Device degradation using same parameters

The film thicknesses at which many strained epitaxial thin film materials begin to degrade in quality due to dislocation formation are too small to permit their use in electronic device development. For very thick substrates of the kind assumed in preceding sections in this chapter, any lattice mismatch between the film and the substrate must be accommodated by deformation of the film. This situation can be alleviated to some degree if the thickness of the substrate is of the same order of magnitude as the thickness of the film deposited on it. In this case, accommodation of a mismatch in lattice parameter can be shared between the film and substrate materials, thereby... 

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