Extended wavelength InGaAs infrared (1.0-2.4 mu m) detector arrays on SCIAMACHY for space-based spectrometry of the Earth atmosphere

Space qualified InGaAs solid-state array detectors, covering the near-infra red 1-2.4 mum wavelength range, have been developed for application in spac e-based spectroscopy of the Earth atmosphere. The SCIAMACHY atmospheric che mistry instrument on the ESA ENVISAT satellite (2002-2005) will be equipped with a series of these novel detectors. Detectors are arranged in linear a rrays of 1024 pixels of 25 x 500 mum(2) dimension and meet requirements on modestly low operating temperature (150 K) and low levels of dark current a nd noise. In this paper the underlying physics of dark current and noise of the detector system is studied on the basis of a theoretical model in comb ination with measurements. At 2.4 mum wavelength the dark-current performan ce achieved is 20-100 fA at an operating temperature of 150 K and a bias vo ltage of -2 mV. This corresponds to a figure of merit for detector resistan ce Ro times detector pixel area A of R(0)A = 2.5-12.5 M Ohm cm(2). This res ult has required the development of a customised multiplexer for parallel d etector read-out at near-zero bias voltage. Further reduction of the operat ing temperature will not result in lowering the dark current and noise of t he InGaAs detectors which are shown to be limited by tunnelling current. A route to future improvement is discussed. (C) 2001 Elsevier Science B.V. Al l rights reserved.