Selected area deposition of diamond films on silicon substrates was successfully achieved using the patterned Pt layer as a nucleation inhibitor in the chemical vapor deposition process. The planar diamond film array thus made possesses good electron field emission properties, that is, emission current density of(Je)Si=150 &mgr;A/cm2(under 23.6 V/&mgr;m) and turn on field of(Eo)Si=10 V/&mgr;m.Precoating a thin Au layer (20 nm) on a Si surface further increased the emission current density to(Je)Au/Si=960 &mgr;A/cm2(under 23.6 V/&mgr;m) with(Eo)Au/Si=10 V/&mgr;m.The effective work functions (&fgr;) estimated by Fowler–Nordheim plots of theI–Vcharacteristics are(&fgr;)Si=0.059 eVand(&fgr;)Au/Si=0.085 eV.The emission properties of both planar diamond film arrays satisfy the requirement for applying as the electron emitters in the flat panel displays. ©1997 American Institute of Physics.