| 摘要 |
PURPOSE:To realize improvement of operating speed, with accumulation of holes being decreased in epitaxial layers just under the first and second base areas, by mounting the second embedded layer of the other conduction-type on the first embedded layer in the second island, to make Wepi become small in a I<2>L. CONSTITUTION:The first embedded layer 2 of N<+> type is formed by diffusion of, e.g., Sb or As, through the surface of a P<-> type substrate 1, and the impurity, e.g., P, which is larger in diffusion coefficient than the impurity forming the first embedded layer 2, is ion-implanted through the surface of the first embedded layer 2 at the I<2>L part, to form the second embedded layer 3 of N-type. B, e.g., is ion-implanted through the surface of the epitaxial layer 4 at the I<2>L part to form the first based area 6a of P<-> type, so as to include at least the inside base area in a reverse-operation NPN transistor. Succeedingly, e.g., POCl3 is diffused to form a N<+> type color area 7. It is desirable to form it, making contact to the first base area 6a and the second embedded layer 3, but sufficient with Wepi at least being made small. |
