| 摘要 |
PURPOSE:To reduce the output coupling capacity, by a method wherein a groove of a specific depth is formed on one main surface of a substrate having on its low-resistivity semiconductor surface of one conductivity type an epitaxial layer of the same conductivity type as that of the surface, such as to surround a predetermined active region, and an insulating film is formed such as to be flush with the substrate surface, thereby to provide an output end in this part. CONSTITUTION:A resist 20 having resistance to chemicals is formed on an n<+> type epitaxial silicon substrate 11 having thereon an n type epitaxial layer 12. A groove 19 is selectively formed by etching such as to have depth, 1.5- 2mum, which is required from the viewpoint of design. A thermal oxide film of SiO2 is formed in the groove 19. The surface of the thermal oxide film formed in the groove 19 is protected by, for example, a resist. Any thermal oxide film formed on the other active region surface is removed. The thermal oxide film and the silicon surface in the active region are maintained such as to be substantially equal in height to each other. A transistor is formed in the active region by a known process. |
