Optical and compositional characterization of GaAs(Ti) thin films deposited by R.F. magnetron sputtering

• Published in: Journal of non-crystalline solids Vol. 359; pp. 21 - 26
• Main Authors: Boronat, A., Silvestre, S., Castañer, L.
• Format: Journal Article Publication
• Language: English
• Published: Oxford Elsevier B.V 01.01.2013; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Cèl·lules solars; Deposition by sputtering; Enginyeria de la telecomunicació; Exact sciences and technology; Fotònica; GaAs(Ti); Iii-v semiconductors; Intermediate band (IB); Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Physics; Solar cells; Sputtering; Telecomunicació òptica; Àrees temàtiques de la UPC; GaAs(Ti); Sputtering; Intermediate band (IB); Gallium arsenides; Fourier transform spectroscopy; Composition effect; XRD; Titanium additions; III-V compound; Operating conditions; Thin films; Cathode sputtering; Electron microprobe analysis; Optical properties; Physical vapor deposition; Chemical composition; Fourier-transformed infrared spectrometry; Sputter deposition; III-V semiconductors; X-ray photoelectron spectra
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2012.09.017

GaAs thin films with Ti incorporated, to which we refer to as GaAs(Ti), have been deposited by R.F. sputtering on fused silica and c-GaAs substrates under different process conditions. The films were characterized by EPMA, XPS and XRD to study the composition and structural dependence on the deposition conditions, paying special attention on the Ti content of the films. The optical responses of the films were analyzed by spectrofotometric, PDS and FTIR measurements. The Ti content is in all the samples above 1020atoms/cm3, so we can consider them as GaAs films highly Ti doped. It has been observed that an evolution of the Ga/As atomic content in relation with the Ti incorporation, which together with the results obtained from XPS measurements, indicates a possible substitution of Ga by Ti atoms in the deposited films. ► GaAs films with high dose of Ti incorporated have been obtained by R.F. sputtering. ► The evolution of Ga molar fraction suggests a possible substitution of Ga by Ti. ► XRD measurements reveal the presence of a new phase structure. ► The XPS measurement only reveals Tiδ+ species. ► The presence of Ti affects the Etauc trend depending on the deposition conditions.