  Microplasma arrays operating in helium in a DC regime have been produced in
silicon microre-actors. Cathode boundary layer (CBL) type microdevices were
elaborated using clean room facilities and semiconductor processing techniques.
Ignition of the micro-discharge arrays having either 50 or 100 m diameter
cavities was studied. Two different structures (isotropically etched or
anisotropically etched cavity) and various conditions (the two different
voltage polarities, pressures etc.) were investigated. 100 microdis-charges of
50 m diameter could be ignited in parallel at 1000 torr. At high current, some
parasitic and transient sparks appeared at the edge of the sample. When the
polarization was reversed (cathode side corresponding the opened electrode),
more current was needed to light all the microdischarges. A thermally affected
zone around the hole on the anode side was obtained after operation.
