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6.2.2 Plasma Deposition

In the same way as the reactive ion etching model introduced above, the model for plasma deposition is formulated in a general way, allowing the simulation of different kind of plasma assisted deposition techniques which are determined by ballistic transport of the particles. Chemical reactions in the gas phase such as reactions of sputtered metal particles with the carrier gas are included under the assumption that the chemical reactions are completely finished when the particles arrive at the wafer surface. In this case it is assumed that the film is deposited from the reaction product with a fully terminated reaction and the incident flux distribution already takes into account the collisions occurring in the reactor space above the feature.

Figure 6.14: Plasma deposition over two metal lines with different widths.

Fig. 6.14 shows an example for plasma assisted deposition of SiO$_2$ on two metal lines. The width for the metal lines is the same as for the mask openings in the example in Section 6.2.1. For demonstration purposes the same parameters as for the reactive ion etching example from above have been used. This is a rather unrealistic assumption for the deposition process but demonstrates that the cellular approach is able to apply the same modeling procedures for the simulation of etching and deposition processes. Only the final index switching determines the sign for the surface propagation.

Prev: 6.2.1 Reactive Ion Etching