Ultrathin layers are deposited by chemical vapor deposition (CVD) with reduced discontinuities, such as pinholes. Embodiments include depositing a material on a wafer by CVD while rotating the CVD showerhead and/or the wafer mounting surface, e.g., at least 45°. Embodiments include rotating the showerhead and/or mounting surface continuously through the deposition of the material. Embodiments also include forming subfilms of the material and rotating the showerhead and/or mounting surface after the deposition of each subfilm. The rotation of the showerhead and/or mounting surface averages out the non-uniformities introduced by the CVD showerhead, thereby eliminating discontinuities and improving within wafer and wafer-to-wafer uniformity.