Electron emission properties of titanium nitride coated volcano-structured silicon emitters

Volcano-structured field emitter arrays (FEAs) have achieved high-beam focusing and have been applied in electron beam lithography and image sensors. However, high current operation on the order of milliamperes is necessary for applications such as x-ray sources and traveling wave tubes. Thus, this study applied a TiN coating to a volcano-structured Si-FEA, which has a high melting point favorable for high-current operation. Transmission electron microscopy and x-ray photoelectron spectroscopy revealed that TiN was uniformly deposited on the Si tip by DC magnetron sputtering with the atomic ratio of Ti to N being 1:1. The TiN-coated volcano-structured FEA exhibited excellent electron emission property (7.7 mA/1027 tips) and an electron emission stability of >6 mA for 60 min in pulse operation. These results are expected to aid in the development of next-generation electron sources that can realize high-current operations under high-beam-focusing conditions.