Multiscale Simulations of the RF Diode Sputtering of Copper

Abstract

The morphology and microstructure of RF diode sputter deposited materials is a complicated function of many parameters of the reactor operating conditions. Using a combination of computational fluid dynamics (CFD), RF plasma, molecular dynamics (MD) sputter, and direct simulation Monte Carlo (DSMC) transport models, a multiscale approach has been used to analyze the RF diode sputtering of copper. The CFD model predicts the velocity and pressure distribution of the working gas flows in the deposition chamber. The plasma model uses these CFD results to compute ion energies and fluxes at the target and substrate. The MD model of sputtering is used to determine the initial energy distribution of sputtered atoms and reflected neutral working gas atoms and both of their angular distributions. A DSMC transport model then deduces the target atom deposition efficiency, the spatial distribution of the film thickness, the target and reflected neutral atoms energy and impact angle distributions given reactor operating input conditions such as background pressure, temperature, gas type, together with the reactor geometry. These results can then be used in atomistic growth models to begin a systematic evaluation of surface morphology, nanoscale structure, and defects dependences upon the reactor design and its operating conditions.

Extendibility Evaluation of Industrial EUV Source Technologies for kW Average Power and 6.x nm Wavelength Operation

“…Higher hydrogen gas pressure is favorable for effective mitigation of Sn sputtering, but the transmission loss is higher. The situation is similar to an ion beam sputtering chamber, and a multi scale numerical simulation is effective to design a better low pressure gas flow for a long time operation without contamination [16].…”

Atomic Assembly of Giant Magnetoresistive Multilayers

“…Due to these collisions, the energy of the metal atoms at the substrate is generally much lower than the energy of the sputtered atoms at the target. Reactor scale simulations indicate that the metal atom energy are in the 0.1-1.0 eV range [19] . In practice, the adatom energy can be reduced by reducing RF power, or by increasing the chamber pressure or target-substrate distance [19] .…”

“…Reactor scale simulations indicate that the metal atom energy are in the 0.1-1.0 eV range [19] . In practice, the adatom energy can be reduced by reducing RF power, or by increasing the chamber pressure or target-substrate distance [19] . Magnetron sputtering results in higher energy metal fluxes because of the lower pressure.…”

“…This sheath's potential can range between 50 and 200 eV. This results in a fraction of the plasma inert gas ions impacting the substrate at normal incidence with energies of 50-200 eV [19] . The energy is again controlled by the plasma power and the background pressure.…”

“…The energy is again controlled by the plasma power and the background pressure. Under some conditions, the relative flux of these ions can be high (an ion to metal flux ratio above 0.5) [19] . Recent experiments have linked these fluxes to strong variations in the magnetoresistance of metal multilayers [20] .…”