Barium, strontium and bismuth contamination in CMOS processes

Research output: Contribution to book/Conference proceedings/Anthology/ReportConference contributionContributedpeer-review

Contributors

  • H. Boubekeur - , Infineon Technologies AG (Author)
  • T. Mikolajick - , Infineon Technologies AG (Author)
  • J. Höpfner - , Infineon Technologies AG (Author)
  • C. Dehm - , Infineon Technologies AG (Author)
  • W. Pamler - , Infineon Technologies AG (Author)
  • J. Steiner - , Infineon Technologies AG (Author)
  • G. Kilian - , Goethe University Frankfurt a.M. (Author)
  • B. O. Kolbesen - , Goethe University Frankfurt a.M. (Author)
  • A. Bauer - , Fraunhofer Institute for Integrated Circuits (Author)
  • L. Frey - , Fraunhofer Institute for Integrated Circuits, Friedrich-Alexander University Erlangen-Nürnberg (Author)
  • H. Ryssel - , Fraunhofer Institute for Integrated Circuits, Friedrich-Alexander University Erlangen-Nürnberg (Author)

Abstract

Contamination aspccts of ferroelectric (SrBi2Ta2O9) and high diclcctric constant (Ba,Sr)TiO3 materials in CMOS processes were investigated in this paper, TXRF, VPD-TXRF, and ToF-SIMS were used to study the desorption and diffusion properties of Sr. Bi. and Ba contamination on Si at 800°C anneals. Sr and Ba dissolve in native or thermal oxide, and only very small quantities diffuse into silicon, whereas Bi - if annealed in N2 - evaporates and its diffusion into silicon cannot be detected; in case of O2 annealing, all Bi is incorporated in the thermal oxide grown. The diffusion constants for Ba and Sr in Si are in the order of I O-16 cm2/s at 800°C. Measurements of minority carrier recombination lifetime of contaminated n and p-type wafers showed no drastic decrease in lifetime for the three elements up to contamination levels of 1014 at/cm2 The leakage currents of diodes contaminated after device processing by Ba, Sr. and Bi up with concentrations between 1012 and 1014" at/cm2 have nearly the same value as for non-contaminatcd diodes. This leads to the conclusion that Sr. Bi. and Ba do not present a drastic risk on minority carrier lifetime and diode leakage current in future Gbit-scale non-volatile Ferroelectric Random Access Memories (NVFeRAMs) or high diclectric constant Dynamic Random Access Memories (high k-DRAMs) generatioas.

Details

Original languageEnglish
Title of host publicationUltra Clean Processing of Silicon Surfaces 2000
EditorsMarc Heyns, Paul Mertens, Marc Meuris
PublisherTrans Tech Publications Ltd
Pages9-14
Number of pages6
ISBN (print)9783908450573
Publication statusPublished - 2001
Peer-reviewedYes
Externally publishedYes

Publication series

SeriesSolid State Phenomena
Volume76-77
ISSN1012-0394

Conference

Title5th International Symposium on Ultra Clean Processing of Silicon Surfaces, UCPSS 2000
Duration18 - 20 September 2000
CityOstend
CountryBelgium

External IDs

ORCID /0000-0003-3814-0378/work/156338384

Keywords

Keywords

  • FeRAMs, High-K DRAMs, Metal contamination