Thermal stability of fullerene (C 70) on the Si(100) 2×1 surface studied with FI-STM

Abstract

We have studied the thermal stability of fullerene C 70 adsorbed on the Si(100)2×1 surface with the field ion-scanning tunneling microscope. The results show that the first layer of C 70 adsorbed considerably strongly due to the existence of Si dangling bonds on the surface. The first layer passivated the surface efficiently so that the multilayer crystalline film could be grown as close-packing array. The C 70 above the first layer can be easily desorbed at temperatures above approximately 250°C, which is similar to that of bulk C 70. In contrast to that, the first layer remains stable without any evidence of cage breaking or reordering until at temperatures above 1000°C, resulting in well-ordered islands: β-SiC(100)3×2 surface, according to our STM observations. The present work reveals a novel fullerene property on the Si(100)2×1 surface.