Field emission from bias grown diamond thin films in a CH4/N2/H2 plasma

We have investigated field emission properties from diamond films grown under substrate bias conditions in a MPCVD system, with a substrate temperature of 800/spl deg/C, microwave power of 600 W and a total pressure of 11 Torr. One group of films was grown with a substrate bias at -100 V in a gas mixture of 1% N/sub 2/, 1% to 20% CH/sub 4/ in H/sub 2/, while a second group of films was grown with a substrate bias ranging from +100 V to -150 V in a gas mixture of 1% N/sub 2/-10% CH/sub 4/-89% H/sub 2/. Field emission performance in terms of turn-on field and emission current improved considerably as CH/sub 4/ concentration and negative bias voltage increase.