Low temperature process and thin SBT films for ferroelectric memory devices

Research output: Contribution to journalConference articleContributedpeer-review

Contributors

  • Manfred Mört - , Infineon Technologies AG (Author)
  • Günther Schindler - , Infineon Technologies AG (Author)
  • Walter Hartner - , Infineon Technologies AG (Author)
  • Igor Kasko - , Infineon Technologies AG (Author)
  • Marcus J. Kastner - , Infineon Technologies AG (Author)
  • Thomas Mikolajick - , Infineon Technologies AG (Author)
  • Christine Dehm - , Infineon Technologies AG (Author)
  • Rainer Waser - , RWTH Aachen University (Author)

Abstract

At crystallization temperatures of about 800°C bismuth layered oxide SrBi2Ta2O9 (SBT) deposited by MOD develops good ferroelectric properties for use in FeRAM devices. But scaling down the film thickness of SBT below 150 nm only shorts are measured at this crystallization temperature after top electrode deposition. Working Pt/SBT/Pt-capacitors are achieved by reducing the crystallization temperature. Also temperatures of 800°C are too high for integration of the SBT module in a stacked capacitor architecture for high density memory devices. Therefore, a process is needed to reduce the crystallization temperature of SBT, called "Low Temperature Process". In this work the electric properties of spin-on processed SBT crystallized in a temperature window from 650°C up to 800°C are investigated. As shown by XRD, transition of the nonferroelectric Fluorite phase to the Aurivillius phase takes place at approximately 625°C. Increasing the crystallization temperature gives better crystallized SBT films with bigger SBT grains. However, film porosity is also increasing with temperature. Electrical results of stoichiometric variations of SBT are presented. SEM pictures show that cluster formation is correlated with less film porosity at lower temperatures.

Details

Original languageEnglish
Pages (from-to)235-244
Number of pages10
JournalIntegrated Ferroelectrics
Volume30
Issue number1-4
Publication statusPublished - 2000
Peer-reviewedYes
Externally publishedYes

Conference

Title12th International Symposium on Integrated Ferroelectrics
Duration12 - 15 March 2000
CityAachen
CountryGermany

External IDs

ORCID /0000-0003-3814-0378/work/155840904

Keywords

Keywords

  • Crystallization, Ferroelectric, Low temperature process, Porosity, SBT, Stoichiometry