MODELS which account for the specific physics in a given semiconductor device are crucial for device modeling. This chapter starts with a discussion of the carrier transport models used, and their boundary conditions, and finally introduces lattice, thermal, and transport properties of the relevant materials. The latter also includes a discussion on polarization effects characteristic to III-N semiconductors and essential to HEMT structures.

- 4.1 Semiconductor Equations
- 4.1.1 Maxwell's Equations
- 4.1.2 Poisson Equation
- 4.1.3 Continuity Equations
- 4.1.4 The Drift-Diffusion Transport Model
- 4.1.5 The Hydrodynamic Transport Model
- 4.1.6 The Lattice Heat Flow Equation
- 4.1.7 Insulator Equations
- 4.1.8 Boundary Conditions

- 4.2 Lattice and Thermal Properties

- 4.3 Band Structure

- 4.4 Carrier Mobility
- 4.4.1 Low-Field Mobility
- 4.4.2 High-Field Mobility for DD Equations
- 4.4.3 High-Field Mobility for HD Equations
- 4.4.4 Energy Relaxation Times

- 4.5 Spontaneous and Piezoelectric Polarization
- 4.6 AC Simulation:

Equivalent Circuits and Parameter Extraction

S. Vitanov: Simulation of High Electron Mobility Transistors