Formation of titanium and cobalt germanides on Si (100) using rapid thermal processing

• DOI: 10.1007/bf02670924
• Publication Date: 2007-07-16T20:58:01Z
• Authors: S. P. Ashburn; M. C. Öztürk; J. J. Wortman; G. Harris; J. Honeycutt; D. M. Maher
• Keywords: Germanide; Rapid thermal processing; Thermal Stability

Titanium and cobalt germanides have been formed on Si (100) substrates using rapid thermal processing. Germanium was deposited by rapid thermal chemical vapor deposition prior to metal evaporation. Solid phase reactions were then performed using rapid thermal annealing in either Ar or N2 ambients. Germanide formation has been found to occur in a manner similar to the formation of corresponding silicides. The sheet resistance was found to be dependent on annealing ambient (Ar or N2) for titanium germanide formation, but not for cobalt germanide formation. The resistivities of titanium and cobalt germanides were found to be 20 µΩ-cm and 35.3µΩ-cm, corresponding to TiGe2 and Co2Ge, respectively. During solid phase reactions of Ti with Ge, we have found that the Ti6Ge5 phase forms prior to TiGe2. The TiGe2 phase was found to form approximately at 800° C. Cobalt germanide formation was found to occur at relatively low temperatures (425° C); however, the stability of the material is poor at elevated temperatures.