Residual Interface Traps at Bird's Beaks of Field Oxide Layers

Abstract

The interface trap density (Dit) of field oxide films is determined from the subthreshold characteristics of parasitic field effect transistors. A Dit of 8×1014 m-2eV-1 persists in the bird's beak regions of local oxidation of silicon (LOCOS) structure after annealing at 723 K in a H2 ambient. This value is almost ten times larger than that observed for a SiO2/Si interface grown on a (100) Si plane.