Investigation on TiSi2 thin-film oxidation by radioactive tracer technique

The tracer technique using radioactive 31Si (T1/2 = 2.62h) was performed to study the oxidation kinetics of TiSi2 thin films on single and polycrystalline silicon. After depositing 1000-Å 31Si which had been activated in a nuclear reactor, radioactive TiSi*2 was formed by coating 500-Å Ti film in situ and then annealing at 850 °C for 45 min. On wet oxidation, the substrate silicon atoms transported through the TiSi*2 layer by grain boundary and/or interstitial diffusion. These results were confirmed by Geiger counting after etching the outer SiO2 layer step by step.