A method of fabricating a substrate includes forming spaced first features and spaced second features over a substrate. The first and second features alternate with one another and are spaced relative one another. Width of the spaced second features is laterally trimmed to a greater degree than any lateral trimming of width of the spaced first features while laterally trimming width of the spaced second features. After laterally trimming of the second features, spacers are formed on sidewalls of the spaced first features and on sidewalls of the spaced second features. The spacers are of some different composition from that of the spaced first features and from that of the spaced second features. After forming the spacers, the spaced first features and the spaced second features are removed from the substrate. The substrate is processed through a mask pattern comprising the spacers. Other embodiments are disclosed.