Nano-second temporal particle behavior in high-power impulse magnetron sputtering discharge in a cylindrical cathode

Systematic analysis of discharge processes is needed for a good understanding of the physical mechanism that enables optimal coating deposition, especially pulsed discharges sustained by high voltages and large currents. Owing to the temporal and complex characteristics of the discharge process and relatively simplistic analytical methods, the discharge process and particle evolution in high-power impulse magnetron sputtering (HiPIMS) are still not well understood. In this work, a cylindrical cathode is introduced to restrict the discharge and delay plasma loss, and a global model is established to simulate the discharge on a Cr target in N₂/Ar. Particles with different reaction energies appearing successively produce an asynchronous discharge phenomenon, and a series of inflection points corresponding to different physical processes including excitation, sputtering, ionization, and diffusion are observed from the particle density evolution curves. High-precision and time-resolved spectrometry (400 ns) is utilized to monitor the evolution of particles with time, and inflection points predicted by the model are observed experimentally to verify the particle behavior in the HiPIMS discharge.