Annealing behaviour of aluminium-implanted InP

The annealing behaviour of aluminium has been studied in single-crystal InP implanted with 40 and 120 keV Al-27(+) ions, The implantation doses were 1 x 10(15) and 1 x 10(16) cm(-2). The aluminium concentration profiles were determined by two techniques, Secondary ion mass spectrometry (SIMS) and th e nuclear resonance broadening technique (NRB) which was used for checking purposes. The usability of the SIMS technique for profiling Al rich layers was studied. Significant inconsistencies were observed in the SIMS profiles with the high dose implanted samples, The 120 keV, 1 x 10(16) cm(-2) impla nted samples were subject to annealing in argon atmosphere in the temperatu re range 380-600 degrees C. Redistribution and a significant aluminium surf ace enrichment took place. The coefficients of Al migration were determined by fitting a concentration independent solution of the diffusion equation to the experimental depth profiles. The deduced activation energy and frequ ency factor for aluminium migration in implanted InP are 0.78 eV and 5.5 x 10(5) nm(2)/s, respectively. The effect of defects on the Al migration is d iscussed. Rutherford backscattering (RBS) spectra measured along (1 0 0) ch anneling direction for 120 keV, 10(16) cm(-2) implanted samples indicated a loss of crystalline structure near the surface both in the as-implanted an d in the annealed samples. (C) 2000 Elsevier Science B.V. All rights reserv ed.