THE EFFECT OF CARBON ON STRAIN RELAXATION AND PHASE-FORMATION IN THE TI SI1-X-YGEXCY/SI CONTACT SYSTEM/

We report the first study of interfacial reactions of a metal with Si1 -x-yGexCy, epitaxially grown on Si. The Ti/Si1-x-yGexCy/Si (0<y<1.7%) contact system was studied after isochronal heat treatments from 500 t o 800 degrees C. The results for Ti/Si1-xGex phase formation agree wit h recent published works. However, C incorporation in the epilayer cau ses a dramatic decrease in strain relaxation during the Ti reaction wi th the epilayer, a delay in the appearance of the C54 phase, a decreas ed Ge concentration in the silicide-germanide phases, and carbon accum ulation (probably in the form of TIC) at the silicide-germanide/epilay er interface. Also, at high annealing temperatures, a roughing of the silicide-germanide/epilayer interface was detected for the C-containin g samples. A possible explanation for the reduced strain relaxation is based on mobility of dislocations. (C) 1996 American Institute of Phy sics.