Crystalline SrZrO3 deposition on Ge (001) by atomic layer deposition for high-k dielectric applications
Abstract
Heteroepitaxial growth of crystalline SrZrO3 (SZO) on Ge (001) by atomic layer deposition is reported. Ge (001) surfaces are pretreated with 0.5-monolayers (ML) of Ba and an amorphous ∼3-nm SZO layer is grown from strontium bis(triisopropylcyclopentadienyl), tetrakis (dimethylamido) zirconium, and water at 225 °C. This ∼3-nm layer crystallizes at 590 °C and subsequent SZO growth at 225 °C leads to crystalline films that do not require further annealing. The film properties are investigated using X-ray photoelectron spectroscopy, x-ray diffraction, aberration-corrected electron microscopy, and capacitance-voltage measurements of metal-oxide semiconductor capacitor structures. Capacitance-voltage measurements of the SrZrO3/Ge heterojunctions reveal a dielectric constant of 30 for SrZrO3 and a leakage current density of 2.1 × 10−8 A/cm2 at 1 MV/cm with an equivalent oxide thickness of 0.8 nm. Oxygen plasma pretreatment of Ge (001), Zintl layer formation with 0.5 ML Ba, and atomic deuterium post-growth treatment were explored to lower interface trap density (Dit) and achieved a Dit of 8.56 × 1011 cm−2 eV−1.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 27, 2018
- Source ID
- 10.1063/1.5026790
Entities
People
- Agham Posadas
- Alexander A Demkov
- Bryce I. Edmondson
- David J Smith
- Edward T. Yu
- Heng-lu Chang
- Hsin Wei Wu
- Ji Li
- John G Ekerdt
- Pei-yu Chen
- Shen Hu
Organizations
- Air Force Office of Scientific Research
- Arizona State University
- National Science Foundation
- University of Texas at Austin