| 摘要 |
PURPOSE:To obtain a single-crystal layer of a required thickness with its surface flattened by a controlled polishing process by a method wherein a polycrystalline layer and insulating film are polished under the supervision of a film thickness measuring unit, which determines the thickness of an insulating film on a semiconductor substrate, until a required thickness is attained in the insulating film. CONSTITUTION:A film thickness measuring unit 4, which is an optical means, determines the thickness of an insulating film 2 on the surface of a silicon substrate 1. Immediately after an epitaxial growth process, there are relatively thick insulating film 2 and silicon single-crystal layer 3, as indicated in the figure by a broken line. With the film thickness measuring unit 4 constantly determining the thickness of the insulating film 2, the surfaces of the insulating film 2 and single- crystal layer 3 are polished, until the insulating film 2 becomes as thin as required, as illustrated by a solid line in the figure. At this stage, the single-crystal layer 3, which was higher than the insulating film 2 at the start of the polishing process, is now flush with the insulating film 2. The surface of the single crystal layer 3 is now in the same plane as the surface of the insulating film 2 after a process wherein polishing is continued under the supervision of the film thickness measuring unit 4 until a required thickness is attained.
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