Method to produce highly transparent hydrogenated carbon protective coating for transparent substrates

A physical vapor deposition (PVD) chamber for depositing a transparent and clear hydrogenated carbon, e.g., hydrogenated diamond-like carbon, film. A chamber body is configured for maintaining vacuum condition therein, the chamber body having an aperture on its sidewall. A plasma cage having an orifice is attached to the sidewall, such that the orifice overlaps the aperture. Two sputtering targets are situated on cathodes inside the plasma cage and are oriented opposite each other and configured to sustain plasma there-between and confined inside the plasma cage. The plasma inside the cage sputters material from the targets, which then passes through the orifice and aperture and lands on the substrate. The substrate is moved continuously in a pass-by fashion during the process.