Control of polystyrene-block-poly(methyl methacrylate) directed self-assembly by laser-induced millisecond thermal annealing

Abstract. Directed self-assembly of polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) during laser thermal annealing at peak temperatures of 300°C–800°C for dwells of 1–10 ms has been explored. The enhanced mobility of polymer chains at these temperatures improves registration compared with conventional thermal anneals. PS-b-PMMA films (forming 15-nm line/space standing lamellae) were cast on chemically patterned substrates with a copolymer neutral layer and annealed by laser and hot plate. Annealing by hot plate or multiple laser scans resulted in well-aligned features over micron length scales. By laser annealing multiple times, defectivity was reduced by ∼60%. However, laser annealing for only 10 ms before performing a hot plate anneal reduced defectivity by >80%. We believe that this reduction arises from improved interfacial alignment of the film to the template during laser annealing near the order–disorder transition.

[1]  Jumi Lee,et al.  Phase Behavior of Polystyrene-b-poly(methyl methacrylate) Diblock Copolymer , 2009 .

[2]  Roel Gronheid,et al.  Towards an all-track 300 mm process for directed self-assembly , 2011 .

[3]  T. Miyashita,et al.  Junction Profile Engineering with a Novel Multiple Laser Spike Annealing Scheme for 45-nm Node High Performance and Low Leakage CMOS Technology , 2007, 2007 IEEE International Electron Devices Meeting.

[4]  L. Leibler.  Theory of Microphase Separation in Block Copolymers , 1980 .

[5]  Kevin G Yager,et al.  Millisecond Ordering of Block Copolymer Films via Photothermal Gradients. , 2015, ACS nano.

[6]  Caroline A. Ross,et al.  Alignment and reordering of a block copolymer by solvent-enhanced thermal laser direct write , 2014 .

[7]  Marcus Müller,et al.  Defect removal in the course of directed self-assembly is facilitated in the vicinity of the order-disorder transition. , 2014, Physical review letters.

[8]  B. Stühn,et al.  The relation between the microphase separation transition and the glass transition in diblock copolymers , 1992 .

[9]  Marc A. Hillmyer,et al.  Synthesis, Thermodynamics, and Dynamics of Poly(4-tert-butylstyrene-b-methyl methacrylate) , 2012 .

[10]  Easan Sivaniah,et al.  SAXS Analysis of the Order−Disorder Transition and the Interaction Parameter of Polystyrene-block-poly(methyl methacrylate) , 2008 .

[11]  P. Nealey,et al.  Block copolymers and conventional lithography , 2006 .

[12]  E. Helfand,et al.  Fluctuation effects in the theory of microphase separation in block copolymers , 1987 .

[13]  Xavier Andre,et al.  Reversible Morphology Control in Block Copolymer Films via Solvent Vapor Processing: An In Situ GISAXS study. , 2010, Macromolecules.

[14]  P. Clancy,et al.  Experimental determination of thermal profiles during laser spike annealing with quantitative comparison to 3-dimensional simulations , 2012 .

[15]  Thomas P. Russell,et al.  Temperature dependence of the interaction parameter of polystyrene and poly(methyl methacrylate) , 1990 .

[16]  Chi-Chun Liu,et al.  Domain Orientation and Grain Coarsening in Cylinder-Forming Poly(styrene-b-methyl methacrylate) Films , 2011 .

[17]  Marcus Müller,et al.  Rapid Directed Assembly of Block Copolymer Films at Elevated Temperatures , 2008 .

[18]  Jaw-Luen Tang,et al.  Rapid formation of block copolymer thin film based on infrared laser irradiation , 2007, 2007 Conference on Lasers and Electro-Optics - Pacific Rim.

[19]  K. W. Gotrik,et al.  Solvothermal annealing of block copolymer thin films. , 2013, Nano letters.

[20]  Glenn H. Fredrickson,et al.  Fluctuation effects in a symmetric diblock copolymer near the order–disorder transition , 1990 .

[21]  Byungki Jung,et al.  Kinetic rates of thermal transformations and diffusion in polymer systems measured during sub-millisecond laser-induced heating. , 2012, ACS nano.

[22]  Eungnak Han,et al.  Integration of block copolymer directed assembly with 193 immersion lithography , 2010 .

[23]  D. R. Paul,et al.  Interaction energies for blends of poly(methyl methacrylate), polystyrene, and poly(.alpha.-methylstyrene) by the critical molecular weight method , 1993 .

[24]  C. Ober,et al.  Selective area control of self-assembled pattern architecture using a lithographically patternable block copolymer. , 2009, ACS nano.

[25]  Russell,et al.  Ordering of thin diblock copolymer films. , 1992, Physical review letters.

[26]  E. W. Edwards,et al.  Graphoepitaxy of cylinder-forming block copolymers for use as templates to pattern magnetic metal dot arrays , 2005, Nanotechnology.

[27]  C. Ross,et al.  Templated Self‐Assembly of Block Copolymers: Top‐Down Helps Bottom‐Up , 2006 .

[28]  Kevin W Eliceiri,et al.  NIH Image to ImageJ: 25 years of image analysis , 2012, Nature Methods.

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

[30]  Christopher K. Ober,et al.  Understanding of PS-b-PMMA phase segregation under laser-induced millisecond thermal annealing , 2015, Advanced Lithography.

[31]  Christopher K. Ober,et al.  Control of PS-b-PMMA directed self-assembly registration by laser induced millisecond thermal annealing , 2014, Advanced Lithography.

[32]  C. Grant Willson,et al.  Block Copolymer Lithography , 2014 .

[33]  D Antonioli,et al.  Rapid thermal processing of self-assembling block copolymer thin films , 2013, Nanotechnology.