Investigation of hyperfine interactions in pure silicon and NTD silicon by means of perturbed angular γ-γ correlation spectroscopy / Investigação de interações hiperfinas em silício puro e silício NTD pela técnica de correlação angular gama-gama perturbada

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

22/02/2007

RESUMO

In the present work, a microscopic investigation of hyperfine interactions in single crystal silicon samples was carried out by means of Perturbed Angular γ-γ Correlation technique (PAC), which is based in hyperfine interactions. In order to achieve these measurements, it was used 111In ->111Cd radioactive probe nuclei, which decay through the well known γ cascade 177-245keV with an intermediate level of 245keV (I = 5+/2 , Q = 0.83b , T1/2 = 84.5ns). The samples were prepared using diferent probe nuclei insertion methods, making possible to increase our understanding on the impact generated by each of these techniques in PAC measurements. Ion implantation, difusion and evaporation were carefully investigated giving emphasis on its characteristics and particularities. Then, it was made a study about the concentration of intrinsic defects as function of several annealing processes. Finally, a comparative analysis was made for all these probe nuclei insertion methods. This work also accomplished PAC measurements in single crystal silicon doped with phosphorus by means of NTD method, carried out in a research nuclear reactor. The extremely high doping uniformity allied to the non-existence of previous measurements in these materials emphasize the importance of the results obtained. These results are then compared with literature results for samples doped by conventional methods presenting the respective conclusions.

ASSUNTO(S)

correlação angular defeitos differential pac doped materials gamma radiation hyperfine structure magnetic fields ntd perturbed angular correlation semicondutores silicon

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