Self-assemblable polymer and method for use in lithography

A method for providing an ordered layer of a block copolymer on a substrate, the block copolymer having a glass transition temperature Tg and comprising a first block of first monomer, a second block of second monomer and a bridging moiety comprising a functional group,

• wherein the block copolymer is adapted to undergo a transition from a disordered state to an ordered state at a temperature less than TOD,
• wherein bridging moieties of adjacent first and second block copolymer molecules when in the ordered state are arranged to be mutually bondable by hydrogen bonding due to the functional group at a temperature that is less than or equal to a transition temperature TH and is in excess of Tg, wherein TOD is greater than TH,
• the method comprising:
• providing a layer of the block copolymer on the substrate,
• maintaining the layer at a first temperature T1 above Tg, wherein the first temperature T1 is less than or equal to TOD and greater than TH, so that the block copolymer assembles to provide an ordered layer,
• cooling the ordered layer to a second temperature T2 wherein T2 is less than or equal to TH and greater than Tg and maintaining the ordered layer at temperature T2 so that hydrogen bonding between the bridging moiety of adjacent molecules is effected, and
• cooling the block copolymer to a temperature below its glass transition temperature Tg.

A method for providing an ordered layer of a block copolymer on a substrate, the block copolymer having a glass transition temperature Tg and comprising a first block of first monomer, a second block of second monomer and a bridging moiety comprising a functional group,

• wherein the block copolymer is adapted to undergo a transition from a disordered state to an ordered state at a temperature less than TOD,
• wherein bridging moieties of adjacent first and second block copolymer molecules when in the ordered state are arranged to be mutually bondable by hydrogen bonding due to the functional group at a temperature that is less than or equal to a transition temperature TH and is in excess of Tg, wherein TH is greater than TOD,
• the method comprising:
• providing a layer of the block copolymer on the substrate,
• maintaining the layer at a first temperature T1 above Tg, wherein the first temperature T1 is greater than TOD and less than or equal to TH, so that hydrogen bonding between the bridging moiety of adjacent molecules is effected and the block copolymer pre-assembles through hydrogen bonding of the bridging moiety,
• cooling the ordered layer to a second temperature T2 wherein T2 is less than TOD or TH and greater than Tg and maintaining the ordered layer at temperature T2 so that the block-copolymer self-assembles, and
• cooling the block copolymer to a temperature below its glass transition temperature Tg.