METHOD OF FORMING A BIPOLAR TRANSISTOR AND THE BIPOLAR TRANSISTOR FORMED THEREOF

摘要

A method for forming a bipolar transistor is provided to form an emitter electrode with low resistance by forming an emitter region and an emitter electrode while using two polysilicon layers that are doped by different methods. A base region of first conductivity type is formed in a collector region formed in a substrate of first conductivity type. A first silicon layer of second conductivity type is formed on the base region. A second silicon layer of second conductivity type is formed on the first silicon layer, formed in a different way from that of the first silicon layer. A heat treatment is performed to form an emitter region made of impurities of second conductivity type in the base region. A heat treatment is performed in a hydrogen atmosphere.