Extended backside-illuminated InGaAs on GaAsIR detectors

Diode structures of short wavelength infrared (SWIR) InGaAs material were grown epitaxially on 3" GaAs substrates by molecular beam epitaxy. Despite the large lattice mismatch of 6% between In0.8Ga0.2M and GaAs the diode performance allows applications in spectroscopy and imaging. Photovoltaic diode characterization measures like R(0)A product and quantum efficiency were extracted from IN curves. The layers are processed with standard photolithography and micro-structuring tools and finally flip-chip bonded on a silicon read out integrated circuit (ROIC). Linear arrays of 256 and 512 pixel with 25 mum pitch were fabricated as well as focal plane arrays (FPA) of 256 x 320 pixel with 30 mum pitch. Functionality is proven by using the assemblies in systems for spectroscopy and beam profiling up to 2.5 mum wavelength.