Cylindrical microdischarge cavities 200–400 &mgr;m in diameter and 0.5–5 mm in depth have been fabricated in silicon and operated at room temperature with neon or nitrogen at specific power loadings beyond10 kW/cm3.The discharges are azimuthally uniform and stable operation atN2and Ne pressures exceeding 1 atm and∼600 Torr,respectively, has been realized for 400 &mgr;m diameter devices. Spectroscopic measurements on neon discharges demonstrate that the device behaves as a hollow cathode discharge for pressures>50 Torr.As evidenced by emission from Ne andNe+(2P,2F)states as well asN2(C→B)fluorescence (316–492 nm), these discharge devices are intense sources of ultraviolet and visible radiation and are suitable for fabrication as arrays. ©1997 American Institute of Physics.