A number of authors reported values for positron diffusion length in Gallium nitride less than 60 nm where the expected values in semiconductors are in the range of 200 nm to 300 nm. As these values are usually obtained from fitting a theoretical diffusion model to experimental Doppler broadening results, a possibility of fitting errors exist. In this study, positron annihilation experimental results for two MBE Gallium nitride samples are used to determine diffusion length. Several models are examined and fitted to the data in order to find reasons behind such short values. The study concluded to rule out errors in theoretical fittings, confirmed the shortness and owed the shortness to trapping of positrons by line defects which have high density in this material.
Abdulnasser Sagr Saleh,
Awla Moftah Elhasi,
Investigation of Positron Annihilation Diffusion Length in Gallium Nitride, American Journal of Modern Physics.
Vol. 3, No. 1,
2014, pp. 24-28.
Shuji Nakamura, Takashi Mukai and Masayuki Senoh " High-Power GaN P-N Junction Blue-Light-Emitting Diodes" Jpn. J. Appl. Phys. Vol 30 , 1991, pp. L1998-L2001
Filip Tuomisto " Chapter Two - Open Volume Defects: Positron Annihilation Spectroscopy, " in Semiconductors and Semimetals, Volume 88, 2013, PP 39-65
J. S Speck, S. J. Rosner "The role of threading dislocations in the physical properties of GaN and its alloys " Physica B: Condensed Matter, Volumes 273–274, 15 December 1999, PP 24-32
Reinhard Krause-Rehberg, Hartmut S. Leipner "Positron Annihilation in Semiconductors: Defect Studies," Heidelberg. Springer, (1999)
L.V. Jørgensen, H. Schut " GaN–a new material for positron moderation " Applied Surface Science, Volume 255, Issue 1, 31 October 2008, PP 231-233
P. J. Schultz and K. G. Lynn, " Interaction of positron beams with surfaces, thin films and interfaces, " Rev. Mod. Phys.. 60, 3 (1988).
P. Rice-Evans, A. S. Saleh, M. Nathwani, J.W. Taylor and C.T. Foxon " Positron studies of MBE-grown gallium nitride," Applied Surface Science, Volume 149, Issues 1–4, 1 August 1999, PP 165-169
P. Asoka-Kumar, M. Alatalo, V. J. Ghosh, A. C. Kruseman, B. Nielsen, and K. G. Lynn "Increased Elemental Specificity of Positron Annihilation Spectra " Phys. Rev. Lett. 77, 2097–2100 (1996)
A. Seeger " Positron Diffusion in solids and liquid metals " Applied Surface Science, Volume 85, 2 January 1995, PP 8-16
S. Eichler, C. Hübner, and R. Krause-Rehberg "A Monte-Carlo simulation of positron diffusion in solids" Appl. Surf. Sci. 116, 155-161 (1997).
F.R. Brotzen, A Seeger , " Diffusion near dislocations, dislocation arrays and tensile cracks " Acta Metallurgica, Volume 37, Issue 11, November 1989, Pages 2985-2992
E. Soininen, J. Mäkinen, D. Beyer, and P. Hautojärvi " High-temperature positron diffusion in Si, GaAs, and Ge . " Phys. Rev. B 46, 13104–13118 (1992)
Yong-Ki Park, James T. Waber, and Michael Meshii , C. L. Snead, Jr. , C. G. Park "Dislocation studies on deformed single crystals of high-purity iron using positron annihilation: Determination of dislocation densities " Phys. Rev. B 34, PP 823–836 (1986)
K O Jensen, M Eldrup, N J Pedersen and J H Evans " Annealing behaviour of copper and nickel containing high concentrations of krypton studied by positron annihilation and other techniques " J. Phys. F: Met. Phys. (1988) PP 18 17
Abdulnasser S Saleh " Analysis of positron profiling data by ROYPROF, VEPFIT, and POSTRAP4 codes: a comparative study , " Journal of Theoretical and Applied Physics , Springer 2013, 7:39
A. van Veen , H. Schut, M. Clement, J.M.M. de Nijs, A. Kruseman, M.R. IJpma " VEPFIT applied to depth profiling problems " Applied Surface Science, Volume 85, 2 January 1995, PP 216-224
J. Oila, V. Ranki, J. Kivioja, K. Saarinen, P. Hautojärvi, J. Likonen, J. M. Baranowski, K. Pakula, T. Suski, M. Leszczynski, and I. Grzegory, " Influence of dopants and substrate material on the formation of Ga vacancies in epitaxial GaN layers ", Physical Review B 63, 045205: PP 1-8 (2001).
