| 摘要 |
PURPOSE:To lessen the area of emitter ohmic contact region by forming it in the same conductivity type as the emitter region and by surrounding it using the emitter regions. CONSTITUTION:The emitter 3 consisting of an N<+> type region is formed by diffusion of impurity within a P type base region 2 which is also formed by impurity diffusion on an N<+> type silicon substrate 1. The emitters 3 are connected in parallel in unit of four through the balast resistors 4 consisting of the N<+> type region and form an emitter block. The emitter blocks are connected to the emitter electrodes 6 by means of respective ohmic contact regions 5. The emitters are isolated and connected to the emitter contact regions only through the balast resistors. The balast resistor operates as the emitter since it is formed with the same conductivity type region as the emitter region. |
