Silicon doped diamond-like carbon films as a coating for improvement of electron field emission

Abstract

To improve the electron field emission parameters of silicon tips diamond-like carbon (DLC) films doped with silicon have been used as a coating. The idea was to enhance the field emission efficiency using DLC film and increase the DLC film conductivity to make easier electron transport from the silicon tip through the DLC film. The emission properties of in situ silicon doped DLC films have been investigated. Undoped and silicon doped DLC films were grown by plasma enhanced chemical vapor deposition from CH4:H2 and CH4:H2:SiH4 mixtures, respectively. In situ gas-phase doping allowed us to deposit DLC films with different concentrations of silicon in them. The concentration of SiH4 in the gas mixture was varied from 0% to 50%. To characterize the electron conductivity of undoped and silicon doped DLC films metal–insulator–semiconductor (Al–DLC–Si) capacitors were prepared on flat silicon wafers. The strong influence of silicon doping on DLC film properties and electron field emission was revealed. The conductivity of the DLC films increased and the electron field emission changed after doping of the DLC films with silicon. It is shown that silicon doped DLC films are a prospective coating for improvement of electron field emission from silicon tip arrays.