A method for the direct writing of metal features from a metal film supported on an optically transparent substrate using a single pulse from a high-energy excimer laser (193 nm) is presented. The technique eliminates the need for gas-phase precursors in many cases and is an inherently clean process. Results of copper depositions onto silicon substrates are shown to exemplify the technique and a mechanism for the process is proposed.

The laser-induced forward transfer technique in which material is ablatively transferred from a thin film to a target substrate by a pulsed excimer laser has been extended to 532 nm using a frequency-doubled YAG laser. Cu and Ag have been deposited on fused silica substrates using microscope objectives for focusing, resulting in reductions in feature size over that obtainable with the multimode excimer laser. The photothermal deposition process has been modeled using the one-dimensional thermal diffusion equation, including a moving solid-melt boundary, with good agreement between theoretical and experimental results.

The photoisomerization of OClO (ClO2) to ClOO in a sulfuric acid glass at 20 to 77 K has been reinvestigated using electron spin resonance (ESR) to observe the reactant and product and to quantitatively determine their relative concentrations. Polarized light photolysis yields a partial orientation of the remaining ClO2 molecules (magnetophotoselection) and shows that the optical transition dipole moment lies in the molecular plane and is perpendicular to the ClO2 rotational symmetry axis, as expected for the well known Ã(2A2)←X̃(2B1) transition of ClO2. Here, however, the photolysis yields only ClOO, in contrast to the gas phase where ClO is observed suggesting photodissociation. The photoisomerization kinetics are nonexponential and suggest that random variations among the ClO2 trapping sites in the H2SO4 glass have a considerable effect on the probability that a photoexcited ClO2 molecule will isomerize.

A new technique for detection of superconductivity which is based upon microwave resistivity is described. This method is similar in both its implementation and execution to the technique of electron-spin resonance, and, as a consequence, exhibits high sensitivity. An additional benefit of this method is the fact that metal-insulator phase transitions of materials are recorded only if they have a magnetic field dependence.

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