| 摘要 |
PURPOSE:To improve the collector-emitter saturating voltage without decreasing the withstand voltage in a collector region formed of uniform low impurity density layer by increasing an impurity density only under an emitter region. CONSTITUTION:A low density N-type epitaxial layer 2 is grown on a high density N-type substrate 1. Then, phosphorus is selectively diffused in the substrate 1 to increase the density in a region 3 to become the collector region under an emitter region formed later than the other collector region. Then, A P-type base region 4 is formed by diffusing boron on the collector region,and phosphorus is again diffused on the region 4 to form an N-type emitter region 5. |
