Formation of MoSi 2 by rapid thermal annealing in vacuum of CVD – Mo films on silicon substrate

Abstract

Silicide formation due to thermal treatment of thin (200–1000 Å) molybdenum films on single-crystal silicon substrates in the temperature range of 800–1000°C was studied. Rapid thermal annealing (RTA) in vacuum was performed on Mo/Si system to form silicides. Molybdenum films were deposited on Si (1 0 0) by chemical vapor deposition (CVD), using Mo(CO) 6 (molybdenum hexacarbonyl) as precursor. The as-deposited films with thicknesses of 200 and 1000 Å were heated in vacuum at RTA temperatures of 800 and 1000°C for time durations of 15 and 30 s, 1 and 3 min. The results from the X-ray diffraction analysis and the Reflection Infrared Spectroscopy measurements show that Mo films after annealing transform into Mo silicides, preferably tetragonal MoSi 2 crystal phase. The presence of Mo 5Si 3 formation is also found. There is a change in the electrical resistance of the films before and after annealing. For the molybdenum silicides obtained the resistivity is in the range 0.9–9.8 mΩ cm.