Abstract: Nanometer boron nitride(BN) thin films with various thickness(54~124 nm) were fixed on the (100)-oriented surface of n-Si(ρ=0.0 08~0.02 Ω·m) by r.f. magnetic sputtering physical vapor deposition(PVD). There are only two absorption peaks of the hexagonal-BN(h-BN) at about 1 380 cm^-1 and 780 cm^-1 in the FTIR spectra of the BN thin films. The field emission characteristics of the thin BN films were measured in a super hi gh vacuum system. It was found that the field emission characteristics of the th in BN films depend evidently on the thickness of the films. A turn-on electric f ield as low as 10 V/μm is obtained for the ～54 nm-thick BN film, and the emiss ion current density is estimated to be higher 240 μA/cm² at an electric field of 23 V/μm. It is shown by F-N curves that the electrons emitted fr om BN penetrate through the potential barrier at the surface of the BN thin film to vacuum tunneling under the exterior electric field action.

Key words: BN thin film, field emission, thickness