Kinetics of Deposition of Cu Thin Films in Supercritical Carbon Dioxide Solutions from a F-Free Copper(II) ␤-Diketone Complex

Kinetics of deposition of Cu thin films in supercritical carbon dioxide solutions from copper bis͑di-isobutyrylmethanate͒ ͕Cu͓͑CH 3 ͒ 2 CH͑CO͒CH͑CO͒CH͑CH 3 ͒ 2 ͔ 2 ͖, Cu͑dibm͒ 2 ͒, a F-free copper͑II͒ complex, via hydrogen reduction were studied. A flow-type reaction system was employed to control each deposition parameter independently and at a constant value. Apparent activation energies for Cu growth were determined for a temperature range of 200-260°C as a function of hydrogen concentration. The determined values varied from 0.35 to 0.63 eV and decreased as hydrogen concentration increased. At a deposition temperature of 200°C, growth rate followed a Langmuir-type dependence against Cu͑dibm͒ 2 and hydrogen concentrations, showing first-order dependence at lower concentrations and zero-order dependence at higher concentrations. At a higher deposition temperature of 240°C, no saturation in the growth rate was observed. A Langmuir-Hinshelwood-type growth mechanism was discussed, and a rate equation for growth was proposed, taking into account the temperature dependence of both the rate constant of the rate-determining reaction and adsorption equilibrium constants. The hydrogen concentration dependence of the apparent activation energy for Cu growth was discussed with this rate equation

Kinetic analysis of gan-movpe via thickness profiles in the gas flow direction with systematically varied growth conditions

We carried out a kinetic analysis of metallorganic vapor phase epitaxy (MOVPE) of GaN to investigate the dependence of the growth rate on the process conditions as a function of residence time of the precursors in the reactor. The wafer was not rotated during growth, allowing us to analyze the thickness profile of the film in the direction of gas flow, and hence the dependence of the growth rate on the residence time. The growth rate is determined mainly by the concentration of the growth species and mass transfer of the growth species to the wafer surface. The growth rate peaked in the flow direction, and the position of this peak could, in most cases, be explained by considering a combination of the linear gas velocity and the time constant for vertical diffusion of trimethylgallium (TMGa) and/or growth species across the NH3 feed stream to the wafer surface. In some cases this was not possible, indicating that more complex effects were significant. This work is expected to contribute to understanDing of the reaction pathways for GaN-MOVPE, and the growth rate data reported here are expected to provide useful benchmarks for growth simulations that combine computational fluid dynamics and reaction models

Material design of plasma-enhanced chemical vapour deposition SiCH films for low-k cap layers in the further scaling of ultra-large-scale integrated devices-Cu interconnects

Cap layers for Cu interconnects in ultra-large-scale integrated devices (ULSIs), with a low dielectric constant (k-value) and strong barrier properties against Cu and moisture diffusion, are required for the future further scaling of ULSIs. There is a trade-off, however, between reducing the k-value and maintaining strong barrier properties. Using quantum mechanical simulations and other theoretical computations, we have designed ideal dielectrics: SiCH films with Si–C2H4–Si networks. Such films were estimated to have low porosity and low k; thus they are the key to realizing a cap layer with a low k and strong barrier properties against diffusion. For fabricating these ideal SiCH films, we designed four novel precursors: isobutyl trimethylsilane, diisobutyl dimethylsilane, 1, 1-divinylsilacyclopentane and 5-silaspiro [4,4] noname, based on quantum chemical calculations, because such fabrication is difficult by controlling only the process conditions in plasma-enhanced chemical vapor deposition (PECVD) using conventional precursors. We demonstrated that SiCH films prepared using these newly designed precursors had large amounts of Si–C2H4–Si networks and strong barrier properties. The pore structure of these films was then analyzed by positron annihilation spectroscopy, revealing that these SiCH films actually had low porosity, as we designed. These results validate our material and precursor design concepts for developing a PECVD process capable of fabricating a low-k cap layer