The growth of Ge nanoclusters on a prepatterned Si (100) surface formed by imprint lithography in combination with subsequent irradiation with Ge+ions is studied. The prepatterned surface presents a...

The radiation-induced phenomena of CaSi₂ crystal growth were investigated, both directly during the epitaxial CaF₂ growth on Si (111) and film irradiation with fast electrons on Si (111) after its formation, while maintaining the specified film thickness, substrate temperature and radiation dose. Irradiation in the process of the epitaxial CaF₂ film growth leads to the formation of CaSi₂ nanowhiskers with an average size of 5 µm oriented along the direction . The electron irradiation of the formed film, under similar conditions, leads to the homogeneous nucleation of CaSi₂ crystals and their proliferation as inclusions in the CaF₂ film. It is shown that both approaches lead to the formation of CaSi₂ crystals of the 3R polymorph in the irradiated region of a 10 nm thick CaF₂ layer.

Electron states in ordered Ge/Si heterostructures with linear chains of quantum dots (QDs) were studied by the electron spin resonance (ESR) method. A new ESR signal with principal g-factor values g_zz = 1.9993 ± 0.0001, g_xx = g_yy = 1.9990 ± 0.0001 was detected. Unlike disordered QD structures, where ESR line broadening is usually observed (evidence of Dyakonov–Perel mechanism efficiency), the structures under study demonstrate the narrowing of ESR line when the external magnetic field deviates from the growth direction. The ESR line width is ΔH = 1.2 Oe for perpendicular magnetic field (along the growth direction) and ΔH = 0.8 Oe for in-plane magnetic field. The narrowing of ESR line can be explained by combination of two mechanisms. The first one is suppression of Dyakonov–Perel spin relaxation due to a settled direction of electron motion and finiteness of QD chains. The second one is cancelation of the wavefunction shrinking effect with decreasing the perpendicular component of the magnetic field.

A method for creation of Ge/Si structures with space-arranged nanoislands by heteroepitaxy on the pre-patterned Si(001) substrates with a square grid of the etched pits is developed. The...

Arrays of Ge quantum dot molecules were grown by molecular beam epitaxy using a template, composed of a multilayer structure with layers of vertically aligned three-dimensional (3D) Ge islands buried in an Si crystal matrix with the Si capping layer on top. Depending on preparation conditions, the molecules assume various configurations, including a square frame with [001]–[010]-oriented sides. It was shown by scanning tunneling microscopy that the 3D islands are located closer to the buried SiGe mound centers with the increase of the capping layer thickness. The mechanism of the quantum dot molecule formation is ascribed to strain relaxation. It was confirmed by Monte Carlo simulations of heteroepitaxial Ge growth on the template, containing the buried Ge mound.