| 摘要 |
PURPOSE:To enable enhancement of an alkaline ion preventive property of the bipolar integrated circuit and enable a self-alignment of a base and emitter contact regions by employing a laminate film of SiO2 and Si3N4 as a passivation film formed on the surface of a substrate, and utilizing it for a diffused mask. CONSTITUTION:An n<+> type buried layer 12 is diffused in a p type Si substrate 11, an n type layer 13 is epitaxially grown on the whole surface, and is separated into an island shape through there oxide films 14. An n<+> type collector region 15 is diffused in the one island-shaped layer 13 to be connected to the layer 12, and a p<+> type base region 16 is diffused in the other layer 13. Thereafter, an SiO2 film 17 and an Si3N4 film 18 are laminated on the entire surface, holes 19-21 are opened only at the film 18, only the film 17 is removed in the hole 19 by a photoetching process, the region 16 is partly exposed, and a polycrystalline Si film 24 including n type impurity is formed thereat. Then, it is heat treated, the impurity in the film 24 is diffused, and an n<+> type emitter region 25 is formed, and aluminum and silicon electrodes are coated on the respective regions. |
