The effect of carbon on strain relaxation and phase formation in the Ti/Si1−<i>x</i>−<i>y</i>Ge<i>x</i>C<i>y</i>/Si contact system

Abstract

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&amp;lt;y&amp;lt;1.7%) contact system was studied after isochronal heat treatments from 500 to 800 °C. The results for Ti/Si1−xGex phase formation agree with recent published works. However, C incorporation in the epilayer causes a dramatic decrease in strain relaxation during the Ti reaction with the epilayer, a delay in the appearance of the C54 phase, a decreased Ge concentration in the silicide–germanide phases, and carbon accumulation (probably in the form of TiC) at the silicide–germanide/epilayer interface. Also, at high annealing temperatures, a roughing of the silicide–germanide/epilayer interface was detected for the C-containing samples. A possible explanation for the reduced strain relaxation is based on mobility of dislocations.