Home – Home – Jornals – Avtometriya 2022 number 2

The optimal design of a cooled flip-chip photodetector in the infrared spectral range for installation in a cryostat is determined both with the possibility of bending during cooling and with rigid attachment to a pedestal through a sapphire plate. A numerical calculation is carried out for a radially symmetric photodetector model: GaAs (first layer) - Indium (ring structures) - Si - GaAs (second layer) with a plate diameter of 10 mm. The maximum deformation loads in the edge indium ring are determined for plates of different thicknesses (from 0 to 700 μm), which occur when the photodetector is cooled to 77 K. For the photodetector model, when it is fixed on a cooled cryostat pedestal with the possibility of bending, the optimal design is determined - GaAs(1) and Si plates with a thickness of about 50 μm and without GaAs(2;, the maximum deformation loads in the edge indium ring (width 15 μm, thickness 5 µm) with this configuration are approximately 427 MPa. When the model is rigidly mounted on the pedestal of the cryostat, the optimal design is GaAs(1) and Si plates 50 µm thick and a GaAs(2) compensation layer 100 µm thick; the maximum deformation loads in the edge indium ring under these conditions are 600 MPa.