| 摘要 |
PURPOSE:To enhance the injection efficiency of the transistor in reverse operation by forming a collector region of an upper low impurity density layer and a lower low impurity density layer and forming high impurity density regions for surrounding the base region at an interval in the upper layer when forming the base region in the upper layer. CONSTITUTION:A semiconductor substrate 3 becoming a collector region is formed of upper N<->-type epitaxial layer 2 and a lower N<+>-type layer 1, a P-type base region 4 is diffused in the upper epitaxial layer 2, an N-type emitter region 5 is formed therein to form the planar type transistor. In this configuration, an N<+>-type region 10 is diffused newly to the layer 2 at an interval while surrounding the region 4, and an insulating film 6 is coated on the entire surface. Thereafter, openings are perforated at the film 6, base, emitter and collector electrodes 8, 9, 11 are mounted therethrough, and the electrode 11 is connected and shorted to the collector electrode 7 formed on the back surface of the layer 1. In this manner, the surface injection efficiency can be improved to increase the current amplification factor thereof. |
