BYPOLAR TRANSISTOR MANUFACTURE METHOD

摘要

PURPOSE: A bipolar transistor manufacture method is provided to reduce a right direction voltage on driving the device by improving an OHMIC contact resistance characteristic between a first semiconductor layer and a collector electrode. CONSTITUTION: The bipolar transistor manufacture method comprises the steps of: a process of forming a n-type second semiconductor layer on a n+-type first semiconductor; a process of forming a p-type third semiconductor layer within the second semiconductor; a process of forming a n-type fourth semiconductor layer within the third semiconductor; a process of selectively doping a n-type impurity in a high concentration only on the back side of the first semiconductor; a process of forming a base electrode at the same time on the second semiconductor; a process of forming the collector electrode on the back side of the first semiconductor.