432X432 SW/MW FPAs with Extended Dynamic Range
Abstract
This is the first report on results for Lockheed Martin's radiation hardened 432x432 MW HgCdTe Focal Plane Arrays (FPAs) with extended dynamic range. The extended dynamic range concept has also been successfully implemented in a 768 x 6 TDI scanning FPA. These large format FPAs are designed for space surveillance applications. The instantaneous dynamic range of the staring FPAs is up to 118dB. Excellent operability and uniformity has been measured. Near BLIP NEI has been demonstrated for SW (3.6 micrometers cutoff) detectors operating at 120K at 1.8E12 ph/cm2-s background irradiance and MW (4.8 mm cutoff) detectors operating at 120K at 8.0E12 ph/cm2-s background irradiance. These FPAs utilize the Lockheed Martin Federal Systems (LMFS) 0.8 mm radiation hardened CMOS process with two layer polysilicon and depletion mode capacitor options for total dose radiation hardness. In this paper we describe the results achieved with our new 432x432 FPAs and also our new 768 x 6 scanning FPAs. The detectors were fabricated using our production LPE material growth process and a multilayer anti-reflection coating to give high and uniform quantum efficiency of 90% over the large active areas. The responsivity standard deviation is only 2.4% of the average responsivity. The ROICs have a dual-gain feature that gives a very high maximum instantaneous dynamic range of 118dB. These FPAs have demonstrated a 80% of-BLIP NEI of 3.0E9 ph/cm2-s at a background of 1.8E12 ph/cm2-s, an integration time of 18 ms and a cutoff of 3.6 mm at 120K. NEI and response operability have been measured at over 99%. Differential responsivity linearity is typically 0.5%. Data for MW 432x432 also show near BLIP limited performance. The FPA is low power, drawing only 85 mW, even though it has a CTIA amplifier input for each detector to give good performance at low backgrounds.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1998
- Accession Number
- ADA400018
Entities
People
- A. Hairston
- P. H. Zimmermann
- P. Norton
- R. Hines
- T. Parodos
Organizations
- Lockheed Martin