It has been recognized that several interesting phenomena, such as low temperature interfacial intermixing reactions or Fermi level pinning, occur at metal-semiconductor (M-S) interfaces. Moreover, from the practical point of view it is necessary to understand the mechanism of low temperature interfacial intermixing reactions in the development of highly reliable very large scale intergrated circuits (VLSI). To understand and control interfacial phenomena, the initial stage in the formation of M-S interface has been studied with electron spectroscopy (AES, ELS and LEED methods) and ion backscattering methods (channeling technique). Observations indicate that for metal films to react with semiconductor substrates to induce room temperature intermixing, the film thickness must exceed a ciritical value. This fact is felt to be an important clue in understanding intial stage mechanisms. In addition to the techniques mentioned above for the interface study, a tunable ELS method, and a method using electron spectroscopy combined with syncrotron orbital radiation (SOR), have been developed for non-destructive observation of M-S interfaces.
A review covering the last ten years of research on the structure of metallic crystal grain boundaries, including epoch-making observations, presently under way, of lattice images using electron microscopy, is prsented. While representative studies carried out in the 1970's on ordered grain structures were limited by the analytical techniques available, the role in alloy design in future investigations is emphasized. Visual models and computer simulations, as methods for analysis of grain boundary atomic configurations, and also information gained by lattice imaging microscopy are explained, and the importance of future studies on grain segregation structures is shown.
Current trends in chemical modification of solid surfaces have been reviewed. Commercially available carrier materials and various methods hitherto reported for surface modification were described in detail. Examples of practical applications to chromatographic separation and immobilized calalysts were also given along with comments.
A new technique for quantitatively determining surface atomic structure to a precision of ∼±0.1 Å was developed by specializing low-energy ion scattering spectroscopy (ISS). It is termed low-energy impact-collision ion scattering spectroscopy (ICISS). This technique was applied to determine the relative positions of a Ti atom in the top layer and neighboring C atoms in the second layer of a TiC(111) clean surface. The result shows that the surface interlayer distance is smaller than the corresponding bulk value by 0.38±0.08 Å.
A study has been made of the friction and hardness of chromium implanted mild steel. Ion implantation was performed with doses of 1×1015-1×1017ions/cm2 at 50-150keV. energies The friction coefficients and the Vickers hardness of Cr-implanted specimens were measured with a Bowden-Leben type friction testing machine and a micro-Vickers hardness tester, respectively. All tests were carried out at atmospheric room temperature. The friction coefficients had a tendency to decrease as the Cr fluence increased, but were independent of the acceleration energy. As the dose increased, the Vickers hardness increased at a lower normal load than 10gf, Concentration profiles of Cr were measured by secondary ion mass analysis in order to investigate the surface layer depth which contributes to friction and hardness properties. The Cr profiles showed abnormally high concentrations of oxidized chromium down to 200Å from the surface, not predicted by the range theory, and which are supposed to cause a decrease in the friction coefficients and an increase in the hardness.
As references for use in trouble shooting concerning industrial aluminum products, depth profiles of typical surfaces of diverse specimens obtained using an Auger electron spectrometer furnished with an argon sputter ion gun are presented. The data consist of depth profiles of a (1) surface frozen during exposure to air, (2) surface frozen while in contact with an iron mould, (3) water cooled surface, (4) rolled surface, (5) weathered surface, (6) extrusion surface, (7) chromated surface, (8) anodized surface and a (9) lathed surface. The following is on the whole noteworthy : (A) Thicknesses of oxide films are very small : 8 nm for sample (1), 50 nm for sample (3). This is not expected to result from the susceptibility a corrosion of aluminum. (B) The industrially produced surfaces show little contamination. Contaminants do not completely cover even the surface of sample (4). (C) Magnesium tends to segregate in the oxide films.
Instruments for surface analyses have greatly improved in the past ten or twenty years. the ion beam technique which has been utilized in the field of nuclear physics. has grown up to a powerful tool for the surface analysis, In this Current Topics, applications to surface science are reviwed. of the backscattering and channeling methods, and of ion-induced X-ray and Auger electron spectroscopies