Film thickness variation with deposition time

In the reflectivity technique, the intensity of specularly reflected x-rays is measured as a function of the incidence angle. Since the reflection coefficient for x-rays is less than unity, it is totally reflected from the sample surface, up to the critical angle of incidence. This critical angle is proportional to the square root of electron density and, hence, of the mass density. The density measured in this way can be used to derive the sp lsp ratio or, said otherwise, the extent to which a film is graphite like (p = 2.25 g/cm ) or diamond like (p = 3.51 g/cm ). The results of a study of the density variation with the time of deposition of diamond-like films (converted to film thickness) in the initial stages of their growth can be found in Ref. 71. 

Fig. 6.16. Variation of the average visible absorption of AP-CVD ZnO B films as a function of film thickness. The films were deposited with different times at 360° C, using DEZ and ter -butanol as precursors and B2H6 as doping gas. Reprinted with permission from [29]...

The open circuit potential of fully porous double-gyroid templates on FTO when immersed in electrolyte was 480 10 mV. A deposition rate of approximately 9.2 nm s was observed for the replication of gyroid templates. The deposited film thickness was measured by SEM imaging of prepared cross-sections. The typical current variation during deposition is shown in Fig. 5.7c. Similarly, nontemplated and inverse opals (lO) were prepared under the same conditions, except that the required deposition time for the same deposition thickness was much shorter. The deposition rate in colloidal arrays made from poly(styrene) mlcrospheres with a diameter of 400 nm, was approximately 60nms . ... 

Figure 12.11 Variation of the thickness of the electrodeposited for (c) 10 s and (d) 30 s the silica films electrodeposited on ITO as a func- whole films electrodeposited for (e) 10 s and tion of deposition time (a) thickness of the (f) 30 s. Scale bars (c and d) 100 nm, (e) 1 pm, well-ordered mesoporous part (b) thickness of and (f) 2.5 pm. (Adapted with permission from the whole film. Cross-sectional SEM images Ref. [28].)...

By combination of ellipsometry and EQCM Gottesfel [24] studied the nucleation and growth of polyaniline (PANI). The mass deposited was obtained by the frequency change while the thickness resulted from the ellipsometry measurements. Therefore the variations of mass and PANI film density were followed in real time, which would otherwise be impossible with either individual technique alone. 

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