AVS 53rd International Symposium
    Electronic Materials and Processing Thursday Sessions
       Session EM-ThP

Paper EM-ThP12
The Structural and Optical Properties of InN Layers Grown by High Pressure CVD

Thursday, November 16, 2006, 5:30 pm, Room 3rd Floor Lobby

Session: Electronic Materials and Processing Poster Session
Presenter: M. Alevli, Georgia State University
Authors: M. Alevli, Georgia State University
G. Durkaya, Georgia State University
W. Fenwick, Georgia Institute of Technology
A. Weerasekara, Georgia State University
V.T. Woods, Georgia State University
I. Ferguson, Georgia Institude of Technology
U. Perera, Georgia State University
N. Dietz, Georgia State University
Correspondent: Click to Email
Indium nitride (InN), with its high mobility and small effective electron mass among the nitrides, is a promising material for advanced optoelectronic device applications. Indium-rich alloys, e.g. (Ga@sub 1-y-x@Al@sub y@In@subx@)N will enable the fabrication of high-efficient light emitting diodes tunable in the whole visible spectral region, as well as advanced high speed optoelectronics for optical communication. The present limitation in this area is the growth of high quality InN and indium-rich group III-nitride alloys as documented in many controversial reports on the true physical properties of InN. The difficulties arise from the low dissociation temperature of InN that requires an extraordinarily high nitrogen overpressure to stabilize the material up to optimum growth temperatures. We developed a novel high-pressure chemical vapor deposition (HPCVD) system, capable to control and analyze the vast different partial pressures of the constituents. Our results show that the chosen HPCVD pathway leads to high-quality single crystalline InN, demonstrating that HPCVD is a viable tool for the growth of indium rich group III nitride alloys. The structural analysis of InN deposited on GaN-sapphire substrate by XRD show single phase InN(0002) peaks with full width half maximum (FWHM) around 430 arcsec. Infrared reflectance spectroscopy is used to analyze the plasmon frequencies, high frequency dielectric constants, the free carrier concentrations and carrier mobilities in these layers. For nominal undoped InN layers, free carrier concentrations in the mid 10E+19cm-3 and mobilities around 600 cm+2-V-1-s-1 are observed. A further improvement is expected as the growth parameters are optimized. At present, the growth of InN is carried out at temperatures as high as 1150 K for reactor pressures around 15 bar, which is a major step towards the fabrication of indium rich heterostructures due to the closer match to the ideal processing temperatures of (Ga1-y-xAlyInx)N.