Journals →  Materialy Elektronnoi Tekhniki →  2010 →  #2 →  Back

PHYSICAL CHARACTERISTICS AND THEIR STUDY
ArticleName Structural and electrical properties of AlN substrates used for the synthesis of LED heterostructures
ArticleAuthor A.Ya. Polyakov, N.B. Smirnov, A.V. Govorkov, I.A. Belogorokhov, K.D. Scherbachev, V.T. Bublik, O.A. Avdeev, T.Yu. Chemekova, E.N. Mokhov, S.S. Nagalyuk, H. Helava, Yu.N. Makarov
ArticleAuthorData A.Ya. Polyakov, e-mail: aypolyakov@gmail.com, N.B. Smirnov, A.V. Govorkov, I.A. Belogorokhov, (OAO Giredmet); K.D. Scherbachev, V.T. Bublik, (National Research University «MISiS»); O.A. Avdeev, T.Yu. Chemekova, e-mail: chemekova@n-crystals.fi.ru, E.N. Mokhov, S.S. Nagalyuk, H. Helava, (Nitride Crystals JSC); Yu.N. Makarov, e-mail:makarov@semicrys.fi.ru, Nitride Crystals JSC, Gallium-N JSC
Abstract Structural and electrical properties of bulk AlN crystals synthesized by physical vapor transport (PVT) have been studied by means of X-ray diffraction, conductivity versus temperature measurements, admittance spectroscopy (AS), photoinduced current transient spectroscopy (PICTS), selective etching and microcathodoluminescence (MCL) spectra and imaging measurements. We show that the crystals consist of large domains with dimensions of some 100 micron and a dislocation density of 102-104 cm-2 inside the domains. The electrical properties in the seed part of the crystals are determined by defects with the level near Ec-0.3 eV (most likely Si donors) and deep traps with the level near Ec-0.7 eV, as determined from conductivity, AS and PICTS measurements. In addition, the MCL spectra revealed the presence of deep traps giving rise to the MCL band near 3.3 eV whose density is enhanced in the vicinity of intergrain boundaries. The resistivity of the crystal increases as one moves from the seed part grown on SiC substrate to the tail part grown on AlN.
keywords Aluminum nitride, sublimation method, single crystals, conductivity, deep traps.
References 1. Schowalter, L. J. Fabrication of native single-crystal AlN substrates / L. J. Schowalter, G. A. Slack, J. B. Whitlock, K. Morgan, S. B. Schujman, B. Raghothamodachar // Phys. status solidi (c). - 2003. - V. 0, N 7. - P. 1997.
2. Herro, Z. G. Seeded growth of AlN on N- and Al-polar (0001) seeds by physical vapor transport / Z. G. Herro, D. Zhlesser, R. Colazo, Z. Sitar // J. Cryst. Growth. - 2006. - V. 286, N 2. - P. 205.
3. Chemekova, T. Ju. Sublimation growth of 2-inch diameter bulk AlN crystals / T. Ju. Chemekova, O. V. Avdeev, I. S. Barash, E. N. Mokhov, S. S. Nagaljuk, A. D. Roenkov, A. S. Segal, Ju. N. Makarov, M. G. Ramm, G. Davis, G. Huminic, H. Helava // Phys. status solidi (c). - 2008. - V. 5, N 6. - P. 1612.
4. Berman, L. S. Emkostnaja spektroskopija glubokih centrov v poluprovodnikah- / L. S. Berman, A. A. Lebedev - L. : Nauka, 1981. - 280 p.
5. Poljakov, A. Y. Deep traps in high resistivity AlGaN films / A. Y. Poljakov, N. B. Smirnov, A. V. Govorkov, J. M. Redwing // Solid State Electron. - 1998. - V. 42. - P. 831.
6. Poljakov, A. Y. Deep centers and their spatial distribution in undoped GaN / A. Y. Poljakov, N. B. Smirnov, A. V. Govorkov, M. Shin, M. Skowronski, D. W. Greve // J. Appl. Phys. - V. 84. P. 870.
7. Poljakov, A. Y. Properties of Si donors and persistent photoconductivity in AlGaN / A. Y. Poljakov, N. B. Smirnov, A. S. Usikov, A. V. Govorkov, B. V. Pushniy // Solid State Electron. - 1998. V. 42. - P. 1959.
8. Zeisel, R. DH-behavior of Si in AlN / R. Zeisel, M. W. Bayerl, S. T. B. Goennenwein, R. Dimitrov, O. Ambacher, M. S. Brandt, M. Stutzmann // Phys. Rev. B. - 2000. - V. 61. - P. R16283.
9. Poljakov, A. Y. Deep centers in bulk AlN and their relation to low-angle dislocation boundaries / A. Y. Poljakov, N. B. Smirnov, A. V. Govorkov, T. G. Jugova , K. D. Scherbatchev, O. A. Avdeev, T. Ju. Chemekova , E. N. Mokhov, S. S. Nagaljuk, H. Helava, Ju. N. Makarov // Phys. B. - 2009. - V. 404. - P. 4939—4941.
10. Monemar, B. Recent developments in the III-nitride materials / B. Monemar, P. P. Paskov, J. P. Bergman, A. A. Toporov, T. V. Shubina // Phys. status solidi (b). - 2007. - V. 244. - P. 1759.
11. Mooney, P. M. DH-centers in compound semiconductors / P. M. Mooney // J. Appl. Phys. - 1990. - V. 67. - P. R1.
Language of full-text russian
Full content Buy
Back