Two-Dimensional Numerical Simulation of Si Schottky/Two-Dimensional Electron Gas Barrier Diode Using Boundary Element Method

In this work, we report on the simulation and physical insight of a Schottky/two-dimensional electron gas (2DEG) silicon barrier diode using a boundary element method (BEM) for the first time. The BEM can effectively reduce the dimensions of equation systems and the computation time as compared to conventional numerical methods such as finite-element or finite-difference methods. Using an efficient algorithm for depletion layer width estimation, the potential and electric field distributions, the dependence of the depletion layer thickness on the applied voltage, and capacitance-voltage ( C-V ) characteristics of the Schottky/2DEG junction under different bias conditions are investigated. It is found that the free boundary condition along the top surface of the Schottky/2DEG barrier diode exerts a strong effect on both the electric field distribution and C-V characteristics. In addition, the calculated results show that the Schottky/2DEG diode has a high C-V nonlinearity which increases with decreasing i-Si layer thickness around the 2DEG layer.