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We have developed a submicron-area high energy resolution photoelectron spectroscopy system equipped with a multilayer-coated Schwarzschild objective for forming a soft x-ray microbeam. We show the photoelectron microspectroscopy results of the cross section of a semiconductor double heterostructure sample, namely an epitaxial film [InP (50 nm thick)/ In0.53Ga0.47As (2.3 μm thick)/InP (100) substrate] grown by metalorganic chemical vapor deposition. The core-level photoelectron spectra were obtained from the cross section of the cleaved sample. The As 3d, Ga 3d, and In 4d peaks were observed in the In0.53Ga0.47As region. In the InP region, the As 3d and Ga 3d peaks were not observed, and only the In 4d peak was. This result corresponds to the structure observed by cross-sectional scanning electron microscopy. Moreover, we observed an irradiation effect that was caused by the microbeam. These results suggest that this photoelectron microspectroscopy system is a powerful tool for studying chemical and electronic states of submicron-area surfaces.

The imaging properties of the soft-X-ray microscopes composed of a Schwarzschild objective and a grazing incidence mirror condenser are discussed. Fundamental formulae on the partially coherent transfer function, the resolution of a two-point object and the edge response have been derived by consideration of the optical properties of an object in soft-X-ray regions. Then these imaging properties for the microscopes are investigated with the formulae and compared with those for a normal circular pupil system.

Proposed is an imaging type Schwarzschild soft X-ray microscope including a condenser optimized for better imaging properties on the basis of Hopkins's theory. The condenser using grazing incidence reflective optics is found most suitable for a Schwarzschild objective. The modulation transfer function (MTF) for the microscope is calculated and it is shown that the MTF is improved with the light intensity distribution on the condenser pupil.

Features and applications of the laser scanning microscope are described, focusing on confocal imaging, the image contrast enhancement effect and three-dimensional surface profile measurement. A longitudinal resolution of 0·01 μm is obtained using a surface profilometer with a position-sensitive detector.

A compact soft x-ray reflectometer usable in a small laboratory is developed for measurement of the soft x-ray reflectance of a multilayer mirror in a wide wavelength range, i.e. , including the water window (23 to 44A). In this reflectometer, the reflectance can be measured as a function of wavelength or incidence angle. A laser-produced plasma soft x-ray source, which is small but has high brightness, makes it possible to construct the compact soft x-ray reflectometer. The soft x rays generated by the source are monochromatized with a grazing incidence reflection grating. Incidence angle dependency of the reflectance can be measured from 2 deg (almost normal incidence) to 85 deg. Reflectances of a Ni/Ti multilayer and a Mo/Si multilayer are measured, and 10.9% at a wavelength of 40.8A and an angle of 75.1 deg and 38% at a wavelength of 135.5A and an angle of 25.7 deg from normal incidence are obtained, respectively.

SUMMARY A beam-deflection type laser scanning microscope for differential phase contrast images using the split-detector technique is developed and the images are obtained in real time (30 images/s). The special optical design allows transfer of the pupil information necessary to the imaging of the differential phase contrast images during beam deflection and the use of acousto-optic deflectors with the associated correction system enables real time imaging. Differential phase images of surface details of crystals are simply obtained without silver coating or etching, which are indispensable in a normal DIC. Biological specimens are also observed.