I. D. Loshkarev

X-ray diffraction analysis of epitaxal film distortions on miscut substrates (001)

A method for determining the structural parameters of epitaxial layers by X-ray difractometry was developed. The proposed model allows us to analyze the triclinic distortions that arise in heterosystems with nonsingular orientations. Slew angles of dislocation film lattice GexSi1 − x with respect to Si substrate have been obtained.

Dependence of plastic relaxation in GaAs films on nucleation of the first as monolayer on Si(001) substrates

The structure of GaAs films grown on Si(001) vicinal substrates (6° rotation about 〈011〉 axis) formed in two ways of nucleation, As deposition on Si and substitution of Si monolayer by As monolayer, is studied. X-ray diffractometry is used to find that the rotation direction of a crystal lattice depends on the manner of nucleation. An optional model of the formation of film dislocation structures is proposed.

Structural state of Ge/Si heterosystems with (001), (111), and (7 7 10) interfaces

It is shown for (111) and (001) interfaces that at an identical degree of strain relaxation in semi-conductor epitaxial films, the ratio of distances D between neighboring dislocations is D(111)/D(001) = 1.5. This allows us to establish that dislocation interface (7 7 10) contains partial 90° Shockley dislocations lying in three directions of 〈110〉.

Theoretical and experimental determination of the initial stage of plastic relaxation of misfit stresses in a (111) substrate-film islands heterosystem

A model for determining the critical thickness of a film hc is developed to introduce misfit dislocations in the slip planes of a film and a substrate parallel to the interphase boundary (111). Experimental values hc that agree with calculated values are determined for the Ge/Si(111) and Si3N4/Ge(111) heterosystems. The two-level epitaxial growth of Ge on Si is attained in the regime of combining the step-layer and 2D island growth mechanisms.

Effect of long-range stresses on the structure of semiconductor heterosystems

The dependence between the misfit value of the interface layers f and the structural parameters of the misfit dislocations is obtained for arbitrary orientation of the interface of a semiconductor heterosystem subjected to the complete relaxation of misfit stresses. Such parameters are the distance Di between neighboring dislocations of the ith family and projection of the edge component of the Burgers vector onto the interface (bie). The number of families incorporated into the interface is determined by the orientation of the boundary and occurrence of the relaxation process. The role of specific cases of this expression for experimental and technological applications is discussed using the appearance of long-range shear and normal stresses in films with orientations of (001) and (111) as examples.

Optimal and Nonoptimal Misfit Stress Relaxation in a Semiconductor Heterosystem

Misfit stress relaxation processes in a semiconductor heterosystem are divided into optimal and nonoptimal. Depending on the type of a process and degree of its completeness, four variants of a uniform stress field are established and experimentally detected in the surface layer of an epitaxial film. The interaction between threading dislocations that favors the transformation of nonoptimal relaxation into optimal is investigated.

The role of misfit dislocations in tilt boundary formation in heterosystems with nonsingular orientations

The structural state of GexSi1 − x films on miscut Si(1 1 13) substrates is studied by X-ray diffraction. Triclinic distortions that arise in the GexSi1 − x film are analyzed. The coincidence of the tilt axis and the miscut axis is established. Different misfit-dislocation networks that generate tilt boundaries are considered.

Role of long-range shear stresses in the plastic deformation of epitaxial films

The dependence of elastic energy on relaxation parameters ρx and ρy varying in limits from 0 to 1 is analyzed for near-surface layers of an In0.1Ga0.9As epitaxial film on a GaAs (001) substrate whose thickness exceeds the distance between neighboring misfit dislocations.

X-Ray Diffraction Analysis of Epitaxial Layers with the Properties of a Dislocation Filter

An approach to instant testing of epitaxial films with a sharp decrease in the threading dislocation density is proposed. High-resolution X-ray diffractometry, including reciprocal space mapping, has been used. The structure of GaAs/Si(001) heterosystems with low-temperature GaAs layers has been analyzed. A decrease in the density of threading dislocations in the GaAs film with the formation of a small-angle boundary has been detected.

Analysis of the Stress Relieving Process in a Semiconductor Heterosystem with a (013) Interface

A theoretical analysis of the process of introducing misfit dislocations into a semiconductor heterostructure with a (013) interface is performed by assuming conditions of quasi-equilibrium process. The mechanism of generation is established for those misfit dislocations, which do not meet the requirement of minimum critical film thickness. The calculations are performed on the basis of the force balance model and allow for the shear stress field in the film and the type of the screw dislocation component.