The major reliability concern in GaN HEMT technology is the current degradation due to electromechanical coupling.Electromechanical coupling is the change in the piezoelectric polarization charge in the device with the application of bias. A theoretical model to simulate the physics behind electromechanical coupling in GaN HEMT was developed in the previous work.A relationship between piezoelectric polarization charge and the vertical component of the electric field in each layer comprising the device structure was derived from the generalization of Gauss law, imposing constraints on the electric displacement vector. In the present work, this model is implemented into a particle based device Monte Carlo simulator for a GaN/AlGaN/AlN/GaN HEMT device. The simulator self consistently solves the Monte Carlo routine for the electron transport with the Poisson routine for the potential. The amount of change in the output current due to the electromechanical coupling effect is shown. The change in the output and transfer characteristics of the device due to electromechanical coupling has also been presented in this work. These results have been compared with experimental data.
Journal: TechConnect Briefs
Volume: 2, Nanotechnology 2012: Electronics, Devices, Fabrication, MEMS, Fluidics and Computational (Volume 2)
Published: June 18, 2012
Pages: 17 - 20
Industry sectors: Advanced Materials & Manufacturing | Sensors, MEMS, Electronics
Topicss: Nanoelectronics, Photonic Materials & Devices