Study on mobility enhancement in MOVPE-grown AlGaN/AlN/GaN HEMT structures using a thin AlN interfacial layer

Makoto Miyoshi, Takashi Egawa, Hiroyasu Ishikawa

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20 Citations (Scopus)


Al0.26Ga0.74N/AlN/GaN high-electron-mobility transistor (HEMT) structures with AlN interfacial layers of various thicknesses were grown on 100-mm-diameter sapphire substrates by metalorganic vapor phase epitaxy, and their structural and electrical properties were characterized. A sample with an optimum AlN layer thickness of 1.0 nm showed a highly enhanced Hall mobility (μHall) of 1770 cm2/Vs with a low sheet resistance (ρs) of 365 Ω/sq. (2DEG density ns = 1.0 × 1013/cm2) at room temperature compared with those of a sample without the AlN interfacial layer (μHall = 1287 cm2/Vs, ρs = 539 Ω/sq., and ns = 0.9 × 1013/cm2). Electron transport properties in AlGaN/AlN/GaN structures were theoretically studied, and the calculated results indicated that the insertion of an AlN layer into the AlGaN/GaN heterointerface can significantly enhance the 2DEG mobility due to the reduction of alloy disorder scattering. HEMTs were successfully fabricated and characterized. It was confirmed that AlGaN/AlN/GaN HEMTs with the optimum AlN layer thickness show superior DC properties compared with conventional AlGaN/GaN HEMTs.

Original languageEnglish
Pages (from-to)1515-1521
Number of pages7
JournalSolid-State Electronics
Issue number9-10
Publication statusPublished - 2006 Sep 1



  • AlGaN
  • AlN
  • GaN
  • HEMT
  • Mobility

ASJC Scopus subject areas

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

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