Investigation of Porous Silicon-Based Edge Termination for Planar-Type TRIAC

This paper aims to investigate a porous silicon (PS)-based edge termination for planar type ac switch. TRIAC device prototypes, specifically dedicated to evaluate blocking performances, are fabricated by integrating electrochemical etching in device processing. A mixed porous morphology containing micro-, meso-, and macropores is obtained in a p-Type through-wafer-diffused via after anodization. The fabricated prototypes show PS-dependent blocking capabilities. The possible impacts of the anodization conditions and the physical features of PS on the electrical characteristics are discussed in detail. Low leakage currents (<;10 μA) have been demonstrated up to several hundred voltages for both bias polarities. The forward blocking voltage decreases with increasing PS thickness, while an opposite trend is observed for the reverse blocking voltage. This paper confirms the interest of PS as a potential insulating material for power device manufacture.