Strain Relaxation In Epitaxial Films Research Articles

TEM studies of stress relaxation in GaAsN and GaP thin films

TEM studies of the strain relaxation driven by lattice mismatch between a film and substrate has been carried out on GaAsN and GaP films grown on (100) GaAs by molecular beam epitaxy. The nature of the defects produced was shown to be directly related to the nature of the surface developed during growth of these compounds. In general, when the surface of the film is smooth, strain relaxation occurred by cracking, while in films with a rough surface relaxation occurred by twinning or by formation of perfect dislocations. The results are discussed in the context of available models for strain relaxation in epitaxial films.

Sharp ferroelectric phase transition in strained single-crystalline SrRuO3/Ba0.7Sr0.3TiO3/SrRuO3 capacitors

Single-crystalline all-perovskite SrRuO3/Ba0.7Sr0.3TiO3/SrRuO3 thin-film capacitors epitaxially grown on SrTiO3 exhibit a sharp paraelectric-to-ferroelectric phase transition at 350 K with a maximum permittivity of about 6660. This value is comparable to that of bulk ceramics and exceeds by several times the highest values reported for Ba0.7Sr0.3TiO3 thin film capacitors. The observed thickness dependence of the dielectric response is analyzed with the aid of a thermodynamic theory. It is shown that a weak decrease of the permittivity with the Ba0.7Sr0.3TiO3 thickness decreasing from 200 to 10 nm can be explained solely by the thickness-dependent strain relaxation in epitaxial films without assuming the presence of low-permittivity layers at the film/electrode interfaces.

Strain relaxation in epitaxial films

Strain relaxation in epitaxial films