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Title: Incorporation of La in epitaxial SrTiO{sub 3} thin films grown by atomic layer deposition on SrTiO{sub 3}-buffered Si (001) substrates

Strontium titanate, SrTiO{sub 3} (STO), thin films incorporated with lanthanum are grown on Si (001) substrates at a thickness range of 5–25 nm. Atomic layer deposition (ALD) is used to grow the La{sub x}Sr{sub 1−x}TiO{sub 3} (La:STO) films after buffering the Si (001) substrate with four-unit-cells of STO deposited by molecular beam epitaxy. The crystalline structure and orientation of the La:STO films are confirmed via reflection high-energy electron diffraction, X-ray diffraction, and cross-sectional transmission electron microscopy. The low temperature ALD growth (∼225 °C) and post-deposition annealing at 550 °C for 5 min maintains an abrupt interface between Si (001) and the crystalline oxide. Higher annealing temperatures (650 °C) show more complete La activation with film resistivities of ∼2.0 × 10{sup −2} Ω cm for 20-nm-thick La:STO (x ∼ 0.15); however, the STO-Si interface is slightly degraded due to the increased annealing temperature. To demonstrate the selective incorporation of lanthanum by ALD, a layered heterostructure is grown with an undoped STO layer sandwiched between two conductive La:STO layers. Based on this work, an epitaxial oxide stack centered on La:STO and BaTiO{sub 3} integrated with Si is envisioned as a material candidate for a ferroelectric field-effect transistor.
Authors:
; ;  [1] ; ;  [2] ;  [3] ; ; ;  [4]
  1. University of Texas at Austin, Department of Chemical Engineering, Austin, Texas 78712 (United States)
  2. University of Texas at Austin, Department of Physics, Austin, Texas 78712 (United States)
  3. University of Dallas, Department of Chemistry, Irving, Texas 75062 (United States)
  4. IBM T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States)
Publication Date:
OSTI Identifier:
22304123
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 22; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANNEALING; BUFFERS; DEPOSITION; ELECTRON DIFFRACTION; FERROELECTRIC MATERIALS; FIELD EFFECT TRANSISTORS; INTERFACES; LANTHANUM ADDITIONS; LAYERS; MOLECULAR BEAM EPITAXY; REFLECTION; SILICON; STRONTIUM TITANATES; SUBSTRATES; THICKNESS; THIN FILMS; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION