Gated p-Si field emission cathode applied in an ionization vacuum gauge

A commercial Bayard-Alpert ionization vacuum gauge was equipped with a field emission electron source based on a cathode consisting of an array of 16 gated, p-doped, and DLC-coated Si-tips and characterized. An anode current of about 1.3 μA led to an ion current of 7 fA at 3×10
^-7
mbar and 0.8 pA at 4×10
^-5
mbar. Whereas at pressures higher than 4×10
^-5
mbar the emission current of the electron source decreased, the ratio of ion and anode current remained linear. A nearly constant sensitivity of ~ 17 mbar
^-1
of the ionization vacuum gauge within the investigated pressure range was depicted.