Effects of vacuum conditions on low frequency noise in silicon field emission devices

Abstract

The effects of pressure on emission current noise have been studied. Field emission currents from silicon devices were observed over a range of pressures. The current fluctuations were analyzed in both the time and frequency domain. Signal to noise ratios between 0.9 and 6.9 were observed. These values appear to be more dependent on operation time than on pressures. Spectral density coefficients of low frequency measurements range from -1.37 to -1.81. Some pressure dependence is suggested in the lower pressure ranges. At higher pressures emission currents seem to be reduced and the current is cut off completely above a threshold pressure which is somewhere in the 10's of Torr.