| 摘要 |
PURPOSE:To prevent Al wirings between gates from being short-circuited each other and also to improve yield of I<2>L by a method wherein a part of p-type base and a collar layer are piled up alternately and thus Al is chemically converted thoroughly at the portion. CONSTITUTION:A p-type base 2 and an n-type collector 3 are formed on an n- epitaxial layer 1. An n<+> collar layer 4 is so formed as to surround the p-type base 2 simultaneously with the n-layer 3, and the p-layer 2 is piled up with the n<+>-layer 4 at a portion 8. Next, a connection hole 5 is provided and the overall surface is covered with an Al-metallized film. Where width L1 2.5mu and length outside from wirings 6 L2 5mu, a full length of the portion 8 is 20mu at the width of wiring 6 being 10mu. In this constitution, where an epitaxial layer 7 is left over between the p-layer 2 and the n<+>-layer 4 from making the Al wiring 6 through selective conversion of the Al-metallized film, and further there should remain Al not yet converted on this portion for a large step difference of the surface oxidized film, Al on the piled-up portion 8 can be converted thoroughly. Therefore, wirings between gates are prevented from being short-circuited each other. |
