### Abstract

In this work we first report on a theoretical model which provides the gate voltage dependence of the piezoelectric polarization charge in GaN HEMT devices. The model utilizes a generalization of Gauss' law, imposing constraints on the electric displacement vector D. The constraint on D is given by the continuity of the perpendicular component of the displacement vector across an interface. Poisson's equation is then solved across various layers under proper boundary conditions for the applied bias. The piezoelectric polarization charge is reduced due to the electromechanical coupling compared to the uncoupled case. Under high sheet electron densities, the correction in the piezoelectric polarization charge is also lower due to smaller electric fields. The theoretical model is then incorporated in the particle-based device simulator and device transfer and output characteristics are calculated without and with the bias dependent polarization charge. We find that percentage change in drain current increases with larger negative bias on the gate, due to the larger vertical electric fields.

Original language | English (US) |
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Title of host publication | Technical Proceedings of the 2012 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2012 |

Pages | 17-20 |

Number of pages | 4 |

State | Published - 2012 |

Event | Nanotechnology 2012: Electronics, Devices, Fabrication, MEMS, Fluidics and Computational - 2012 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2012 - Santa Clara, CA, United States Duration: Jun 18 2012 → Jun 21 2012 |

### Other

Other | Nanotechnology 2012: Electronics, Devices, Fabrication, MEMS, Fluidics and Computational - 2012 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2012 |
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Country | United States |

City | Santa Clara, CA |

Period | 6/18/12 → 6/21/12 |

### Fingerprint

### Keywords

- Electro-Mechanical coupling
- GaN HEMTs
- Polarization charges

### ASJC Scopus subject areas

- Ceramics and Composites
- Surfaces, Coatings and Films

### Cite this

*Technical Proceedings of the 2012 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2012*(pp. 17-20)

**Current degradation due to electromechanical coupling in GaN HEMT's.** / Padmanabhan, Balaji; Vasileska, Dragica; Goodnick, Stephen.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

*Technical Proceedings of the 2012 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2012.*pp. 17-20, Nanotechnology 2012: Electronics, Devices, Fabrication, MEMS, Fluidics and Computational - 2012 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2012, Santa Clara, CA, United States, 6/18/12.

}

TY - GEN

T1 - Current degradation due to electromechanical coupling in GaN HEMT's

AU - Padmanabhan, Balaji

AU - Vasileska, Dragica

AU - Goodnick, Stephen

PY - 2012

Y1 - 2012

N2 - In this work we first report on a theoretical model which provides the gate voltage dependence of the piezoelectric polarization charge in GaN HEMT devices. The model utilizes a generalization of Gauss' law, imposing constraints on the electric displacement vector D. The constraint on D is given by the continuity of the perpendicular component of the displacement vector across an interface. Poisson's equation is then solved across various layers under proper boundary conditions for the applied bias. The piezoelectric polarization charge is reduced due to the electromechanical coupling compared to the uncoupled case. Under high sheet electron densities, the correction in the piezoelectric polarization charge is also lower due to smaller electric fields. The theoretical model is then incorporated in the particle-based device simulator and device transfer and output characteristics are calculated without and with the bias dependent polarization charge. We find that percentage change in drain current increases with larger negative bias on the gate, due to the larger vertical electric fields.

AB - In this work we first report on a theoretical model which provides the gate voltage dependence of the piezoelectric polarization charge in GaN HEMT devices. The model utilizes a generalization of Gauss' law, imposing constraints on the electric displacement vector D. The constraint on D is given by the continuity of the perpendicular component of the displacement vector across an interface. Poisson's equation is then solved across various layers under proper boundary conditions for the applied bias. The piezoelectric polarization charge is reduced due to the electromechanical coupling compared to the uncoupled case. Under high sheet electron densities, the correction in the piezoelectric polarization charge is also lower due to smaller electric fields. The theoretical model is then incorporated in the particle-based device simulator and device transfer and output characteristics are calculated without and with the bias dependent polarization charge. We find that percentage change in drain current increases with larger negative bias on the gate, due to the larger vertical electric fields.

KW - Electro-Mechanical coupling

KW - GaN HEMTs

KW - Polarization charges

UR - http://www.scopus.com/inward/record.url?scp=84864950349&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84864950349&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:84864950349

SN - 9781466562752

SP - 17

EP - 20

BT - Technical Proceedings of the 2012 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2012

ER -