Temperature effect on the photolytic deposition of platinum ohmic contacts and Schottky diodes

An argon laser is used to induce Laser Chem. Vapor Deposition (LCVD) of platinum using platinum bihexafluoroacetylacetonate as precursor. The process can be photolytic or pyrolytic depending on the laser power used. These processes are studied by recording the laser light transmitted through deposit and substrate. Photolytic deposition takes place either in the adsorbed phase or in the gaseous phase depending on the temp. induced by radiation absorption. The induced-temp. calcn. using a model developed by the authors confirms the exptl. results obtained. The influence of the substrate base temp. and the precursor product vapor pressure confirms photolytic deposition from the adsorbed phase for low powers and from the vapor phase onwards for high powers. The deposits obtained present a typical 96% Pt compn., and its use in Schottky diode manuf. permits one to obtain devices with good characteristics in spite of exptl. limitations.