| 摘要 |
PURPOSE:To prevent an increase of the base resistance that is located directly below the ballast and to improve the characteristic of a transistor on making the size of a pellet smaller by making the pattern of ballast in perforation form and by selecting its interval properly when the ballast is provided along the circumference of the emitter of the transistor. CONSTITUTION:The base region 2 is formed in the semiconductor substrate 1, which is to be the collector region, by a diffusion method, and the emitter region 3 is provided in the region 2. Next the ballast resistance 5 is formed between both the regions 2, 3 along the circumference of the region 3 by a diffusion method and the ballast pattern is selected as follows. The pattern is made in perforation form, while the interval of the perforated form is properly selected, however, when it is excessively dense, the diffused layer 5 is deeply overlapped in the diffusion process and the resistance of the base that is located directly below the layer 5 becomes greater. Thus the interval of the perforated pattern is made rough, the diffused layer is made less overlapped and shallow, the base resistance is reduced to improve the hFE, and the intensity against the surge breakdown is increased. |
