THE MICROSTRUCTURE AND ELECTRICAL-PROPERTIES OF CONTACTS FORMED IN THE TI/AL/SI SYSTEM DUE TO RAPID THERMAL-PROCESSING

The microstructure and electrical properties of the contacts formed in the Ti(30 nm)/Al(10 nm)/〈100〉p-type Si system due to rapid thermal processing at temperatures between 300 and 800°C were studied extensively. An eutectic melting, initiated at the Al/Si interface, was already observed after 2 s at 580°C. This rapid melting, which was first observed by the authors in the Ni/Al/Si system, resulted in the formation of a Al3 Ti(20 nm)/Ti7Al5Si12 (5 nm), epi-TiSi 2 (45 nm)/p-type Si layered structure with smooth interfaces. The TiSi2 layer grew epitaxially on the 〈100〉Si substrate with the following relationships: (101)TiSi2 (C54)∥(001)Si and [151]TiSi2 (C54)∥[220]Si. The melting reaction influenced the sheet resistance and the Schottky barrier height of the formed contacts, which decreased from 0.67 to 0.49 eV at 580°C. The correlation between the electrical properties and the microstructure of the contacts formed in the Ti/Al/Si system due to the rapid thermal processing is discussed in comparison with the Ni/Al/Si system.