Compositional dependence of crystallization and structural stability in Ge-Sb-Se chalcogenide films
Abstract
We systematically investigated the structural properties of as-deposited and annealed GexSbySez (x + y + z = 100, 9.5 ≤ x ≤ 59, 6.2 ≤ y ≤ 42.9, 34.8 ≤ z ≤ 51.5) chalcogenide films. For films with x < 34.5, some main Sbsbnd Sb homopolar bonds as well as Sbsbnd Se heteropolar bonds appeared in the as-deposited films, while increasing the Ge content replaced some Se atoms, forming Gesbnd Se heteropolar bonds, which increased the optical band gap. For films with x ≥ 34.5, the structures of the as-deposited films were dominated by Gesbnd Ge and Sesbnd Se homopolar bonds. The annealed Ge-Sb-Se films exhibited a phase transition from amorphous to crystalline for phase-change memory. We ascribed the crystal grains of the GexSbySez films (x = 9.5, 12.8) to be the Sb phase, while we confirmed those of the films (x = 14.2, 21.3, 22.9, 25.2) to be a mixture of Sb and Sb2Se3 phases. The films with high Ge content (x = 40.2, 59) exhibited a stable amorphous phase for optical waveguide application.
- Publication:
-
Journal of Non Crystalline Solids
- Pub Date:
- December 2016
- DOI:
- 10.1016/j.jnoncrysol.2016.10.003
- Bibcode:
- 2016JNCS..453..108W
- Keywords:
-
- Thin films;
- Phase transitions;
- Crystal structure;
- Laser processing