A microdischarge lamp formed in a one piece integral substrate, preferably a silicon wafer, via micromachining techniques commonly used in integrated circuit manufacture. The lamp is formed by defining an anode separated from a semiconductor cathode, and then micromachining a hollow cavity penetrating the anode, dielectric and cathode. The hollow cathode is formed in the semiconductor and is filled with a discharge medium and sealed to complete the formation process. The lamp includes a micromachined cavity area for enclosing discharge filler, such as mercury vapor. The one piece substrate includes one or more semiconductor regions which act as electrodes for the lamp. A light transmissive cap seals the cavity area. Selection of particular aperture to length ratios for the cavity area permits the lamp to be operated either as a positive column or hollow cathode discharge. Hollow cathode discharge has been demonstrated at pressures of up to about 200 Torr. The small aperture of the cavity area, of about 1 to 400 micrometers, enable the electrons in the discharge to be ballistic. In addition, the small dimensions permit discharges based upon resonance radiation, such as the 253 nm line of atomic mercury.
|Original language||English (US)|
|U.S. patent number||6139384|
|State||Published - Oct 31 2000|