XPS, LEED and AFM investigation of the Si(100) surface after the deposition and annealing of tellurium thin films

In this study the structural properties and the morphology of the Te/Si(100) 2 X 1 system after an annealing process have been investigated. Several Te/Si(100) samples have been annealed at different temperatures. Up to about 150 degrees C no changes are observed in the samples. At about 200 degrees C the tellurium films evaporate from the silicon substrate leaving one monolayer of Te on the Si(100) surface indicating a higher strength in the Te-Si bonds with respect to the Te-Te one. The remaining monolayer of Te on Si(100) induces a 1 X 1 reconstruction of the surface. The annealing procedure performed at higher temperatures (more than about 400-500 degrees C), leads to the complete removal of the tellurium. The resulting silicon surface is 2 X 1 reconstructed with a different morphology with respect to the one observed before the Te film deposition. Repeating several times the deposition of Te and the annealing procedure, at temperatures higher than about 400 degrees C, a picturesque morphology of the silicon surface is observed.