Abstract
Metal-insulator-metal (MIM) capacitors with excellent electrical properties have been fabricated using high-κ TaAlOx-based dielectrics. TaAlOx films having thickness of 11.5-26.0 nm, with equivalent oxide thickness (EOT) of ∼ 2.3-5.3 nm were deposited on top of Au/SiO2 (180 nm)/Si (100) structures by radio frequency magnetron co-sputtering of Ta2O5 and Al2O3 targets. The surface chemical states of the as-deposited TaAlOx films were characterized by high-resolution X-ray photoelectron spectroscopy. The crystallinity of the TaAlOx films for various post-deposition annealing treatments was characterized by grazing incident X-ray diffraction, which reveals that an amorphous phase is still retained for rapid thermal annealing up to 500 °C. Besides a high capacitance density (∼ 5.4 to 6.6 fF/μm2 at 1 kHz), a low value of voltage coefficients of capacitance and a stable temperature coefficient of capacitance have also been obtained in MIM capacitors with TaAlOx films. Degradation phenomenon of TaAlOx-based MIM capacitors under constant current stressing at 20 nA is found to be strongly dependent on dielectric thickness. It is shown that Al-incorporated Ta2O5 (TaAlOx) films with high band gap and good thermal stability, low leakage current and good voltage linearity make it one of the most promising candidates for metal-insulator-metal capacitor applications.
Original language | English |
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Pages (from-to) | 423-429 |
Number of pages | 7 |
Journal | Thin Solid Films |
Volume | 519 |
Issue number | 1 |
DOIs | |
State | Published - 29 Oct 2010 |
Keywords
- Capacitance I
- High-κ dielectrics
- Metal-insulator-metal structure
- Radio-frequency co-sputtering
- Tantalum aluminum oxide
- X-ray photoelectron spectroscopy