Low-field electron emission from thin films of metals

The paper presents an experimental study of the low-threshold field electron emission from thin films of metals (Mo, W, Zr, Ni and Ti) deposited on silicon substrates by magnetron sputtering. Several samples of such films having effective thickness in the range 6–10 nm were capable of room-temperature electron emission in electric field with macroscopic intensity as low as a few kV/mm. Optimized thermofield treatment procedure further improved their emission properties reducing the threshold field by several times. AFM study revealed a correlation between film’s emission properties and their surface topography. At the same time, no equally pronounced correlation of the emissivity with other characteristics of coatings (including the sort of the metal and the silicon substrate conductivity type) was detected. Results of the study witness in favor of two-temperature (or hot-electron) emission mechanism for the investigated coatings.