Metalorganic vapor phase epitaxy growth of AlxIn1-xP alloys and its CuPt type atomic ordering
Zhao, Jing Hua
Date of Issue2010
School of Electrical and Electronic Engineering
Photonics Research Centre
The phenomenon of atomic scale ordering in III-V semiconductor alloys, which modifies their electronic and optical properties, is observed to occur spontaneously during epitaxial growth of semiconductor and attracts much interest. AlxIn1-xP alloy provides wide bandgap energy in the non-nitride III-V semiconductors and has been wide applied in electronic and photonic devices. In this thesis, high quality AlInP epilayers have been successfully grown by metalorganic vapor phase epitaxy (MOVPE) using tertiarybutylphosphine (TBP) as phosphorus precursor in pure nitrogen (N2) ambient. Effects of MOVPE growth conditions, such as growth temperature and V/III ratio, on the aluminum (Al) incorporation into AlInP alloys have been investigated. The experimental data agreed well with the simulation result using adsorption-trapping model. These results enableus to accurately control the Al solid composition during MOVPE growths. The CuPt-B type atomic ordering in the AlInP epilayer grown by MOVPE was studied and characterized by using transmission electron diffraction (TED), photoluminescence (PL), X-ray diffraction (XRD), and polarized Raman. The MOVPE growth conditions, including growth temperature, V/III ratio, growth rate, reactor pressure, and carrier gas, were found to strongly affect the degree of order. The results provide a feasible way of controlling the degree of order by using MOVPE growth. Post-growth techniques, rapid thermal anneal (RTA) and inductively coupled plasma (ICP), were found to reduce the degree of order for AlInP layers, indicating these techniques can also be used to tailor the degree of order for AlInP. Uni-compositional AlInP quantum wells (QWs), which profits from the bandgap reduction induced by the CuPt-B ordering in AlInP layers, were produced and demonstrated by using PL, XRD and transmission electron microscopy (TEM). These results highlight the readiness of the atomic ordering application in bandgap engineering and optoelectronic devices.
DRNTU::Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics