Two-Dimensional Long-Wavelength and Very Long-Wavelength Focal-Plane Arrays at AIM

• Published in: Journal of electronic materials 2010-07, Vol.39 (7), p.846-851
• Main Authors: Wenisch, J., Eich, D., Hanna, S., Bauer, A., Bitterlich, H., Bruder, M., Mahlein, K.-M., Lutz, H., Wollrab, R., Ziegler, J.
• Format: Article
• Language: English
• Subjects: Applied sciences; Characterization and Evaluation of Materials; Chemistry and Materials Science; Circuit properties; Cross-disciplinary physics: materials science; rheology; Electric, optical and optoelectronic circuits; Electronics; Electronics and Microelectronics; Exact sciences and technology; Infrared radiation; Instrumentation; Integrated optics. Optical fibers and wave guides; Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids); Materials Science; Mercury cadmium telluride; Methods of deposition of films and coatings; film growth and epitaxy; Optical and Electronic Materials; Optical and optoelectronic circuits; Optoelectronic devices; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Solid State Physics
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-010-1235-z

In recent years AIM has expanded its portfolio of standard infrared (IR) focal-plane arrays in the 3  μ m to 5  μ m (mid-wavelength infrared, MWIR) and 8  μ m to 10  μ m (long-wavelength infrared, LWIR) spectral ranges with two-dimensional IR detectors, sensitive in the 0.9  μ m to 2.5  μ m (short-wavelength infrared, SWIR) and especially in the 10  μ m to 15  μ m (very long-wavelength infrared, VLWIR) spectral ranges. This paper reports on the latest technological advancements that will benefit not only prototype applications for which they are demonstrated but a wide range of AIM products. A reduction of the pixel pitch from 24  μ m to 15  μ m is the result of increasing demands for compact detection modules with reduced weight, size, power consumption, and cost efficiency. Performance characterization for such a reduced-pitch 640 × 512 module in the LWIR (cut-off 10.5  μ m at 67 K) yields mean noise equivalent temperature difference of 32.2 mK and defective pixel rate of only 0.5%. Extending the detection wavelength further into the VLWIR is of major interest for space applications such as the Meteosat Third Generation, which poses challenging requirements for sensor material homogeneity and dark-current density. To meet this requirement, an extrinsic doping approach is utilized on a 256 × 256 mercury cadmium telluride (MCT) focal-plane array with ∼14  μ m cut-off wavelength at 55 K operating temperature, and a dark- current density of about 1 pA/ μ m 2 is demonstrated.