Download or read book Patterning Organosilane Self assembled Monolayers Block Copolymer Lithography and Thin Film Behavior and the Photoinduced Formation of Polymer Brushes and Monolayers written by Adam W. Harant and published by . This book was released on 2004 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pattern Formation and Phase Behavior in PS B SI Containing Block Copolymer Thin Film written by I-Fan Hsieh and published by . This book was released on 2013 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the top-down approaches, such as the extremely ultraviolet (EUV) technique and the high-index fluid-based immersion ArF lithography, may be cover one or two generations, these lithography technologies are getting more severe for the feature size scaling down to sub 10 nm. The directed self-assembly technology of block copolymers is one of the candidates for next generation lithography which can afford feature sizes that are dictated by the molecular weight of the block copolymer and are typically 15 to 30 nm. Directed self-assembly of block copolymers has attracted attention as a technology to extend photoresist-based lithography to smaller dimensions. It has been demonstrated that the directed self assembly of block copolymer offers a new route to perfect nanolithographic pattering at sub-50 nm length scale with molecular scale precision. For application in electronic media, it requires large-area, long-range ordered structures, which is both a kinetic and thermodynamic problem and requires subtle balance of various parameters and processing conditions. So far, block copolymer thin films have already achieved certain success, mainly with higher molecular weights and a feature size of ~30 nm. Several challenges still remain, such as (a) the generation of long-range ordered structure with smaller feature sizes (domain size

Download or read book Self assembly of Block Copolymers and Polymer Brushes written by Wei Wei and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Self-assembly of block copolymer materials (BCPs) and polymer brushes in the sub-50 nm length scale are explored in this thesis. BCPs and mixed polymer brushes have the ability to self-assemble into well-ordered structures which are ideal for surface patterning, templating and growth of nanomaterials. Compared to the extensively studied morphologies resulting from BCPs, phase behavior of mixed brushes is experimentally less explored, mainly due to the synthetic and characterization challenges. In this thesis we derive from the studies in the BCP self-assembly in thin films to study the melt phase behavior of mixed brushes on a planar substrate. In the first part of the thesis we study the thin film assembly of a strongly phase-separating cylinder forming poly(styrene-b-2 vinylpyridine) (PS-b-P2VP). The cylinders are used to template arrays of sub-20-nm-wide molybdenum disulfide (MoS2) nanowires. In the second part of the thesis we develop a synthetic route to grow uniform, high-grafting density polymer brushes with controlled brush length on planar substrates. This method starting from an initiator coating overcomes all the previous synthetic challenges. This chemistry is first tested by growing a mixed brush poly(methyl methacrylate)/polystyrene (PMMA/PS). We validate for the first time the predicted morphology for mixed brush in melt using the PS/PMMA. The deviation from the expected phase behavior as we move to strongly segregating PS/P2VP mixed brush system is discussed. Lessons learned from the thin film assembly of the PS-b-P2VP in the first part of the thesis led to the largely unexplored area of chain-end effects on morphology in mixed polymer brushes. Potential solutions towards the self-assembly of PS/P2VP mixed bushes in melt is discussed. Three major contributions are made in this thesis: 1) development of an universal method to synthesize A/B mixed brushes with uniform grafting of A/B chains; 2) development of a model to experimentally evaluate the grafting densities of the two brushes; and 3) discovery of chain end effect on thermal stability of mixed brushes and its influence on the morphology. This thesis paves the way for synthesizing mixed brushes with unprecedented level of control, hence opening up new phase behavior and potential surface patterning methods.

Download or read book Directed Self assembly of Diblock Copolymer Thin Films on Chemically Nanopatterned Substrates written by Erik WiIliam Edwards and published by . This book was released on 2005 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Directory of Graduate Research written by American Chemical Society. Committee on Professional Training and published by . This book was released on 2005 with total page 1932 pages. Available in PDF, EPUB and Kindle. Book excerpt: Faculties, publications and doctoral theses in departments or divisions of chemistry, chemical engineering, biochemistry and pharmaceutical and/or medicinal chemistry at universities in the United States and Canada.

