Trapping in Tunnel Oxides Grown on Textured Polysilicon

Abstract

The generation of electron traps in Poly Silicon Oxide by the application of an electric field in the absence of current is described. The assymetric I-V curves of textured poly-silicon oxide tunneling layers allow high "reverse bias" electric fields to be applied with no measureable current. After these fields are applied, new traps are observed that reduce the "forward bias" conduction. These traps appear to be empty until the resumption of forward bias conduction fills them. They are roughly linear with applied field and appear to saturate with time. A floating gate circuit that allows convenient measurement of the passage of 10¿8 coulombs/cm2 and current density from 10¿2 amps/cm2 to 10¿12 amps/cm2 to be conveniently measured is described.