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Keywords:

  • BN;
  • sputtering deposition;
  • AlGaN/GaN;
  • MIS-HFET;
  • temperature-dependent characteristics

Abstract

We investigated BN/AlGaN/GaN metal-insulator-semiconductor heterojunction field-effect transistors (MIS-HFETs) with sputtering-deposited BN gate dielectric. Amorphous BN thin films obtained by RF magnetron sputtering deposition were applied to MIS-HFET device fabrication. The MIS-HFET devices exhibit very low gate leakage current indicating good insulating properties of BN, and almost no negative drain conductance. The device characteristics and its temperature dependence were investigated, where we observe decreasing drain current and increasing gate current with increase in temperature. The relative decrease in the drain current for the low field region is larger than that for the high field region, according to the temperature dependence of low- and high-field electron velocities. The temperature dependence of the gate leakage current is explained by a mechanism with thermally activated tunneling and direct tunneling. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)