| 摘要 |
PURPOSE:To prevent an emitter current from increasing by connecting a polysilicon resistor as a bias resistor between the base and the emitter of a transistor of the front stage of Darlington connected transistors. CONSTITUTION:After a silicon oxide film is formed on a semiconductor substrate 1 formed with an epitaxial layer 1, a diffusing hole is opened in the film, boron is implanted, it is again covered with a silicon oxide film, and a base region 2 is formed by thermally diffusing. Then, an N-type impurity is used to thermally diffuse an emitter region 3. A contact region 4 is simultaneously formed on the region 2 corresponding to a transistor of rear stage. Accordingly, contact regions 4 are formed in a transistor of front stage, a rear stage transistor, and the region 2 of the rear stage transistor. A polysilicon resistor 5 formed on the film, transistors 7, 8, a polysilicon resistor 5, and a diffused resistor 9 are coupled in a Darlington connection. Thus, hFE which has small temperature dependency can be provided. |
