TITLE

Observation of thermally activated conduction at a GaN–sapphire interface

AUTHOR(S)
Mavroidis, C.; Harris, J. J.; Kappers, M. J.; Sharma, N.; Humphreys, C. J.; Thrush, E. J.
PUB. DATE
August 2001
SOURCE
Applied Physics Letters;8/20/2001, Vol. 79 Issue 8, p1121
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Temperature-dependent differential Hall measurements have been performed on an undoped GaN epitaxial layer grown by metalorganic chemical vapor deposition on a sapphire substrate. The resultant depth profile shows that, for this sample, the epitaxial material is mostly insulating, and that the observed thermally activated conduction arises from an interface region ≤0.65 μm thick. Comparison with cross-sectional transmission electron microscope micrographs suggests that this conducting region is correlated to the highly defective three-dimensional growth region, while the two-dimensional growth mode beyond this thickness corresponds to the insulating portion with a lower dislocation density. Such behavior is consistent with the presence of an impurity band in a heavily doped interface region formed by oxygen outdiffusion from the substrate. © 2001 American Institute of Physics.
ACCESSION #
5017216

 

Related Articles

  • Low temperature inorganic chemical vapor deposition of heteroepitaxial GaN. McMurran, Jeffrey; Todd, M.; Kouvetakis, J.; Smith, David J. // Applied Physics Letters;7/8/1996, Vol. 69 Issue 2, p203 

    We have developed a highly efficient method of growing thin oriented films of GaN on basal plane sapphire and (100) Si substrates using an exclusively inorganic single-source precursor free of carbon and hydrogen. Cross sectional transmission electron microscopy of the highly conformal films...

  • Growth of Si delta-doped GaN by metalorganic chemical-vapor deposition. Zhao, G. Y.; Zhao, G.Y.; Adachi, M.; Ishikawa, H.; Egawa, T.; Umeno, M.; Jimbo, T. // Applied Physics Letters;10/2/2000, Vol. 77 Issue 14 

    Si delta-doped GaN has been grown by metalorganic chemical-vapor deposition. A very high peak density and narrow full width at half maximum (FWHM) of the carrier profile are obtained. It is found that the peak carrier density of Si delta doping increases with the doping time and SiH[sub 4] flow...

  • In situ, real-time measurement of wing tilt during lateral epitaxial overgrowth of GaN. Fini, P.; Munkholm, A.; Thompson, Carol; Stephenson, G. B.; Stephenson, G.B.; Eastman, J. A.; Eastman, J.A.; Murty, M. V. Ramana; Murty, M.V. Ramana; Auciello, O.; Zhao, L.; DenBaars, S. P.; DenBaars, S.P.; Speck, J. S.; Speck, J.S. // Applied Physics Letters;6/26/2000, Vol. 76 Issue 26 

    By performing in situ, real-time x-ray diffraction measurements in the metalorganic chemical-vapor deposition environment, we have directly observed the emergence and evolution of wing tilt that occurs during the lateral overgrowth of GaN from stripes patterned in a SiO[sub 2] mask. This was...

  • Influence of sapphire nitridation on properties of gallium nitride grown by metalorganic.... Keller, S.; Keller, B.P. // Applied Physics Letters;3/11/1996, Vol. 68 Issue 11, p1525 

    Presents the properties of gallium nitride (GaN) influenced by sapphire nitridation. Use of metalorganic chemical vapor deposition in the growth of GaN; Influence of nitridation schemes of sapphire on the dislocation structure of GaN films; Deterioration of photoluminescence quality for samples...

  • Picosecond four-wave-mixing in GaN epilayers at 532 nm. Taheri, Bahman; Hays, J. // Applied Physics Letters;1/29/1996, Vol. 68 Issue 5, p587 

    Investigates the picosecond four-wave-mixing (FWM) in gallium nitride (GaN) epilayers. Growth of GaN epilayers on metalorganic chemical vapor deposition; Importance of intensity and time response for scattering efficiency; Influence of carrier lifetime on the time response of FWM signals.

  • Conductive layer near the GaN/sapphire interface and its effect on electron transport in unintentionally doped n-type GaN epilayers. Cheong, M. G.; Cheong, M.G.; Kim, K. S.; Kim, K.S.; Oh, C. S.; Oh, C.S.; Namgung, N. W.; Namgung, N.W.; Yang, G. M.; Yang, G.M.; Hong, C.-H.; Lim, K. Y.; Lim, K.Y.; Suh, E.-K.; Nahm, K. S.; Nahm, K.S.; Lee, H. J.; Lee, H.J.; Lim, D. H.; Lim, D.H. // Applied Physics Letters;10/16/2000, Vol. 77 Issue 16 

    Temperature-dependent Hall effect measurements on unintentionally doped n-type GaN epilayers show that, above room temperature, the Hall-mobility values of different samples vary parallel with each other with temperature. We demonstrate that this anomaly is mainly due to a conductive layer near...

  • Pressure dependence of the blue luminescence in Mg-doped GaN. Ves, S.; Venkateswaran, U. D.; Venkateswaran, U.D.; Loa, I.; Syassen, K.; Shahedipour, F.; Wessels, B. W.; Wessels, B.W. // Applied Physics Letters;10/16/2000, Vol. 77 Issue 16 

    We report the hydrostatic pressure dependence of the blue luminescence band observed at ∼2.8 eV in heavily magnesium-doped GaN (GaN:Mg) epilayers grown on sapphire by metalorganic chemical vapor deposition. Photoluminescence (PL) studies carried out up to 6 and 8 GPa, respectively, at room...

  • GaN nanotweezers. Li, Z.J.; Chen, X.L.; Dai, L.; Li, H.J.; Liu, H.W.; Gao, H.J.; Xu, Y.P. // Applied Physics A: Materials Science & Processing;2003, Vol. 76 Issue 1, p115 

    A new form of GaN nanomaterial (nanotweezers) has been obtained by chemical vapor deposition on an etched cubic MgO (100) plane. The nanotweezers consist of a bottom rod and two arms. The bottom rods have diameters of about 100�150 nm and lengths of about 200�500 nm, on which two arms...

  • Growth of device quality GaN at 550 degrees C by atomic layer epitaxy. Karam, N.H.; Parodos, T. // Applied Physics Letters;7/3/1995, Vol. 67 Issue 1, p94 

    Presents the initial optical and electrical results for gallium nitride crystal films grown at low temperature using atomic layer epitaxy. Use of metalorganic chemical vapor deposition in achieving sufficient cracking of NH[sub 3]; Effect of low growth temperature on GaN; Regulation of the film...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics