A software tool for the design of high power PiN diodes based on the numerical study of the reverse characteristics

A physically based model of power PiN diodes was developed to simulate the reverse voltage behavior with purpose of design optimization for specific application. The model includes process simulation and 2D drift-diffusion simulation of the defined geometrical diode structure. The process simulation was adjusted to obtain the same doping profile measured on a known sample. Since bulk silicon and dopants used in high power device production are different from those used in VLSI, various analytical models of impurity diffusion phenomena were considered and parameters calibration was carried out within the range found in the literature to obtain the best fit with measurements. Impact ionization coefficients of the reverse biased diode model were tuned by comparison with measurements on a reference device and exploited to study the dependence of breakdown voltage vs. various technological parameters. A simulation campaign for many different diode structures was conducted. An ad hoc interpolation algorithm was developed and applied for using measurement and simulation results in quick design of diode structures for specific application.