The effect of carbon and germanium on phase transformation of nickel on Si1-x-yGexCy epitaxial layers

The influence of carbon and germanium on phase transformation and sheet resistance of Ni on epitaxially grown Si1-x-yGexCy (0less than or equal toxless than or equal to0.24 and 0less than or equal toyless than or equal to0.01) layers annealed in a temperature range of 360 to 900degreesC has been investigated. The role of strain relaxation or compensation in the reaction of Ni on Si1-x-yGexCy layers due to Ge or C out-diffusion to the underlying layer during the phase transformation has also been investigated. The formed NiSiGe layers were crystalline, with strong (020)/(013) growth orientation in the direction, but the thermal stability decreased rapidly with increasing Ge amount due to agglomeration. However, this thermal behavior was shifted to higher annealing temperatures when carbon was incorporated in the SiGe layers. A carbon accumulation at the interface of NiSiGeC/SiGeC has been observed even at low-temperature annealing, which is suggested to retard the phase transformation and agglomeration of Ni/SiGeC system. (C) 2004 American Institute of Physics.