Jd. Carey et Srp. Silva, Current-induced conditioning of hydrogenated amorphous carbon thin films for field emission, DIAM RELAT, 10(3-7), 2001, pp. 873-877
The field emission characteristics of hydrogenated amorphous carbon (a-C:H)
thin films subjected to electrical current stressing have been examined. I
n these a-C:H films, deposited by radio frequency PECVD, an initially high,
applied electric field (> 40 V mum(-1)) is sometimes required before the o
nset of electron emission. The threshold field in subsequent voltage cycles
tend to converge after three or four cycles. By current stressing of the a
-C:H films to different current levels it is shown that it is possible to r
emove the need for a conventional conditioning cycle. Measurements performe
d on unstressed films sometimes show that conditioning is required even aft
er initial testing when samples are retested. In films, which have been cur
rent-stressed, the films remain fully conditioned even after 87 h after the
original tests have been performed. The surface morphology of the current-
stressed films is examined using atomic force microscopy and shows that the
surface of the stressed area has been altered with three distinct regions
present. The prime novelty of this work shows that conditioning of a-C:H fi
lms can be achieved through the use of current stressing. (C) 2001 Elsevier
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