Tunneling Current through Ultrathin Silicon Dioxide Films under Light Exposure

Abstract

Tunneling current through ultrathin silicon dioxide films with a thickness of approximately 3.1 nm, formed on n-Si (100) by controlling preoxide growth during heating, is examined using Al/oxide/n-Si structures. Electron tunneling current through the oxide from n-Si to Al is decreased and the dielectric breakdown voltage is increased by the preoxide growth control. Electron tunneling current from Al to n-Si is increased by light exposure. The increase in electron tunneling current can be explained by the increase in oxide voltage with an inversion layer formed by photoexcitation.