No abstract

MOCVD TiSiN was evaluated as a barrier for Cu interconnects application. The TiSiN f i l m was formed by Si% soaking of MOCVD TiN. The TiSiN film showed improved wetting and adhesion to Cu as well as less stress hysteresis in its integration with Cu. The low stress hysteresis yields higher resistance to Cu void generation during hot storage testing. Electrical tests on DLM Cu test structures demonstrated comparable line and via chain resistance and equivalent line-to-line leakage current in BTS testing compared to conventional PVD Ta(N).

Titanium zirconium nitride ͓͑Ti,Zr͒N͔ films were prepared on Si substrates by dc reactive magnetron sputtering from a Ti-5 atom % Zr alloy target in N 2 /Ar gas mixtures. Material characteristics of the ͑Ti,Zr͒N films were investigated by X-ray photoelectron spectroscopy, four-point probe, X-ray diffraction, atomic force microscopy, and cross-sectional transmission electron microscopy. According to those results, the deposition rate, chemical composition, crystalline structure, and film resistivity of the deposited films correlate with the N 2 /Ar flow ratio. The microstructure of the ͑Ti,Zr͒N films was an assembly of very small columnar crystallites with a rock-salt ͑NaCl͒ structure and an enlarged lattice constant ͑over pure TiN͒. A minimum film resistivity of 59.3 ⍀ cm was obtained at an N 2 /Ar flow ratio of 2.75, corresponding to near stoichiometric film composition ͓N/(Ti,Zr) ϭ 0.96͔ and crystalline structure.

No abstract

The need for new low-k materials for interconnect dielectrics to meet the requirements stated in the International Technology Roadmap for Semiconductors ( I ) offers many new challenges to the etch and cleans processes. One significant challenge is the absorbance of process chemicals in open porous low-k films and incomplete removal of these contaminants. Porous low-k voiding is an integration issue recently addressed at International Sematech. This work proposes a mechanism of porous low-k voiding and an analytical technique to detect contamination in porous low-k films at sub 1% levels. Additionally, possible solutions to prevent low-k voiding are presented.