| 摘要 |
PURPOSE:To improve the electric characteristics of and to enhance the integration of the semiconductor device having a low resistance buried layer as a part of an element region by forming the buried layer of the first region with the first impurity and the second region with the second impurity having larger diffusion coefficient than that. CONSTITUTION:An N<-> type epitaxial collector layer 2 is formed on a P type substrate 1 and a P type base 6 and N type emitter 7 are sequentially formed on the surface of the layer 2 in the bipolar semiconductor device. N<+> type buried layers 3a, 3b are formed between the substrate 1 and the epitaxial layer 2. The diffusion coefficient of the impurity of the layer 3a is small, and the diffusion coefficient of the impurity of the layer 3b is large. A collector pickup N<+> type region 5 is connected to the layer 3b. Thus, the output resistance can be lowered and the expansion of the pickup region can be reduced. Accordingly, the integration can be reduced. This can be applied to the photoelectric conversion diode and the junction gate type FET having buried layer. |
