Barrier property of TiSiN films formed by low frequency, high density inductively coupled plasma process

Abstract

A ternary barrier film TiSiN was prepared by low frequency, high density inductively coupled plasma (ICP) implantation of N into TiSi substrate. This leads to the formation of Ti–N and Si–N compounds in the ternary film. Using this technique, 5–20-nm-thick TiSiN films were successfully grown over different deposition conditions including external bias, argon gas flow rate and nitrogen plasma treatment time. Barrier film structure was characterized by X-ray diffraction (XRD). For compositional analysis, X-ray photoelectron spectroscopy was used. The diffusion study was carried out by depth profiling of Cu using time-of-flight secondary ion mass spectrometer (ToF-SIMS) after annealing treatment at various temperatures. Discussion on the relationship between the barrier performance and the film structures is made in an attempt to elucidate the controlling factor for Cu diffusion in such a mixed microstructure. The implication to process conditions is also discussed.