Investigation of high mobility two-dimensional electron gas in AlGaN/GaN heterostructures grown by hydride vapor phase epitaxy (HVPE)

Document Type : Original Article

Authors

1 Department of Electrical and Computer Engineering, King Abdulaziz University, PO Box 80204, Jeddah 21589, Saudi Arabia.

2 National Key Laboratory on High Power Semiconductor Lasers Changchun University of Science and Technology No. 7083, Weixing Road, Changchun, P. R. China, 130022.

Abstract

Abstract:
Two-inch-diameter sapphire (0001) substrates were used for the growth of AlGaN/GaN
structure by hydride vapor phase epitaxy (HVPE). The two-dimensional electron gas
(2DEG) structure consisted of a 2 mm undoped GaN layer substrate, followed by 30 nm
thick Al0.3Ga 0.7N layer. Structural and optical properties of GaN layer were
characterized by high resolution X-ray diffraction, transmission electron microscopy
(TEM) and photoluminescence (PL) measurements. TEM images showed the
dislocation density in the GaN layer was ~ 9 ´ 109 /cm2 . The full width at half
maximum (FWHM) values of the x-ray rocking curve for GaN (0002) was 0.156 deg.
PL spectra of our sample exhibited a predominant band-edge emission of the wurzite
GaN epilayer near 3.36 eV with FWHM = 45 meV at 50 K and 75 meV at room
temperature, respectively. The Hall effect measurements gave a sheet electron
concentration of 7.8´1012 cm-2 and a mobility of 850 cm2/Vs at 300K. The experimental
data indicated that the HVPE grown GaN layers exhibited superior quality compared to
GaN layers grown by metal organic chemical vapor deposition in prior art literatures.

Keywords

Files

Share

How to cite

Statistics