Electron emission from a∼100-nm-thick,laser ablated and laser annealed, carbon-doped BN film deposited on polycrystalline diamond was measured at room temperature and at pressures of about1×10−8 Torr.For a 500-&mgr;m-diam extraction electrode, currents of several mA were obtained which corresponds to current densities of>1 A/cm2.At low currents, the current–voltage characteristics follow the classical Fowler–Nordheim behavior. At higher currents, deviations occur which are correlated to a nonlinear BN film resistance which ranges from3×106 &OHgr;to5×104 &OHgr;.For comparison, similar measurements were performed for the polycrystalline diamond film. Current densities of only1 mA/cm2were obtained which is attributed to a much higher sample resistance of about1×109 &OHgr;.©1997 American Institute of Physics.