Open AccessRigidity Enhancement of GeO2 by Y-Doping for Reliable Ge Gate Stacks
Author(s) -
Tomonori Nishimura,
Xiaoyu Tang,
Cimang Lu,
Takeaki Yajima,
Akira Toriumi
Publication year - 2018
Publication title -
ieee journal of the electron devices society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.69
H-Index - 31
ISSN - 2168-6734
DOI - 10.1109/jeds.2018.2875927
Subject(s) - components, circuits, devices and systems , engineered materials, dielectrics and plasmas
The poor reliability of the GeO2/Ge stack is improved by appropriate cation doping [e.g., Yttrium (Y)-doping] into amorphous GeO2 as a result of the enhancement of the GeO2 network structure stability. In this paper, we discuss the impact of Y-doping on structural modulation of GeO2 on a Ge substrate in thermal treatment. By doping a small amount of Y into amorphous GeO2, the crystallization of GeO2 to $\alpha $ -quartz and $\alpha $ -cristobalite structures is efficiently suppressed without toughening the local Ge-O bond. This is direct evidence of rigidity enhancement of the GeO2 tetrahedral network structure by cation doping.