In accordance with an embodiment of the present invention, a method and semiconductor device is described, including forming a plurality of gaps of variable size between device features, each of the gaps including vertical sidewalls perpendicular to a substrate surface and a horizontal surface parallel to the substrate surface. Spacer material is directionally deposited concurrently on the horizontal surface in each gap and in a flat area using a total flow rate of gaseous precursors that minimizes gap-loading in a smallest gap compared to the flat area such that the spacer material is deposited on the substrate surface in each gap and in the flat area to a uniform thickness.