| 초록 |
Creating a regular surface pattern on the nanometer scale is important for many technological applications, such as the periodic arrays constructed by optical microlithography that are used as separation media in electrophoresis, and island structures used for high-density magnetic recording devices. Block copolymer patterns can also be used for lithography on length scales below 50 nanometers thanks to not only the scale of microdomains but also convenience to tune the size of microdomains with changing their molecular weights.Two different approaches are present for potential nanoscientific applications, using block copolymers. One is to use block copolymers for creating nano-scale regular patterns. The other is to generate nano-scale inorganic particles with help of phase separated block copolymer microdomains. The former is achieved by a process including a new type of interaction (directional solidification) with block copolymer microdomains to produce a long range order. This new method is based on the use of crystalline organic materials, which are solvents for the block copolymers above their melting temperatures. The directional crystallization of the solvent induces the directional microphase separation of the block copolymer. Combined with a topographically pre-patterned substrate, the process allows further control of the block copolymer patterns. Subsequent removal of selective microdomains by oxygen plasma reactive ion etching generates regularly patterned holes, which may be useful for nanolithographic template.In the second way, a block copolymer is used as a template to create nanoscale oxide particles on its surface. The specially designed block copolymer containing iron molecules converts its iron molecules into iron oxide nanoparticles with thermal treatment under oxygen environment. The phase separated microdomain structure helps control the size of the nanoparticles created on the polymer surface. |
