Ultrafast Metal-Semiconductor-Metal Photoconductive Switches Fabricated Using an Atomic Force Microscope

Abstract

The oxidation using an atomic force microscope was applied in the fabrication of ultrafast metal-semiconductor-metal photoconductive switches. The photoconductive gap was formed by the oxidation of a 4 nm-thick-titanium layer. The photoconductive gap which was 100 nm wide and covered with the oxidized titanium which is not only a good insulator but also transparent to the excitation beam. A full width at half-maximum response of 380 fs was obtained at a bias voltage of 10 V.