SOLID-STATE INFRARED IMAGE SENSOR

PURPOSE:To prevent the decrease in S/N ratio due to insufficient device cooling or erroneous temperature measurement with dark current by forming a diffused layer with a high impurity concentration in a semiconductor substrate so that the diffused layer may serve as an optical black part that absorbs infrared radiation to shield some of infrared detectors. CONSTITUTION:Infrared detectors 11 and 14 are mounted on a semiconductor silicon substrate 1, which includes a diffused layer 9 having a high impurity concentration. The diffused layer forms an optical black part 13 that absorbs incident light to shield the infrared detector 11. The output from the infrared detector 11 can be considered to be dark current. As a result, an accurate optical signal can be obtained by subtracting the dark current from image signal produced by the other infrared detector. This enables the temperature of an object to be measured accurately. In addition, if cooling is insufficient, the dark current increases, resulting in prevention of the decrease in S/N ratio.