Optimized Structured Absorbers For CMOS Infrared Detectors

thickness irl ir5 ir6 irl0 1 pm + @ This paper reports the characterization and optimization of absorbers for CMOS thermoelectric infrared sensors. We measured the spectral absorptivities of four unstructured and six structured absorber sandwiches. The absorbers were fabricated with a commercial CMOS IC process. For the unstructured absorbers mean absorptivities of 5% and 25% were measured in the two atmospheric infrared transmission bands. These figures could be enhanced to 10% and 32%, respectively, by structuring the absorbers.