Digitale Medien
[S.l.]
:
American Institute of Physics (AIP)
Journal of Applied Physics
83 (1998), S. 139-144
ISSN:
1089-7550
Quelle:
AIP Digital Archive
Thema:
Physik
Notizen:
For tantalum pentoxide capacitors in 1 Gbit dynamic random access memory, titanium nitride is adopted as the top electrode. After postannealing at temperatures higher than 750 °C, the capacitance of Ta2O5 reduces due to an interfacial reaction between TiN and Ta2O5. This was studied by high resolution electron microscopy and energy dispersive spectroscopy with a 1 nm electron probe. It is found that voids form along the interface between TiN and Ta2O5 and a large proportion of Ta dissolves into the TiN film. The origin of the reaction is concluded to be a large solid solubility of Ta in TiN. After Ta outdiffusion into TiN, vacancies agglomerate and form voids in Ta2O5 and thereby reduce its capacitance. Since the driving force of the reaction is the solid solubility of Ta in TiN, the amount of the reaction is affected by the thickness of the TiN films. © 1998 American Institute of Physics.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1063/1.366732
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