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All Nitride NbN/AlGaN/GaN Schottky Gate HEMT on (0001) 4H-SiC: Improved DC Performance and Threshold Voltage Stability
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  • Umang Singh,
  • Ritam Sarkar,
  • Aakash Shandilya,
  • Apurba Laha
Umang Singh

Corresponding Author:[email protected]

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Ritam Sarkar
Aakash Shandilya
Apurba Laha


This work reports NbN as a schottky gate contact material on AlGaN/GaN HEMT. Due to higher schot-tky barrier height of NbN as compared to Ni with respect to n-type GaN, the gate leakage and subsequently the off current is observed to decrease by order of 3 and 4 respectively. No significant change in transconductance maxima is seen with a decrease only of 2.6 mS/mm in case of NbN MSHEMT as compared to Ni/Au MSHEMT. The NbN MSHEMT also has a good thermal stability with an increase in off current by only one order at 200°C as compared to 27°C. The subthreshold slope is also seen to decrease from 266 mV/decade for Ni/Au MSHEMT to 72 mV/decade for NbN MSHEMT. Lastly, as the NbN is metallic in nature, the threshold voltage stability of the resulting MSHEMT, is very high with the hysteresis in C-V curve being almost negligible.
15 Dec 2023Submitted to TechRxiv
22 Dec 2023Published in TechRxiv