Band Engineering of the Si(001):H Surface by Doping with P and B Atoms
Si(001):H surfaces doped with phosphorus (P) and with boron (B) were explored as conducting contact pads for a dangling bond (DB) wire. Heavily doped Si(001):H surface patches are proposed as an alternative to metallic nano-islands or as an intermediate scale between the DB wire and the metallic islands to precisely contact a DB wire. Our calculations show that patches of B dopants incorporated in Si(001):H surface introduce states in the surface band gap with a significant dispersion along the dimer rows and which overlap well with the DB wire band states, demonstrating the possibility of using patches a B-doped Si(001):H as viable and robust contact pads for DB wires.
Two devices have been constructed for the development of biaxial stresses and the study of deformation potentials on thin layers. In the first device hydrostatic pressure was employed to develop a two-dimensional stress environment on thin silicon wafers. The deformation of the plates was found to be related to the third root of the pressure applied, in good agreement with theory. The second apparatus used a central force for the bending of the wafer, and the stresses, as detected from the frequency shift of the silicon phonon line in the Raman spectra, were confined to a small area of the plate. In both devices and analytic relation between the radius of curvature at the centre of the wafer and the stresses developed was established.