A method for forming spacers of specific dimensions on a polysilicon gate electrode protects the sidewalls of the polysilicon gate electrode during selective epitaxial growth. The spacers, whether asymmetric or symmetric, are precisely defined by using the same specific exposure tool, such as a 193 nm wavelength step and scan exposure tool, and the same pattern reticle, in both the defining of the polysilicon gate electrode pattern and the pattern spacer, while employing tight alignment specifications.