| 摘要 |
PURPOSE:To thin an n-type epitaxial layer, and to increase the working speed of an n-p-n bipolar-transistor by independently forming a p<+> buried layer at a place deeper than the n-type epitaxial layer regardless of the film thickness of the n-type epitaxial layer shaping the bipolar-transistor. CONSTITUTION:A p<+> buried layer 5 is buried deeply to a p-type silicon substrate 1, and n<+> buried layers 3, 4 are buried onto a p-type epitaxial layer 10 formed onto the p-type silicon substrate 1. Consequently, the n<+> buried layers 3, 4 are formed where higher than the p-type silicon substrate 1 only by a section controlled by the thickness of the p-type epitaxial layer 10, and the p<+> buried layer 5 is shaped where lower than the n<+> buried layers 3, 4 only by the section relatively. That is, the relative positional relationship of the n<+> buried layers and p<+> buried layer is set arbitrarily by the film thickness of the p-type epitaxial layer 10 regardless of the film thickness of an n-type epitaxial layer 2. Accordingly, a semiconductor integrated circuit device having double well-Bi-CMOS structure capable of attaining the thinning of the epitaxial layer is acquired. |
