Structural and optical characterization of GaAs and InGaAs thin films deposited by RF magnetron sputtering

Abstract

III-V semiconductors thin film with high crystalline quality by non-crystal growth method is a topic of interest due to its application in the field of optoelectronics, since it would significantly reduce the prohibitive cost of the devices fabricated with such materials. In this article, we focus on the investigation of the structural and optical properties of III–V thin films of GaAs and InGaAs prepared by magnetron sputtering on glass substrates. The characterization of the thin films were carried out by X-ray diffraction from which GaAs and InGaAs alloys with a zinc blende structure and preferential growth along the direction (111) were identified. The compositions of the samples were determined by Secondary Ion Mass Spectroscopy (SIMS) and Energy Dispersive Spectroscopy (EDS) measurements. The optical parameters such as refractive index, absorption coefficient and band gap, were determined from Swanepoel method, taking advantage of interference lines of reflectance and transmittance measurements performed in a wavelength range of 400–2500nm. The relevance of obtaining these III–V semiconductors by a non-epitaxial technique is mentioned throughout the text.