Semiconductor device comprising high-speed and high-current transistors formed in a common substrate and having matched characteristics

摘要

A semiconductor device having a submicron miniaturization level structure comprises a first high-current bipolar transistor having a first wide emitter width and a second high-speed bipolar transistor having a narrow emitter width relatively to the first emitter width, which transistors are formed in a second common semiconductor substrate. According to a first embodiment, the base region of the first transistor is thicker than that of the second transistor, and thus a suitable h.sub. Fe balance is maintained; and according to another embodiment, the first, base region of the first transistor has a higher impurity concentration than the second base region of the second transistor and has the same depth as that of the second base region, so that a suitable h.sub.FE balance is maintained.