Study on simulation model of high cut-off frequency Schottky diode

Based on the basic structure of surface channel planar Schottky barrier diode, and adopt GaAs 0.15 μm pHEMT process, a Schottky diode model of the vertical channel extended span air bridge is proposed. The influence of different anode diameters on the Schottky diode cascade resistance is studied. The simulation results of S parameters of Schottky diode models with different pad spacing are compared and analyzed. The optimal air bridge length is obtained. The TCAD model of diode Schottky junction with optimal pad spacing is simulated. The SPICE parameters of Schottky diode are extracted according to the simulation characteristic curve. The experimental results show that the diode has an extremely low zero bias junction capacitance, and the cut-off frequency is up to 9 THz. The simulation results agree well with the measured results, and can be used in the terahertz band.