| 摘要 |
PURPOSE:To eliminate signal leakage between circuits during the high-frequency operation of the titled device, by constituting an IC having a dielectric isolation structure such that a support substrate with electric conductivity is provided on its surface with a plurality of first single crystal semiconductor island regions separated from each other by dielectric layers and with a second single crystal island region whose bottom is low-resistance contacted with the substrate so that the substrate is applied with a potential through the second region. CONSTITUTION:An N type Si substrate 31 to be a collector is provided on its uppermost layer with V-shaped grooves 33 for defining regions 32a and 32b on which elements are to be formed, the grooves being formed by anisotropic etching. Impurity ions are implanted to form an N<+> type implantation layer 34 for reducing the collector resistance. An SiO2 film 35 is then adhered over the whole surface including the side walls of the grooves 33. After the film 35 on the region 32a only is removed, an N<+> type polycrystalline Si layer 37 is grown on the whole surface of the film 35, while, on the region 32a, a polycrystalline Si layer 37S is grown directly on the substrate 31 without interposition of the film 35 so as to be low-resistance contacted with the substrate. The substrate 31 is then turned upside down, and P type base and emitter regions are provided on the Si layers 33a having an island shape isolated by the film 35 and on the island-shaped Si layer 33b without the interposition of the film 35, respectively. |
