2D SWIR Image sensor with extended wavelength cutoff of 2.5 μm on InP/InGaAs epitaxial wafers with graded buffer layers

摘要

Two-dimensional photo detector arrays with a cutoff wavelength of 2.5 μm were fabricated on InP/TnGaAs epitaxial wafers with graded buffer layers in a 320×256 geometry on a 12.5μm pitch. Novel growth and fabrication techniques were employed to fabricate these arrays and optimize the performance. The dark current of the detector was investigated for a wide range of temperatures. The fabricated detector array was mated with a ROIC and packaged with a multi-stage TEC and investigated further at the FPA level. The effect of the graded buffer layers on the sensor performance was investigated and the results were compared to other methods used to develop and fabricate 2D image sensors on extended wavelength materials.