| 摘要 |
PURPOSE:To prevent migration of impurity to the side wall of groove and simplify the manufacturing processes by forming an overhung mask layer and conduct ion implantation to form high concentration impurity region from the gap of the mask layer. CONSTITUTION:A method of manufacturing an NPN bipolar transistor, wherein a P type silicon substrate 1 is used and a groove 4 is formed in the determined depth from the main surface of semiconductor substrate, namely the N type epitaxial growth layer 3 of the surface to the substrate 1 is formed, for example, by using the photolithography by the RIE method. Next, an overhung silicon oxide film 5 is formed by the normal pressure DVD method. Thereafter, the P<+> type impurity (boron) is introduced by the ion implantation in order to form the channel stop region with the formed silicon oxide film 5 used as the mask. Next, introduction of unwanted ion to the side wall is prevented and the silicon oxide film 5 as the mask to form high concentration impurity region 7 only on the bottom of groove 4 is removed effectively. The element isolation oxide film 8 is formed by oxidation.
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