Sputtering and Pulsed Laser Deposition for Near- and Mid-Infrared Applications: A Comparative Study of Ge25Sb10S65 and Ge25Sb10Se65 Amorphous Thin Films

Abstract

International audienceThe deposition of Ge25Sb10S65 and Ge25Sb10Se65 amorphous chalcogenide thin films was performed by radio-frequency magnetron sputtering and pulsed laser deposition technique. The deposited layers were characterized by studying their morphology, topography, chemical composition, structure, and optical functions permitting a direct comparison of two deposition methods for obtaining attractive amorphous chalcogenide films. Reactive ion etching was then used to pattern rib/ridge waveguides in sulfide and selenide films with low surface roughness, vertical sidewalls, and reasonable etching rate. Optical losses of fabricated waveguides were measured at 1550 nm with values better than 1 dB/cm obtained for sulfide/selenide films deposited by both techniques

RF sputtered amorphous chalcogenide thin films for surface enhanced infrared absorption spectroscopy

“…4(a)). These two bands are assigned to the symmetric stretching mode of [GeSe 4/2 ] tetrahedra connected by the corners and to the vibrations of [GeSe 4/2] tetrahedra connected by edges, respectively [21,[33][34][35]]. An addition of antimony to GeSe 2 glasses leads to an intensity ratio decrease of the bands at ~200 compared to ~215 cm −1 (Fig.…”

“…Thin films with Ge 25 Sb 10 Se 65 composition can be obtained by sputtering with good optical properties and low optical losses [21]. Using Ge 25 Sb 10 Se 65 target, we prepared a series of corresponding Ge-Sb-Se thin films at different sputtering parameters.…”

“…Other properties, specifically their extended optical transmission window from the visible to the far infrared (up to 20 µm), their high refractive index (usually between 2 and 3) or their nonlinear optical properties make them a class of optical materials with growing interest [15,16]. The fabrication of chalcogenide thin films is usually carried out using chemical vapor deposition [17], thermal evaporation [18,19], pulsed laser deposition, or radio-frequency sputtering [20,21]. Since the thin films parameters, i.e.…”

“…stoichiometric fidelity, structure, and optical properties can be affected by the deposition process, the choice of the deposition technique is crucial. Radio-frequency sputtering has been widely used due to its relative simplicity, easy control, often stoichiometric material transfer from target to substrate and large and multiple area coating [21].…”

Plasma diagnostics in pulsed laser deposition of GaLaS chalcogenides

“…the development of amplifiers and laser sources, optical sensors and all-optical processing components based on non-linear properties [1][2][3][4][5]. In this frame, a special chalcogenide glasses class, namely gallium lanthanum sulphide (GLS), has been evidenced (in particular when doped with rare earth elements) as an attractive non-toxic alternative to arsenic-based glasses, with optical transparency from the visible to infrared wavelengths, thermal stability, high refractive indices, high rare-earth solubility, high transition temperature and large photoinduced effects [6][7][8][9].…”