Thermal stability of thin CoSi2 layers grown on amorphous silicon

The thermal stability of thin cobalt suicide layers grown on amorphous silicon deposited by chemical vapor deposition has been studied in the temperature range between 950 and 1100¬?C. The relation between the agglomeration process and the increase of the sheet resistance has been evidenced. The range of thermal stability of the suicide is reduced if the CVD amorphous silicon is previously implanted with Si ions. The occurrence of some epitaxial CoSi2 grains in the case of CVD amorphous Si can account for this difference.