Silicon microdischarge devices having inverted pyramidal cathodes: Fabrication and performance of arrays

Microdischarge devices having inverted, square pyramidal cathodes as small as 50 mu mx50 mum at the base and 35 mum in depth, have been fabricated in silicon and operated at gas pressures up to 1200 Torr. For the polyimide dielectric incorporated into these devices (epsilon (r)=2.9), the discharges produced exhibit high differential resistance (similar to 2x10(8) Omega in Ne), ignition voltages for a single device of similar to 260-290 V, and currents typically in the muA range. Arrays as large as 10x10 have been fabricated. For an 8 mum thick polyimide dielectric layer, operating voltages as low as 200 V for a 5x5 array have been measured for 700 Torr of Ne. Array lifetimes are presently limited to several hours by the thin (1200-2000 Angstrom) Ni anode. (C) 2001 American Institute of Physics.