Ambient Dependent Metal Interconnection Failure of Flexible Poly-Si TFTs Under Dynamic Stretch Stress

This study investigates the source-drain metal line microcrack propagation and failure behavior of flexible lowtemperature poly-Si thin-film transistors (LTPS TFTs) under dynamic stretch stress. It is observed for the first time that the microcrack growth and failure of the device under dynamic stretch are correlated with ambient conditions. Ambient <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{H}_{2} \mathrm{O}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{O}_{2}$</tex> influence microcrack propagation and failure of the device under dynamic stretch, where <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{H}_{2} \mathrm{O}$</tex> is the key factor leading to mechanical reliability decline, while <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{O}_{2}$</tex> requires <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{H}_{2} \mathrm{O}$</tex> to take effect. Clarifying the ambient-dependent microcrack growth and failure behavior of the device under dynamic stretch is of great significance for ensuring the mechanical reliability of TFTs.