Study of Ta(N,O) diffusion barrier stability: analytical and electrical characterization of low level Cu contamination in Si

Control the Composition of Tantalum Oxynitride Films by Sputtering a Tantalum Target in Ar/O2/N2 Radiofrequency Magnetron Plasmas

“…It is used into electronic device as Copper diffusion barrier but grain boundary through crystalized TaN may originate diffusion and device failure. In this case, amorphous TaO x N y was shown to be a promising solution . On the other hand, tantalum pentoxide (Ta 2 O 5 ) presents a high band gap ( E g = 4.2 eV), a high dielectric constant (around 25), a high refractive index (≈2.3 at 632.8 nm) a high transparency, and a very low optical loss.…”

Fourier transform infrared spectroscopic observation of the surface reactions during electroless copper deposition in formaldehyde based electrolyte

“…Among the different ECD techniques, the bottom-up filling method is of particular interest. This process inevitably requires a Cu seed layer, which is commonly deposited by means of the sputtering technique, because of the difficulty in electroplating Cu directly on barrier metal layers such as TiN, Ta, and TaN [4,5]. However, due to the continuous shrinkage in the size of the interconnection along with its increasingly high aspect ratio features, the step coverage of the sputtered barrier and Cu seed layers is expected to become the limiting factor for the subsequent filling of the vias and lines with electroplated copper.…”

Bonding properties and their relation to residual stress and refractive index of amorphous Ta(N,O) films investigated by x-ray absorption spectroscopy

“…Films of transition-metal ͑TM͒ nitrides are known to be good candidates for these purposes. [4][5][6] Among these nitrides, Ta-based compounds have attracted much interest in recent years because they have high thermal stability and do not react much with Cu. 3,[6][7][8] One of the main difficulties encountered in barrierlayer applications is the diffusion of Cu through grain boundaries, which finally causes device failure.…”

“…Alternatively, films prepared in the amorphous form can also be used as barrier layers. 6 Ta͑N,O͒ films, which are thermally stable and chemically inert toward Cu are promising as barrier material and can be prepared in the amorphous form. 6 Chang et al 9 found that increasing the N 2 flow rate reduces grain sizes and increases the resistivity of TaN films.…”

“…6 Ta͑N,O͒ films, which are thermally stable and chemically inert toward Cu are promising as barrier material and can be prepared in the amorphous form. 6 Chang et al 9 found that increasing the N 2 flow rate reduces grain sizes and increases the resistivity of TaN films. In earlier investigations, 10,11 Jong et al prepared Ta͑N,O͒ films in the amorphous form and examined their optical properties, residual stress, and microstructure.…”