Studying the effects of chemistry and geometry on DSA hole-shrink process in three dimensions

Acquiring three-dimensional information becomes increasingly important for the development of block copolymer (BCP) directed self-assembly (DSA) lithography, as 2D imaging is no longer sufficient to describe the 3D nature of DSA morphology and probe hidden structures under the surface. In this study, using post-DSA membrane fabrication technique and STEM (scanning transmission electron microscopy) tomography we were able to characterize the 3D structures of BCP in graphoepitaxial DSA hole shrink process. Different DSA structures of singlets formed in templated holes with different surface chemistry and geometry were successfully captured and their 3D shapes were reconstructed from tomography data. The results reveal that strong PS-preferential sidewalls are necessary to create vertical DSA cylinders and that template size outside of process window could result in defective DSA results in three dimensions. Our study as well as the established 3D metrology would greatly help to develop a fundamental understanding of the key DSA factors for optimization of the graphoepitaxial hole shrink process.

[1]  Yi Cao,et al.  Implementation of surface energy modification in graphoepitaxy directed self-assembly for hole multiplication , 2015 .

[2]  H. Wong,et al.  Flexible Control of Block Copolymer Directed Self‐Assembly using Small, Topographical Templates: Potential Lithography Solution for Integrated Circuit Contact Hole Patterning , 2012, Advanced materials.

[3]  Hon-Sum Philip Wong,et al.  Cross-sectional imaging of directed self-assembly block copolymers , 2015, Advanced Lithography.

[4]  Leonidas E. Ocola,et al.  Three Dimensional Assembly in Directed Self-assembly of Block Copolymers , 2016 .

[5]  Marcus Müller,et al.  Monte Carlo Simulations of a Coarse Grain Model for Block Copolymers and Nanocomposites , 2008 .

[6]  G. Fredrickson.  The equilibrium theory of inhomogeneous polymers , 2005 .

[7]  Ralu Divan,et al.  Quantitative Three-Dimensional Characterization of Block Copolymer Directed Self-Assembly on Combined Chemical and Topographical Prepatterned Templates. , 2017, ACS nano.

[8]  Juan J. de Pablo,et al.  Interpolation in the Directed Assembly of Block Copolymers on Nanopatterned Substrates: Simulation and Experiments , 2010 .

[9]  Kris T. Delaney,et al.  The Hole Shrink Problem: Directed Self-Assembly Using Self-Consistent Field Theory , 2013 .

[10]  Bong Hoon Kim,et al.  Directed self-assembly of block copolymers for next generation nanolithography , 2013 .

[11]  Warren Montgomery,et al.  Optical critical dimension metrology for directed self-assembly assisted contact hole shrink , 2016 .

[12]  Shoji Mimotogi,et al.  Optimization of directed self-assembly hole shrink process with simplified model , 2014 .

[13]  Marcus Müller,et al.  Monte carlo simulation of coarse grain polymeric systems. , 2009, Physical review letters.

[14]  Roel Gronheid,et al.  Dual brush process for selective surface modification in graphoepitaxy directed self-assembly , 2017, Advanced Lithography.

[15]  Benjamen M. Rathsack,et al.  Graphoepitaxial assembly of cylinder forming block copolymers in cylindrical holes , 2015 .

[16]  Juan J de Pablo,et al.  Characterizing the Three-Dimensional Structure of Block Copolymers via Sequential Infiltration Synthesis and Scanning Transmission Electron Tomography. , 2015, ACS nano.

[17]  Takayuki Toshima,et al.  Contact hole shrink process using graphoepitaxial directed self-assembly lithography , 2013 .

[18]  Roel Gronheid,et al.  Via patterning in the 7-nm node using immersion lithography and graphoepitaxy directed self-assembly , 2017 .

[19]  Christophe Navarro,et al.  Contact holes patterning by directed self-assembly of block copolymers: process window study , 2015 .

[20]  R. Ruiz,et al.  Density Multiplication and Improved Lithography by Directed Block Copolymer Assembly , 2008, Science.

[21]  R. J. Kline,et al.  Post-directed-self-assembly membrane fabrication for in situ analysis of block copolymer structures , 2016, Nanotechnology.

[22]  Mark Neisser,et al.  Implementation of a chemo-epitaxy flow for directed self-assembly on 300-mm wafer processing equipment , 2012 .

[23]  Michael Schick,et al.  Stable and Unstable Phases of a Linear Multiblock Copolymer Melt , 1994 .