Deposit acoustic wave analysis

Miller and Bolef [74] applied a continuous acoustic wave analysis to the compound resonator formed by the quartz crystal and the deposited film. As shown in Fig. 5, they considered a continuous acoustic wave of frequency v propagating in the form of a damped plane wave from the quartz into the deposited film. At the interface, the wave is partially reflected and partially transmitted. Provided that the acoustic losses in the quartz and thin film are small, one can use the following relation to determine the complete set of resonance frequencies v (fundamental and harmonics) for the compound resonator ... 

The first method is an optical method based on the use of a laser sheet at grazing incidence. With this method, it is possible to follow the deposit thickness and kinetics in situ and real-time. The second method is an acoustic method. The analysis of the acoustic wave of the deposit with time enables its thickness to be followed. Moreover, variations of the amplitude of the acoustic wave are linked to possible changes in the structural properties of the deposit. Nonetheless, only qualitative variations are available. The use of both methods on the same apparatus will enable a complete characterization to be obtained (Figure 11.1). 

---