| 摘要 |
PURPOSE: To obtain high-quality SOI substrates by inspecting and evaluating defects in silicon layers and to improve yields in manufacturing semiconductor devices. CONSTITUTION: An SOI substrate in which a silicon layer is formed on a buried oxide layer is prepared in a step ST11. An exposed surface of the silicon layer is thermally oxidized to form a thermal oxide film in a step ST12. The thermal oxide film is formed in a shape surrounding a defect in the silicon layer and reflecting or transcribing the defect. At this time, the thermal oxide layer is thermally oxidized in such a degree that the transcribing part of the thermal oxide layer comes into contact with the buried oxide layer. The SOI substrate is immersed in a hydrofluoric acid solution in a step ST13. By this immersion, the thermal oxide film is removed, and the buried oxide layer is eroded via a part in contact with the thermal oxide film. As the defect is reliably transcribed into the buried oxide layer in the thermal oxide step AT12 by this inspecting method ST10, it is possible to evaluate even contained defects which cannot be detected and evaluated by a conventional inspecting method.
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