M. Elfwing

Bio: M. Elfwing is an academic researcher. The author has contributed to research in topics: Thin film & Sputter deposition. The author has an hindex of 1, co-authored 1 publications receiving 83 citations.

Synthesis of α-Al2O3 thin films using reactive high-power impulse magnetron sputtering

Abstract: α-alumina coatings have been deposited directly onto cemented-carbide and Mo substrates at a temperature as low as 650 °C using reactive high-power impulse magnetron sputtering (HiPIMS) of Al in an ...

High power pulsed magnetron sputtering: A review on scientific and engineering state of the art

Abstract: High power pulsed magnetron sputtering (HPPMS) is an emerging technology that has gained substantial interest among academics and industrials alike. HPPMS, also known as HIPIMS (high power impulse ...

An introduction to thin film processing using high-power impulse magnetron sputtering

Abstract: High-power impulse magnetron sputtering (HiPIMS) is a promising sputtering-based ionized physical vapor deposition technique and is already making its way to industrial applications. The major difference between HiPIMS and conventional magnetron sputtering processes is the mode of operation. In HiPIMS the power is applied to the magnetron (target) in unipolar pulses at a low duty factor (<10%) and low frequency (<10 kHz) leading to peak target power densities of the order of several kilowatts per square centimeter while keeping the average target power density low enough to avoid magnetron overheating and target melting. These conditions result in the generation of a highly dense plasma discharge, where a large fraction of the sputtered material is ionized and thereby providing new and added means for the synthesis of tailor-made thin films. In this review, the features distinguishing HiPIMS from other deposition methods will be addressed in detail along with how they influence the deposition conditions, such as the plasma parameters and the sputtered material, as well as the resulting thin film properties, such as microstructure, phase formation, and chemical composition. General trends will be established in conjunction to industrially relevant material systems to present this emerging technology to the interested reader.

Short- and long-term plasma phenomena in a HiPIMS discharge

Abstract: Using a time-resolved Langmuir probe the temporal evolution of the bulk plasma parameters in a high-power impulse magnetron sputtering (HiPIMS) discharge was investigated for a number of different discharge conditions. The magnetron was operated in argon between 0.5 and 1.6 Pa with a titanium target and with peak target power densities up to 1000 W cm−2. The pulse width and repetition rate were held constant at 100 µs and 100 Hz, respectively. Using an OML analysis as well as a Druyvesteyn formulation, the electron densities, effective temperatures and energy distribution functions were obtained throughout the pulse period (0–9 ms), including a detailed study of the first 10 µs, which was achieved with a temporal resolution better than 0.5 µs. In the initial phase of the voltage pulse (t ~ 1–4 µs), three distinct groups of electrons (indistinguishable from Maxwellian electrons) were observed, namely 'super-thermal', 'hot' and 'cold' populations with effective temperatures of 70–100 eV, 5–7 eV and 0.8–1 eV, respectively. After 4 µs these groups become energetically indistinguishable from each other to form a single distribution with an electron temperature that decays from about 5 to 3 eV during the rest of the pulse on-time. The presence of the 'super-thermal' electron group pushes the probe floating potential to a very negative value (significantly deeper than −95 V) during the initial period of the pulse. In the off-time, the electron density decays with two-fold characteristic times, revealing initially short-term (30–40 µs) and ultimately long-term (3–4 ms) decay rates. These long decay times lead to a relative high density remnant plasma (2 × 109 cm−3) at the end of the off-time, which serves to seed the next voltage pulse. The electron temperature and plasma potential also exhibit two-fold decay in the off-time, but with typically somewhat faster decays, particularly for the long-term decay (100–500 µs) up to the end of the off-time. The time evolution of the plasma potential shows that for a considerable fraction of the on-time the plasma potential remains negative (down to −12 V) only becoming positive after t ~ 60 µs which corresponds to a time of maximum plasma density (typical values of 2 × 1012 cm−3). The generation of super-thermal electrons in the initial phase of the discharge is argued through the development of a simple magnetized-electron bounce model of the expanding sheath.

Transition between the discharge regimes of high power impulse magnetron sputtering and conventional direct current magnetron sputtering

Abstract: Current and voltage have been measured in a pulsed high power impulse magnetron sputtering (HiPIMS) system for discharge pulses longer than 100 mu s. Two different current regimes could clearly be ...

Microstructure control of CrNx films during high power impulse magnetron sputtering

Abstract: The microstructure and composition of CrNx (0 andlt;= x andlt;= 1) films grown by reactive high power pulsed magnetron sputtering (HIPIMS or HPPMS) have been studied as a function of the process pa ...