DEPENDENCE OF DEPOSITION KINETICS ON PRECURSOR CONCENTRATION AND WRITING SPEED IN PYROLYTIC LASER DEPOSITION FROM SOLUTION

The main results of a systematic study are summarized with particular emphasis on the determination of the fundamentals governing electroless pyrolytic (CW Ar+) laser deposition from solutions using aqueous solutions of ammonium heptamolybdate and organic solutions of gold complexes as model materials. The morphology and chemical composition of the deposits reveal that the deposition kinetics is determined by the interplay of precursor concentration (0.005 M-0.05 M) and writing speed (0.01-1.0 mm s-1). At relatively low writing speeds, high deposition rates and a wide variety of characteristic macrostructures are observed, whereas at high writing speeds, flat patterns without macrostructure and of excellent morphology are obtained. In between the low and high scanning speed domains there is a transitional region which is gradually shifted to higher speeds with increasing precursor concentration. These structural data are discussed in the frame of a material transport model which can include LCVD and condensed phase processes as extreme cases.