A high-power pulsed-magnetron discharge (several kW/cm2) is described. It operates at pulse duration of the order of few μs, significantly shorter than in usual similar devices. The breakdown delay was reduced by using a low-current DC preionization. The study was performed for Cu target in Ar and He buffer gases by optical emission spectroscopy and electrical measurements. Saturation magnetron current is reached in a few μs which permits to shorten the pulse duration avoiding arc formation. Unusual high current density up to 10 A/cm2 induces very fast transition toward the stable self-sputtering regime. High plasma density favours high ion flux to the substrate. Preliminary result on Cu deposit in trenches is reported.