| AVS 60th International Symposium and Exhibition | |
| Electronic Materials and Processing | Friday Sessions |
| Session EM+NS+SS+TF-FrM |
| Session: | Growth and Characterization of Group III-Nitride Materials |
| Presenter: | N. Dietz, Georgia State University |
| Authors: | R.L. Samaraweera, Georgia State University F. Gueth, Georgia State University J.K.S. Nanayakkara, Georgia State University M.K.I. Senevirathna, Georgia State University N. Dietz, Georgia State University |
| Correspondent: | Click to Email |
Group III-nitrides possess a number of attractive physical, optical, and electronic properties that allow the fabrication of novel materials and device structures as presented in numerous reviews over the last two decades. However, encountered ternary and quarternary materials stabilization and integration problems under presently deployed processing conditions limit the indium incorporation to a narrow composition range. Potential pathways to stabilize group III-nitride alloys with higher indium content, include the pressure dependency of the surface chemistry, as well as kinetic stabilized growth concepts such as plasma-assisted MBE. Recent advances in remote-plasma-enhanced CVD and RF microwave plasma assisted MOCVD for the growth of group III-nitrides, demonstrate the epitaxial growth of InN and InGaN at growth temperatures of 450°C - 650°C with growth rates that are comparable to MOCVD.
In this contribution, we will present first results on epitaxial InGaN growth under migration-enhanced, remote-plasma MOCVD (MERP-MOCVD). The growth system is based on a rotating turbo-disc showerhead configuration with added provisions for the spatial and temporal control of plasma, metalorganic (MO) and hydride precursor injections, as well as real-time optical monitoring to study the evolution of surface chemistry processes as function of the process parameter. A remote plasma is generated by a nitrogen/hydrogen mixture injected in a hollow cathode, sustained by a 50W and 600W rf-power source. The reactive nitrogen species (e.g. N*/NH*/H* fragments) in the after glow regime of a remote plasma are directed to the growth surface using the after glow regime of the remote plasma.
Data will be presented and discussed for the GaN and InN process window as function of nitrogen/hydrogen plasma mixture, reactor pressure, substrate temperature, and rf-power setting. The layers have been characterized by x-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) reflectance and optical absorption spectroscopy.