Optical and structural properties of Er2O3 films grown by magnetron sputtering

Abstract

The structural properties and the room temperature luminescence of Er2O3 thin films deposited by magnetron sputtering have been studied. In spite of the well-known high reactivity of rare earth oxides towards silicon, films characterized by good morphological properties have been obtained by using a SiO2 interlayer between the film and the silicon substrate. The evolution of the properties of the Er2O3 films due to thermal annealing processes in oxygen ambient performed at temperatures in the range of 800–1200°C has been investigated in detail. The existence of well defined annealing conditions (rapid treatments at a temperature of 1100°C or higher) allowing to avoid the occurrence of extensive chemical reactions with the oxidized substrate has been demonstrated; under these conditions, the thermal process has a beneficial effect on both structural and optical properties of the film, and an increase of the photoluminescence (PL) intensity by about a factor of 40 with respect to the as-deposited material has been observed. The enhanced efficiency of the photon emission process has been correlated with the longer lifetime of the PL signal. Finally, the conditions leading to a reaction of Er2O3 with the substrate have been also identified, and evidences about the formation of silicate-like phases have been collected.

Real-time synchrotoron radiation X-ray diffraction and abnormal temperature dependence of photoluminescence from erbium silicates on SiO2/Si substrates

“…[1][2][3][4][5][6][7][8] In the erbium compounds, the density of erbium ions is 10 22 atoms/cm 3 , which is orders of magnitude greater than that typically obtained by Er ion implantation in silicon substrate, allowing access to a large number of emitting centers.…”

“…Consequently, we can say that the abnormal temperature dependence of the Er 3+ PL intensity of the Er 2 O 3 films is mainly due to the phonon-assisted resonant excitation (anti-Stokes excitation) at the 2 H 11/2 levels that is followed by the subsequent energy transfers to the 4 I 13/2 levels for the 1.53-μm emission. In order to confirm the validity of this mechanism, we pumped the Er 2 Fig. 9 in Ref. 2), while we observed the abnormal temperature dependence at λ exc = 992.08 nm, as was observed at λ exc = 532 nm [ Fig.…”

“…• C. The I 15/2 -I 13/2 Er 3+ photoluminescence from the erbium oxide and erbium silicate exhibits abnormal temperature dependence, which can be explained by the phonon-assisted resonant absorption of the 532-nm excitation photons into the 2 O 7 , are promising materials as light emitters at the telecommunications wavelength and as optical amplifiers in the field of silicon photonics. [1][2][3][4][5][6][7][8] In the erbium compounds, the density of erbium ions is 10 22 atoms/cm 3 , which is orders of magnitude greater than that typically obtained by Er ion implantation in silicon substrate, allowing access to a large number of emitting centers.…”

“…Previous work revealed that the processes in the growth methods significantly affect the photoluminescence (PL) intensities of Er +3 ions in the materials. [1][2][3][4][5][6][7][8] According to Ref. 7, for example, the PL intensity of Er 2 O 3 grown on Si and SiO 2 by magnetron sputtering becomes large with an increase of annealing temperature up to 1200…”

Monoclinic B-phase erbium sesquioxide (Er2O3) thin films by filtered cathodic arc deposition

“…Due to the high dielectric constant (≈14) it is a candidate material to replace the gate dielectric SiO 2 in the next generation of complementary metal oxide semiconductor devices (CMOS) with an oxide layer thickness below 2 nm [1,2]. Recent research also comprised optoelectronic applications [3,4] and antireflective coatings [5]. For nuclear fusion applications Er 2 O 3 coatings are currently investigated as effective hydrogen diffusion barrier [6,7] and corrosion resistant, electrically insulating layers [8].…”