Thermal stability of ultra-thin CoSi2 films on Si(100)-2x1 surfaces

The thermal stability of epitaxial Co disilicide on Si(100) substrates has been investigated by coaxial impact-collision ion scattering spectroscopy (CAICISS), scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). After the Co deposition of 1 ML on Si(100)-2 X 1 clean surfaces and the subsequent annealing at 540 degrees C for 10 min, CoSi2 (110) islands are formed on Si(100) and the island surfaces are covered with Si layers with a thickness of about 0.4 nm. For the 3 ML Co deposition, atomically flat and pinhole-free epitaxial CoSi2(100)-(root 2 X root 2)R45 films on Si(100) are obtained, whose surfaces are not covered with additional Si layers. The CoSi2(110) islands and the CoSi2(100) films are dissolved into Si substrates by thermal annealing above 600 degrees C.