BIB mid-infrared detectors for space missions

Fig.1:One of the BIB prototypes, flip-chip mounted on the cold readout and front end electronics developed by IMEC. (Click on image to enlarge)

The mission would require high performance infrared detector arrays in the 4-20 μm range with an operating temperature as high as possible. MPIA is collaborating with the Belgium company IMEC on the fabrication and characterization of such detectors and of the related Cryogenic Readout Electronics (CRE). Si:As BIB detectors have been fabricated by IMEC on an infrared transparent silicon substrate enabling backside illumination.

The CRE is composed of an input stage based on an integrating amplifier in AC coupled feedback with four selectable integrator capacitors, of a sample and hold stage which provides isolation between input and sampling capacitance, and of an output buffer with multiplexing switch. Test-setups have been established at the MPIA to characterize two prototype detector arrays and to determine their relative spectral response, their absolute quantum efficiency, their NEP, and the dark current. All these properties are measured as a function of operating temperature, ranging from 4 to 13 K, and of detector bias. In addition the effects of ionizing radiation on the detector arrays and the CREs are studied.