Investigation of magnetic guiding of laser plasmas for thin film deposition

Summary form only given. One complication with pulsed laser deposition of thin films is the inclusion of micron and submicron size debris particles from the source material. These particles arise from the release of solid material and liquid droplets from the shock wave produced by the laser produced plasma. In some cases these inclusions lead to undesirable defects, reducing the quality of the resultant coating. We have proposed the application of a curved magnetic field to guide the laser produced plasma and direct it to the coating surface while using a set of baffles to stop the particles which are not guided by the magnetic field from reaching the target. In order to do so a magnetic field of several kilogauss is required to capture and deflect the plasma which is moving with a velocity on the order of several times 10/sup 6/ cm s/sup -1/ around a curved trajectory. An experimental study using a 20 ns duration 248 nm wavelength KrF laser pulse source has been carried out to characterize the ion flux at the exit of such a curved magnetic solenoid. We have found that 20% of the total initial laser plasma flux can be captured by the magnetic field and guided around a bend to a 2 cm diameter coating spot. A 3D curvilinear numerical simulation code has been developed on the basis of an existing Cartesian code in order to model the experimental results and to allow prediction of scaling to different magnetic field conditions. The results of the experimental measurements and comparison to the 3D modeling code will be presented.