Implementations described herein generally relate to the fabrication of integrated circuits and particularly to the deposition of a boron-doped amorphous silicon layers on a semiconductor substrate. In one implementation, a method of forming a boron-doped amorphous silicon layer on a substrate is provided. The method comprises depositing a predetermined thickness of a sacrificial dielectric layer over a substrate, forming patterned features on the substrate by removing portions of the sacrificial dielectric layer to expose an upper surface of the substrate, depositing conformally a predetermined thickness of a boron-doped amorphous silicon layer on the patterned features and the exposed upper surface of the substrate and selectively removing the boron-doped amorphous silicon layer from an upper surface of the patterned features and the upper surface of the substrate using an anisotropic etching process to provide the patterned features filled within sidewall spacers formed from the boron-doped amorphous silicon layer.