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 electroles s pyrolytic (CW Ar+) laser deposition from solutions using aqueous sol utions of ammonium heptamolybdate and organic solutions of gold comple xes as model materials. The morphology and chemical composition of the deposits reveal that the deposition kinetics is determined by the int erplay 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 ra tes 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 gradual ly shifted to higher speeds with increasing precursor concentration. T hese structural data are discussed in the frame of a material transpor t model which can include LCVD and condensed phase processes as extrem e cases.