Dielectric properties of epitaxial Ba0.5Sr0.5TiO3 films on amorphous SiO2 on sapphire

Abstract

The strain-relieved crystalline Ba0.5Sr0.5TiO3 (BST) film on SiO2∕Al2O3 was achieved by combining a molecular-beam epitaxy of BST on Si∕Al2O3 and a post-growth anneal in oxygen at elevated temperatures. The oxidation anneal not only converted the thin Si interlayer into amorphous SiO2 and eliminated the dielectric loss from the Si, but also relieved local strain in the film. The resulting BST film showed promising dielectric properties with 66% tunability and 0.016 dielectric loss, respectively. Additionally, temperature-dependent permittivity of the BST film resembled that of the bulk BST ceramics.

Perfectly (001)‐ and (111)‐Oriented (Ba,Sr)TiO3 Thin Films Sputtered on Pt/TiOx/SiO2/Si Without Buffer Layers

“…For high‐density ferroelectric memory, the preferentially oriented films should be fabricated in order to continue scaling of ferroelectric memory devices. Epitaxial Ba x Sr 1− x TiO 3 films have been prepared, using various techniques, on different single‐crystal substrates such as LaAlO 3 and Al 2 O 3 3,4 . However, the use of these substrates is associated with major drawbacks from an industrial point of view due to their high cost and small‐sized geometries (∼1 × 1 in.…”

Polycrystalline Ba0.6Sr0.4TiO3 thin films on r-plane sapphire: Effect of film thickness on strain and dielectric properties

“…2,3 One of the challenges, which have so far limited the implementation of BST in commercial radio frequency integrated circuits ͑RFICs hereafter͒, is the poor compatibility of BST with conventional semiconductor processes. 2,3 One of the challenges, which have so far limited the implementation of BST in commercial radio frequency integrated circuits ͑RFICs hereafter͒, is the poor compatibility of BST with conventional semiconductor processes.…”

“…2 The BST film was grown on Si/ Al 2 O 3 , and the underlying Si layer was converted to amorphous SiO 2 by annealing at 1000°C for 48 h in an oxygen atmosphere. 2 The BST film was grown on Si/ Al 2 O 3 , and the underlying Si layer was converted to amorphous SiO 2 by annealing at 1000°C for 48 h in an oxygen atmosphere.…”

Molecular Beam Epitaxial Growth and Dielectric Characterization of Ba0.6Sr0.4TiO3 Films

“…Ba 0.6 Sr 0.4 TiO 3 films were previously grown by a number of techniques, including pulsed laser deposition [1,3,4,6], sputtering [5,8], metal organic chemical vapor deposition [3,9], and sol-gel processing [7,10]. Molecular beam epitaxy (MBE) of Ba 0.6 Sr 0.4 TiO 3 has been much less studied [11].…”