Emission characteristics of Spindt-type platinum field emitters improved by operation in carbon monoxide ambient

The electron emission characteristics of Spindt-type platinum field emitter s that were improved by operation in a carbon monoxide gas ambient were inv estigated in detail. We present differences in the emission characteristics , such as the change of Fowler-Nordheim characteristics in the S-K chart, c hange in current fluctuation and emission pattern, and resistance against o xygen exposure due to the improvement. We found that the work function incr eased slightly during the introduction of carbon monoxide gas up to 10(-4) Pa; but when the gas was evacuated, the work function recovered. The work f unction finally decreased at a pressure of 10(-3) Pa. The emission characte ristics were degraded during the oxygen exposure both for the nontreated an d treated emitters. However, degradation was less significant for the carbo n-monoxide-treated emitter than for the nontreated emitter. All these resul ts suggest that the improvement can be attributed to the presence of carbon atoms or a carbon layer at the surface of the emitter. (C) 2001 American V acuum Society.