1
|
Kuschlan S, Chiarcos R, Laus M, Pérez-Murano F, Llobet J, Fernandez-Regulez M, Bonafos C, Perego M, Seguini G, De Michielis M, Tallarida G. Periodic Arrays of Dopants in Silicon by Ultralow Energy Implantation of Phosphorus Ions through a Block Copolymer Thin Film. ACS APPLIED MATERIALS & INTERFACES 2023; 15:57928-57940. [PMID: 37314734 PMCID: PMC10739587 DOI: 10.1021/acsami.3c03782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 05/30/2023] [Indexed: 06/15/2023]
Abstract
In this work, block copolymer lithography and ultralow energy ion implantation are combined to obtain nanovolumes with high concentrations of phosphorus atoms periodically disposed over a macroscopic area in a p-type silicon substrate. The high dose of implanted dopants grants a local amorphization of the silicon substrate. In this condition, phosphorus is activated by solid phase epitaxial regrowth (SPER) of the implanted region with a relatively low temperature thermal treatment preventing diffusion of phosphorus atoms and preserving their spatial localization. Surface morphology of the sample (AFM, SEM), crystallinity of the silicon substrate (UV Raman), and position of the phosphorus atoms (STEM- EDX, ToF-SIMS) are monitored during the process. Electrostatic potential (KPFM) and the conductivity (C-AFM) maps of the sample surface upon dopant activation are compatible with simulated I-V characteristics, suggesting the presence of an array of not ideal but working p-n nanojunctions. The proposed approach paves the way for further investigations on the possibility to modulate the dopant distribution within a silicon substrate at the nanoscale by changing the characteristic dimension of the self-assembled BCP film.
Collapse
Affiliation(s)
- Stefano Kuschlan
- CNR-IMM,
Unit of Agrate Brianza, Via C. Olivetti 2, Agrate Brianza I-20864, Italy
- Università
del Piemonte Orientale ‘‘A. Avogadro’’, Viale T. Michel 11, Alessandria I-15121, Italy
| | - Riccardo Chiarcos
- Università
del Piemonte Orientale ‘‘A. Avogadro’’, Viale T. Michel 11, Alessandria I-15121, Italy
| | - Michele Laus
- Università
del Piemonte Orientale ‘‘A. Avogadro’’, Viale T. Michel 11, Alessandria I-15121, Italy
| | | | - Jordi Llobet
- Institute
of Microelectronics of Barcelona (IMB-CNM, CSIC), Bellaterra 08193, Spain
| | | | - Caroline Bonafos
- CEMES-CNRS,
Université de Toulouse, CNRS, Toulouse 31055, France
| | - Michele Perego
- CNR-IMM,
Unit of Agrate Brianza, Via C. Olivetti 2, Agrate Brianza I-20864, Italy
| | - Gabriele Seguini
- CNR-IMM,
Unit of Agrate Brianza, Via C. Olivetti 2, Agrate Brianza I-20864, Italy
| | - Marco De Michielis
- CNR-IMM,
Unit of Agrate Brianza, Via C. Olivetti 2, Agrate Brianza I-20864, Italy
| | - Graziella Tallarida
- CNR-IMM,
Unit of Agrate Brianza, Via C. Olivetti 2, Agrate Brianza I-20864, Italy
| |
Collapse
|
2
|
Murphy JG, Raybin JG, Ansay GE, Sibener SJ. Spatiotemporal Mapping of Hole Nucleation and Growth during Block Copolymer Terracing with High-Speed Atomic Force Microscopy. ACS NANO 2023; 17:5644-5652. [PMID: 36912602 DOI: 10.1021/acsnano.2c11672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
As a platform for investigating two-dimensional phase separation, we track the structural evolution of block copolymer thin films during thermal annealing with environmentally controlled atomic force microscopy (AFM). Upon thermal annealing, block copolymer films with incommensurate thickness separate into a terraced morphology decorated with holes. With in situ imaging at 200 °C, we follow the continuous progression of terrace formation in a single region of a cylinder-forming poly(styrene-block-methyl methacrylate) thin film, beginning with the disordered morphology on an unpatterned silicon substrate and continuing through nucleation and coarsening stages. Topographic AFM imaging with nanoscale resolution simultaneously captures ensemble hole growth statistics while locally tracking polymer diffusion through measurements of the film thickness. At early times, we observe homogeneous hole nucleation and isotropic growth, with kinetics following the predictions of classical nucleation theory. At later times, however, we find anomalous hole growth which arises due to the combination of Ostwald ripening and coalescence mechanisms. In each case, our real-space observations highlight the importance of hole interactions for determining coarsening kinetics, mediated either through the interconnected phase for Ostwald ripening or through binary collision events for coalescence.
