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Direct evidence for abrupt postcrystallization germanium precipitation in thin phase-change films of Sb–15at.% Ge

Authors :
Lia Krusin-Elbaum
Vaughn R. Deline
Cyril Cabral
Teresa L. Pinto
Simone Raoux
Anita Madan
John Bruley
Source :
Applied Physics Letters. 93:071906
Publication Year :
2008
Publisher :
AIP Publishing, 2008.

Abstract

We present evidence for the instability in the crystalline (metallic) state of binary Te-free phase-change Ge–Sb thin films considered for integration into nonvolatile nanosized memory cells. We find that while the amorphous (semiconducting) phase of eutectic Sb–15at.% Ge is very robust until Sb crystallization at 240°C, at about 350°C, germanium rapidly precipitates out. Ge precipitation, visualized directly with transmission electron microscopy, is exothermic and is found to affect the films’ reflectivity, resistance, and stress. It converts melting into a two-step process, which may seriously impact the switching reliability of a device.

Details

ISSN :
10773118 and 00036951
Volume :
93
Database :
OpenAIRE
Journal :
Applied Physics Letters
Accession number :
edsair.doi...........42274914b2b06e3683ce2e0c3f45dc1d
Full Text :
https://doi.org/10.1063/1.2970106