Abstract
In this paper, we present the study of the electrical, structural and optical properties of p-type GaN grown on sapphire by RF
plasma-assisted molecular beam epitaxy (RF-MBE). Hall effect measurement shows that the film was highly doped with
carrier concentration of 6.58 x 1018cm-3. X-ray diffraction (XRD) measurement reveals that the GaN was epitaxially grown
on sapphire substrate. For the photoluminescence (PL) measurement, a sharp and intense peak at 363.8 nm indicates that
the sample is of high optical quality. The presence of the peak at 658.4 cm-1 in Raman measurement confirmed that our ptype GaN sample was highly doped with Mg. Low resistance ohmic contacts on p-type GaN utilizing Ni/Ag metallization
were fabricated and characterized. A good ohmic contact with a specific contact resistance as low as 8.5 x 10−3 Ω cm2
was
achieved without any annealing treatments.
Keywords
p-type GaN, RF-MBE, Carrier concentration, Hall effect, Ohmic contact.
Citation
C.W. CHIN, Z. HASSAN, F.K. YAM, Highly Mg-doped GaN thin film grown by RF plasmaassisted molecular beam epitaxy, Optoelectronics and Advanced Materials - Rapid Communications, 2, 9, September 2008, pp.533-536 (2008).
Submitted at: July 9, 2008
Accepted at: Aug. 28, 2008