| 摘要 |
A silicon epitaxial layer 2 is grown in vapor phase on a silicon single crystal substrate 1 manufactured by the Czochralski method, and doped with boron so as to adjust the resistivity to 0.02 &OHgr;·cm or below, oxygen precipitation nuclei 11 are formed in the silicon single crystal substrate 1, by carrying out annealing at 450° C. to 750° C., in an oxidizing atmosphere, for a duration of time allowing formation of a silicon oxide film only to as thick as 2 nm or below on the silicon epitaxial layer 2 as a result of the annealing, and thus-formed silicon oxide film 3 is etched as the first cleaning after the low-temperature annealing, using a cleaning solution. By this process, the final residual thickness of the silicon oxide film can be suppressed only to a level equivalent to native oxide film, without relying upon the hydrofluoric acid cleaning.
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