Ge–Sb–S–Se–Te amorphous chalcogenide thin films towards on-chip nonlinear photonic devices

• Published in: Scientific reports Vol. 10; no. 1; p. 11894
• Main Authors: Dory, J.-B., Castro-Chavarria, C., Verdy, A., Jager, J.-B., Bernard, M., Sabbione, C., Tessaire, M., Fédéli, J.-M., Coillet, A., Cluzel, B., Noé, P.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 17-07-2020; Nature Publishing Group
• Subjects: 639/301/1019/385; 639/624/399; Condensed Matter; Engineering Sciences; Humanities and Social Sciences; Materials; Micro and nanotechnologies; Microelectronics; multidisciplinary; Nonlinear systems; Optical properties; Optics; Photonic; Photonics; Physics; Science; Science (multidisciplinary); Silicon; Thermal stability; Thin films
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-67377-9

Thanks to their unique optical properties Ge–Sb–S–Se–Te amorphous chalcogenide materials and compounds offer tremendous opportunities of applications, in particular in near and mid-infrared range. This spectral range is for instance of high interest for photonics or optical sensors. Using co-sputtering technique of chalcogenide compound targets in a 200 mm industrial deposition tool, we show how by modifying the amorphous structure of GeSb
w
S
x
Se
y
Te
z
chalcogenide thin films one can significantly tailor their linear and nonlinear optical properties. Modelling of spectroscopic ellipsometry data collected on the as-deposited chalcogenide thin films is used to evaluate their linear and nonlinear properties. Moreover, Raman and Fourier-transform infrared spectroscopies permitted to get a description of their amorphous structure. For the purpose of applications, their thermal stability upon annealing is also evaluated. We demonstrate that depending on the GeSb
w
S
x
Se
y
Te
z
film composition a trade-off between a high transparency in near- or mid-infrared ranges, strong nonlinearity and good thermal stability can be found in order to use such materials for applications compatible with the standard CMOS integration processes of microelectronics and photonics.