Effect of lateral dimension scaling on thermal stability of thin CoSi2 layers on polysilicon implanted with Si

The thermal stability of patterned cobalt silicide layers grown on amorphous silicon has been studied in the temperature range between 850 and 1000 °C. The degradation of patterned CoSi2, detected by resistance measurements, occurs via grain agglomeration at a temperature approx. 100 °C lower than in blanket film. The reduction of the stability window in patterned samples is due to geometric constraints, which results in a greater growth rate of the median grains with respect to lateral grains.