| 摘要 |
PURPOSE:To obtain a hetero junction bipolar transistor of high performance through simple manufacture by diffusing only one of P type or N type impurities to a hetero junction epitaxial layer. CONSTITUTION:A low-concentration N type epitaxial layer is grown on a P type high-concentration substrate material, a high-concentration N type epitaxial layer on said epitaxial layer and a low-concentration N type epitaxial layer on said high-concentration N type epitaxial layer. Consequently, the problem, etc. of pollutions among each layer are reduced because of the same type epitaxial growth, and a crystal can be grown in succession through one-time process in the same oven. As a result, processes are simplified and accelerated while an excellent interface can be grown. A P-type impurity is diffused after such growth. According to such diffusion, a P-N-P type junction is obtained through one- time diffusion process. With transistors manufactured in this manner, base resistance is small because of a high-concentration base, and high injection efficiency is acquired, and the transistors of high performance are obtained at the same time. |
