Interfacial roughness scaling and strain in lattice mismatched Si0.4Ge0.6 thin films on Si

Abstract

Influence of lattice strain on charge/orbital ordering and phase separation in Pr0.7(Ca0.6Sr0.4)0.3MnO3 thin films

Real-time X-ray study of roughness scaling in the initial growth of epitaxial BaTiO3/LaNiO3 superlattices

“…From comparison of interface and surface roughness in superlattices with a modulation length below the critical value (d ¼ 2 and 6 nm), a trend of slightly smaller rms roughness of interface was observed with respect to that of the surface. In other heteroepitaxial systems, the surface exhibits larger rms roughness than that of the interface in a regime of the layer thickness less than a critical value [32]. In other superlattice systems, the multilayer structure suppresses an increase of interface roughness by providing a periodic restarting layer [36,37]; this suppression of the interface roughness would not be observed if a single layer of similar thickness was deposited [10].…”

“…Under the conditions of a multilayer stack for d ¼ 2 or 6 nm along with the initial several bilayers, a coherent strain between constituent sublayers is expected [9]. The presence of coherent strain in the heteroepitaxial superlattice structure might also provide a pinning force during epitaxial growth so that constituent atoms are not allowed to relax or to diffuse freely [32]. This mechanism is not taken into consideration in derivation of most theoretical models, which possibly explains that observed b values are larger than predicted according to Kardar-Parisi-Zhang theory [33].…”

Migration of constituent atoms and interface morphology in a heterojunction between CdS and CuInSe2 single crystals

“…The experimental setup and procedures, as well as details of data analysis, have been reported elsewhere. [12][13][14][15][16] Through a control of the x-ray probing depth and field distribution by varying the incidence angle, GIXS measurements allow a nondestructive method to obtain important microstructural information about the interfaces, such as the layer thickness, interfacial roughness, and correlation lengths of interface height fluctuations. For a multilayer structure, the specular reflection ͑with photon momentum transfer q z perpendicular to the interface͒ can usually be treated by a matrix formulation using the Fresnel law of classical optics.…”

Interface morphology of CdS thin films grown on cadmium stannate and glass substrates studied by grazing incidence x-ray scattering

“…From these diffuse scattering results, the roughness parameters (Јs) and the lateral correlation length ͑͒ were determined for each film, as shown in Table I. [8][9][10][11][12][13][14][15][16][17] If the film thickness is assumed to be directly proportional to the time of growth, this result also suggests a possible roughness scaling in the growth dynamics. This shows that the correlation function of the height fluctuations is essentially Gaussian.…”

“…The texture coefficient h was also obtained, with values close to 1.0 for all the three CdS/glass samples. 17 The surface morphology of one of the CdS/glass junctions ͑S-CdS-7͒ was also investigated by AFM. It is interesting to note that the surface roughness of CdS increases with the film thickness t, and this dependence can be approximated by a power-law behavior ϰt ␤ , as shown in Fig.…”