Si dangling bonds

The early work of Sakurai and Hagstrum (1976) addressed the question of adsorption of H on the surface of Si crystals. They found that a (111) surface is covered with monohydrides and trihydrides, whereas a (100) surface is covered with monohydrides and dihydrides. The termination of Si dangling bonds by a small H atom allows the lattice perturbed at the surface to restructure or reconstruct itself, as though there were no... 

As was pointed out in previous chapters, the role of hydrogen in silicon is to passivate all the Si dangling bonds. It is the realization that there is a Si dangling bond near every acceptor that led us to search for the possibility that H might neutralize the acceptor. 

Hamers, R. J., and Demuth, J. E. (1988b). Electronic structure of localized Si dangling bond defects by tunneling spectroscopy. Phys. Rev. Lett. 60, 2527-2530. 

Typical point defects present at the Si02 surface are the so called E centres, holes trapped at oxygen vacancies, and Si dangling bonds. These latter defects are particularly important when present at the Si/SiOz interface because they markedly affect the electrical properties of electronic devices. These defects, which are also known as Pb centres, have been widely investigated in the past. Recently however, the microscopic origin of these defects has been unravelled by means of a sophisticated UHV-ESR system by Futako et al, 178 who elucidated the formation processes of interface dangling bonds (Pb centres) during the initial oxidation of a clean Si(lll) surface. After oxidation of one or two Si layer(s), the... 

To analyze the role played by the dimensionality we considered three different Si[ ]-SiC>2 wells with n (the number of elementary Si cells) equal to 1,2 and 3 the thickness of the wells, taken as the distance between the Si atoms at the two interfaces along the growth direction, is 0.543,1.086 and 1.629 nm, respectively. To understand the role played by O related defects at the interface of the well we considered two systems, the first fully passivated through the double bonded extra O atom (the black atoms in Figure 38) added to saturate the Si dangling bonds, and the second with an O vacancy at the interface produced removing the same extra O atom. 

Enokida et al. (1991) measured hole mdbilities of PMPS before and after ultraviolet exposures. The exposures were of the order of 1 erg/s-cm2. Prior to the exposures, the mobilities were approximately 10-4 cm2/Vs and weakly field dependent. Following the exposures, a decrease in the mobility was observed. Under vacuum exposure conditions, a decrease of approximately 40% was observed for a 1 h exposure. Under atmospheric conditions, however, the decrease was approximately a factor of 4. Enokida et al. attributed the decrease in mobility to the formation of Si-O-Si bonds in the Si backbone chain. A similar study of PMPS was described by Naito et al. (1991). While the field and temperature dependencies of the mobility were not affected by the ultraviolet exposures, the dispersion in transit times increased significantly. The change in dispersion could be removed by subsequent annealing. The authors attributed the increase in transit time dispersion to a reduction in the hole lifetime, induced by Si dangling bonds created by the ultraviolet radiation. 

Figure 4 Structure of a Cus cluster interacting with an Si E defect center (an Si dangling bond) at the surface of Si02-... 

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