1. Charge Transport in Vertical GaN Schottky Barrier Diodes: A Refined Physical Model for Conductive Dislocations.
- Author
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Chen, Leilei, Schrimpf, Ronald D., Fleetwood, Daniel M., Lu, Hai, Jin, Ning, Yan, Dawei, Cao, Yanrong, Zhao, Linna, Liang, Hailian, Liu, Bin, Zhang, En Xia, and Gu, Xiaofeng
- Subjects
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SCHOTTKY barrier diodes , *FIELD emission , *THERMIONIC emission , *CURRENT-voltage characteristics , *CONDUCTION bands - Abstract
Charge transport mechanisms of forward and reverse leakage currents in vertical GaN Schottky barrier diodes are investigated by measuring the temperature-dependent current–voltage characteristics. The results show that the leakage current is primarily governed by dislocation-associated thermionic field emission (TFE). The primary transport path is the reduced, localized conduction band around the dislocation core rather than the continuum defect states. A refined phenomenological physical model is developed for conductive dislocations in GaN, emphasizing that: 1) surface donors, surrounding the core of dislocations, can significantly shrink the barrier region after ionization, causing severe TFE leakage; 2) the ON donors likely to be responsible for TFE have a typical density of ~ 1 × 1018 cm−3 at 300 K and activation energy of 78 meV; and 3) the barrier height at donor sites is ~0.65 eV at 300 K, which is reduced by ~0.4 eV with respect to the dislocation-free region. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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