TEMPERATURE-DEPENDENCE OF IV CHARACTERISTICS OF VACUUM TRIODES FROM 24 TO 300-K

Collector and gate currents as a function of collector voltage have be en measured for molybdenum Spindt emitters, for n-type monocrystalline , and for n-type polycrystalline silicon emitters in the temperature r ange from 24 to 300 K and at a pressure of 1 X 10(-8) Torr. The device s were tested in an as-fabricated mode with a modest in situ bake of 1 00-degrees-C. The silicon devices which were fabricated in two differe nt laboratories using different processes showed very little temperatu re dependencies, whereas the molybdenum emitter exhibited an increase in work function with decreasing temperature. It is conjectured that a dsorption/desorption events from the background gas onto the emitter t ips are responsible for the observed temperature dependency.