Open AccessA Demonstration of Nitrogen Polar Gallium Nitride Current Aperture Vertical Electron Transistor
Author(s) -
Saba Rajabi,
Saptarshi Mandal,
Burcu Ercan,
Haoran Li,
Matthew A. Laurent,
Stacia Keller,
Srabanti Chowdhury
Publication year - 2019
Publication title -
ieee electron device letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.337
H-Index - 154
eISSN - 1558-0563
pISSN - 0741-3106
DOI - 10.1109/led.2019.2914026
Subject(s) - engineered materials, dielectrics and plasmas , components, circuits, devices and systems
We report the first demonstration of Nitrogen polar (N-polar) GaN current aperture vertical electron transistor with a blocking electric field over 2.9 MV/cm. The devices were grown by metalorganic chemical vapor deposition on a c-plane sapphire substrate. The fabrication involved a maskless planar regrowth of a very thin-AlN layer above the current blocking layer, which induced a two-dimensional electron gas (2DEG) in the channel, and also prevented the out-diffusion of activated Mg ions into the GaN channel layer. The alloyed source and drain ohmic contacts on the regrown n + -GaN layer offered the low-contact resistance of 0.18 $\text{m}\Omega \cdot \text {cm}^{2}$ ( $0.22~\Omega \cdot \text {mm}$ ). The device displayed a maximum drain current of 1.68kA/cm 2 with a low R ON, SP of 2.48 $\text{m}\Omega \cdot \text {cm}^{2}$ . With just about 200 nm drift layer, a three-terminal breakdown voltage of 58 V was achieved. The output characteristics were free of dispersion under pulsed measurements with $80~\mu \text{s}$ and 500 ns pulse widths. The N-polar current aperture vertical electron transistors show fundamentally significant advantages in favor of using Mg 2+ -implanted GaN as current blocking layers compared with Ga-polar counterparts.