Epitaxial stabilization of a monoclinic phase in Y2O3 films on c-plane GaN

Controllable phase formation and physical properties of yttrium oxide films governed by substrate heating and bias voltage

“…Taking monoclinic phase as an example, monoclinic yttrium oxide can be only obtained by certain conditions. Studies have shown that monoclinic yttrium oxide films have been prepared by Chang et al by MBE [16], by Lacroix through ion beam deposition [20] and by Gaboriaud with ion irradiation [22]. Similar results have also been observed for erbium oxide [23,24].…”

“…Numerous studies have reported that yttrium oxide films can be used in a wide variety of scientific and engineering applications due to their natural properties. They include high crystallographic stability (up to 2325 1C) [1,2], superior mechanical strength [3], high permittivity ($ [14][15][16][17][18] [4,5], high refractive index ($ 2) [6,7], wide band gap ($ 5.8 eV) [8], low lattice mismatch with silicon (cubic phase) [9] and graphene (hexagonal phase) [10], wellknown host matrix for rare-earth ions [11,12], and a component of several complex materials [13,14].…”

“…Up to now, yttrium oxide films have been prepared by various methods, including molecular beam epitaxy (MBE) [16,17], pulsed laser deposition (PLD) [8,18], sputtering [7,19,20], electron beam deposition [21] etc. Most reports synthesized the cubic phase, while just a few papers reported the successful formation of other phases of yttrium oxide films.…”

MBE—Enabling technology beyond Si CMOS

“…Another example is epitaxy-stabilized monoclinic nm-thick Y 2 O 3 films grown on GaN (0 0 0 1) using MBE [55], in which excellent electrical properties were obtained. At atmospheric pressure, Y 2 O 3 exists in either cubic or hexagonal structure.…”

Growth and application of epitaxial heterostructures with polymorphous rare-earth oxides

“…This seems to be a serious obstacle because growth of a semiconductor with a cubic crystal structure on a hexagonal dielectric with a hexagonal structure leads to the formation of stacking defects in the semiconductor layer as was demonstrated by Schroeder et al [3]. Epitaxial stabilization of pseudomorphic rare-earth oxides grown on cubic substrate [4] and hexagonal substrate was reported [5,6].…”