Growth of Semiconductors Thin Films by Radio Frequency Sputtering with Two Phases: GaInNAs and GaAs Nanocrystals

Abstract

We present results on the growth of GaInNAs semiconductor thin films which present evidence of a nanocrystalline GaAs background. The films were grown using the radio frequency sputtering deposition technique in a working gas atmosphere mixture of argon and nitrogen. X-ray diffractograms show evidence of the presence of a phase of GaInNAs material with high N concentration, and of a phase of GaAs material with crystallite sizes in the order of nanometers. From the absorption spectra measured by the photoacoustic technique we show that we have obtained the GaInNAs alloys with variable band gap energies, but also that this alloy is embedded in a background of nanocrystalline GaAs material. We discuss the nature of this formation, the quantum confinement effects evidenced from the absorption spectra, and the grain sizes obtained from the use of a spherical quantum dot model.