Field emitter based extractor gauges and residual gas analyzers

Attempts at using the Spindt-type molybdenum held emitter arrays in the ext ractor gauges and a residual gas analyzer are presented in this article. Th e sensitivity of the field emitter gauge is as high as 11 Torr(-1). The dep arture from linearity of the pressure versus ion current measurements did n ot exceed 10% over the pressure range of 10(-10)-10(-6) Torr. Stable sensit ivities for nitrogen, helium, and hydrogen were achieved below 10(-7) Torr with the field emitter residual gas analyzer. The slightly reduced emission current and sensitivity, after long-term operation, are of concern and nee d to be addressed. Residual gas spectra indicate that when using field emit ters; the electron stimulated desorption ions (O+, F+, and Cl+) are reduced as compared to those made using a hot filament source. (C) 1999 American V acuum Society. [S0734-2101(99)18004-7].