Postannealing Temperature Effects on the Etching Behavior and Field Emission Properties of Cu-Implanted Diamond

To investigate the postannealing temperature effects on the surface etching behavior and electron field emission (EFE) properties of the Cu-implanted microcrystalline diamond (MCD) films, they are subjected to furnace annealing in a temperature range of 600-900 degrees C under N-2 atmosphere at a rapid annealing rate. The etching behavior happens when the samples are annealed at 700 degrees C and above. The EFE performances enhance first and then decrease with the increasing annealing temperature. The optimum EFE property with a low turn-on field of 6.42 V mu m(-1) is obtained after the Cu-implanted MCD film is annealed at 700 degrees C. The enhancement in EFE properties originates from the presence of nanographitic phase and the formation of electron-rich Cu nanoparticles, which encourage a higher efficient electron transport. In contrast, the structural studies reveal that when the samples annealed at 800 degrees C and above, Cu nanoparticles evaporate from the diamond surface and the sp(2)-bonded carbon decomposes. Consequently, etch pits appear on the surface of the MCD sample. Moreover, it demonstrates that graphitization is the dominant mechanism of the diamond surface etching behavior and the enhancing of EFE properties.