Fig. 1.
Schematic diagram of the fabricated AlGaN/GaN heterostructure Schottky diode.
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| Citation: |
Dawei Yan, Fuxue Wang, Zhaomin Zhu, Jianmin Cheng, Xiaofeng Gu. Capacitance and conductance dispersion in AlGaN/GaN heterostructure[J]. Journal of Semiconductors, 2013, 34(1): 014003. doi: 10.1088/1674-4926/34/1/014003
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D W Yan, F X Wang, Z M Zhu, J M Cheng, X F Gu. Capacitance and conductance dispersion in AlGaN/GaN heterostructure[J]. J. Semicond., 2013, 34(1): 014003. doi: 10.1088/1674-4926/34/1/014003.
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Capacitance and conductance dispersion in AlGaN/GaN heterostructure
DOI: 10.1088/1674-4926/34/1/014003
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Abstract
The dispersion mechanism in Al0.27Ga0.73N/GaN heterostructure was investigated using frequency-dependent capacitance and conductance measurements. It was found that the significant capacitance and conductance dispersion occurred primarily for measurement frequency beyond 100 kHz before the channel cutoff at the interface, suggesting that the vertical polarization electrical field under the gate metal should be closely related with the observed dispersive behavior. According to the Schottky-Read-Hall model, a traditional trapping mechanism cannot be used to explain our result. Instead, a piezoelectric polarization strain relaxation model was adopted to interpret the dispersion. By fitting the obtained capacitance data, the corresponding characteristic time and charge density were determined 10-8 s and 5.26×1012 cm-2 respectively, in good agreement with the conductance data and theoretical prediction. -
References
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