Embodiments of the present invention generally relate to an apparatus and method for uniform sputter depositing of materials into the bottom and sidewalls of high aspect ratio features on a substrate. In one embodiment, a sputter deposition system includes a collimator that has apertures having aspect ratios that decrease from a central region of the collimator to a peripheral region of the collimator. In one embodiment, the collimator is coupled to a grounded shield via a bracket member that includes a combination of internally and externally threaded fasteners. In another embodiment, the collimator is integrally attached to a grounded shield. In one embodiment, a method of sputter depositing material includes pulsing the bias on the substrate support between high and low values.