| 摘要 |
PURPOSE:To reduce or vanish a P<-> type diffused layer formed with boron mixed at diffusing time by ion-implanting in advance phosphorus as second impurity. CONSTITUTION:A silicon oxide film 12 of predetermined thickness is formed on a P-type semiconductor substrate 11 of plane azimuth 100, a region to become a buried layer 17 is opened, coated with SbCl3 solution of silane series, heat treated to form a glass film 13 which contains SbCl3, and an N<+> type first impurity deposited layer 14 is formed as a diffusion source. Then, the films 12, 13 are removed, P ions are implanted on the entire substrate 11 to form a second impurity deposited layer 15, an N-type epitaxial layer 16 is formed, heat treated as predetermined, a first impurity deposited layer 14 is diffused elevationally to obtain an N<+> type buried layer 17. Thus, the P<-> type diffused layer to be formed by B having larger diffusion coefficient than Sb of first impurity at diffusing time is stopped, reduced or vanished by second impurity P having equivalent diffusion coefficient to the P<-> type diffused layer.
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