Deposition of Platinum from Bis(Acetylacetonato)Platinum(II)

Abstract
The evaporation and deposition process of Bis(acetylacetonato)platinum(II) (Pt(acac)₂) was examined in a computerized microbalance system, which allows the measuring of the mass of evaporating precursor and depositing layer simultaneously. The investigations were carried out in an argon-atmosphere and an argon/oxygen-atmosphere with pressure ranging from 250 Pa to 1000 Pa. The deposition kinetics were investigated in the temperature range between T_dep = 523 K and T_dep = 733 K. A strong dependence of the deposition rate on the pretreatment of the substrate was observed. Beginning the deposition on alumina with low deposition temperatures T_dep an activation energy of 204 [MATH] 9 kJ/mol was found. On platinum precoated substrates we observed higher deposition rates and lower values for the activation energy, if the precoating was carried out at temperature T_pre > T_dep. At long deposition times with T_dep = const. the deposition rates on precoated substrates decreased to the values obtained without precoating at higher temperatures. This effect has not been clarified. In argon-atmosphere platinum layers containing carbon were deposited. Increasing the deposition temperature caused increased carbon contamination. The carbon can be removed by oxidation in air after the deposition. Platinum coatings without carbon contamination were obtained by adding oxygen during the deposition process.