Modeling edge capacitances in ultra-scaled GaAs Schottky barrier diodes for THz applications
Nanometer scale planar Schottky barrier diodes with realistic geometries have been simulated by means of a two-dimensional ensemble Monte Carlo simulator. The intrinsic capacitance of such small devices, which due to edge effects strongly deviates from the ideal value, has been calculated. By means of Monte Carlo simulations we analyze the influence of the 2D geometry of the Schottky contact, the doping level of the epilayer and the surface charges at the semiconductor-dielectric interface on the value of the edge capacitance. The final aim is to develop a compact model that can be easily implemented in design automation software such as ADS. The topology of the devices studied in this work is based in real planar GaAs Schottky barrier diodes used in THz applications such as passive frequency mixing and multiplication, in which accurate models for the diode capacitance are required.