We examine the effect of growth temperature in the 150−300 °C range on the structural and morphological properties of Al2O3 films deposited using atomic layer deposition, contrasting the effect of H2O and O3 as oxygen sources. Trimethylaluminum (TMA) is the metal source. A mechanism for the O3 reaction is investigated using ab initio calculations and provides an explanation for the observed temperature dependence. The simulations show that hydroxyl groups are produced at the surface by the oxidation of adsorbed methyl groups by O3. This is confirmed by the measured rates; both H2O and O3 processes show molar growth rates per cycle that decrease with increasing reactor temperature, consistent with a decrease in hydroxyl coverage. At no temperature does the O3 process deposit more Al2O3 per cycle than the H2O process. Morphological characterization shows that O3 as the oxygen source yields lower-quality films than H2O; the films are less dense and rougher, especially at low growth temperatures. The existence of voids correlates with the low film electronic density. This may indicate the low mobility of surface hydroxyl at low temperatures, an effect that is washed out by repeated exchange with the vapor phase in the H2O case.

NiO films were grown on Si͑100͒ by atomic layer deposition using Ni͑Cp͒ 2 ͑Cp = cyclopentadienyl, C 5 H 5 ͒ or Ni͑EtCp͒ 2 ͓EtCp = ethylcyclopentadienyl, ͑C 2 H 5 ͒͑C 5 H 4 ͔͒ and ozone in the 150-300°C temperature range. The growth temperature dependence of structure, electronic density, and impurity levels for the prepared NiO films was studied using X-ray reflectivity, X-ray diffraction ͑XRD͒, Fourier transform infrared ͑FTIR͒ spectroscopy, time of flight-secondary ion mass spectroscopy ͑ToF-SIMS͒, and transmission electron microscopy. The behavior of films deposited using Ni͑Cp͒ 2 and Ni͑EtCp͒ 2 is compared and discussed. NiO films with good stoichiometry and low amounts of contaminants are obtained at a growth temperature ͑T g ͒ of 250°C or above. At a fixed T g , the growth rate for NiO films deposited using Ni͑Cp͒ 2 is higher than the one of films deposited using Ni͑EtCp͒ 2 . Furthermore, the growth rate for NiO deposited using Ni͑Cp͒ 2 at T g = 150°C is 0.32 nm/cycle and decreases substantially in films deposited at higher temperatures. The electronic density of NiO films deposited at 300°C is close to the one of bulk NiO ͑1.83 e − /Å 3 ͒. According to XRD and FTIR results, films deposited at T g ജ 200°C have a simple cubic polycrystalline structure. Impurities in NiO films decrease with increasing T g , as detected by ToF-SIMS.

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A method of obtaining quantitative two-dimensional (2D) maps of strain by the convergent beam electron diffraction technique in a transmission electron microscope is described. It is based on the automatic acquisition of a series of diffraction patterns generated from digital rastering the electron spot in a matrix of points within a selected area of the sample. These patterns are stored in a database and the corresponding strain tensor at each point is calculated, thus yielding a 2D strain map. An example of application of this method to cross-sectioned cells fabricated for the 0.15 μm technology of flash memories is reported.

In this paper, the correlation between dislocation density and transistor leakage current is demonstrated. The stress evolution and the generation of defects are studied as a function of the process step, and experimental evidence is given of the role of structure geometry in determining the stress level and hence defect formation. Finally, the role of high-dose implantations and the related silicon amorphization and recrystallization is investigated.