Influence of Gate Doping Concentration on the Characteristics of Amorphous InGaZnO Thin-Film Transistors with HfLaO Gate Dielectric

Hui Su, Yuan Xiao Ma, Pui To Lai, Wing Man Tang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

5 Citations (Scopus)


Amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) with HfLaO as high-k gate dielectric have been fabricated, and p-type silicon wafers with resistivities of 0.001 0.002, 0.005, 0.02 0.021 and 5\sim 10\Omega \cdot cm are used as their gate electrodes. The carrier mobility of the samples show an increase with increasing gate acceptor concentration, indicating that the TFT performances are affected by the hole concentration in the gate electrode. The HfLaO gate dielectric is highly polarizable and so produces surface-optical phonons, which can scatter the electrons in the IGZO channel to reduce their mobility. Therefore, this work directly demonstrates that the holes in the gate electrode can have a screening effect to suppress this remote phonon scattering of the gate dielectric on the channel carriers, just like the electrons in the metal gate, ITO gate and n-silicon gate of field-effect transistors.

Original languageEnglish
Article number8886593
Pages (from-to)1953-1956
Number of pages4
JournalIEEE Electron Device Letters
Issue number12
Publication statusPublished - Dec 2019


  • a-IGZO
  • high-k dielectric
  • remote phonon scattering
  • thin-film transistor

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

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