Naslov
Perturbed angular correlation measurements and lattice site location of Br in GaAs

Autori
Wehner, M. ; Vianden, R. ; Dalmer, M. ; Hofsass, H. ; Ridgway, M.C. ; Petravić, Mladen

Izvornik
Materials science forum (0255-5476) 258-263 (1998), 1-3; 899-904

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
angular correlation measurements ; Br ; GaAs

Sažetak
Perturbed angular correlation (PAC) measurements with the probe Br-77(Se-77) in semiinsulating GaAs gave evidence for a metastable behaviour of the Br-As double donor, similar to the well known EL2 and DX defects in GaAs. Since, according to theoretical calculations, this would imply a substitutional lattice position of Br in GaAs, we applied the emission channelling technique for a lattice site location measurement. After 30 keV implantation of the electron emitter Br-82(Kr-82) and subsequent annealing at 1123 K, channelling of the emitted electrons was observed along the <100> and <110> crystal axis, which is expected for a substitutional lattice site occupation of the emitters. Since a quantitative analysis of the data requires the knowledge of the emitter depth profile, it was determined by Secondary ion mass spectroscopy (SIMS). A broadening of the depth profile due to Br diffusion during the annealing process was observed for a sample implanted with 1.10(13) Br/cm(2) at 160 keV. However, SIMS spectra of a second sample implanted with a higher dose (3.10(13) Br/cm(2), 160 keV) indicated some precipitation of Pr. The theoretical channelling effect has been calculated in the many-beam formalism, taking into account the results of the SIMS measurements. The experimental channelling effect is consistent with the assumption that 38(10)% of the emitters occupy substitutional lattice sites. The remaining Br probes most probably are found in precipitates.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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