Transport properties of polarization-induced 2D electron gases in epitaxial AlScN/GaN heterojunctions

Abstract

AlScN is attractive as a lattice-matched epitaxial barrier layer for incorporation in GaN high electron mobility transistors due to its large dielectric constant and polarization. The transport properties of polarization-induced two-dimensional (2D) electron gas of densities of ∼2×1013/cm2 formed at the AlScN–GaN interface is studied by Hall-effect measurements down to cryogenic temperatures. The 2D electron gas densities exhibit mobilities limited to ∼300 cm2/V s down to 10 K at AlScN/GaN heterojunctions. The insertion of a ∼2 nm AlN interlayer boosts the room temperature mobility by more than five times from ∼300 cm2/V s to ∼1573 cm2/V s, and the 10 K mobility by more than 20 times to ∼6980 cm2/V s at 10 K. These measurements provide guidelines to the limits of electron conductivities of these highly polar heterostructures.

Document Details

Document Type
Pub Defense Publication
Publication Date
Nov 07, 2022
Source ID
10.1063/5.0108475

Entities

People

  • Chandrashekhar Savant
  • Daniel Hannan
  • Debdeep Jena
  • Huili Grace Xing
  • Joseph Casamento
  • Shamima Afroz
  • Thai‐Son Nguyen
  • Timothy Vasen
  • Yong-Jin Cho

Organizations

  • Air Force Office of Scientific Research
  • Cornell University
  • Defense Advanced Research Projects Agency
  • National Science Foundation
  • Northrop Grumman

Tags

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.
  • Quantum Dot Semiconductor Device Photonics and Graphene Optoelectronic Materials and THz Physics.
  • Space Exploration and Orbital Mechanics.

Technology Areas

  • Microelectronics
  • Microelectronics - Graphene