Electron field emission from silicon tip arrays coated by magnetron sputtering carbon nitride film

The field emission properties of silicon tip arrays coated by magnetron sputtering carbon nitride films (CNx) were investigated. The coated Si tip arrays with the height of 3 μm and the density of 106 tips/cm2 exhibit good field emission properties with the lowest threshold field of 2 V/μm, which is much better than that of uncoated Si tip arrays. The results demonstrate that CNx films effectively lower a surface potential barrier to improve the electron field emission properties of silicon tips. In particular, it was found that the variation of deposition conditions of CNx films coated on the Si tips had a significant influence on the field emission property of Si tip arrays. The dc substrate bias could reduce the field emission property of silicon tips, but a higher nitrogen partial pressure and moderate input power are favorable to the enhancement of the field emission property of Si tips. The effects of deposition conditions on the electron field emission are attributed to the change of sp2 C–N bonds content in the CNx films and the apex shape of Si tip.