| 摘要 |
PURPOSE:To increase strength against electrostatic breakdown without increasing the occupied area required for the separation and insulation of elements. CONSTITUTION:p-Type resistor layer to be provided for the n-layer of semiconductor substrate 4 is divided into layers 7a and 7b. Resistor 7a on the external terminal side is separated and insulated by n-layer 6, and it is connected in series with n-layer 5 including resistor 7b via thin film resistor 11. By this structure, parastic diode 8 from resistor 7b to the power source is produced; and diode 9 from resistor 7a to separator-insulator layer 6, and diode 10 from separator-insulator layer 6 to substrate 4 are connected in parallel to the electrostatic pulse discharge route. In this structure, since resistor 7a is separated and insulated, no discharge pulse enters power supply side wiring 3 from input terminal 1, so that it becomes sufficiently strong against electrostatic breakdown. Further, the area occupied by the layer which separates and insulates the small resistor connected to the external terminal can be made smaller compared with the conventional device. |
