Thermal stability of Er2O3 thin films grown epitaxially on Si substrates

Abstract

Articles you may be interested inThe thermal stability of Er 2 O 3 thin films grown epitaxially on Si substrates has been investigated in this paper by x-ray diffraction and high resolution transmission electron microscopy. The Er 2 O 3 /Si͑001͒ films are found to react with Si to form silicates at the temperature of 450°C in N 2 ambience, whereas O 2 ambience can prevent the silicate formation even at the temperature of 600°C. However, at a high temperature of 900°C in either N 2 or O 2 ambience, Er 2 O 3 films react with Si, and both silicate and SiO 2 are formed in the films. In addition, the Er 2 O 3 films grown on Si͑111͒ substrates show poorer thermal stability than those grown on Si͑001͒ substrates; Er silicide is formed at the interface in the films annealed at 450°C in O 2 ambience, which is attributed to that the reaction product hexagonal ErSi 2 is formed more easily on Si͑111͒ than on Si͑001͒ due to structure similarity as well as small lattice mismatch.

Study on the Energy Structure of Amorphous Antireflection Er₂O₃ Films on Si(001) Substrates

“…And no pinholes or micro-cracks are observed from the AFM image, indicating a rough and uniform surface. The above results have been reported other journals [8], so, it is not shown here.…”

“…Therefore, amorphous AR films are the best choice nowadays. Furthermore, it has been established that amorphous Er 2 O 3 films have superior thermal and chemical stability [8], which are also desired for AR films in solar cell devices. From the peak intensities of O 1s and Er 4d peaks at 531 and 168 eV taken from XPS spectrum of the Er 2 O 3 film, the O to Er atomic ratio is estimated to be 1.5 by using their relative atomic sensitivity factors, which indicates that the Er 2 O 3 film is stoichiometric.…”

Atomic layer deposition of Er2O3 thin films from Er tris-guanidinate and water: process optimization, film analysis and electrical properties

“…11,12 In addition, the lattice constant of Er 2 O 3 is twice as large as that of Si, 13 thus the growth of epitaxial Er 2 O 3 on Si substrates should be possible. 14,15 Physical vapor deposition (PVD) techniques that include among others, evaporation, molecular beam epitaxy (MBE), sputtering, etc. 16,17 and chemical coating techniques namely, chemical vapor deposition (CVD), 18 atomic layer deposition (ALD), 19 sol-gel deposition 20 and spin coating, 21 are the two major thin lm fabrication processes.…”

Comparison of the structural properties and electrical characteristics of Pr2O3, Nd2O3and Er2O3charge trapping layer memories

“…The Si 2p XPS spectra of the Nd 2 O 3 films after annealing at various temperatures were composed of two different component peaks at binding energies of 102.5 and 103.4 eV, as shown in figure 4(c). The Nd silicate peak was fixed at 102.5 eV, whereas the peak position of SiO 2 was assigned at 103.4 eV [13]. The Si 2p peaks corresponding to silicate and SiO 2 for the Nd 2 O 3 sample annealed at 900 • C exhibited a larger intensity than other temperatures, indicating the formation of a thicker interfacial layer at the Nd 2 O 3 /oxide interface.…”

“…Recently, the rare-earth metal oxides, such as Pr 2 O 3 (k = 14.9), Nd 2 O 3 (k = 16), Gd 2 O 3 (k = 13.6) and Er 2 O 3 (k = 13), are attractive materials to be considered as promising gate dielectrics because they offer a combination of high dielectric constants, large bandgaps and high conduction band offsets on Si [9][10][11][12][13][14]. A high-k dielectric-based flash memory allows for thinner equivalent oxide thickness without sacrificing nonvolatility.…”