Abstract
Depletion-mode poly-Ge thin-film transistors (TFTs) with an effective hole mobility of 110 cm2/Vs and an ON/OFF ratio of 104 have been fabricated on flexible polyethylene therephtalate (PET) substrates, taking advantage of a novel stress-assisted crystallization technique. Proper manipulation of an otherwise destructive mechanical stress leads to a drastic drop of crystallization temperature from 400°C to 130°C. External compressive stress is transferred to the Ge/PET interface by bending the flexible substrate inward, during the thermal post-treatment. Proper patterning of the a-Ge layer before thermomechanical post-treatment leads to a minimal crack density in the processed poly-Ge layer. Reduction in the crack density plays a crucial role in alleviating the stress-induced gate leakage current emanated from the crack traces propagating from the channel into the gate oxide.
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Shahrjerdi, D., Hekmatshoar, B., Mohajerzadeh, S.S. et al. High mobility poly-Ge thin-film transistors fabricated on flexible plastic substrates at temperatures below 130°C. J. Electron. Mater. 33, 353–357 (2004). https://doi.org/10.1007/s11664-004-0142-6
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DOI: https://doi.org/10.1007/s11664-004-0142-6