A developement of a new method to observe the direct image of surface atomic arrangements and a research of surface superlattice structures on semiconductors

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This project intend to study the furface superstructures by detecting X-rays emitted from crystal surfaces irradiated by an electron beam or an ion beam. applying "total reflection angle X-ray spectroscopy (TRAXS)" which has discovered by ourselves.According to this purpose. we constructed some new apparatus. such as an electron-beam TRAXS apparatus (1985), a photoelectron-diffraction apparatus (1985), an ion-beam TRAXS apparatus (1987), an apparatus for observation of surface atomic arrangements (1986) etc. We studied at first in detail the phenomena and mechanism of electron-beam TRAXS. As a result, it was clarified that the method have many advantages. such as (1):It is possible that the surface analysis of an area from where the RHEED pattern is produced,(2):Surface analysis is possible for the adsorbate ranging from 0.01 monoatomic layer to 10.000 monoatomic layers. (3):It is possible to measure the amount of the adsorbates irrespective of the growth modes. (4):It is possible to control the depth of the detection layers. (5):It is possible to study elementary analysis and the structure analysis at the interfaces inside the crystals.Considering the above advantages and others. we developed new methods for surface structure analysis. such as. electron-beam TRAXS. ion-beam AES and ion-beam TRAXS. During photoelectron diffraction studies. we invented a new type electron energy analyzer. It is possible to observe directly the two-dimensional intensity distribution within the large solid angle of 2 . for the electrons emitted from a point of surface and having the same energy. We constructed a new apparatus for observation of surface atomic arrangement. in which the diameter of the electron beam is about 5A and operated in an ultra high vacuum of 1.7x10-10 Torr. Obtained resolution was about 1.4 A゜ at present.