ArF laser-induced discharge interruption in a mixture of C/sub 2/H/sub 3/Cl/CF/sub 4//CH/sub 4/, CF/sub 4//CH/sub 4/, and C/sub 2/H/sub 3/Cl/He

The ArF-laser (193-nm)-induced discharge interruption is comparatively described in a mixture of C/sub 2/H/sub 3/Cl/CF/sub 4//CH/sub 4/, CF/sub 4//CH/sub 4/, and C/sub 2/H/sub 3/Cl/He using a hollow-cathode-type discharge tube. The unfocused ArF laser (typically 27 mJ/cm/sup 2/ and 10 ns duration) illuminated both the negative glow inside the hollow cathode and the column between the two electrodes. With a 1.8-torr mixture of C/sub 2/H/sub 3/Cl/CF/sub 4/, the discharge current of 1 mA was decreased rapidly with a current-decay time constant of 1 mu s and a current-decay rate of 1 kA/s. With a 1.5-torr mixture of CF/sub 4//CH/sub 4/, 2.2 mu s and 450 A/s were obtained. With a 1.5-torr mixture of CH/sub 2/H/sub 3/Cl/He, a time constant of over 3 mu s and a rate of less than 300 A/s were obtained. An analysis of the discharge interruption induced by ArF-laser irradiation is given in terms of photon-plasma kinetics. The current peak induced by ArF irradiation is also explained for a mixture of C/sub 2/H/sub 3/Cl/He in terms of photoionization and photodetachment processes.<
>