| 摘要 |
PURPOSE:To obtain a power transistor with a protective diode formed in one body by a method wherein a base contact region is formed, overhanging toward the circumference of the base, on the front side of the collector region of a junction transistor and a high density region is provided in a depletion layer region. CONSTITUTION:An N<+> region 5 is provided in the area, whereon the depletion layer will be formed, on the front side of an N<-> collector region 2 and a shallow base contact region 3a is formed in such manner that it is stretching out to the circumference of the base region 3. The depth (curvature of junction) of the regions 3 and 3a is established in proportion to the density ratio of the regions 5 and 2 and in such manner that the withstand voltage of the diode consisting of the regions 3a and 5 will be made lower than that between the regions 3 and 2. Through these procedures, a small-sized device 8, wherein a protective diode is connected in parallel between the base and collector and formed in one body, can be manufactured at a low cost and the reliability of which can also be improved. |
