ELECTRON-EMISSION FROM A LASER-ABLATED AND LASER ANNEALED BN THIN-FILM EMITTER

Electron emission from a similar to 100-nm-thick, laser ablated and la ser annealed, carbon-doped BN film deposited on polycrystalline diamon d was measured at room temperature and at pressures of about 1x10(-8) Torr. For a 500-mu m-diam extraction electrode, currents of several mn were obtained which corresponds to current densities of >1 A/cm(2). A t low currents, the current-voltage characteristics follow the classic al Fowler-Nordheim behavior. At higher currents, deviations occur whic h are correlated to a nonlinear BN film resistance which ranges from 3 x10(6) Omega to 5 x 10(4) Omega. For comparison, similar measurements were performed for the polycrystalline diamond film. Current densities of only 1 mA/cm(2) were obtained which is attributed to a much higher sample resistance of about 1 x 10(9) Omega. (C) 1997 American Institu te of Physics.