Deposition geometry

There are, in principle, two driving forces for obtaining the compositional separation, namely the temperature and deposition geometry. 

Figure 16.2 Thickness determination of An deposition onto a bare silicon wafer using a 10 x 10 contact mask in two geometries (see insets), using (a) AFM along the diagonal of an array of 100 electrodes and (b) AFM and ellipsometry for a deposition geometry that allowed an average of 10 fields of identical thickness across the wedge. The source temperatures and deposition times were (a) 1548K, 7200 s and (b) 1623K and 4500 s.

The deposition geometry, i.e., the relative position of the substrate and sources, is of paramount importance when fabricating OLEDs (see Figure 7.4). For a substrate on a plane at right angles to a point evaporation source, the deposited film thickness d can be expressed by the following relationship ... 

Fig. 4. Schematic depositional geometry of the Zia Formation. Facies associations are from Table 1.

The carrier gas flow field can be visualized by numerically solving the complete Navier-Stokes equations for the deposition geometry. The momentum balance is given by... 

Catalyst Deactivation by Fouling from Interactions of Pore Structure and Foulant Deposit Geometries, Am. Chem. Soc. Symp. Ser., 5, (1978) 201-213. 

Interpretation of Catalyst Deactivation by Fouling from Interactions of Pore Structure and Foulant Deposit Geometries... 

The vapour evaporation of thin silver films onto suitable surfaces will produce structures resembling islands for mass thicknesses between 4 and 20 nm. These nanostructures show exceptional stability under normal conditions, but will always have thin oxide layers formed on their surfaces. There are several important experimental factors that will affect strongly the morphology and optical properties of these films and they include the substrate used, substrate temperature, mass thickness, deposition geometry, and evaporation rate. It is very easy to control all of these factors to attain reproducible results, and so film preparation is reduced to a matter of using optimum conditions, and maintaining consistency in experimental methods. 

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