Vacuum emission in large-area nanogap fabricated by MEMS-controlled cleavage of single crystal silicon

Nanoscale thermotunneling emission (TTE) phenomenon, governed by tunneling of electrons across a nanogap, promises many applications, ranging from chip integratable solid state refrigeration to waste heat energy harvesting; however, inability of current technology to produce large emission area electrode pairs with uniform nanogaps across large overlapping areas remains the main challenge. Extreme distance sensitivity of emission current renders TTE energy exchange insignificant for bulk scale applications. We propose a micro-electromechanical system (MEMS) based controlled inter-planar cleaving method to fabricate large emission area Si electrode pairs to potentially overcome this problem. A silicon microbeam is cleaved across <; 111 > planes using an integrated thermal actuator. Resulting cleaved planes that include a nanogap (~100 nm) between them are used as emission electrodes.