Research on physical framework and theoretical model

In this work, I develop the physical framework and theoretical model of GaN power MEMS devices.

Outline

In this work, a semi-classical physical model of the MEMS device with a cantilever structure based on AlGaN/AlN/GaN heterojunction has been established by using piezoelectric theory. The mathematical relationship between the lattice strain and the piezoelectric polarization charge of the multilayer heterojunction film is deduced through the piezoelectric constitutive equation and biaxial stress model. Then the finite element analysis method of material mechanics is used to calculate the piezoelectric polarization charge intensity of the heterojunction film under different external stresses, and the one-dimensional Schrödinger-Poisson self-consistent coupling model was used to calculate the modulation characteristics of the external stress on the energy band of the AlGaN/AlN/GaN heterojunction and the electrical properties of the MEMS device.

Research Method

Finite element analysis and finite difference method

Mechanics of materials and biaxial stress model

One-dimensional Schrödinger-Poisson self-consistent coupling model

Piezoelectric constitutive equation and electromagnetism theory

MATLAB programming and COMSOL Multiphysics finite element analysis

Conclusion

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The developed theoretical model successfully reveals the working mechanism of GaN power MEMS devices.

Presentations

Full text

Development of Gallium Nitride Power MEMS Devices

Reference

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