TY - JOUR

T1 - Novel Approach for Assessing Cyclic Thermomechanical Behavior of Multilayered Structures

AU - Seligmann, Benjamin

AU - Alfreider, Markus

AU - Wurmshuber, Michael

AU - Kiener, Daniel

PY - 2023

Y1 - 2023

N2 - Microelectronic devices require material systems combining multiple layers ofmaterial for proper operation. These inevitably have different properties, forexample, the elastic modulus or the coefficient of thermal expansion. Permanentlyreoccurring Joule heating and successive cooling during the operation of suchdevices lead to high thermal stresses within the materials and even failure due tothermomechanical fatigue or delamination of layers. This is dependent on theinternal stress state and the amount of plastic strain accumulated. Here, in situthermomechanical cantilever bending experiments on a Si–WTi–Cu materialsystem to investigate these internal stress states and their influence on defor-mation behavior using a novel experimental methodology are shown. Duringheating toTmax¼400°C, the Cu layer undergoes partial plastic deformation, whichmay lead to the failure of a potential device using this material combination. Toassess the internal stress and strain states based on the in situ observation, amodel incorporating plastic deformation and known residual stresses of layers isproposed and verified by Finite Element Analysis

AB - Microelectronic devices require material systems combining multiple layers ofmaterial for proper operation. These inevitably have different properties, forexample, the elastic modulus or the coefficient of thermal expansion. Permanentlyreoccurring Joule heating and successive cooling during the operation of suchdevices lead to high thermal stresses within the materials and even failure due tothermomechanical fatigue or delamination of layers. This is dependent on theinternal stress state and the amount of plastic strain accumulated. Here, in situthermomechanical cantilever bending experiments on a Si–WTi–Cu materialsystem to investigate these internal stress states and their influence on defor-mation behavior using a novel experimental methodology are shown. Duringheating toTmax¼400°C, the Cu layer undergoes partial plastic deformation, whichmay lead to the failure of a potential device using this material combination. Toassess the internal stress and strain states based on the in situ observation, amodel incorporating plastic deformation and known residual stresses of layers isproposed and verified by Finite Element Analysis

U2 - 10.1002/adem.202201209

DO - 10.1002/adem.202201209

M3 - Article

VL - 2023

JO - Advanced engineering materials

JF - Advanced engineering materials

SN - 1527-2648

IS - 3

M1 - 2201209

ER -