| The energy flux at the substrate during physical vapour deposition has been shown to influence the microstructure of the growing thin films. For many applications in microelectronics and nanotechnology, even slight changes in the amount of the deposited energy can affect the nanostructure and the suitability of the film. To meet the challenges of fabricating films with the desired properties, a more complete knowledge of the energy flux towards the substrate is required.Models have been developed for the deposition rate of sputtered flux, and the energy deposited onto an un-biased substrate. The models compare well with the experimentally determined values for aluminum (Al) and copper (Cu). The energy per deposited atom is determined, and it trends towards being independent of power and pressure, especially at high magnetron powers. At low powers, the energy per deposited atom increases with pressure due to lower deposition rates. The energy per atom also increases with spatial distance. However, for those regions not too far from the target, the energy per atom is independent of the spatial distance. For the magnetron system used, plasma effects are shown to be important in determining the total energy flux to the substrate. Contributions of the electrons and thermal radiation from the target region are included in the model.Numerical simulation of gas heating is also carried out. Thermal conduction of heat from the heating sources has been identified as the major issue with gas heating. The type of sputtering gas, target material, substrate plane location and pressure determines the extent of gas heating. Sputtered particles have been shown to be the main source of energy for heating the gas. Contributions from electrons, ions and reflected neutrals are only significant at high pressures.In this thesis, both the experimental and theoretical determination of the energy flux in a direct current (dc) magnetron sputtering system is explored. Experimental energy flux was determined by measuring the transient response of a micro-machined polysilicon sensor. The steady state energy flux at the substrate was measured to vary from 9.6 to 46 mW/cm2, and 14 to 114 mW/cm2 at a substrate-target distance of 10.8 cm depending on the magnetron power (75--300 W) and gas pressure for aluminum (Al) and copper (Cu) respectively. The energy deposition efficiency depends on pressure, distance and the type of material. |
