TaN was sputter-deposited with radio frequency (rf) bias in Xe gas for a barrier film of Cu interconnects of advanced large-scale integration (LSI). Xe gas has been reported to reduce damage on substrates due to small ion bombardment. While crystalline TaN was formed by sputtering with rf bias, amorphous TaN was formed by sputtering without rf bias. TaN with rf bias shows superior barrier properties against Cu diffusion to that without rf bias. When Cu/TaN/fluorocarbon was annealed in temperatures higher than 200°C, delamination was found at the interface between the Cu and TaN. The SiCN cap layer over fluorocarbon improved adhesion, which increased the critical temperature to an acceptable range for LSI production. Assuming a simple center-of-mass elastic collision of the isolated particle, values of energy-transfer efficiency from an impinging ion to various kinds of substrate atoms were calculated. These result revealed that Xe ions efficiently transfer energy to TaN to build a crystalline structure without energy transferring to fluorocarbon.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry