Effect of target modification on deposition rates of hexaphenyldisilane by laser ablation

The effects of target modification on film deposition rates of hexaphenyldisilane HPDS.due to ablation by a 248-nm KrF excimer laser at different fluences and repetition rates were studied. When the repetition rate was less than 20 Hz and the laser fluence was below 100 mJrcm2, some interlocked cones were generated on the surface of the HPDS targets, which caused the laser ablative process to grind to a halt after a given number of laser pulses. However, when the repetition rates exceeded 20 Hz, it was possible to prevent the cones from being interlocked, so that the laser ablative process or film deposition process could continue, even though a similar laser fluence was used. The doping of other Si-based organic materials into HPDS affected the critical laser fluences and repetition rates below which the interlocked cones were generated. Finally, a general physical model of the target modification for laser ablation of Si-based organic materials was suggested based on the laser processing parameters. q1999 Elsevier Science B.V. All rights reserved.