| 摘要 |
PURPOSE:To enable establishment of an optimum resistance value for epitaxial resist even when the grown condition forming the epitaxial layer varied widely by forming a donor or acceptor impurity added are in an epitaxial layer. CONSTITUTION:A P<+>-type buried layer 2 is formed on P-type Si substrate 1, and on the above layer an n-type epitaxial layer 3 is formed. At this time, upon measuring the specific resistance and the thickness of the layer 3, let it be supposed that the resistance value is staggered to the larger figure from the design value. In this case, a new semiconductor region 4 is formed by injecting donor impurities. After that, the acceptor impurities are diffused from the surface of the layer 13, a P<+>-type insulation isolated region 5 is formed. At this time, the region 4 is also diffused and a deeper semiconductor region 4 is formed. Hence, the resistance value of the epitaxial resistance region differs from the resistance value of the layer 3 and the resistance value becomes almost the same as the design value. |
