Search

Presents a study which investigated the oxidation of titanium disilicide on polycrystalline silicon-coated substrates by steam oxidation. Analysis of the films by Rutherford backscattering spectrometry and transmission electron microscopy; Comparison of oxidation and pressure to the calculated values for single-crystal silicon substrate oxidation; Relation between temperature and the diffusional transport of silicon through the silicide grain boundaries.

Observes germanium island formation during growth on silicon(001) by chemical vapor deposition. Discussion of the four-step growth process; Uniform pseudomorphic conventional epitaxial reactor; Three-dimensional island growth with a constant aspect overlayer formation.

The atomic structure of the GaAs/Si(100) interface is studied using high resolution transmission electron microscopy. The samples studied were grown by molecular beam epitaxy using a conventional two-step growth process of a relatively low-temperature (405 °C) GaAs buffer layer followed by a higher temperature (575 °C) device layer. Following this growth procedure, the interface is found to be atomically rough with nonuniform distributions of steps, and to contain regions of disrupted crystallinity. These regions are found to be more prevalent in material which has undergone only low-temperature (buffer layer) GaAs deposition. By using the atomic resolution microscope at the National Center for Electron Microscopy, Lawrence Berkeley Laboratories, we are also able to atomically image the same area of interface along orthogonal <011> directions, observing qualitatively similar structures. [ABSTRACT FROM AUTHOR]

Thin films (less than 1000 nm) of heteroepitaxial GaAs on Si were grown by organometallic vapor phase epitaxy with the intent of comparing the initial stages of growth with the authors’ previous experience in examining films grown by molecular beam epitaxy (MBE). The films were found to be epitaxial after 10 nm of growth at 425 °C, and to uniformly cover the substrate completely, unlike the asymmetrical island nature of MBE films grown under comparable conditions. The relaxation of strain was found to be quite similar to the MBE case. [ABSTRACT FROM AUTHOR]

We study the effect of surface structure upon the nucleation of GaAs in molecular beam epitaxy growth on vicinal Si(100) surfaces. In general, cross-sectional transmission electron microscopy reveals that nucleation of GaAs islands is associated with surface steps produced by the deliberate substrate misorientation. Furthermore, it is found that standard in situ cleaning of the Si surface prior to deposition can result in steps grouping together, producing local surface facets. GaAs nucleation then occurs on these facets, the nucleation sites being correspondingly further apart than for an equilibrium distribution of monolayer steps. [ABSTRACT FROM AUTHOR]