Oxygen-free and low resistivity nickel (Ni) thin films are successfully prepared by plasma-assisted atomic layer deposition using nickelocene (NiCp2) as a metal precursor and ammonia (NH3) as a reactant.

For advanced Cu interconnect technology, Co films have been widely investigated to serve as the liner and seed layer replacement because of a better wettability to Cu than Ta. In this article, the Co films are grown by plasma-enhanced atomic layer deposition using Co(EtCp) 2 as a precursor, and the influences of process parameters on the characteristics of the Co films are elaborately investigated. The results indicate that the process window is 125–225 °C with a growth rate of ~ 0.073 Å/cycle. That is to say, the connection of Et group to Cp ligand can enable a stable film growth at 125 °C, while the corresponding temperature must be higher than 200 °C in terms of Co(Cp) 2 and Co(MeCp) 2 . The deposited films contain N and O elements besides dominant Co and C. Furthermore, the prolongation of the NH 3 pulse time significantly enhances the conductivity of the Co film and a low resistivity of 117 μΩ cm can be achieved with a NH 3 pulse time of 40 s. The root mean square roughness shows a smaller variation with the deposition temperature and maintains a low value of ~ 0.3 nm, indicative of a flat Co film.

No abstract

Ultralow dielectric-constant (k) SiOCH films were prepared from triethoxymethylsilane (MTES) and cinene (LIMO) by plasma-enhanced chemical vapor deposition (PECVD). By changing the mass flow rate ratio (MFRR) of LIMO/MTES, the properties of the low k films were investigated. In particular, the chemical composition and bonding structure of the deposited film were analyzed with the help of Fourier transforms infrared spectroscopy and x-ray photoelectron spectroscopy. It was revealed that the bonding configurations of O-Si-C 3 , O 2 -Si-C 2 , Si-C and C-C/C-H in the low-k film increased with increasing the MFRR of LIMO/MTES. Further, as the MFRR increased from 1.0 to 1.5, the k value decreased gradually to 2.3, and then increased again with a continuing increment of the MFRR. Such changes accorded with the evolvement of porosity within the film. In the case of our interested ultralow k film (k = 2.3) with a maximum porosity of 29.1%, it exhibited a very low leakage current density of 3.35 × 10 −9 A cm −2 at 1 MV cm −1 and 25 °C while maintaining good mechanical properties such as an Young's modulus of 4.26 GPa and a hardness of 0.41 GPa.