Influence of diamond film thickness on field emission characteristics

Diamond films with various thicknesses (0.15-9 mum) were grown by microwave plasma chemical vapor deposition. The lowest threshold field strength for electron emission was 3 V/mum for the similar to1.5-mum-thick diamond film. The results were analyzed by effective emission areas and effective work f unction according to Fowler-Nordheim theory. It was found that the threshol d voltage was strongly affected by the ratio of (111) and (110) oriented gr ains in the films. The larger the fraction of (111) oriented grains, the lo wer the effective work function in agreement with the reported negative ele ctron affinity of (111) surfaces. (C) 2000 American Vacuum Society. [S0734- 211X(00)18106-5].