| 摘要 |
PURPOSE:To enable the simultaneous formation of transistors having different current amplification factors by a method wherein transistors of non-walled emitter structure and walled emitter structure are formed simultaneously on the same substrate. CONSTITUTION:N<+>-type buried layers 32a-32c, N-type epitaxial layers 33a-33c, a separating oxide film 35, base regions 36a-36c, emitter regions 37a-37c, collector regions 38a-38c are formed on a P-type semiconductor substrate 31. For an example, a transistor TrA is consisted in a non-walled emitter structure, TrB is in a two-directional walled emitter structure and TrC is in a three-directional walled emitter structure. As a result, the formation of transistors having the structure of different effective base width becomes possible, and the formation of transistors having different current amplification factors on the same substrate becomes possible simultaneously. Therefore, for a semiconductor device having need of to form plural transistors of various sorts, the simplification of standardization process of transistor size can be attempted to contributes to the constitution of high density and high integration. |
