Thermal anneal of block copolymer films with top interface constrained to wet both blocks with equal preference

A method of forming a nanostructured polymer material on a substrate, comprising:

• applying a solid material that is non-preferential to any block over and in contact with a cylindrical-phase block copolymer material within a trench in a material layer on the substrate, the trench having a neutral wetting floor, opposing sidewalls and ends that are preferentially wetting to a minority block of the block copolymer;
• and
• annealing the block copolymer material at a temperature above the glass transition temperature (Tg) of the block copolymer material while in contact with said non-preferential solid material;
• wherein the block copolymer material self-assembles into cylindrical domains of a first block of the block copolymer within a matrix of a second block of the block copolymer, the self-assembled block copolymer material having a thickness, and the cylindrical polymer domains oriented perpendicular to the floor of the trench and extending through the thickness of the self-assembled block copolymer material in a single array for the length of the trench.

A method of etching a substrate, comprising:

• annealing a block copolymer material in a solvent vapor that is non-preferential to any block while heating at a temperature above the glass transition temperature (Tg) of the block copolymer material, the block copolymer material within a trench in a material layer overlying the substrate, the trench having a width, a length, a neutral wetting floor, and opposing sidewalls and ends that are preferentially wetting to a minority block of the block copolymer material;
• wherein the block copolymer material forms a single array of perpendicular-oriented cylinders of the minority block in a matrix of a majority block, the annealed block copolymer material having a thickness, and the perpendicular-oriented cylinders extending through the thickness of the annealed block copolymer to the floor of the trench;
• selectively removing the minority block to form openings within the matrix of the majority block and expose the substrate;
• and
• etching the substrate through the openings.

A method of etching a substrate, comprising:

• annealing a block copolymer material by heating at a temperature above the glass transition temperature (Tg) of the block copolymer material with a solid material that is non-preferential to any block over and in contact with the block copolymer material, the block copolymer material within a trench in a material layer overlying the substrate, the trench having a width, a length, a neutral wetting floor, and opposing sidewalls and ends that are preferentially wetting to a minority block of the block copolymer material;
• wherein the block copolymer material forms a single array of perpendicular-oriented cylinders of the minority block in a matrix of a majority block, the annealed block copolymer material having a thickness, and the perpendicular-oriented cylinders extending through the thickness of the annealed block copolymer material to the floor of the trench;
• selectively removing the minority block to form openings within the matrix of the majority block and expose the substrate;
• and
• etching the substrate through the openings.