Monomer and polymer compositions for reversible overcoat wafer patterning

A composition for patterning substrates, the composition comprising:

• a polymer comprising:
• an organic backbone;
• a thermally or photochemically activatable crosslinking structure;
• and
• an acid-cleavable de-crosslinking structure, the polymer being soluble in an organic solvent.

A method of patterning a substrate, the method comprising:

• forming a plurality of first mandrels over a substrate;
• coating an overcoat layer over the plurality of first mandrels, the overcoat layer being coated from a composition comprising:
• a polymer comprising:
• an organic backbone;
• a thermally or photochemically activatable crosslinking structure;
• and
• an acid-cleavable de-crosslinking structure;
• and
• an organic solvent;
• inducing a crosslinking reaction within the overcoat layer that renders the overcoat layer insoluble to a predetermined solvent and forms a crosslinked overcoat layer;
• exposing the substrate to an actinic radiation to generate a plurality of acid particles within the plurality of first mandrels;
• diffusing a portion of the plurality of acid particles from the plurality of first mandrels into portions of the crosslinked overcoat layer;
• inducing a de-crosslinking reaction within the portions of the crosslinked overcoat layer to form de-crosslinked regions, wherein unmodified regions of the crosslinked overcoat layer form a plurality of second mandrels;
• and
• selectively removing the de-crosslinked regions, wherein the plurality of first mandrels and the plurality of second mandrels form a mandrel pattern over the substrate.