MSc Thesis Presentation:Investigation of the Si(111)-√3x√3R30 Surface Reconstruction by Scanning Tunnelling Microscopy

MSc Candidate

Daniel Cuthbert

Abstract

A scanning tunnelling microscopy (STM) study of the B induced phase transition between the (7x7) and √3x√3R30° reconstructions on a Si(111) surface is presented. STM images indicate that this phase transition takes upwards of two hours of thermal annealing at temperatures greater than 1100°C to induce a long range ordered √3x√3R30° surface. During the annealing procedure, many different atomic arrangements are observed to coexist on the surface including another dimer, adatom, stacking-fault (DAS) surface reconstruction similar to the (7x7), known as the (5x5). Large stable clusters of Si atoms were observed to exist on top of the disordered regions of the surface, which propagate the surface reconstructions along the step edges. The results obtained assist in our understanding of the formation of the Si(111)-√3 surface, which will aid in our ability to produce a clean, defect free surface for use in industrial applications.

Examination Committee

• Dr. Robert Wickham, Chair 
• Dr. Xiao-Rong Qin, Advisor 
• Dr. De-Tong Jiang 
• Dr. Paul Rowntree