Download or read book Patterning and Characterization Approaches of Polymer Thin Films written by Marvin Young Paik and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymers have been used in thin film coatings as a way to produce tailor made surfaces. These thin films have been explored for use in a variety of applications to produce antifouling coatings, corrosion resistant coatings, biocompatible surfaces, and biomedical devices. Polymer brushes, polymer chains tethered to a substrate or surface, synthesized by surface-initiated polymerization have gained significant attention in recent years. As brushes offer a new pathway towards the preparation of functional surfaces and offer long term stability, even in adverse environments, they are attractive for use as high-tech coatings. Patterned polymer thin films have also seen growing interest for various applications. This dissertation will focus on the top-down direct patterning of polymer brushes and the bottom-up self-assembly of block copolymer thin films. A new approach to creating patterned polymer brushes is highlighted, which is a simpler approach than what is conventionally done. Various polymer brushes were patterned directly using electron beam lithography to create high resolution patterned polymer brushes in a single step. This method was then used to demonstrate the unique ability to create sub-surface patterns within the brush. Additionally, direct patterning was used to create high resolution patterned binary polymer brushes of PMMA and PEGMA. With this binary patterned surface, a surface that responds to its local environment was created. This thesis also details characterization techniques used in probing polymer thin films to better understand how to improve block copolymer self-assembly. By using a powerful technique called grazing incidence small angle X-ray scattering (GISAXS) on solvent vapor annealed block copolymer thin films while monitoring the solvent vapor swollen film thickness and controlling the film swelling with a nitrogen counterflow, the work presented demonstrates how to accurately determine the processing conditions necessary for the annealing process to take place. This process also provides information as to what changes are occurring during the annealing process. Another characterization technique known as near edge X-ray absorption fine structure (NEXAFS) is also highlighted. A more exact calculation of the electron escape depth (EED) for NEXAFS is done using polymer brushes as the calibration sample. With this information, we can do composition depth profiling on our polymer thin films to identify what is at the surface.

Download or read book Materials Design for Block Copolymer Lithography written by and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block copolymers (BCPs) have attracted a great deal of scientific and technological interest due to their ability to spontaneously self-assemble into dense periodic nanostructures with a typical length scale of 5 to 50 nm. The use of self-assembled BCP thin-films as templates to form nanopatterns over large-area is referred to as BCP lithography. Directed self-assembly of BCPs is now viewed as a viable candidate for sub-20 nm lithography by the semiconductor industry. However, there are multiple aspects of assembly and materials design that need to be addressed in order for BCP lithography to be successful. These include substrate modification with polymer brushes or mats, tailoring of the block copolymer chemistry, understanding thin-film assembly and developing epitaxial like methods to control long range alignment. The rational design, synthesis and self-assembly of block copolymers with large interaction parameters (chi) is described in the first part of this dissertation. Two main blocks were chosen for introducing polarity into the BCP system, namely poly(4-hydroxystyrene) and poly(2-vinylpyridine). Each of these blocks are capable of ligating Lewis acids which can increase the etch contrast between the blocks allowing for facile pattern transfer to the underlying substrate. These BCPs were synthesized by living anionic polymerization and showed excellent control over molecular weight and dispersity, providing access to sub 5-nm domain sizes. Polymer brushes consist of a polymer chain with one end tethered to the surface and have wide applicability in tuning surface energy, forming responsive surfaces and increasing biocompatibility. In the second part of the dissertation, we present a universal method to grow dense polymer brushes on a wide range of substrates and combine this chemistry with BCP assembly to fabricate nanopatterned polymer brushes. This is the first demonstration of introducing additional functionality into a BCP directing layer and opens up a wide slew of applications from directed self-assembly to biomaterial engineering.

Download or read book Coarse Grained Modeling of Block Copolymer Lithography The Effects of Pattern Design on the Thermodynamics and Kinetics of the Directed Self Assembly of Block Copolymers written by Grant Parker Garner and published by . This book was released on 2017 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prior to the work presented in Chapter 2, the TICG model has been used in conjunction with a chemical pattern that is approximated as a hard-impenetrable surface. As many experimental systems use polymer brushes to help guide the polymer melt deposited on the substrate, this work analyzes the consequences of such an assumption by comparing a model where the polymer brush is explicitly implemented to the hard-wall substrate used in the past. Then, a methodology which utilizes a evolutionary optimization method is used to map the parameters of the more detailed model to the hard-surface model. This provides a qualitative understanding of how to interpret the model parameters used in previous works in the context of real experimental pattern designs.

