Abstract

PULZARA-MORA, C.A. et al. Characterization of GaAs and GaAsMn layers deposited by magnetron sputtering. Superf. vacío [online]. 2016, vol.29, n.3, pp.98-104.  Epub Oct 30, 2020. ISSN 1665-3521.

In this work we present results on the growth and characterization of layers of GaAs and the semi-magnetic alloy GaAsMn deposited by magnetron sputtering over silicon (100) substrate. X ray diffraction patterns of GaAs and GaAsMn indicate that GaAs layer is polycrystalline with preferential orientation along the (111) direction, while the GaAsMn layer has a phase of GaAs (002) and a phase associated to MnAs. The Raman spectra of GaAs and GaAsMn evidence LO and TO vibrational modes associated to GaAs and other vibrational modes associated to defects in the GaAsMn layer. The spectra for X ray photoelectrons indicate that the surface of GaAs layer contains bonds at 18.45 and 18.46 eV due to Ga3d and As3d, respectively. SIMS measurements in deepth profile of concentration on the GaAsM layer indicate signals associated with Ga, As and Mn elements, being a good indicative on the formation of the ternary alloy GaAsMn. The magnetic characterization showd that GaAs layer has a diamagnetic behaviour at low and high temperatures, while the GaAsMn layer exhibits a paramagnetic behaviour from 50 to 300 K. The M vs T curve shows an anomalous behaviour below 50 K, where the increment on magnetization is owed to an increase in spin polarization. Finaly, it is concluded that it is feasible to obtain GaAs and GaAsMn polycrystalline layers with interesting physical properties using a non epitaxial deposition technique.

Keywords : Semiconductores; Magnetron sputtering; Espectroscopia Raman.