Temperature dependence of the properties of heteroepitaxial Y2O3 films grown on Si by ion assisted evaporation

Abstract

Heteroepitaxial growth behavior of SrRuO 3 / SrTiO 3 (001) by pulsed laser depositionHeteroepitaxial Y 2 O 3 films were grown on an Si͑111͒ substrate by ion assisted evaporation in an ultrahigh vacuum, and their properties such as crystallinity, film stress, and morphological change were investigated using the various measurement methods. The crystallinity was assessed by x-ray diffraction ͑XRD͒ and reflection high-energy electron diffraction. Interface crystallinity was also examined by Rutherford backscattering spectroscopy ͑RBS͒ channeling and transmission electron microscopy. The strain of the films was measured by RBS channeling and XRD. Surface and interface morphological characteristics were observed by atomic force microscopy and x-ray scattering method. By comparing the interface with the surface characteristics, we can conclude that many defects at the interface region were generated by interface interaction between the yttrium metal and Si substrate. Moreover, the film quality dominantly depended on the deposition temperature. The crystallinity was greatly improved and the surface roughness was drastically decreased in the temperature range 500-600°C. On the other hand, in the temperature range 600-700°C, the compressive stress and film density were further increased, and the island size decreased. Also, the shape of the surface islands was transformed from elliptical to triangular. The film stress was found primarily at the interface area because of the interaction between yttrium and Si substrate.

High red emission intensity of Eu:Y2O3 films grown on Si(1 0 0)/Si(1 1 1) by electron beam evaporation

“…This fact suggests that the probability of the occupancy of Eu 3 þ at the C 2 sites increases upon thermal treatment in oxygen atmosphere, therefore favoring the formation of electric dipoles. In this manner, we confirmed that the electric dipole transitions are hypersensitive to the ligand environment, as already indicated in the literature [18][19][20][21][22][23][24][25][26][27][28][29][30].…”

“…The growth of these Eu:Y 2 O 3 films can yield Y 2 O 3 (1 1 0) [17,18] or Y 2 O 3 (1 1 1) on Si (1 0 0) [19], and similar behavior was also observed by Jones et al [20]. Similarly, films grown on Si (1 1 1) show a preferred (1 1 1) direction [21,22]. Therefore, from our experimental conditions, a pronounced difference between the peaks in the (4 0 0) and (4 1 1) directions for the Y 2 O 3 compound was observed prior to the thermal treatment, and this behavior was closely related to the type of substrate used ( Fig.…”

PLD-Grown Y2O3 Thin Films from Y Metal: An Advantageous Alternative to Films Deposited from Yttria

“…A variety of physical and chemical methods have been used over the past decade to synthesize dielectric Y 2 O 3 films. These include methods such as chemical vapor deposition (CVD), rf magnetron sputtering, ion-assisted evaporation, anodization, electron-beam evaporation, sol−gel techniques, and reactive synthesis and undoped 2 Y 2 O 3 films.…”

Heteroepitaxial growth of LaAlO3 films on Si (100) by laser molecular beam epitaxy

“…The change of the lattice constant of the LAO films is mainly because the film was forced by compressive stress during the annealing process, which resulted from the variation of the film density. During the annealing process, the thermal energy provided to the atoms of LAO films migrated further into the site with the minimized energy, then high crystallinity of LAO film was obtained and film density was increased [21].…”