Simulation and measurement of residual stress and warpage in a HgCdTe-based infrared detector at 100 K

A thermomechanical analysis on a 320 × 256, 30 μm pitch, middle wave infrared detector operating at 100 K is conducted. The stress induced in the HgCdTe single crystal layer needs to be minimized to avoid electro-optical perturbations and the planarity of the detector has to respect strict optical requirements. The work includes stress determination by X-ray-diffraction (XRD), warpage measurements with laser scanning, analytical calculation and finite-element modelling. The hybridized detector is studied both alone and after being glued to an AlN hosting substrate. The results show that the initial stress in HgCdTe at room temperature is biaxial for all samples, with either tensile or compressive values (±10 MPa), mainly due to the lattice mismatch during epitaxy from CdZnTe. A stress increase of +45 MPa is induced after cooling to 100 K, with a maximum value of 57 MPa. The warpage of the hybridized circuit is then about 2.5 μm and is reduced after being glued to the hosting substrate. Finally, the model is used to extrapolate the behavior of such a detector for larger formats until 2 K2; there is no significant impact on the stress in the HgCdTe layer, but warpage increases proportionally to the squared diagonal of the detector

Contribution a la valorisation des proteines du lactoserum : de la purification au sequencage

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Quand l'héparine conduit à la thrombose!

CAEN-BU Médecine pharmacie (141182102) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF

Influence of oxygen partial pressure on the wetting of SiC by a Co-Si alloy

International audienc

Wetting and interfacial interactions in the CaO-Al2O3-SiO2/silicon carbide system

International audienceIn this article, the wetting of 23 wt% CaO-15 wt% Al2O3-62 wt% SiO2 molten glass on polycrystalline silicon carbide is studied under air at temperatures between 1,100 and 1,590 A degrees C. Wetting experiments are performed by the sessile drop technique. Good wetting (final contact angle lower than 50A degrees) is observed regardless of the experimental temperature when it is higher than 1,300 A degrees C. Moreover, some specific experiments of wetting of glass on platinum, silica and monocrystalline SiC substrates are also performed. The character of molten glass spreading on silicon carbide (reactive or non-reactive) as well as the role of the atmosphere on interfacial interactions with SiC are identified and discussed

Characterizations of indium interconnects for 3D quantum assemblies

International audienceLarge-scale integration of quantum bits and quantum technologies relies on multi-chip assemblies. In that context, we focus on indium microbumps to connect chips made from different materials and technological nodes. We have fabricated two test vehicles, comprising GaAs and Si chips stacked by die-to-die process on a Si-based multi-chip module. GaAs on Si and Si on Si daisy chains were compared to evaluate the impact of thermal expansion coefficient mismatch on the chip connection. Electrical measurements in a cryostat from 300 K to 2 K, as well as morphological and mechanical characterizations were used to support this study and qualify In interconnect technology for heterogeneous quantum assemblies