Download or read book Directed Self assembly of Block Copolymer Films on Chemically Nanopatterned Surfaces written by Adam M. Welander and published by . This book was released on 2009 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Flow Controlled Solvent Vapor Annealing of Block Copolymers for Lithographic Applications written by Kevin Willy Gotrik and published by . This book was released on 2013 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Self-assembly of block copolymer thin-films may provide an inexpensive alternative to patterning lithographic features below the resolution limits of traditional optical methods. Block copolymers (BCPs) are polymers made of two or more distinct monomer/block units that are covalently bonded. Due to their differences in surface energy, the different blocks tend to phase segregate like oil and water; but because of the covalent linkage, this segregation is practically limited to size scales ranging from only a few nm to ~ 100 nm. A thin film of a BCP can be used in much the same way as a photoresist in the lithographic process, whereas a desired pattern morphology can be obtained by etching one block away and leaving behind a self-assembled hard mask for the underlying substrate. After a thin film of BCP is coated onto a given substrate, the BCP must be given an annealing step, where the disordered entangled polymer networks can be allowed to diffuse and equilibrate into lower free energy configurations which result in periodic patterns of micelles with different morphologies such as spheres, in/out of plane cylinders, etc. This work explored the technique of solvent vapor annealing, where organic solvents were allowed to interact with BCP thin films to facilitate annealing and act as surrogates for the different BCP polymer blocks. This allowed for a wide range of control over the BCP self-assembly (morphology, periodicity, etc.) for a given molecular weight BCP. Additionally, by adding heat at critical times during the self-assembly, time scales for solvent vapor enhanced self-assembly could be reduced from hours to seconds making the prospects for this technology to become industrially applicable more promising.

Download or read book Influence of Architecture on the Behavior of Microphase Separated Block Copolymers written by and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The nanoscale self-assembly of block copolymers at the ~10-100 nm length scale has exciting potential applications in next-generation nanolithography and nanotemplating, wherein the feature sizes are governed by the overall copolymer degree of polymerization, N. However, the thermodynamics of block copolymer microphase separation intrinsically limit the size of the smallest features accessible by this approach. This limitation stems from the fact that AB diblock copolymer self-assembly only occurs above a critical N that depends inversely on the magnitude of the effective interaction parameter cChi, which quantifies the energetic repulsions between the dissimilar monomer segments. In this dissertation, we first provide an overview of current routes to smaller periodicities in self-assembled block copolymers. While numerous reports have focused on developing "high Chi" AB diblocks that self-assemble at smaller values of N, the use of complex macromolecular architectures to stabilize ordered block copolymer nanostructures remains relatively unexplored. We report the melt-phase self-assembly behavior of block copolymer bottlebrushes derived from linking the block junctions of low molecular weight, symmetric poly(styrene-b-lactide) (PS-b-PLA) copolymers. These studies quantitatively demonstrate that increasing the bottlebrush backbone degree of polymerization (Nbackbone) reduces the critical PS-b-PLA copolymer arm degree of polymerization (Narm) required for self-assembly into lamellar mesophases by as much as 75%, thus reducing the nanoscale feature sizes accessible with this monomer chemistry. In studies of asymmetric block copolymer bottlebrushes, we observe a less significant reduction in the Narm required for self-assembly into a hexagonally-packed cylinders morphology. These results are rationalized in terms of how monomer concentration fluctuation effects manifest upon ordering a disordered copolymer into either a lamellar or cylindrical morphology. Finally, the chemistry and physics of two other block copolymer systems are explored: (1) the self-assembly, thin film template fabrication, and post fabrication-template modification of reactive poly(styrene-b-vinyl dimethyl azalactone) block copolymers, and (2) the synthesis and rheological characteristics of amphiphilic poly(vinyl alcohol)-based ABA triblock copolymer hydrogels

