Field emission characteristics of CoSi2/TiN-coated silicon emitter tips

A CoSi2/TiN bilayer was coated on Si emitter tips and the emission characteristics of the tips were investigated. The CoSi2 layer was grown in situ by a reactive chemical vapor deposition of cyclopentadienyl dicarbonyl cobalt at 650 °C and then the TiN was deposited on the CoSi2 layer at 550 °C by a reactive sputtering of Ti with N as a reactive gas. The CoSi2 layer was conformally coated on the Si tips and the TiN layer adhered well to the CoSi2 layer. The CoSi2/TiN-coated emitters showed a low turn-on voltage due to the low work function by TiN and a steep current increase caused by CoSi2. The current fluctuation of the CoSi2/TiN-coated Si emitter was smaller than that of the TiN-coated emitter. The long-term emission stability of the CoSi2/TiN-coated Si emitter was also greatly improved compared to the CoSi2-coated emitter because of the superior high temperature stability of the TiN layer.