An improvement of retention property by using surface treatment in sol-gelderived PZT films

Citation
Hh. Kim et al., An improvement of retention property by using surface treatment in sol-gelderived PZT films, INTEGR FERR, 33(1-4), 2001, pp. 9-18
Citations number
5
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Eletrical & Eletronics Engineeing
Journal title
INTEGRATED FERROELECTRICS
ISSN journal
1058-4587 → ACNP
Volume
33
Issue
1-4
Year of publication
2001
Pages
9 - 18
Database
ISI
SICI code
1058-4587(2001)33:1-4<9:AIORPB>2.0.ZU;2-S
Abstract
The retention property of PZT (PbTixZr1-xO3) films has been a major obstacl e to commercial FRAM (Ferroelectric Random Access Memory) products. The ret ention phenomenon is mainly due to undesired interfacial layers or defects such as oxygen vacancy or Pb vacancy, which is generated by fabricating PZT films. In sol-gel process, the undesired layer is formed at the surface of the PZT films during the annealing process. which greatly degrades the ret ention property. It was found that the degradation of retention property is caused by a Pb-deficient and Zr-rich layer with high defect density on the surface of PZT film. The undesired surface layer was clearly removed by ad opting a novel surface-cleaning technique. The surface-modified PZT films s howed excellent Q(OS) value of 34 muC/cm(2) after baking for 175 hours at 1 25 degreesC, which is about 4 times larger than that of as-grown PZT film. The Q(OS)-rate of the surface-modified PZT film was about -9%, which is abo ut one third of that of as-grown PZT film. In spite of the harsh pulse trai n, where V-write = 4.0 V. V-read = 3.1 V for switching charge and 3.3 V for non-switching, the Q(OS) value and Q(OS)-rate of surface modified PZT film were drastically improved.