Buried Dislocation Networks Research Articles

Ordered growth of Ge islands above a misfit dislocation network in a Ge layer on Si(111)

A flat Ge layer on Si(111) with a buried dislocation network at the Si/Ge interface is used as substrate. This flat Ge film was grown with Sb as surfactant. During subsequent growth and coarsening of two-dimensional Ge islands, ordering of the islands with respect to the underlying dislocation network (which has a periodicity of ∼100 Å) is observed using scanning tunneling microscopy (STM). During coarsening, preferred growth of the islands occurs near the minima of the height undulations induced by the buried dislocation network. This ordering effect is explained by strain induced preferred diffusion towards these areas and energetically favorable binding at these positions above the dislocations.

Grazing incidence X-ray studies of twist-bonded Si/Si and Si/SiO 2 interfaces

Twist-bonded Si/Si (0 0 1) and Si/SiO 2 interfaces have been investigated by grazing incidence X-ray scattering methods. For Si/Si (0 0 1) bonding, conventional X-ray reflectivity reveals the good quality of the interfaces in terms of flatness and roughness. In-plane grazing incidence diffraction measurements around the (2 2 0) reflection show satellite peaks close to the substrate and the layer diffraction peaks. These sharp satellites are produced by a periodic displacement resulting from a very regular buried dislocation network. The Si/SiO 2 bonding has been studied with X-ray reflectivity within a transmission geometry. The analysis of the data shows the high quality of both bonded Si/SiO 2 and thermal oxide SiO 2/Si interfaces.

A theory of ion beam induced charge collection

The ion beam induced charge technique can image the depletion regions of microelectronic devices through their thick metallization and passivation layers, and buried dislocation networks in semiconductor material by measuring the number of charge carriers created by a focused MeV light ion beam scanning over the sample surface. In this paper it is shown how the charge pulse height can be calculated in terms of the ion type and energy, and the minority carrier diffusion length. The effect of surface layers, depletion layers, ion induced damage, and ion channeling on the measured charge pulse height are also considered. It is shown how this approach can be used to simulate the charge pulse height reduction due to ion induced damage.