Electron field emission from silicon nanoprotrusions

Recently, enhanced field emission of electrons from a variety of nanostructured materials such as carbon nanotubes, and porous Si has been extensively studied for application to displays and other vacuum electronic devices. In this work, we have studied field emission of electrons by using a diode experimental setup without gate electrodes from the most fundamental Si nanostructure, i.e., Si nanoprotrusions with both vertical and lateral sizes of 10∼20 nm and the density of 3∼5×10¹¹ cm^-2. The protrusions were fabricated by our original self-organized selective oxidation technique, referred to as "nano-LOCOS". Although the Si protrusions were quite small, high emission current was detected at low anode voltages, depending on the microscopic shape controlled by oxidation conditions. This result encourages us to develop "bright" and "highly functional" electron emitting devices using the Si nanosystem.