High-quality AlN wafers are urgently needed for the fabrication of AlGaN-based ultraviolet(UV) optoelectronic device and high-power, high-frequency electronic devices.
Compositionally graded AlGaN epilayer was grown by HVPE (hydride vapor phase epitaxy) on (0001) c-plane sapphire substrate.
In order to grow the Al graded AlGaN epilayer and AlN epilayer, metal Al, metal Ga and NH3 as the source precursors with N2 carrier gas were prepared. During the growth, temperatures of source and the growth zone were set at 750℃ and 1145℃, respectively. In the reactor by the synthesis of NH3, AlCl and GaCl by using only one boat of the advanced HVPE method.
The epilayers were investigated by field emission scanning electron microscope(FE-SEM), and energy dispersive spectroscopy(EDS), atomic force microscope(AFM) and x-ray diffraction(XRD).
From these result, we expect to use of the graded AlGaN epilayer grown by HVPE for the application of electron and optical devices.