Simulated oxide thickness

Figure 2.16 Simulated oxide thickness formed on components of two ADS systems using the MATLIM code [59].

Also shown in Fig. 2 are the measured spectrum of a TEOS (tetra-ethyl-ortho-silicate)-TiN-Al stack, overlaid with the theoretical spectrum. The theoretical spectrum was based on such substrate modeling treatment. Given this empirical spectrum, both the TiN and TEOS thicknesses can be simulated and determined simultaneously. Alternatively, the TiN thickness can be fixed with only the TEOS needing to be measured. The latter method is better than the former because the more unknown film thicknesses there are, the more error is introduced. This can be demonstrated by the data in Table I, where the measurement results of the oxide thicknesses on TiN-Al substrates on the same wafer, for TiN thickness fixed and varying, are compared. 

Comparison of Oxide Thickness Measurement on TiN/Al Substrate with the TiN Thickness Fixed and as a Variable in the Response Spectra Simulation... 

Comparison of the simulated inner-oxide growth kinetics for the low-alloy steel B (X60, ccr = 1.44 wt.%) with three different grain sizes and with the experimentally measured inner-oxide thickness for specimens having a grain size of d = 10 pm. 

As a second example, results from a TOP ERDA measurement for a multi-element sample are shown in Fig. 3.65 [3.171]. The sample consists of different metal-metal oxide layers on a boron silicate glass. The projectiles are 120-MeV Kr ions. It can be seen that many different recoil ions can be separated from the most intense line, produced by the scattered projectiles. Figure 3.66 shows the energy spectra for O and Al recoils calculated from the measured TOF spectra, together with simulated spectra using the SIMNRA code. The concentration and thickness of the O and Al layers are obtained from the simulations. 

RAT grinding operations. This surface layer was removed except for a remnant in a second grind. Spectra - both 14.4 keV and 6.4 keV - were obtained on the undisturbed surface, on the bmshed surface and after grinding. The sequence of spectra shows that nanophase Oxide (npOx) is eiu-iched in the surface layer, while olivine is depleted. This is also apparent from a comparison of 14.4 keV spectra and 6.4 keV spectra [332, 346, 347]. The thickness of this surface layer was determined by Monte-Carlo (MC)-Simulation to about 10 pm. Our Monte Carlo simulation program [346, 347] takes into account all kinds of absorption processes in the sample as well as secondary effects of radiation scattering. For the MC-simulation, a simple model of the mineralogical sample composition was used, based on normative calculations by McSween [355]. 

Based on the use of the NARCM regional model of climate and formation of the field of concentration and size distribution of aerosol, Munoz-Alpizar et al. (2003) calculated the transport, diffusion, and deposition of sulfate aerosol using an approximate model of the processes of sulfur oxidation that does not take the chemical processes in urban air into account. However, the 3-D evolution of microphysical and optical characteristics of aerosol was discussed in detail. The results of numerical modeling were compared with observational data near the surface and in the free troposphere carried out on March 2, 4, and 14, 1997. Analysis of the time series of observations at the airport in Mexico City revealed low values of visibility in the morning due to the small thickness of the ABL, and the subsequent improvement of visibility as ABL thickness increased. Estimates of visibility revealed its strong dependence on wind direction and aerosol size distribution. Calculations have shown that increased detail in size distribution presentation promotes a more reliable simulation of the coagulation processes and a more realistic size distribution characterized by the presence of the accumulation mode of aerosol with the size of particles 0.3 pm. In this case, the results of visibility calculations become more reliable, too. 

The optical band gap of SI (4.3 eV) is larger than the simulated band gap (3.9 eV) of Hf02 (CN 7.0). The inherent error for the band gap calculation using DFT method is considered as reason about the difference (0.4 eV) between the optical band gap and the simulated band gap. However, the difference (1.7eV) between the optical (3.98 eV) and simulated band gap (2.28 eV) of S2 is larger than that of SI. Considering the difference (0.8 eV) between the optical band gap and the simulated band gap of the crystallized monoclinic hafnium oxide with the thickness of 900 nm, the transition rate for the optical absorption is suggested as another reason for the band gap difference of S2. 

This mechanistic scheme leads to a system of differential equations expressing the build-up or consumption rate of the reactive species. P°, P02°, POOH, O2 and PH concentrations can be derived from the above mechanistic scheme in which the only adjustable parameter is the initial hydroperoxide concentration. Oxygen diffusion and consumption can be coupled (see Colin et al. in the same Issue) but in the case under study here, the low sample thickness (70 pm) leads to a quasi uniform oxidation within that thickness. POOH build up (5) and oxygen consumption (7) can be measured, allowing us to partially verify this model. Carbonyl build-up can also be simulated by assuming that carbonyls result mainly from rearrangements of P0° radicals and by using a new adjustable parameters 72, that accounts for the yield of carbonyl buil-up in initiation and termination steps of the mechanistic scheme. 

NPT ensemble anti used the shell-model to describe polarizability. All simulation runs were performed at atmospheric pressure and in the temperature range 10 - 1100 K. For all three surfaces at both 300 and 1100 K it was found that the surface mean square displacements are generally larger for the oxide ions than for the cations and that the out-of-plane surface motion is usually larger than the in-plane surface motion. At room temperature, the oxygen mean square displacements at the (111) surface arc a factor 1.2 larger than in the bulk, a factor 1.6 for the (Oil) surface and approximately five limes larger at the metastable (001) surface compared to the bulk. The effect of the presence of a surface on the ion dynamics (and on the structure for (011)) persists all the way to the slab centers, even for these rather thick slabs. 

Fig. 3. Illustration of the effects of multiple scattering in an image of an intergrowth bismuth-tungsten oxide bronze, nominally Bio.iWOa. The simulated images shown correspond to thicknesses of 20a (near the crystal edge) and 60a respectively, with an underfocus of 1220a.

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