Field emission of polycrystalline diamond films grown by microwave plasma chemical vapor deposition. II. Effect of p-type doping in diamond

The effects of boron (B) doping on the field emission (FE) of diamond films grown by a microwave plasma chemical vapor deposition technique were studi ed. Raman scattering spectroscopic analysis revealed that B-doping signific antly suppressed formation of non-diamond components in the diamond film. T he B-doped p-type diamond films had low resistivity, ranging from 0.07 to 2 0 Omega cm, and various volume fractions of non-diamond components in the d iamond films. The turn-on electric field, F-T, was independent of the resis tivity, the film thickness, and the volume fraction of the non-diamond comp onents. The lowest F-T value of 8 V mum (-1) and the highest emission curre nt of 3 X 10 (- 2) A cm (-2) were obtained in the B-doped diamond films. Th e high efficiency of the electron emission in the B-doped diamond films was believed to be due to the increase in volume fraction of the conductive re gions in the film and the high density of emission sites on the film surfac e. (C) 2001 Elsevier Science B.V. All rights reserved.