Embodiments of a process chamber are provided herein. In some embodiments, a process chamber includes a chamber body having an interior volume, a substrate support disposed in the interior volume, a target disposed within the interior volume and opposing the substrate support, a process shield disposed in the interior volume and having an upper portion surrounding the target and a lower portion surrounding the substrate support, the upper portion having an inner diameter that is greater than an outer diameter of the target to define a gap between the process shield and the target, and a gas inlet to provide a gas to the interior volume through the gap or across a front opening of the gap to substantially prevent particles from the interior volume from entering the gap during use.