Substrate mask patterns, methods of forming a structure on a substrate, methods of forming a square lattice pattern from an oblique lattice pattern, and methods of forming a pattern on a substrate

A method of forming a structure on a substrate, comprising:

• forming an opening into a substrate;
• after forming the opening into the substrate, forming a first anisotropically etched sidewall spacer about laterally internal sidewalls of the opening;
• after forming the first anisotropically etched sidewall spacer about laterally internal sidewalls of the opening, removing material into which the opening was formed laterally outside of the opening to leave the first anisotropically etched sidewall spacer as an upwardly-open, cylinder-like structure projecting longitudinally outward relative to an elevationally outer surface of the substrate;
• and
• forming second anisotropically etched sidewall spacers over laterally inner and outer sidewalls of the cylinder-like structure.

A method of forming a pattern on a substrate, comprising:

• forming an array of openings in first material that is elevationally outward of substrate material;
• after forming the openings, widening the openings;
• forming second material elevationally over the first material and to line sidewalls and bases of the widened openings, the second material being of different composition from that of the first material;
• removing the second material back at least to the first material to form an upwardly-open cylinder-like structure comprising the second material within individual of the widened openings;
• removing the first material selectively relative to the cylinder-like structures;
• lining tops, inner sidewalls, and outer sidewalls of the cylinder-like structures with spacer material that longitudinally contacts with itself to form interstitial spaces laterally outward of the cylinder-like structures, the interstitial spaces being individually surrounded by the longitudinally-contacting spacer material that is over outer sidewalls of four of the cylinder-like structures, the interstitial spaces individually comprising bases of spacer material that is elevationally over the substrate material;
• and
• removing the spacer material from the tops of the cylinder-like structures and from the bases of the interstitial spaces to extend the interstitial spaces to the substrate material.