Readout of IR detector arrays below LHe temperatures

The readout electronics of the telescope cameras aboard the European Infrared Space Observatory will have to be operated at temperatures of about 2-4 K. To develop a suitable CMOS process, the authors studied the influence of different technological parameters on cryogenic device behavior. On the basis of research on cryogenic CMOS processing, they developed a design approach for the readout circuitry of the far-infrared photometric camera required for the ISOPHOT experiment. Since long time drifts of device characteristics due to cosmic ionizing radiation have to be considered, they propose a concept based on differential double sampling and detection of soft errors by nondestructive readout.<>