Lateral diamond field emitters were fabricated by a diamond patterning technique that utilizes oxide patterning and lift-off process on a silicon-on-insulator, wafer. An anode-cathode spacing of 2 mum between the diamond anode and cathode was achieved. The fabricated lateral diamond emitter diode exhibits excellent emission characteristics with a low turn-on voltage of similar to 5 V and a high emission current of 6 muA, from four diamond fingers, at an anode voltage of 25 V. The emission current is stable over time, even at high emission current. The low turn-on voltage (turn-on field similar to 3 V/mum) and high emission characteristics are among the best of reported lateral field emitter structures. The lateral diamond field emitter has potential applications in vacuum microelectronics, sensors, and microelectromechanical systems. (C) 2003 American Vacuum Society.