High Mobility Poly-Ge Thin-Film Transistors Fabricated on Flexible Plastic Substrates at Temperatures below 130°C

D. Shahrjerdi, B. Hekmatshoar, S. S. Mohajerzadeh, A. Khakifirooz, M. Robertson

Research output: Contribution to journalArticle


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.

Original languageEnglish (US)
Pages (from-to)353-357
Number of pages5
JournalJournal of Electronic Materials
Issue number4
StatePublished - Apr 2004



  • High mobility
  • Plastic substrates
  • Poly-Ge TFTs

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Materials Chemistry

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