| 摘要 |
PURPOSE:To obtain a bipolar IC through a novel method by isolating an epitaxial layer grown on a substrate into elements by a reverse conduction type region through a BSG film, boring openings to SiO2 films on the isolated epitaxial layers and forming regions being in contact with the epitaxial layers in the openings when the bipolar IC is prepared. CONSTITUTION:An n<+> type layer 2 is grown on a p type Si substrate 1 in an epitaxial manner, a U-shaped groove 3 for an element isolation band intruding to the substrate 1 is bored by using a photo-precess, and the whole surface containing the side wall of the groove 3 is oxidized at a high temperature to form an SiO2 film 4. A BSG film 5 is attached on the side wall of the groove 3 and extending over the upper end edge of the groove 3, the film 5 on the base of the groove is removed, the inside of the groove 3 is buried with a p type epitaxial layer 8 while a hole 6 for forming a base contact region and a hole 7 for collector contact are bored to the film 4 on one side of the groove 3, and these holes are buried with n type epitaxial layers 9 and 10. A p<+> type base region 12 is diffused and shaped to the surface layer section of the layer 9 while an impurity is doped to the layer 10 to form an n<+> type layer 11. Accordingly, the degree of integration of a bipolar IC is improved. |
