I-V characteristics of silicon field emission diode and triode were investigated. The maximum emission current of 17 muA and the lowest onset voltage of 60 V were obtained by an array of 245 silicon tips. The typical reverse recovery time of the diode was 350 ps. The typical transconductance of the triode was about 10(-7) S. The fabrication processes for forming sharp silicon conical tips with a gate hole diameter 1 mum smaller than the corresponding oxide mask is described. The results of a high temperature activation process for improving emission characteristics of the device are presented. The stability and uniformity of the devices affected by the fabrication process and emission environment are also discussed in this paper.