| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of inspecting fine trenches of semiconductor device, which can measure the depth and the size of the bottom part of an isolation trench of SOI substrate, on the basis of a nondestructive method. SOLUTION: When an isolation trench 6 for measuring a size of the trench width, which is almost equal to the element region, is provided on the surface of the SOI substrate, the fine region at the surface thereof is irradiated with a laser beam of 410 nm, the laser reflection beam 7 after the irradiation is received with a laser microscope, and the depth or the like of the isolation trench 6 is inspected with an optical system, which can perform the scanning in Z-axis direction with the higher accuracy, when an n-type SOI layer 3 is left at the bottom part of the isolation trench 6, the reflection intensity of the laser reflection beam 7 becomes strong. However, when the n-type SOI layer 3 is etched perfectly and an embedded oxide film 2 under the n-type SOI layer 3 is exposed to the bottom part of the trensh isolation groove 6, the intensity of the laser reflection beam 7 from the embedded oxide film 2 becomes very weak. Accordingly, complete etching can be confirmed.
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