In capacitance-voltage (C-V) measurements, frequency dispersion in high-k dielectrics is often observed. The frequency dependence of the dielectric constant (k-value), that is the intrinsic frequency dispersion, could not be assessed before suppressing the effects of extrinsic frequency dispersion, such as the effects of the lossy interfacial layer (between the high-k thin film and silicon substrate) and the parasitic effects. The effect of the lossy interfacial layer on frequency dispersion was investigated and modeled based on a dual frequency technique. The significance of parasitic effects (including series resistance and the back metal contact of the metal-oxide-semiconductor (MOS) capacitor) on frequency dispersion was also studied. The effect of surface roughness on frequency dispersion is also discussed. After taking extrinsic frequency dispersion into account, the relaxation behavior can be modeled using the Curie-von Schweidler (CS) law, the Kohlrausch-Williams-Watts (KWW) relationship and the Havriliak-Negami (HN) relationship. Dielectric relaxation mechanisms are also discussed.

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Thin films of lanthanum zirconium oxide, LaxZr1−xO2−δ (x=0.22,0.35,0.63), have been grown by liquid injection atomic layer deposition using [(PriCp)3La] and [(MeCp)2ZrMe(OMe)] precursors. At lower La atomic fractions (x=0.22) films were stabilized in the cubic phase after annealing at 700°C in air. At higher La atomic fractions (x>0.35), the films remained amorphous after annealing. The films deposited showed good dielectric properties with low hysteresis voltages and negligible flatband voltage shifts. The relative permittivity (κ) ranged from 11 to 14 with leakage current densities at 1MVcm−1 in the range of 2.6×10−6–5.3×10−7Acm−2.

Thin films of praseodymium aluminate (PrAlO x ) and neodymium aluminate (NdAlO x ) have been deposited by liquid injection metalorganic chemical vapor deposition (MOCVD) and atomic layer deposition (ALD) using the bimetallic alkoxide precursors [PrAl(OPri)6(PriOH)]2 and [NdAl(OPri)6(PriOH)]2. Auger electron spectroscopy showed that all the films were high purity, with no carbon detectable (est. detection limit ≈ 0.5 at %). X-ray diffraction showed that the PrAlO x and NdAlO x films remained amorphous up to temperatures of 900 °C. Films grown by ALD were all Pr- or Nd-deficient (Pr/Al = 0.54−0.71; Nd/Al = 0.30−0.42), but near-stoichiometric films of PrAlO x (Pr/Al = 0.76) and NdAlO x (Nd/Al = 0.87) were obtained by MOCVD at deposition temperatures of 500 and 450 °C, respectively. The electrical properties of the films were assessed using C − V and I − V on MOS capacitors. Post-metalization annealing (PMA) in forming gas was effective in reducing charge levels in all films. Following PMA, the dielectric properties of NdAlO x were superior to those of PrAlOx, MOSCs fabricated with NdAl x O y (Nd/Al = 0.87) and PrAlO x (Pr/Al = 0.76) showed leakage current densities below 7.5 × 10-10 A cm-2 (κ ∼ 14) and 1 × 10-6 A cm-2 (κ ≈ 12), respectively.

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, whereas the leakage current density is significantly higher for the MOCVD-grown films.

Thin films of neodymium aluminate (NdAlO x ) have been deposited by liquid injection metalorganic chemical vapor deposition (MOCVD) using the bimetallic alkoxide precursor [NdAl(OPr i ) 6 (Pr i OH)] 2 . The effects of high-temperature postdeposition annealing on NdAlO x thin films are reported. The as-deposited thin films are amorphous in nature. X-ray diffraction (XRD) and medium energy ion scattering (MEIS) show, respectively, no crystallization or interdiffusion of metal ions into the substrate after annealing at 950 • C. The capacitance-voltage (C-V) and current-voltage (I-V) characteristics of the thin films exhibited good electrical integrity following annealing. The dielectric permittivity (κ) of the annealed NdAlO x was 12, and a density of interface states at flatband (D it ) of 4.01 × 10 11 cm −2 eV −1 was measured. The deposited NdAlO x thin films are shown to be able to endure high-temperature stress and capable of maintaining excellent dielectric properties.

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