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

Journal Article · Sat Jun 14 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4883767· OSTI ID:22304123

McDaniel, Martin D.; Ngo, Thong Q.; Posadas, Agham; Demkov, Alexander A. ^[1]; Karako, Christine M. ^[2]; Bruley, John; Frank, Martin M.; Narayanan, Vijay ^[3]

---

1. University of Texas at Austin, Department of Physics, Austin, Texas 78712 (United States)
2. University of Dallas, Department of Chemistry, Irving, Texas 75062 (United States)
3. IBM T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States)

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.

• OSTI ID: 22304123
• Journal Information: Journal of Applied Physics, Vol. 115, Issue 22; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

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