Control of step structures of Si 001/ by highly doped As

We investigated the influence of highly doped As on the step structures of Si 001.by using a Scanning Tunneling Microscope STM.. Line shaped protrusions on the terraces and regularly aligned triangular-shaped step structures were observed. To clarify the formation mechanism of the peculiar structures, an Atom Probe combined with an STM system was used to know the chemical species on the surface. The AP mass spectrum showed that As as well as Si atoms were clearly detected. Further As concentration was much higher than the bulk concentration. The surface structures may be formed by the outdiffusion of As atom to the surface. q1998 Elsevier Science B.V. All rights reserved.