Growth of nanostructured tungsten using pulsed direct current and bipolar high power impulse magnetron sputtering systems
Year: 2025
Type: article
Abstract: Nanostructured tungsten (W) has been studied for the first time in pulsed direct current (DC) and bipolar-high power impulse-magnetron sputtering (HiPIMS) systems operating in helium (He). In pulsed DC magnetron sputtering (DCMS), a nano-fiber-form layer was produced over the pulse frequency range (from 100 to 150 kHz), surface temperatures (Ts) of 1075 and 1175 K, and helium ion fluences (ΦHe) of 5.84 × 1024 and 5.29 × 1024 m−2. Time-resolved measurements of ion bombarding energy (EHe) and helium ion flux (ΓHe) were evaluated during both the pulsed-DCMS and bipolar-HiPIMS pulses, with a net width of 833 μs, utilizing the advanced Langmuir Probe Instrument. The experimental results indicated that the fuzz thickness (hfuzz) decreased by approximately 25% at 1075 K and 45% at 1175 K as the system pulse frequency increased from 100 to 150 kHz. The time-averaged growth rate, dhfuzz/dt, of a fuzz layer produced in a bipolar-HiPIMS with a positive cathode pulse voltage range, Vrev, from 90 to 100 V, was found to be 30% lower than that observed in the HiPIMS system at the same temperature range (Ts). In this scenario, the reduced (dhfuzz)/dt in the bipolar-HiPIMS system can be attributed to the fuzzy layer's exposure to highly energetic ionized metal particles and helium ions [of energies above the sputtering threshold of tungsten (W) atoms] during the fuzz formation process.
Source: Journal of Applied Physics
DOI: 10.1063/5.0250673
Authors: Zeyad Ali, Mounib Bahri, James W. Bradley
Institution: University of Liverpool
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,500
Funder: University of Liverpool
OpenAlex ID: W4410096494