Image formation processes of LEEM and PEEM are described in detail. This study is important in understanding the surface processes by use of such microscopes. LEEM images can be understood by the diffraction and interference contrast. The latter can be classified into geometric phase and quantum size contrast. The LEED patterns that are obtained with LEEM optics are different from those observed with the conventional LEED optics. This characteristic should be taken into consideration in the analysis of LEED patterns in LEEM optics. The future trend in LEEM and PEEM is also described. Improvement of the lateral resolution is being made by adopting the mirror corrector and the new image processing method.

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The growth processes of Cu nano-structure on hydrogen terminated Si(111) surfaces were investigated by low energy electron microscopy (LEEM). The structure analysis of the Cu nano-structure was also carried out by low energy electron diffraction (LEED) using a LEEM apparatus. Cu nano-structures grow preferentially at step edges and domain boundaries. LEED patterns observed in LEEM show a different dependence on electron energies observed by using the conventional grid-type LEED optics. Taking this difference into consideration, we carried out a structure analysis of Cu nano-structures. It is shown that the Cu nano-structure is a β-phase Cu-Si alloy structure, and has {554} and {15 16 13} facets.

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Decay kinetics of two-dimensional islands and holes with diameters of a few micrometers to ∼100 nanometers on Si(111) was studied by low-energy electron microscopy close at the “1×1”-to-7×7 phase transition temperature. It is shown that the decay is governed by diffusion rather than attachment/detachment of the atoms at steps. Comparison of the decay rates of island and hole indicates that there is an upper limit for the Ehrlich-Schwoebel barrier. We also show that the surface mass diffusion constant on 7×7 is smaller than that on “1×1”. Slower surface mass diffusion on 7×7 than on “1×1”, coupled with preferential formation of 7×7 on the upper terrace of a step, produces a diffusion barrier during the phase transition, resulting in an asymmetry in the thermal decay rate between island and vacancy island. The diffusion barrier also causes the mass flow induced by the atom density difference between “1×1” and 7×7 asymmetric in the step-up and step-down directions.

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Photoemission electron microscopy (PEEM) using ultraviolet light has been developed for imaging the surface chemical reactions. Recently, the combination of the PEEM techniques and the synchrotron radiation (SR) light, vacuum-ultraviolet (VUV) or low-energy soft X-ray, enables us to image the surface chemical states by detecting the photoelectrons from shallow core levels. Our PEEM system using higher energy X-ray at SPring-8 BL15XU was designed in order to make the identification of XPS peaks easy and to obtain photoelectrons from deeper layers or interfaces. In this work, we indicate the detail of PEEM objective lens that covers keV electrons excited by high energy SR light.

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Surfaces of organic ultra-thin films were observed by two different surface sensitive microscopies, metastable electron emission microscopy (MEEM) and photoelectron emission microscopy (PEEM). We describe here our experimental evidence of diffusion of a large organic semiconductor molecule, chloroaluminum phthalocyanine (ClAlPc), on a MoS₂ crystal surface. The PEEM and MEEM images showed that a micropattern of ClAlPc ultrathin film prepared on the MoS₂ surface by vacuum deposition shrinks with time and finally disappears even at room temperature at which the molecules do not evaporate. As another example, we also show the diffusion of ClAlPc molecules on an oriented monolayer of ClAlPc. These results indicate that control of molecular diffusion is necessary for the preparation of stable micro or nanostructure of organic thin films.

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We have observed magnetic domains of magnetic nano-structures of nickel by photoemission electron microscopy (PEEM) using synchrotron radiation. The magnetic nano-structures were fabricated by electron beam lithography and lift-off. From the magnetic contrast observed by PEEM and micromagnetic simulations, it is indicated that the square, hexagonal and circular structures form flux closure structures whereas the triangular structure does not form the flux closure structure.

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Regularity of Ga⁺ primary ion TOF-SIMS fragment pattern of inorganic compounds is discussed. For an inorganic compound as formulated M-A, where the valence of cation M is +n and that of anion A is −p, the molecular formulas of appeared TOF-SIMS fragments are MxAy, which satisfy the rule nx ≥ (py + 1) for positive ion fragments and nx ≤ (py + 1) for negative ones. For example, for oxide fragments of molecular formula, MxOy (the valence of M is +n), the fragment pattern obeys the rule nx ≥ (2y + 1) for positive ions and nx ≤ (2y + 1) for negative ones, respectively. The regularity of TOF-SIMS fragment patterns of sulfides, nitrates, sulfates, etc. is discussed.

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