| 摘要 |
PURPOSE:To eliminate any human reading of code numbers by a method wherein electrode pads independent of an inner functional part are connected to a gate of an MOS type transistor while a source or drain is connected in parallel with multiple electrode pads to form a part of connecting wiring in the state either electrically conductive or non-conductive. CONSTITUTION:A semiconductor device 1 as ROM or gate array impresses an electrode pad 3 with voltage immediately before starting an inspection to make an MOS type transistor 4 conductive. A semiconductor substrate is supplied with OV and then a source of the MOS type transistor 4 is also supplied with OV through a diffused layer 5. When multiple electrode pads 6a-6d are impressed with voltage, each pad is supplied with current or no current conforming to electrically conductive or non-conductive state of a part of wirings 7a-7d. Through these procedures, numbers may be displayed on codes by electrical conductive or non-conduction while any code number may by automatically known immediately before starting an inspection by means of making the numbers correspond to the code numbers. Besides, any increase in chip dimension of a semiconductor device may be reduced by means of providing only one additional pad for code checking. |
