RBS\channeling and TEM study of damage buildup in ion bombarded GaN


RBS\channeling and TEM study of damage buildup in ion bombarded GaN

Pagowska, K.; Ratajczak, R.; Stonert, A.; Turos, A.; Nowicki, L.; Sathish, N.; Jozwik, P.; Muecklich, A.

A systematic study on structural defect buildup in 320 keV Ar-ion bombarded GaN epitaxial layers has been reported, by varying ion fluences ranged from 5x1012 to 1x1017 at/cm2. 1μm thick GaN epitaxial layers were grown on sapphire substrates using the MOVPE technique. RBS\channeling with 1.7 MeV 4He beam was applied for analysis. As a complementary method High Resolution Transmission Electron Microscopy (HRTEM) has been used. The later has revealed the presence of extended defects like dislocations, faulted loops and stacking faults. New version of the Monte Carlo simulation code McChasy has been developed that makes it possible to analyze such defects on the basis of the Bent Channel (BC) model. Damage accumulation curves for two distinct types of defects, i.e. Randomly Displaced Atoms (RDA) and extended defects (i.e BC) have been determined. They were evaluated in the frame of the MultiStep Damage Accumulation (MSDA) model, allowing numerical parameterization of defect transformations occurring upon ion bombardment. Displaced atoms buildup is a three step process for GaN and whereas extended defect buildup is always a two step process.

Keywords: GaN; ion bombardment; ion channeling; TEM; defect transformations

  • Lecture (Conference)
    VIII-th International Conference Ion Implantation and Other Applications of Ions and Electrons, 14.-17.06.2010, Kazimierz Dolny, Poland

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Publ.-Id: 14200