THE INFLUENCE OF FILM-TO-SUBSTRATE CHARACTERISTICS ON THE ELECTRON FIELD-EMISSION BEHAVIOR OF THE DIAMOND FILMS

Diamond films possessing large electron field emission properties were obtained using B(OCH3)(3) as dopants in chemical vapor deposition pro cess. The CH4:B(OCH3)(2) ratio and total gas flow rate markedly influe nced the emission current density (J(e)) without significantly alterin g the turn-on electric field (E-0) and effective work function (phi(e) ) of the films. The emission current density attainable is (J(e))(Si)= 280 mu A/cm(2) (at 20 V/mu m) with (E-0)(Si)=10.2 V/mu m and (phi(e))( Si)=0.0934 eV for the films deposited using CH4:B(OCH3)(3):H-2=18:6:30 0 sccm. Analysis using Raman spectroscopy revealed that the improvemen t of the J(e) value could be attributed to the modification on the def ect concentration of the films. Precoating an Au layer on Si substrate s pronouncedly lowered the turn-on electric field to [(E-0)(Au,Si)=7.1 V/mu m] without markedly altering the effective work function [(phi(e ))(Au/Si)=0.0534 eV]. This is ascribed to a modification on the film-t o-substrate interface which reduced the conduction barrier for electro ns to transplant from substrates to the emission sites, i.e. the diamo nd surfaces. The emission current density attainable is (J(e))(Au/Si)= 700 mu A/cm(2) (at 20 V/mu m). (C) 1998 Elsevier Science S.A.