We fabricated field-emission vacuum microelectronic devices such as diode and triode devices, using high-resolution electron-beam lithography in combination with the reactive ion etching (RIE) technique. The turn-on voltage of the diode is 13 V, which is the lowest value reported for single-crystalline lateral silicon field-emission devices. An emission current of 1.4 mu A was obtained at an anode bias of 40 V. Field emission was confirmed by the linearity of the Fowler-Nordheim plots. The anode current of the triode was effectively modulated as a function of gate voltage. The device stability results show that the proposed devices are stable and reproducible.