Cleavage fracture fabricated nanogap device in SEM for gap control and current measurement

Abstract

In this research, single crystal silicon was cleaved in a scanning electron microscope (SEM) and then current measurement was conducted in order to clarify the electrical characteristics between vacuum cleavage nanogap. Vacuum nanogaps are expected as small-sized, high-efficiency thermal power generation devices. However, nanogaps produced by the conventional method have the problem that the gap surface is not smooth and the opposing area is as small as nm² order. In order to solve the problem, we proposed cleavage of single crystal silicon as a method to form nanogaps. We fabricated devices and systems capable of continuously performing cleavage fracture, gap interval control, and current measurement in the SEM, and we performed cleavage in the SEM and current measurement. As a result, we succeeded in fabricating a nanogap with an opposing area of 8-μm² and a gap spacing of several tens of nanometers in the SEM. In addition we measured 1 mA current, which is suggested to be due to field emission current.