Optimizing HiPIMS pressure for deposition of high-k (k=18.3) amorphous HfO2

•Deposition of High dielectric constant (k=18.3) HfO2 films by HiPIMS.•Modification of optical and electrical properties of film by HiPIMS pressure.•Coincidence of the compressive stress maximum with turning points in electrical and optical properties of the film. Stoichiometric amorphous HfO2 films have been deposited by reactive High Power Impulse Magnetron Sputtering (HiPIMS) from a Hf target in a 1:1 Ar:O2 atmosphere at pressures 2–4.5mTorr. An optimum pressure was found for depositing smooth, high refractive index and amorphous films. Stress and refractive index reached a maximum as deposition pressure was increased to 3.5mTorr. At 3.5mTorr, HfO2 films were deposited with a refractive index of 2.15 at 500nm, low leakage currents, moderate fixed charge density and a high dielectric constant of ∼18.3. The intensification of energetic ion bombardment upon the film with increase in HiPIMS pressure plays a dominant role in film properties. Increase in pressure above the optimum relieved the stress in the films and degraded the optical and electrical properties. HiPIMS pressure enables to gain indirect control of ion flux and energy in the plasma and can be used to modify the properties of depositing films.