| 摘要 |
PURPOSE:To increase the integration degree by making a color region much closer to a base region, by a method wherein the color region surrounding the base region is made as a deep diffused layer of gentle gradient of impurity concentration which reaches the neighborhood of a buried layer. CONSTITUTION:The surface of the island region 5 of a P<->-type epitaxial layer 3 formed on a P-type substrate 1 is provided with an N<+>-type color region 15 so that this may surround an injector region 6 and a base region 7. The surface concentration of this color region 15 is set slightly lower than that of the base region 7, and the color region 15 is made as a deep diffused layer of gentle gradient of impurity concentration which reaches the neighborhood of an N<+>-type buried layer 2. This construction generates no intrusion to the base region even when lateral diffusion comes to contact with the base region; therefore, the gap between the color region and the base region can be reduced, thus improving the integration degree of elements. Besides, the stabilization of the process and the improvement in yield can be contrived by preventing the decrease in reverse current amplification factor. |
