Life Sciences Commons^™

Secondary Ion Mass Spectrometry Studies Of Isotope Effect In Diffusion, U. Södervall, H. Odelius, A. R. E. Lodding

Scanning Microscopy

The mass effect of diffusion is of interest in connection with interactions between defects and impurities and with the mechanisms of atomic displacements in the condensed states. The delineation entails the precise measurement of the isotope ratio as function of tracer concentration, varying within several orders of magnitude along the diffusion profile. The measurement by SIMS (secondary ion mass spectrometry), using stable isotopes, has proved to possess advantages compared to familiar techniques with radiotracers. However, the aims require the utmost counting economy and optimal precision available in SIMS, including the control of the mass fractionation and of some features peculiar …

Topographic Evolution In The Atomic Scale Growth And Erosion Continuum, G. Carter, I. V. Katardjiev, M. J. Nobes, J. L. Whitton

Scanning Microscopy

This review gives a detailed survey of the range of fascinating surface features which develop under growth or erosion conditions under the combined influence of thermal and more energetic atomic particle fluxes. Collisionally induced atomic ejection and migration, and thermally and radiation induced atom and defect diffusion processes are outlined and their relevance to topographic initiation and evolution explored. A range of experimental observations of surface feature elaboration is discussed from net growth to net erosion conditions and models for their explanation are considered. It is concluded that while much data have been accumulated, much of these have been in …

The Depth Resolution Of Secondary Ion Mass Spectrometers: A Critical Evaluation, D. S. Mcphail, E. A. Clark, J. B. Clegg, M. G. Dowsett, J. P. Gold, G. D. T. Spiller, D. Sykes

Scanning Microscopy

The ability of five Secondary Ion Mass Spectrometry (SIMS) instruments to resolve thin layer and modulated dopant structures by depth profiling has been assessed. Three magnetic sector instruments (two Cameca IMS 3f's and one 4f), which use optical gating and a high extraction field, were used, together with two different quadrupole based instruments (EVA 2000 and Atomika) , which use electronic gating and a low extraction field. The test structure, a thirty-one peak boron-in-silicon modulating dopant structure, was grown by Molecular Beam Epitaxy (MBE).

In all the depth profiles the near surface peaks appeared narrow and asymmetric, being broadened only …