Stress distribution of IGZO TFTs under mechanical rolling using finite element method for flexible applications

• Stress analysis with dielectrics and rolling curvatures is by finite element method.
• Inverted-coplanar with SiOx has the smallest stress for mechanical rolling.
• The local extreme stress would also induce film cracks or warps.
• The feasibility of oxide TFT with optimization the structures and dielectrics.

The stress analysis of IGZO TFT in structures, dielectrics, and rolling curvatures using finite element method is proposed. The inverted-coplanar with SiOx has the smallest stress for mechanical rolling. The local extreme stress would also induce film cracks or peeling at the corner. For example, inverted-coplanar structure has the maximum stress at the corner of IGZO/Al with −0.65 GPa (x-direction stress), −0.22 GPa (y-direction stress), and −0.21 GPa (shear stress). The stress of IGZO TFT with high PPI under mechanical rolling is also discussed.

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