SILICIDE LAYER GROWTH-RATES IN MO SI MULTILAYERS/

The thermal stability of sputter-deposited Mo/Si multilayers was inves tigated by annealing studies at relatively low temperatures (approxima tely 250-350-degrees-C) for various times (0.5-3000 h). Two distinct s tages of thermally activated Mo/Si interlayer growth were found: a pri mary surge, followed by a (slower) secondary steady-state growth in wh ich the interdiffusion coefficient is constant. The interdiffusion coe fficients for the interlayer formed by deposition of Mo-on-Si are high er than those of the interlayer formed by deposition of Si-on-Mo. Assu ming that the activation energy is constant, an extrapolation of our r esults to ambient temperature finds that interlayer growth is negligib le, suggesting long-term thermal stability in soft-x-ray projection li thography applications.