Abstract
Diffusion barrier properties of Ta films with and without plasma treatments have been investigated in the study. The nitrogen-incorporated Ta films were prepared by NH3 plasma treatment or reactive sputtering. Barrier properties were evaluated by sheet resistance, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and reverse-biased junction leakage current. An amorphous-like TaNx layer was formed on Ta barrier film after plasma treatments. The thickness of the amorphous TaNx layer is about 3 nm and NH3 plasma-treated Ta films (TaNx/Ta) possess lower resistivity and smaller grain sizes. The Cu/TaNx/Ta(10 nm)/Si remained stable after annealing at 750 °C for 1 h. NH3 plasma-treated Ta films (TaNx/Ta) possess better thermal stability than Ta and TaN films. It is attributed to the formation of a new amorphous layer on the surface of Ta film after the plasma treatments. For thermal stability of Cu/Ta(-N)/n +-p diodes, Cu/Ta/n+-p and Cu/TaN/n+-p junction diodes resulted in large reverse-bias junction leakage current after annealing at 500 and 525 °C, respectively. On the other hand, TaN x/Ta diffusion barriers will improve the integrity of Cu/Ta(-N)/n+-p junction diodes to 650 °C.
Original language | English |
---|---|
Pages (from-to) | 44-52 |
Number of pages | 9 |
Journal | Microelectronic Engineering |
Volume | 81 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jul 2005 |
Keywords
- Diffusion barrier
- Junction diode
- Plasma treatment
- Thermal stability
ASJC Scopus subject areas
- Hardware and Architecture
- Electrical and Electronic Engineering
- Electronic, Optical and Magnetic Materials
- Surfaces, Coatings and Films
- Atomic and Molecular Physics, and Optics