Self assembling growth of triangular pyramidal ge islands on a Si 111/–(3 =(3 –R308–B surface phase

Due to the crystallographic identity of Si and Ge, a very interesting system for the preparation of quantum dot arrays is a Ge deposition on top of a cleaned Si surface. The critical thickness for relaxation of the Ge layer on Si amounts to -2 nm caused by the lattice mismatch. Therefore, Ge quantum dots on Si are very small, strained, and generally statistically distributed over the Si substrate. We will show that the Si 111.–ʹ3 =ʹ3 –R308–B surface phase BSP., a two-dimensional superlattice of B atoms on top a of Si 111. substrate deposited between Si and Ge, has the potential to overcome this problem by completely passivating the Si dangling bonds and, therefore, acting as a lubricant between the Si substrate and the epitaxially grown Ge atoms. In general, we will discuss a step-by-step growth model for Ge epitaxy on BSPs, depending on B concentration, degree of misalignment of the Si surface, and growth temperature using atomic force microscopy AFM.and scanning tunneling microscopy STM.studies of samples prepared by molecular beam epitaxy MBE.. q2000 Elsevier Science B.V. All rights reserved