| 摘要 |
PURPOSE:To make the surface of a substrate flat by a method wherein a base lead-out layer and a resistance layer are composed of a same polycrystalline Si layer and, after a part in the thickness direction of the polycrystalline Si layer for the base lead-out layer is removed, a silicide layer is formed. CONSTITUTION:An oxide film 1B is formed in the surface part of a substrate around a transistor forming part and under a resistance forming part and a P-type polycrystalline Si layer 2 is made to grow. Then element isolation regions 2A are formed by selective oxidization with Si3N4 layers 2' as a mask. The Si3N4 layers 2' on the transistor forming part is removed and a half of the thickness of the polycrystalline Si layer 2 is etched away. Then a tungsten layer 3 is selectively made to grow on the polycrystalline Si layer 2. Then the Si3N4 layer 2' on the resistance forming part is removed and an SiO2 layer 4 is formed over the whole surface of the substrate as an insulating layer. An emitter window is drilled in the SiO2 layer 4, the W layer 3 and the polycrystalline Si layer 2 and an SiO2 layer is formed over the whole surface of the substrate and a side wall 5 of SiO2 is formed on the inside surface of the emitter window by anisotropic etching. A window 7 and windows 8 and 9 are drilled in the SiO2 layer 4 on the W layer 3 and on the polycrystalline Si layer 2 respectively and electrodes are formed. With this constitution, a base lead-out layer and a resistance layer can be formed by one polycrystalline semiconductor growth.
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