The invention includes masking methods. In one implementation, a masking material comprising boron doped amorphous carbon is formed over a feature formed on a semiconductor substrate. The masking material comprises at least about 0.5 atomic percent boron. The masking material is substantially anisotropically etched effective to form an anisotropically etched sidewall spacer comprising the boron doped amorphous carbon on a sidewall of the feature. The substrate is then processed proximate the spacer while using the boron doped amorphous carbon comprising spacer as a mask. After processing the substrate proximate the spacer, the boron doped amorphous carbon comprising spacer is etched from the substrate. Other implementations and aspects are contemplated.