| 摘要 |
PURPOSE:To increase the switching speed of IIL by a method wherein the active region of an N-P-N bipolar transistor is formed on the buried layer located in the first epitaxial layer and on the second epitaxial layer, and the active region of IIL is formed on the second epitaxial layer. CONSTITUTION:An N type buried layer 13 and a P type epitaxial layer 14 are formed on the surface of a P type silicon substrate 1, and an N type layer 15 is obtained by performing a heat treatment. An N type buried layer 16 and an N type epitaxial layer 17 are formed, an isolation region 18 is formed by diffusing high density P type impurities, and the above is divided into region 17a where an N-P-N bipolar transistor will be formed and the region 17b where the IIL will be formed. The thickness of the N type epitaxial layer 17b which will be turned to the emitter region of the IIL 200 can be arbitrally selected, and the switching speed can also be increased as occasion demands. |
