Hybrid line–dot nanopatterns from directed self-assembly of diblock copolymers by trenches

Abstract

We demonstrate that the directed self-assembly of AB diblock copolymers by periodic trenches can be used to fabricate large-scale ordered hybrid line–dot nanopatterns in addition to a defect-free dot nanopattern.

Controlled Spacing between Nanopatterned Regions in Block Copolymer Films Obtained by Utilizing Substrate Topography for Local Film Thickness Differentiation

“…Then, the extreme sensitivity of morphology to film thickness leads to different patterns in each area. 42 As one of these morphologies could be lying lamellae, an important consequence is the ability to create patterned domains that are spaced by featureless domains that are defined by the topographic design, as shown in Figure 1.…”

“…The topography of the substrate could be looked upon as providing a differentiating mechanism, which causes the film in certain areas of the substrate (i.e., the trenches) to differ in thickness from other areas of the substrate (i.e., the plateaus). Then, the extreme sensitivity of morphology to film thickness leads to different patterns in each area . As one of these morphologies could be lying lamellae, an important consequence is the ability to create patterned domains that are spaced by featureless domains that are defined by the topographic design, as shown in Figure .…”

“…Considerable recent progress in the directed self-assembly of block copolymers (BCPs) now enables not only fabricating thin films with highly aligned domains − but also obtaining complex morphologies such as various meshes, − layered structures, − nonregular patterns, − and mixed morphologies. − These dense structures are obtained through the application of elegantly designed processes that combine nanofabrication and self-assembly steps. The most important directed self-assembly approaches rely on either chemoepitaxy, , that is, the orientation and registration of copolymer domains that are directed by a chemically patterned, two-dimensional substrate, or graphoepitaxial alignment using a topographically patterned substrate. − ,− Graphoepitaxy has the advantage of being three-dimensional (3D) in nature, which could be used to induce truly three-dimensionally structured BCP films (e.g., meshes). − …”

Dual Block Copolymer Morphologies in Ultrathin Films on Topographic Substrates: The Effect of Film Curvature

“…Directed self-assembly (DSA) of block copolymers (BCPs) is one of the leading approaches in the fabrication of nanopatterned substrates and bears great potential for advances in nanoelectronics and nanophotonics [1][2][3][4]. Since its inception over twenty years ago, DSA has progressed from affording highly aligned domains of stripes or dots [5][6][7][8][9][10][11] to facilitating a variety of complex and irregular morphologies [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. The most common DSA approaches rely on chemoepitaxial and graphoepitaxial growth of BCP domains on lithographically patterned substrates [29].…”

Non-Bulk Morphologies of Extremely Thin Block Copolymer Films Cast on Topographically Defined Substrates Featuring Deep Trenches: The Importance of Lateral Confinement

“…DSA is one of the most promising approaches for high-end applications requiring oriented nano-domains. To this end, research in the field of DSA of BCPs for nanofabrication applications has centered on achieving highly ordered periodic features [ 5 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ] and programmable design control for defect-intolerant applications such as integrated circuits [ 10 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 ]. The prerequisites to these applications are the ability to obtain complex patterns, exacting control over feature size, and reproducibility [ 58 , 59 , 60 , 61 , 62 , 63 , 64 ].…”