Collapse
Affiliation(s)
- Julia G Murphy
- Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - Jonathan G Raybin
- Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - Genevieve E Ansay
- Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - Steven J Sibener
- Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
| |
Collapse
|
3
|
Seguini G, Motta A, Bigatti M, Caligiore FE, Rademaker G, Gharbi A, Tiron R, Tallarida G, Perego M, Cianci E. Al 2O 3 Dot and Antidot Array Synthesis in Hexagonally Packed Poly(styrene- block-methyl methacrylate) Nanometer-Thick Films for Nanostructure Fabrication. ACS APPLIED NANO MATERIALS 2022; 5:9818-9828. [PMID: 35937588 PMCID: PMC9344376 DOI: 10.1021/acsanm.2c02013] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Nanostructured organic templates originating from self-assembled block copolymers (BCPs) can be converted into inorganic nanostructures by sequential infiltration synthesis (SIS). This capability is particularly relevant within the framework of advanced lithographic applications because of the exploitation of the BCP-based nanostructures as hard masks. In this work, Al2O3 dot and antidot arrays were synthesized by sequential infiltration of trimethylaluminum and water precursors into perpendicularly oriented cylinder-forming poly(styrene-block-methyl methacrylate) (PS-b-PMMA) BCP thin films. The mechanism governing the effective incorporation of Al2O3 into the PMMA component of the BCP thin films was investigated evaluating the evolution of the lateral and vertical dimensions of Al2O3 dot and antidot arrays as a function of the SIS cycle number. The not-reactive PS component and the PS/PMMA interface in self-assembled PS-b-PMMA thin films result in additional paths for diffusion and supplementary surfaces for sorption of precursor molecules, respectively. Thus, the mass uptake of Al2O3 into the PMMA block of self-assembled PS-b-PMMA thin films is higher than that in pure PMMA thin films.
Collapse
Affiliation(s)
- Gabriele Seguini
- IMM-CNR,
Unit of Agrate Brianza, Via C. Olivetti 2, Agrate Brianza I-20864, Italy
| | - Alessia Motta
- IMM-CNR,
Unit of Agrate Brianza, Via C. Olivetti 2, Agrate Brianza I-20864, Italy
| | - Marco Bigatti
- IMM-CNR,
Unit of Agrate Brianza, Via C. Olivetti 2, Agrate Brianza I-20864, Italy
| | | | | | - Ahmed Gharbi
- Univ.
Grenoble Alpes, CEA, Leti, Grenoble F-38000, France
| | - Raluca Tiron
- Univ.
Grenoble Alpes, CEA, Leti, Grenoble F-38000, France
| | - Graziella Tallarida
- IMM-CNR,
Unit of Agrate Brianza, Via C. Olivetti 2, Agrate Brianza I-20864, Italy
| | - Michele Perego
- IMM-CNR,
Unit of Agrate Brianza, Via C. Olivetti 2, Agrate Brianza I-20864, Italy
| | - Elena Cianci
- IMM-CNR,
Unit of Agrate Brianza, Via C. Olivetti 2, Agrate Brianza I-20864, Italy
| |
Collapse
|
4
|
Ren Y, Li W. Droplet-like Defect Annihilation Mechanisms in Hexagonal Cylinder-Forming Block Copolymers. ACS Macro Lett 2022; 11:510-516. [PMID: 35575331 DOI: 10.1021/acsmacrolett.1c00670] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The annihilation of typical individual defects in hexagonal cylinder-forming block copolymers is investigated using the self-consistent field theory (SCFT) in conjunction with the string method. Usually, defect removal in two-dimensional hexagonal patterns involves reorganizing the cylindrical domains. Unlike atoms in solid crystals, the self-assembled cylindrical domains of block copolymers are "soft". Thus, the kinetic motions of the cylindrical domains resemble liquid droplets. Dislocations in hexagonal patterns are eliminated via creating and removing cylindrical domains. Our results show that new cylindrical domains are created via either a nucleation-like process or a fission-like process, whereas excessive domains are eliminated via a fusion-like or evaporation-like process. For weakly segregated block copolymers, the nucleation-like and evaporation-like processes are preferred.
Collapse
Affiliation(s)
- Yongzhi Ren
- Key Lab of In-fiber Integrated Optics, Ministry Education of China, Harbin 150001, China
- College of Physics and Optoelectronic Engineering, Harbin Engineering University, Harbin 150001, China
| | - Weihua Li
- State Key Laboratory of Molecular Engineering of Polymers, Key Laboratory of Computational Physical Sciences, Department of Macromolecular Science, Fudan University, Shanghai 200433, China
| |
Collapse
|
5
|
Leniart A, Pula P, Style RW, Majewski PW. Pathway-Dependent Grain Coarsening of Block Copolymer Patterns under Controlled Solvent Evaporation. ACS Macro Lett 2022; 11:121-126. [PMID: 35574792 PMCID: PMC8772373 DOI: 10.1021/acsmacrolett.1c00677] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 12/27/2021] [Indexed: 11/28/2022]
Abstract
Solvent evaporation annealing (SEA) is a straightforward, single-step casting and annealing method of block copolymers (BCP) processing yielding large-grained morphologies in a very short time. Here, we present a quantitative analysis of BCP grain-coarsening in thin films under controlled evaporation of the solvent. Our study is aimed at understanding time and BCP concentration influence on the rate of the lateral growth of BCP grains. By systematically investigating the coarsening kinetics at various BCP concentrations, we observed a steeply decreasing exponential dependence of the kinetics power-law time exponent on polymer concentration. We used this dependence to formulate a mathematical model of BCP ordering under nonstationary conditions and a 2D, time- and concentration-dependent coarsening rate diagram, which can be used as an aid in engineering the BCP processing pathway in SEA and also in other directed self-assembly methods that utilize BCP-solvent interactions such as solvent vapor annealing.
Collapse
Affiliation(s)
| | - Przemyslaw Pula
- Department
of Chemistry, University of Warsaw, Warsaw 02089, Poland
| | - Robert W. Style
- Department
of Materials, Soft and Living Materials, ETH Zürich, Vladimir-Prelog-Weg 10, 8093 Zürich, Switzerland
| | | |
Collapse
|
6
|
Li J, Rincon-Delgadillo PA, Suh HS, Mannaert G, Nealey PF. Understanding Kinetics of Defect Annihilation in Chemoepitaxy-Directed Self-Assembly. ACS APPLIED MATERIALS & INTERFACES 2021; 13:25357-25364. [PMID: 34004117 DOI: 10.1021/acsami.1c03830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Directed self-assembly (DSA) of block copolymers (BCP) has attracted considerable interest from the semiconductor industry because it can achieve semiconductor-relevant structures with a relatively simple process and low cost. However, the self-assembling structures can become kinetically trapped into defective states, which greatly impedes the implementation of DSA in high-volume manufacturing. Understanding the kinetics of defect annihilation is crucial to optimizing the process and eventually eliminating defects in DSA. Such kinetic experiments, however, are not commonly available in academic laboratories. To address this challenge, we perform a kinetic study of chemoepitaxy DSA in a 300 mm wafer fab, where the complete defectivity information at various annealing conditions can be readily captured. Through extensive statistical analysis, we reveal the statistical model of defect annihilation in DSA for the first time. The annihilation kinetics can be well described by a power law model, indicating that all dislocations can be removed by sufficiently long annealing time. We further develop image analysis algorithms to analyze the distribution of dislocation size and configurations and discover that the distribution stays relatively constant over time. The defect distribution is determined by the role of the guiding stripe, which is found to stabilize the defects. Although this study is based on polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA), we anticipate that these findings can be readily applied to other BCP platforms as well.
Collapse
Affiliation(s)
- Jiajing Li
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | | | | | | | - Paul F Nealey
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
- Argonne National Laboratory, Materials Science Division, Lemont, Illinois 60439, United States
| |
Collapse
|
7
|
Leniart A, Pula P, Tsai EHR, Majewski PW. Large-Grained Cylindrical Block Copolymer Morphologies by One-Step Room-Temperature Casting. Macromolecules 2020; 53:11178-11189. [PMID: 33380751 PMCID: PMC7759006 DOI: 10.1021/acs.macromol.0c02026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 11/13/2020] [Indexed: 12/11/2022]
Abstract
We report a facile method of ordering block copolymer (BCP) morphologies in which the conventional two-step casting and annealing steps are replaced by a single-step process where microphase separation and grain coarsening are seamlessly integrated within the casting protocol. This is achieved by slowing down solvent evaporation during casting by introducing a nonvolatile solvent into the BCP casting solution that effectively prolongs the duration of the grain-growth phase. We demonstrate the utility of this solvent evaporation annealing (SEA) method by producing well-ordered large-molecular-weight BCP thin films in a total processing time shorter than 3 min without resorting to any extra laboratory equipment other than a basic casting device, i.e., spin- or blade-coater. By analyzing the morphologies of the quenched samples, we identify a relatively narrow range of polymer concentration in the wet film, just above the order-disorder concentration, to be critical for obtaining large-grained morphologies. This finding is corroborated by the analysis of the grain-growth kinetics of horizontally oriented cylindrical domains where relatively large growth exponents (1/2) are observed, indicative of a more rapid defect-annihilation mechanism in the concentrated BCP solution than in thermally annealed BCP melts. Furthermore, the analysis of temperature-resolved kinetics data allows us to calculate the Arrhenius activation energy of the grain coarsening in this one-step BCP ordering process.
Collapse
Affiliation(s)
| | - Przemyslaw Pula
- Department
of Chemistry, University of Warsaw, Warsaw 02089, Poland
| | - Esther H. R. Tsai
- Center
for Functional Nanomaterials, Brookhaven
National Laboratory, Upton, New York 11973, United States
| | | |
Collapse
|