| 摘要 |
PURPOSE: To make it possible to measure an incident angle highly accurately by forming thin films having the different reflectivities on the cleavage planes of GaAs substrate, and injecting primary ions along the cleavage planes, which are arranged so as to face each other. CONSTITUTION: In a sample holder, gold thin films 3 having the different reflectivities are formed on cleavage planes 2 of two GaAs substrates 1 whose cleavage planes 2 are arranged so as to face each other. Furthermore, the planes 2 are closely arranged in parallel with a primary-ion track, and the interval is made sufficiently smaller than the size of a sample. Then, O2 <+> ions generated by an ion gun are injected along the planes 2. The O2 <+> ion energy becomes 5.5keV effectively since a sample potential is 4.5kV. Since the interval between the planes is narrow, the equipotential space is formed. Therefore, the ions freely run and etch the films 3 with the incident angle being kept, and the etching trace is formed. At the etched part, where GaAs is exposed, the reflectivity of the visible light becomes low. Therefore, the etching trace can be readily observed with an ordinary microscope, and the incident angle can be measured highly accurately by photographing. |
