| 摘要 |
PURPOSE:To obtain a transistor without the decrease of current amplification factors even when emitter current increases by a method wherein the junction surface between an emitter and a base is formed in wave form, and, in order to form it, first an emitter impurity is evaporated in island form on the base surface, next the island form impurity is joined by heat treatment, thus forming the junction surface between the base and the emitter in wave form, when a transistor is manufactured. CONSTITUTION:The base region 2 is diffusion-formed in the surface layer of a semiconductor substrate 3 serving as the collector region, and the dotted emitter impurity 4 is deposited thereon in island form. At this time the interval of the impurity 4 is kept approximately the same as the final emitter diffusion depth. Next, emitter diffusion is performed, and thus the boundary surface between the emitter region 1 and the base region 2 generated is formed in wave form or a wave form approximate thereto. In such a manner, the junction area between the emitter and the base increases, and the current density reduces; therefore, even when the emitter current increases, the current amplification factor does not decrease. |
