APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

22 Feb 1999

Volume 74, Issue 8, pp. 1057-1183

Return to All Sections
back to top
RSS Feeds

Studies of hydrogen-induced degradation processes in SrBi2Ta2O9 ferroelectric film-based capacitors

J. Im, O. Auciello, A. R. Krauss, D. M. Gruen, R. P. H. Chang, S. H. Kim, and A. I. Kingon

Appl. Phys. Lett. 74, 1162 (1999); http://dx.doi.org/10.1063/1.123474 (3 pages) | Cited 33 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
It is known that the forming gas (N2–H2 mixture) annealing process required for microcircuit fabrication results in an unacceptable electrical degradation of SrBi2Ta2O9 (SBT) ferroelectric capacitors due mainly to the interaction of H2 with the ferroelectric layer of the capacitor. We have found a strong relationship between changes in the surface composition of the ferroelectric layer and the electrical properties of SBT capacitors as a result of hydrogen annealing. Mass spectroscopy of recoiled ions (MSRI) analysis revealed a strong reduction in the Bi signal as a function of exposure to hydrogen at high temperatures ( ∼ 500 °C). The Bi signal reduction correlates with Bi depletion in the SBT surface region. Subsequent annealing in oxygen at temperatures in the range of 700–800 °C resulted in the recovery of the MSRI Bi signal, corresponding to the replenishment of Bi in the previously Bi-depleted surface region. X-ray diffraction (XRD) analysis (probing the whole SBT film thickness) showed little difference in the XRD spectra of the SBT films before and after hydrogen and oxygen-recovery annealing. The combined results of the MSRI and XRD analyses can be interpreted as an indication that the degradation of the electrical properties of the SBT capacitors, after hydrogen annealing, is mainly due to the degradation of the near surface region of the SBT layer. © 1999 American Institute of Physics.
Show PACS
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
84.32.Tt Capacitors
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.55.-g Dielectric thin films
68.35.Dv Composition, segregation; defects and impurities
82.80.Ms Mass spectrometry (including SIMS, multiphoton ionization and resonance ionization mass spectrometry, MALDI)

A low-loss composition region identified from a thin-film composition spread of (Ba1−x−ySrxCay)TiO3

H. Chang, I. Takeuchi, and X.-D. Xiang

Appl. Phys. Lett. 74, 1165 (1999); http://dx.doi.org/10.1063/1.123475 (3 pages) | Cited 56 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have generated the thin-film ternary composition spread of (Ba1−x−ySrxCay)TiO3 on an equilateral-triangle-shaped LaAlO3 substrate. Compositional variation within the triangle was achieved by a precisely controlled shutter system inside a pulsed laser deposition chamber, which allows the deposition of precursors with gradient thickness over the length of the substrate. Appropriate postannealing afforded high-quality epitaxial thin films over almost the entire composition region. Mapping of the microwave dielectric properties of the composition-spread chip was performed using a scanning evanescent microwave microscope at 1 GHz. Composition region Ba0.12–0.25Sr0.35–0.47Ca0.32–0.53TiO3 was found to have desirable properties for electronic applications. © 1999 American Institute of Physics.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
84.40.-x Radiowave and microwave (including millimeter wave) technology
77.55.-g Dielectric thin films
68.55.Nq Composition and phase identification
77.80.-e Ferroelectricity and antiferroelectricity
77.22.Ch Permittivity (dielectric function)
77.22.Gm Dielectric loss and relaxation
81.15.Fg Pulsed laser ablation deposition
61.72.Cc Kinetics of defect formation and annealing

Schottky barrier heights of tantalum oxide, barium strontium titanate, lead titanate, and strontium bismuth tantalate

J. Robertson and C. W. Chen

Appl. Phys. Lett. 74, 1168 (1999); http://dx.doi.org/10.1063/1.123476 (3 pages) | Cited 144 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The Schottky barrier heights of various metals on the high permitivity oxides tantalum pentoxide, barium strontium titanate, lead zirconate titanate, and strontium bismuth tantalate have been calculated as a function of the metal work function. It is found that these oxides have a dimensionless Schottky barrier pinning factor S of 0.28–0.4 and not close to 1 because S is controlled by Ti–O-type bonds not Sr–O-type bonds, as assumed in earlier work. The band offsets on silicon are asymmetric with a much smaller offset at the conduction band, so that Ta2O5 and barium strontium titanate are relatively poor barriers to electrons on Si. © 1999 American Institute of Physics.
Show PACS
73.40.Ns Metal-nonmetal contacts
73.30.+y Surface double layers, Schottky barriers, and work functions
73.20.At Surface states, band structure, electron density of states
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close