Method of depositing a metallization structure, comprising: providing a substrate, depositing a TaN layer by providing a target formed at least in part from tantalum to be sputtered onto the substrate, supplying a sputtering gas comprising nitrogen and inert gas, applying a power supply between an anode and a cathode in a plurality of pulses, the cathode including the target, wherein the pulses are applied with a frequency in the range 10 Hz to 1000 Hz and with a duty cycle of between 0.01% and 20% and produce a current density of between 0.1 A/cm2 and 10 A/cm2 on the target, applying a magnetic field adjacent to a surface of the target, during each pulse of the power supply, reactively sputtering tantalum from the target onto the substrate to form a TaN seed layer, depositing a Ta layer onto the TaN seed layer by providing a magnetic field adjacent to the surface of the target, supplying an inert sputtering gas, applying the power supply between an anode and a cathode in a plurality of pulses, the cathode including the target, wherein the pulses are applied with a frequency in the range 10 Hz to 1000 Hz and with a duty cycle of between 0.01% and 20% and produce a current density of between 0.1 A/cm2 and 10 A/cm2 on the target, applying a magnetic field adjacent to a surface of the target, applying a high-frequency signal to a pedestal supporting the substrate to generate a self-bias field adjacent to the substrate, and during each pulse of the power supply, depositing tantalum from the target onto the TaN layer to form a tantalum layer, wherein the high-frequency signal is not applied to the pedestal during deposition of the TaN seed layer. providing a substrate, depositing a TaN layer by providing a target formed at least in part from tantalum to be sputtered onto the substrate, supplying a sputtering gas comprising nitrogen and inert gas, applying a power supply between an anode and a cathode in a plurality of pulses, the cathode including the target, wherein the pulses are applied with a frequency in the range 10 Hz to 1000 Hz and with a duty cycle of between 0.01% and 20% and produce a current density of between 0.1 A/cm2 and 10 A/cm2 on the target, applying a magnetic field adjacent to a surface of the target, during each pulse of the power supply, reactively sputtering tantalum from the target onto the substrate to form a TaN seed layer, depositing a Ta layer onto the TaN seed layer by providing a magnetic field adjacent to the surface of the target, supplying an inert sputtering gas, applying the power supply between an anode and a cathode in a plurality of pulses, the cathode including the target, wherein the pulses are applied with a frequency in the range 10 Hz to 1000 Hz and with a duty cycle of between 0.01% and 20% and produce a current density of between 0.1 A/cm2 and 10 A/cm2 on the target, applying a magnetic field adjacent to a surface of the target, applying a high-frequency signal to a pedestal supporting the substrate to generate a self-bias field adjacent to the substrate, and during each pulse of the power supply, depositing tantalum from the target onto the TaN layer to form a tantalum layer, wherein the high-frequency signal is not applied to the pedestal during deposition of the TaN seed layer.