of surface traps on breakdown voltage and switching speed of GaN power switching HEMTs

Cited by 75 publications

References 5 publications

Contact Resistance and Leakage Current of GaN Devices with Annealed Ti/Al/Mo/Au Ohmic Contacts

Contact Resistance and Leakage Current of GaN Devices with Annealed Ti/Al/Mo/Au Ohmic Contacts

High-Voltage AlGaN/GaN High-Electron-Mobility Transistors Using Thermal Oxidation for NiO_xPassivation

Effect of SiO₂ Surface Passivation on the Performance of GaN Polarization Superjunction Heterojunction Field Effect Transistors

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Effects of surface traps on breakdown voltage and switching speed of GaN power switching HEMTs

Cited by 75 publications

References 5 publications

Contact Resistance and Leakage Current of GaN Devices with Annealed Ti/Al/Mo/Au Ohmic Contacts

Contact Resistance and Leakage Current of GaN Devices with Annealed Ti/Al/Mo/Au Ohmic Contacts

High-Voltage AlGaN/GaN High-Electron-Mobility Transistors Using Thermal Oxidation for NiOxPassivation

Effect of SiO2 Surface Passivation on the Performance of GaN Polarization Superjunction Heterojunction Field Effect Transistors

Contact Info

Product

Resources

About

High-Voltage AlGaN/GaN High-Electron-Mobility Transistors Using Thermal Oxidation for NiO_xPassivation

Effect of SiO₂ Surface Passivation on the Performance of GaN Polarization Superjunction Heterojunction Field Effect Transistors