Etching and surface caracterisation of Ge-Sb-Se chalcogenide materials
Christophe Cardinaud, Aurélie Girard
PhD : Thibaut Meyer (2019)
The chalcogenide materials (S, Se, Te) formed in association with the elements of columns 13 (Ga, In) 14 (Si, Ge) or 15 (As, Sb) have particular or remarkable properties: excellent transmission in the mid-infrared and optical non-linearity for amorphous phases, low resistivity for crystalline phases, phase transition under electrical or thermal stress, which open the way to applications in integrated optics or for non-volatile PCRAM memories.
Device manufacturing requires structuring the material at the micrometer or nanometer scale. This step is decisive since the functionality and performance of the component depends on the chemical and physical surface quality of the structure produced.
Our work is focused on the GeSbSe family; it concerns the characterisation of solid and thin film materials made from them as well as the study of etching processes in fluorine-based plasmas (SF6, SF6-Ar, SF6-O2) or in CH4-H2-Ar mixtures with the aim of developing the knowledge on the etching mechanisms, assessing the damage induced and the viability of the processes. To know more, refer to Meyer et al 2020, or 2021
Keywords : HgCdTe, Plasma etching, Infra-red photodetectors, CH4-H2 plasmas
Expertises : Fluorine-based and CH4-H2 plasmas, In situ surface characterisation: XPS, ellipsometry, Plasma diagnostics: optical emission spectrometry, mass spectrometry, electrostatic probes.
Collaborations : ISCR-Rennes, KPF-Pardubice