Characteristics enhancement of a GaAs based heterostructure field-effect transistor with an electrophoretic deposition (EPD) surface treated gate structure

Chun Chia Chen, Huey Ing Chen, I. Ping Liu, Po Cheng Chou, Jian Kai Liou, Yu Ting Tsai, Wen Chau Liu

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A Pt/AlGaAs/InGaAs/GaAs heterostructure field-effect transistor (HFET), prepared by an electrophoretic deposition (EPD) approach on gate Schottky contact region, is fabricated and studied. The EPD-based Pt-gates with three different molar ratios (ω 0 ) are examined by scanning electron microscopy (SEM) image. Good Pt-gate coverage with effective reduction of thermal-induced defects at Pt/AlGaAs interface is achieved through a low temperature EPD approach. Experimentally, for a gate dimension of 1 μm × 100 μm, a lower gate current of 1.9 × 10 -2 mA/mm, a higher turn-on voltage of 0.85 V, a higher maximum drain saturation current of 319.3 mA/mm, and a higher maximum extrinsic transconductance of 146.8 mS/mm are obtained for an EPD-based HFET at 300 K. Moreover, comparable microwave characteristics of an EPD-based HFET are demonstrated at different temperature ambiences. Therefore, based on the improved DC performance and inherent benefits of low cost, simple apparatus, flexible deposition on varied substrates, and adjustable alloy grain size, the proposed EPD approach shows the promise to fabricate high-performance electronic devices.

Original languageEnglish
Pages (from-to)120-126
Number of pages7
JournalApplied Surface Science
Publication statusPublished - 2015 Jun 30


All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Condensed Matter Physics
  • Physics and Astronomy(all)
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films

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