Here, a study was made of the diffusion barrier performances of Mo, Mo-N and Mo/Mo-N metallization layers deposited by sputtering Mo in Ar/N2 atmospheres. Samples were subsequently annealed at 400 to 800C under vacuum condition. The film properties and their suitability as diffusion barriers and protective coatings in Si devices were characterized by using 4-point probe measurements, X-ray diffractometry, scanning electron microscopy, Auger electron spectroscopy and transmission electron microscopy. The experimental results revealed that a Mo(20nm)/Mo-N(30nm) layer was able to prevent diffusion reaction between Cu and Si substrates after being annealed at 600C for 0.5h. A Mo layer between Cu and Mo-N diluted the high N concentration of the barrier and enhanced the barrier performances.

Diffusion Barrier Performances of Thin Mo, Mo-N and Mo/Mo-N Films between Cu and Si. S.Song, Y.Liu, D.Mao, H.Ling, M.Li: Thin Solid Films, 2005, 476[1], 142-7