The electronic and optical properties of Al 2 O 3 /SiO 2 dielectric thin films grown on Si(1 0 0) by the atomic layer deposition method were studied by means of x-ray photoelectron spectroscopy and reflection electron energy loss spectroscopy (REELS). The band gaps of the Al 2 O 3 /SiO 2 thin films before annealing and after annealing were 6.5 eV and 7.5 eV, respectively, and those of the γ-Al 2 O 3 and α-Al 2 O 3 phases were 7.1 eV and 8.4 eV, respectively. All of these were estimated from the onset values of the REELS spectra. The dielectric functions were determined by comparing the effective cross-section determined from experimental REELS with a rigorous model calculation based on dielectric response theory, using available software packages. The determined energy loss function obtained from the Al 2 O 3 /SiO 2 thin films before annealing showed a broad peak at 22.7 eV, which moved to the γ-Al 2 O 3 position at 24.3 eV after annealing. The optical properties were determined from the dielectric function. The optical properties of the Al 2 O 3 /SiO 2 thin films after annealing were in good agreement with those of γ-Al 2 O 3. The changes in band gap, electronic and optical properties of the Al 2 O 3 /SiO 2 thin films after annealing indicated a phase transition from an amorphous phase to the γ-Al 2 O 3 phase after annealing.

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The band alignment of HfZrO 4 gate oxide thin films on Si (100) deposited by the atomic layer deposition method has been investigated using reflection electron energy loss spectroscopy and XPS. The band gap of HfZrO 4 gate oxide thin film is 5.40 AE 0.05 eV. The valence band offset (ΔE v ) and the conduction band offset (ΔE c ) are 2.50 AE 0.05 eV and 1.78 AE 0.05 eV, respectively. These values satisfy the minimum requirement for the hole and electron barrier heights of larger than 1 eV for device applications. We have demonstrated that the quantitative analysis of reflection electron energy loss spectroscopy spectra obtained from HfZrO 4 thin films provides us a straightforward way to determine the optical properties and the inelastic mean free path of ultrathin gate oxide materials.

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+ ions at 80• . To illustrate how the damaged layer thickness can be decreased down to 0.5 nm, molecular dynamics simulations were used. The SIMS depth resolution estimated with trailing-edge decay length for a Ga delta-layer in Si with grazing-incident 650 eV O 2 + was 0.9 nm, which is in good agreement with the measured damaged layer thickness.