High-temperature phase transitions on the Si(100) surface monitored by photoemission spectroscopy

The Si(1 0 0) surface has been studied by synchrotron radiation valence ban d photoemission as a function of temperature starting from the room tempera ture (2 x 1) reconstructed surface up to 1660 K. The analysis of the emissi on intensity at the Fermi level reveals that the surface acquires increasin g metallic character as the temperature is raised. A sign of a possible bre ak up of the dimer structure has been detected at 1485 K and associated, in accordance with Metois and Heyraud [Surf. Sci. 446 (2000) L127], with the disruption of the (2 x 1) reconstruction. A further transition has been obs erved at 1610 K, which could be indicative of surface melting. (C) 2001 Els evier Science B.V, All rights reserved.