Stress Buildup Upon Crystallization of GeTe Thin Films: Curvature Measurements and Modelling

Rajkiran Tholapi (1) , Manon Gallard (2, 1) , Nelly Burle (1) , Christophe Guichet (1) , Stephanie Escoubas (1) , Magali Putero (1) , Cristian Mocuta (2) , Marie-Ingrid Richard (1, 3) , Rebecca Chahine (4) , Chiara Sabbione (4) , Mathieu Bernard (5) , Leila Fellouh (5) , Pierre Noé (5) , Olivier Thomas (1)

1 IM2NP - Institut des Matériaux, de Microélectronique et des Nanosciences de Provence
2 SSOLEIL - Synchrotron SOLEIL
3 ESRF - European Synchrotron Radiation Facility [Grenoble]
4 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
5 LETI - Laboratoire d'électronique et des technologies de l'Information [Sfax]

Phase change materials are attractive materials for non-volatile memories because of their ability to switch reversibly between an amorphous and a crystal phase. The volume change upon crystallization induces mechanical stress that needs to be understood and controlled. In this work, we monitor stress evolution during crystallization in thin GeTe films capped with SiOx, using optical curvature measurements. A 150 MPa tensile stress buildup is measured when the 100 nm thick film crystallizes. Stress evolution is a result of viscosity increase with time and a tentative model is proposed that renders qualitatively the observed features.

Mots clés: phase-change materials; wafer curvature; GeTe; stress; crystallization

Domaines: Mécanique des matériaux [physics.class-ph]

Rajkiran Tholapi, Manon Gallard, Nelly Burle, Christophe Guichet, Stephanie Escoubas, et al.. Stress Buildup Upon Crystallization of GeTe Thin Films: Curvature Measurements and Modelling. Nanomaterials, 2020, 10 (6), pp.1247. ⟨10.3390/nano10061247⟩. ⟨hal-02903089⟩