Ta-Si-N thin films were fabricated by using reactive magnetron cosputtering at different Si/Ta power ratios and nitrogen (N2) to total gas (Ar + N2) flow ratios (FN2% = FN2/(FAr + FN2) × 100%). Both levels of high-vacuum furnace annealing (FA) and low vacuum rapid thermal annealing (RTA) were performed to investigate the thermal stability of films. The microstructure, morphology and electrical property of the Ta-Si-N thin films were characterized by grazing incidence X-ray diffraction, scanning electron microscope and four-point probe method, respectively. Ta-Si-N thin films at low FN2% could endure temperature up to 900 °C for 1 h under high-vacuum FA at 6.5 × 10-3 Pa while their phase and morphology had changed under RTA at 750-900 °C for 1 min at 2.6 Pa. The resistivity increased with increasing both FN2% and Si/Ta power ratios. However, the variation percentage of resistivity of Ta-Si-N films at high-temperature annealing decreased with increasing Si/Ta power ratio and inversely increased with increasing FN2%. In brief, the thermal stability of Ta-Si-N films increased with increasing level of vacuum and Si/Ta power ratio. Increasing FN2% and Si/Ta power ratio could enhance the thermal stability of films at RTA but also increased the resisitivity of films. Therefore, Ta-Si-N films prepared at 2 FN2% and Si/Ta power ratio of 2/1 can be a good candidate for the application of diffusion barrier with low resistivity, low variation percentage and high stability of microstructure.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Electrical and Electronic Engineering