Effects of substrate bias on the structural and field emission properties of diamond films

The effect of electron bombardment on modification of the structural proper ty and the surface morphology of diamond films, and consequently the field emission properties have been investigated by introducing positive substrat e bias. When increasing the bias voltage, the structural properties of diam ond films are significantly deteriorated together with the increase of nond iamond carbon component and the surface morphologies of the films lost thei r unique facet shape. The reason for the increase of nondiamond carbon cont ent is described in terms of both the increase of substrate temperature and the excessive generation of CHn radicals. The field emission properties of diamond films were substantially improved with increasing bias voltage. En hancement of field emission property for the firms prepared by increasing b ias voltage and/or methane concentration has been discussed by correlating between the substrate-diamond interface property and the slope of the Fowle r-Nordheim plot. (C) 2000 American Vacuum Society. [S0734-211X(00)05102-7].