A. Uedono , S. F. Chichibu , Z. Q. Chen , M. Sumiya , R. Suzuki , T. Ohdaira , T. Mikado , T. Mukai and S. Nakamura "Study of defects in GaN grown by the two-flow metalorganic chemical vapor deposition technique using monoenergetic positron beams " J. Appl. Phys. 90, 181 (2001)
XD Pi, PG Coleman, CL Tseng, CP Burrows, B Yavich and WN Wang "Defects in GaN films studied by positron annihilation spectroscopy" J Phys.:Condens. Mat. 14, L243-L248 (2002)
H.M Weng C.C Ling, I.P Hui, C.D Beling, S Fung " A compact mono-energetic positron beam for re-emitted positron measurement ," Applied Surface Science, Volume 194, Issues 1–4, 2002, PP 24-28
C.X. Peng , H.M. Weng, C.F. Zhu, B.J. Ye, X.Y. Zhou, R.D. Han, W.K. Fong, C. Surya " Influence of polarity and intermediate-temperature buffer layers on strain relaxation and defects " Physica B: Condensed Matter, Volume 391, Issue 1, ( 2007), PP 6-11
A. Uedono , S. Ishibashi, T. Ohdaira, R. Suzuki " Point defects in group-III nitride semiconductors studied by positron annihilation " Journal of Crystal Growth, Volume 311, Issue 10, 2009, PP 3075-3079
K. Saarinen , T. Laine , S. Kuisma , J. Nissilä , P. Hautojärvi , L. Dobrzynski, J. M. Baranowski , K. Pakula , R. Stepniewski , M. Wojdak , A. Wysmolek , T. Suski , M. Leszczynski ,I. Grzegory , and S. Porowski "Observation of Native Ga Vacancies in GaN by Positron Annihilation" Phys. Rev. Lett. 79, pp. 3030–3033 (1997)
P. J. Hansen , Y. E. Strausser , A. N. Erickson , E. J. Tarsa , P. Kozodoy , E. G. Brazel , J. P. Ibbetson , U. Mishra , V. Narayanamurti , S. P. DenBaars and J. S. Speck " Scanning capacitance microscopy imaging of threading dislocations in GaN films grown on (0001) sapphire by metalorganic chemical vapor " deposition Appl. Phys. Lett. 72, pp. 2247 (1998)
X. H. Wu, P. Fini. , S. Keller , E. J. Tarsa , B. Heying , U. K. Mishra , S. P. DenBaars and J. S. Speck "Morphological and Structural Transitions in GaN Films Grown on Sapphire by Metal-Organic Chemical Vapor Deposition ". Jpn. J. Appl. Phys. 35 1996 pp. L1648-L1651.
E. Calleja, M. A. Sánchez-García, D. Basak, F. J. Sánchez, F. Calle, P. Youinou, E. Muñoz, J. J. Serrano, J. M. Blanco, C. Villar, T. Laine, J. Oila, K. Saarinen, P. Hautojärvi, C. H. Molloy, D. J. Somerford, and I. Harrison "Effect of Ga/Si interdiffusion on optical and transport properties of GaN layers grown on Si(111) by molecular-beam epitaxy," Phys. Rev. B 58 1998 pp. 1550-1559
O. Moutanabbir Y.J. Chabal, M. Chicoinec, S. Christiansen , R. Krause-Rehberg , F. Schiettekatte , R. Scholz , O. Seitz , S. Senz , F. Süßkraut , U. Gösele " Mechanisms of ion-induced GaN thin layer splitting " Nuclear Instruments and Methods in Physics Research B 267 (2009) PP 1264–1268.
F. Tuomisto " Vacancy profiles and clustering in light-ion-implanted GaN and ZnO" Applied Surface Science, Volume 255, Issue 1, 2008, PP 54-57