A NOVEL LOW-FIELD ELECTRON-EMISSION POLYCRYSTALLINE DIAMOND MICROTIP ARRAY FOR SENSOR APPLICATIONS

Electron field emission from an array of patterned pyramids of polycry stalline diamond has been investigated for microsensor applications. S elective deposition and molding of a polycrystalline diamond film in a silicon cavity mold and subsequent creation of a freestanding polycry stalline diamond diaphragm with diamond pyramidal microtips has been a chieved, The processing techniques are compatible with IC and micromac hining technologies. High current emission from the patterned diamond microtip arrays is obtained at low electric fields. Field emission for these diamond microtips exhibits significant enhancement in total emi ssion current compared to silicon emitters. Moreover, field emission f rom patterned polycrystalline diamond pyramidal-tip arrays is unique i n that the applied field is found to be lower than that required for e mission from Si, Ge, GaAs, and metal surfaces. The findings suggest th e potential use of diamond-based field-emitter arrays in microsensors such as pressure sensors, accelerometers, and tactile sensors.