Download or read book Block Copolymer Self assembly a Computational Approach Towards Novel Morphologies written by Karim Raafat Gadelrab and published by . This book was released on 2019 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spontaneous self-assembly of materials is a phenomenon exhibited by different molecular systems. Among many, Block copolymers (BCPs) proved to be particularly interesting due to their ability to microphase separate into periodic domains. Nonetheless, the rising need for arbitrary, complex, 3D nanoscale morphology shows that what is commonly achievable is quite limited. Expanding the range of BCPs morphologies could be attained through the implementation of a host of strategies that could be used concurrently. Using directed self-assembly (DSA), a sphere forming BCP was assembled in a randomly displaced post template to study system resilience towards defect creation. Template shear-like distortion seemed to govern local defect generation. Defect clusters with symmetries compatible with that of the BCP showed enhanced stability. Using 44 and 32434 Archimedean tiling templates that are incompatible with BCP six-fold symmetry created low symmetry patterns with an emergent behavior dependent on pattern size and shape. A variation of DSA is studied using modulated substrates. Layer-by-layer deposition of cylinder forming BCPs was investigated. Self-consistent field theory (SCFT) and strong segregation theory SST were employed to provide the understanding and the conditions under which particular orientations of consecutive layers were produced. Furthermore, deep functionalized trenches were employed to create vertically standing high-[chi] BCP structures. Changing annealing conditions for a self-assembled lamellar structure evolved the assembled pattern to a tubular morphology that is non-native to diblock copolymers. A rather fundamental but challenging strategy to go beyond the standard motifs common to BCPs is to synthesize multiblock molecules with an expanded design space. Triblock copolymers produced bilayer perforated lamellar morphology. SCFT analysis showed a large window of stability of such structures in thin films. In addition, a model for bottlebrush BCPs (BBCPs) was constructed to investigate the characteristics of BBCPs self-assembly. Pre-stacked diblock sidechains showed improved microphase separation while providing domain spacing relevant to lithography applications. A rich phase diagram was constructed at different block concentrations. The ability to explore new strategies to discover potential equilibrium morphologies in BCPs is supported by strong numerical modeling and simulations efforts. Accelerating SCFT performance would greatly benefit BCP phase discovery. Preliminary work discussed the first attempt to Neural Network (NN) assisted SCFT. The use of NN was able to cut on the required calculations steps to reach equilibrium morphology, demonstrating accelerated calculation, and escaping trapped states, with no effect on final structure.

Download or read book Directed Self assembly of High 1D7C0 Block Copolymers for Advanced Patterning Applications written by Gabriela Alva and published by . This book was released on 2016 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-{1D7C0} block copolymers (BCP) have gained interest to be used as an alternative to currently used multiple patterning techniques for obtaining sub-lithographic features due to their ability to self-assemble at the nanoscale. However, there is a challenge in controlling the orientation of high-{1D7C0} BCPs at the air interface. This work describes the use of a formulation-based approach wherein different surface active polymers (SAP) were added as additives to control the orientation of poly(styrene-b-methyl carbonate) (PS-b-PMeCAR) lamellae at the air interface. The resulting thin films made from these formulations showed successful formation of perpendicular lamellae on neutral underlayer substrates upon thermal annealing. The higher surface active SAP demonstrated better orientation control with lower loadings and on thicker films. These films were characterized by atomic force microscopy, grazing incidence small angle x-ray spectroscopy, and x-ray photoelectron spectroscopy to confirm the perpendicular orientation of the lamellar domains and the distribution of the SAP in the BCP thin film. The vertically oriented BCP domains were used as an etch mask by selectively removing the more etch labile PMeCAR block by reactive ion etching using oxygen plasma. A technique called sequential infiltration synthesis (SIS), followed by removing the PS block to obtain ~9.5 nm half pitch domains, was also used. Directed self-assembly via graphoepitaxy was also successfully demonstrated. Future work includes investigation of different BCP platforms and morphologies other than lamellae for patterning work.

Download or read book Orthogonal Patterning of Block Copolymer written by Yefei Zhang and published by . This book was released on 2012 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block copolymer self-assembly presents a method for pattern and template application on the 10 to 50 nm length scale. However, the research in this area has been limited to the use of only one block copolymer per layer due to the damage and intermixing when spin coating of a second polymer layer. Here we propose a new method that neatly solves the intermixing problem by using a fluorinate photoresist and solvent system. The microdomain orientation within the block copolymer film can be controlled by solvent vapor annealing. And we also observed an improvement of the long-rang order of the microdomains by depositing the block copolymer into lithographical patterned trenches. This orthogonal patterning method allows for the deposition of multiple block copolymers, with ordered microdomains, adjacent to each other on the same layer. The self-assembled patterns can be transferred to the substrate and propose a potential route for the next-generation lithography.

