Two-Dimensional Electron Gas in Thin N-Polar GaN Channels on AlN on Sapphire Templates
Markus Pristovsek,
Itsuki Furuhashi,
Xu Yang,
Chengzhi Zhang,
Matthew D. Smith
Affiliations
Markus Pristovsek
Center for Innovative Research of Future Electronics, Institute for Material Science and Systems for Sustainability, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
Itsuki Furuhashi
Center for Innovative Research of Future Electronics, Institute for Material Science and Systems for Sustainability, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
Xu Yang
Center for Innovative Research of Future Electronics, Institute for Material Science and Systems for Sustainability, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
Chengzhi Zhang
Center for Device Thermography and Reliability, School of Physics, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
Matthew D. Smith
Center for Device Thermography and Reliability, School of Physics, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
We report on 2-dimensional electron gases realized in binary N-polar GaN channels on AlN on sapphire templates grown by metal–organic vapor phase epitaxy. The measured sheet carrier density of 3.8×1013 cm−2 is very close to the theoretical value of 3.95×1013 cm−2 due to the low carbon and oxygen background doping in the N-polar GaN if grown with triethyl-gallium. By inserting an intermediate AlN transition layer, room temperature mobilities in 5 nm channels up to 100 cm2/Vs were realized, probably limited by dislocations and oxygen background in N-polar AlN. Thicker channels of 8 nm or more showed relaxation and thus much lower mobilities.
