Lateral polysilicon pn diodes: current-voltage characteristicssimulation between 200 K and 400 K using a numerical approach

The current-voltage characteristics of lateral pn diodes fabricated in polysilicon layer grown by LPCVD on oxidized silicon substrates are analyzed versus temperature. The simulation proposed by Greve (1985) using the analytical current modeling is applied to forward and reverse junction currents for various temperatures; this modeling shows its limitations. Then to fit the experimental characteristics at low and high temperatures as well as at low and high current levels, a numerical modeling is developed taking into account the local electrical field effect on recombination and generation mechanisms at grain boundaries in the whole of the structure, i.e., quasi-neutral and depleted regions. This modeling allows one to fit the complete I-V experimental curves in the whole of the considered temperature range (200 K-400 K) with physical acceptable parameters