Download or read book Design Synthesis and Engineering of Advanced Materials for Block Copolymer Lithography written by William John Durand and published by . This book was released on 2015 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block copolymers (BCPs) are an attractive alternative for patterning applications used to produce next-generation microelectronic devices. Advancements require the development of high interaction parameter [chi] BCPs that enable patterning at the sub-10 nm length scale. Several organosilicon BCPs were designed to both enhance [chi] and impart an inherent etch selectivity that facilitates pattern transfer processes. Increasing the BCP silicon content both increases [chi] and bolsters the etch resistance, providing a pathway to designing new high-[chi] materials. Unfortunately, the BCPs investigated are not amenable to thermal annealing because the organosilicon block preferentially segregates to an air/vacuum interface and drives orientation parallel to the surface. A series of spin-coatable, polarity-switching top coats (as well as other strategies) were developed to provide a "neutral" top interface and promote the perpendicular orientation of BCP domains. In addition, a methodology for evaluating the neutral condition, relying on thickness quantization and the corresponding wetting behavior (i.e. island/hole topography) of lamellae. The top coat strategy was demonstrated for several BCP systems, and perpendicular structures can successfully be etched on commercial tools and be transferred into underlying substrates. The interaction parameter [chi] was evaluated using two methods to compare the performance of several BCPs: the order-disorder transition (ODT) of symmetric diblock copolymers, and the absolute scattering profile of a disordered BCP melt. Both methods, while severely limited for quantitative comparison, indicate trends towards higher [chi] with additional appended polar and organosilicon functional groups. Furthermore, the pattern fidelity is shown to be a function of the overall BCP segregation strength. The free energy of confined lamella was modeled algebraically to produce response surface plots capable of identifying process conditions favorable for perpendicular orientation. Thickness independent perpendicular orientation is only favorable using two neutral interfaces. Incommensurate film thicknesses are the most favorable, with commensurability conditions dependent on the wetting behavior at each interface. The modeling was supplemented with an extensive body of thin film experimental work that qualitatively agrees well with the above conclusions.

Download or read book Self assembly of Silicon containing Triblock Copolymer and Terpolymers written by Sangho Lee (S. M.) and published by . This book was released on 2019 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: The block copolymer (BCP) self-assembly has garnered significant interest due to its ability to generate periodic nanostructures with a variety of morphologies. Compared to diblock copolymers that have been extensively studied to form the conventional morphologies such as spheres, cylinders, and lamellae depending on the block volume fraction, more complex polymer architectures are expected to offer additional degrees of freedom and a wider range of structures. Solvent vapor annealing (SVA) using a continuous gas flow system allows a precise control over the annealing condition, which can capture intermediate morphologies including perforated lamellae and gyroids and can create unique nanostructures that have not been observed in diblock copolymers. Combining with self-consistent field theory (SCFT) modeling and in situ grazing-incidence small-angle X-ray scattering (GISAXS) measurement, the phase behavior of advanced polymer architectures can be revealed in details. Here, the self-assembly behavior of silicon-containing triblock copolymer and terpolymers in multi-layered films under SVA is presented. Using both experimental and SCFT approaches, the phase behavior of poly(stryrene-b-dimethylsiloxane-b-styrene) (PS-b-PDMS-b-PS or SDS32) thin films was investigated as a function of the as-cast film thickness and the ratio of two different solvent vapors, toluene and heptane. In comparison with diblock PS-b-PDMS with same molecular weight, the SDS32 offers a simple route to produce a diversity of well-ordered bilayer structures with smaller feature sizes, including the formation of bilayer perforated lamellae over a large process window. In addition, the morphological evolution of core-shell cylinder-forming triblock terpolymers during SVA was monitored in situ using GISAXS. A reversible order-order phase transformation between spheres and cylinders occurred during the annealing process. One of the final morphologies consisted of the regions of in-plane cylinders, with the majority of the film comprising vertical core-shell cylinders passing through perforated lamellae of poly 1,1-dimethyl silacyclobutane (PDMSB).

Download or read book Self assembling Block Copolymers as Photoresists and Photoresist Additives written by Evan Lawrence Schwartz and published by . This book was released on 2008 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: