LATERAL FIELD-EMISSION DEVICES WITH SUBTENTH-MICRON EMITTER TO ANODE SPACING

Field-emission vacuum microelectronic devices, which operate at a low voltage, require sharp emitters and minimal emitter to anode spacing. Using high resolution electron beam lithography in combination with metal lift-off, we have fabricated lateral multitip diodes with emitter to anode spacings ranging from 0.03 to 0.5 mum. This is the smallest emitter to anode gap spacing of any lateral structure reported in the literature. The devices were tested in the sample chamber of our scanning electron microscope (SEM) which has been adapted with fixed probe tips and associated electrical feed throughs. The SEM's secondary electron detector was used to confirm field emission by detecting electrons generated during device operation. The electrical data show low voltage operation and the linearity of the Fowler-Nordheim plots provides another confirmation of field emission. We have also fabricated triodes with 0.5 mum emitter to anode spacing by adding a columnar gate electrode to the basic diode structure.