Atomic layer deposition of crystalline SrHfO{sub 3} directly on Ge (001) for high-k dielectric applications
- Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758 (United States)
- Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States)
- Department of Physics, The University of Texas at Austin, Austin, Texas 78712 (United States)
The current work explores the crystalline perovskite oxide, strontium hafnate, as a potential high-k gate dielectric for Ge-based transistors. SrHfO{sub 3} (SHO) is grown directly on Ge by atomic layer deposition and becomes crystalline with epitaxial registry after post-deposition vacuum annealing at ∼700 °C for 5 min. The 2 × 1 reconstructed, clean Ge (001) surface is a necessary template to achieve crystalline films upon annealing. The SHO films exhibit excellent crystallinity, as shown by x-ray diffraction and transmission electron microscopy. The SHO films have favorable electronic properties for consideration as a high-k gate dielectric on Ge, with satisfactory band offsets (>2 eV), low leakage current (<10{sup −5} A/cm{sup 2} at an applied field of 1 MV/cm) at an equivalent oxide thickness of 1 nm, and a reasonable dielectric constant (k ∼ 18). The interface trap density (D{sub it}) is estimated to be as low as ∼2 × 10{sup 12 }cm{sup −2 }eV{sup −1} under the current growth and anneal conditions. Some interfacial reaction is observed between SHO and Ge at temperatures above ∼650 °C, which may contribute to increased D{sub it} value. This study confirms the potential for crystalline oxides grown directly on Ge by atomic layer deposition for advanced electronic applications.
- OSTI ID:
- 22413046
- Journal Information:
- Journal of Applied Physics, Vol. 117, Issue 5; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
Similar Records
Exploring the Pb 1− x Sr x HfO 3 System and Potential for High Capacitive Energy Storage Density and Efficiency
DIELECTRIC BEHAVIOR IN THE SYSTEMS PbHfO$sub 3$-BaHfO$sub 3$ AND PbHfO$sub 3$-SrHfO$sub 3$