Electron field emission from polycrystalline silicon tips

Arrays of 10 polysilicon field emitter tips were fabricated using plasma etch and oxidized to form sharp tips. Phosphorus doped polysilicon tips emit at around 10-15 V regardless of the degree of their sharpness. Similarly, intrinsic polysilicon tips emit at around 50 V (at 2 mu m tip to anode spacing). The same turn on voltages have been observed on Hat polysilicon surfaces. Field emission data of the diode structures revealed a significant difference between phosphorous doped and intrinsic polysilicon tips and flat surfaces. The phi(3/2)/beta versus applied voltage was obtained from the transconductance data and was used to compare the performance of the doped and intrinsic polysilicon tips. A qualitative comparison of phi(3/2)/beta ratio reveals an increase in the effective work function of the intrinsic polysilicon device which is related to the field penetration inside the emitting surfaces. Furthermore, field emission data reveal the conduction limitation of the intrinsic polysilicon films associated with the single carrier injection mechanism. (C) 2000 American Vacuum Society. [S0734-211X(00)08402-X].