| 摘要 |
PURPOSE:To prevent breakage on the input side or in the whole resistor and to improve the reliability by increasing a breakdown voltage on the input side by making a cross-sectional area of the input protective resistor on the input side larger than the output side in order to make a resistance value for an unit length of said resistor on the input side larger than the output side. CONSTITUTION:An input protective resistor 32 is formed on the main plane of the semiconductor substrate 31 and a protective diode 33 is connected to said resistor 32 to compose the gate protective circuit 34, which is then connected between an electrode pad 35 and an internal circuit 36. This input protective resistor 32 is formed simultaneously with the source region 37 and the drain region 38 of the MOS transistor which composes the protective diode 33. Also, the source 37 is connected to the internal circuit 36 through the Al wiring 39 connected to the source 37. Then a gate 40 is connected, e.g. to an earth electrode together with the drain 38. The width of the input protective resistor 32 is reduced gradually from the input side end 32a toward the output side end 32b so as to enlarge the cross-sectional area on the input side compared with that on the output side. |
