| 摘要 |
PURPOSE:To obrain the semiconductor integrated circuit which withstands the fluctuations of source voltage and the like by a method wherein a constantcurrent element is formed by an epitaxial layer and a resistor (diffused resistance, for example) having an impurity density gradient. CONSTITUTION:The epitaxial layer 6 on a p type substrate 1 is isolated 4 into island form reqions, and an n<+> buried layer 2 is provided at the prescribed section on the interface of the island form regions. A transistor Q is formed on a region 6, and diffused resistors R2 and R3 of a p layer 5, an epitaxial resistor R1 and a diode D1 are formed on a region 6 respectively. The diode is formed by short-circuiting the base and the collector of the transistor. When the diode is connected as prescribed, a depletion region is extended into the epitaxial layer 3 on the epitaxial resistor R1 in proportion to the falling voltage of the resistor due to the grounding of the isolated layer 4. As a rusult, curved type characteristics can be given to the resistor R1, whereas linear type characteristics are given to the resistors R2 and R3, and the resistor R1 is turned to a constant-current element having a little current fluctuations caused by voltage fluctuations. |
