Dr. XiaoMin Yang Profile

Dr. XiaoMin Yang

Research Manager at Seagate Technology LLC

SPIE Involvement:

Author | Science Fair Judge

Publications (13)

Proceedings Article | 25 March 2019 Presentation

Design of selective brush chemistry and surface functionalization for directed self-assembly of block copolymers (Conference Presentation)

Ji Yeon Kim, Natsuko Ito, XiaoMin Yang, Stephen Sirard, Austin Lane, Gregory Blachut, Yusuke Asano, Christopher Ellison, Nathaniel Lynd, C. Grant Willson

Proceedings Volume 10960, 109600S (2019) https://doi.org/10.1117/12.2514793

KEYWORDS: Directed self assembly, Chromium, Chemistry, Polymers, Photomasks, High volume manufacturing, Manufacturing, Nanoimprint lithography, Lithography, Photoresist processing

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Proceedings Article | 19 March 2018 Presentation

Block copolymers for sub-10nm directed self-assembly lithography (Conference Presentation)

Natsuko Ito, Gregory Blachut, Yusuke Asano, Christopher Ellison, Grant Willson, Stephen Sirard, XiaoMin Yang, Austin Lane

Proceedings Volume 10584, 105840J (2018) https://doi.org/10.1117/12.2297030

KEYWORDS: Directed self assembly, Lithography, Silicon, Polymerization, Silicon films, Reactive ion etching, Thin films, Photomasks, Thin film coatings, Chemistry

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Directed self-assembly (DSA) of block co-polymers (BCPs) is a next-generation lithography technique that shows promise for extending Moore’s Law into the 10 nm regime and below. The minimum size of the features that can be produced by BCPs is controlled by the interaction parameter (chi) and the degree of polymerization (N). We have developed silicon containing BCPs for sub-20 nm line-and-space lithography. These BCPs were synthesized by living anionic polymerization, thermally annealed in thin films between neutral layers to generate the requisite perpendicular orientation [1, 2]. The silicon-containing blocks provide excellent development contrast under both oxidizing and reducing reactive ion etching (RIE) conditions. The developed patterns work well as masks for transfer of the developed patterns into useful substrate materials [3]. Through optimizing the design of the block copolymers and the “hybrid” DSA process [1], we have now obtained 10 nm full pitch gratings. Recently we have studied silicon containing BCPs that incorporate a poly(2-vinylpyridine) block as a path to achieving still higher chi. For example, we have synthesized poly(4-pentamethyldisilylstyrene-block-2-vinylpyridine) (PDSS-b-P2VP) and found that this material has a chi parameter that is significantly higher than that of the BCP used for 10 nm lithography, meaning that even smaller feature sizes should be possible. Neutral top coats and cross-linked surface treatment layers were identified for PDSS-b-P2VP using the island and hole techniques that have been described previously [5]. We have succeeded in demonstrating 8 nm full pitch finger print patterns that are oriented perpendicular to the substrate. These are the smallest patterns we have managed to obtain in our system to date. 1. Blachut, G., et al. Chem. Mater (2016), 28 (24), 8951-8961. 2. Bates C. M., et al. Science (2012), 338 (6108), 775. 3. Azarnouchea, L., et al. J. Vac. Sci. Technol. B (2016) 34 (6), 061602/1-061602/10. 4. Lane A. P., et al. ACS Nano (2017), 11 (8), 7656-7665. 5. Maher, M. J., et al. Chemistry of Materials (2014), 26 (3), 1471-1479.

Proceedings Article | 19 March 2018 Presentation

A progress report on DSA of high-chi silicon containing block co-polymers (Conference Presentation)

C. Grant Willson, Natsuko Ito, Gregory Blachut, Stephen Sirard, Yasunobu Someya, Jan Doise, Ryuta Mizuochi, Austin Lane, Geert Vandenberghe, Paulina Rincon-Delgadillo, XiaoMin Yang, Christopher Ellison

Proceedings Volume 10586, 105860O (2018) https://doi.org/10.1117/12.2299966

KEYWORDS: Silicon, Reactive ion etching, Scanning transmission electron microscopy, Optical lithography, Spectroscopy, Semiconducting wafers, Chromium

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We have developed block co-polymers (BCPs) in which one of the blocks incorporates silicon and the other does not [1]. These materials provide access to BCPs with high Flory-Huggins interaction parameters (χ) and dry etch selectivity under reactive ion etching (RIE) conditions to provide Sub-20 nm patterns [2]. Recently we have investigated a hybrid chemo/grapho-epitaxy process that provides 20 nm and 10 nm full pitch patterning and we have transferred these patterns into useful substrates. This hybrid process produced 20 nm DSA with fewer defects with this material than the conventional chemo-epitaxial process. Cross-sectional scanning transmission electron microscopy (STEM) with electron energy loss spectroscopy (EELS) confirmed that the BCP features span the entire film thickness on hybrid process wafers [3]. We have now succeeded in demonstrating DSA with poly(4-methoxystyrene-block-4-trimethylsilylstyrene) (PMOST-b-PTMSS) aligned by guidelines comprised of cross linked poly(2-vinylpyridine) (Figure a). The process was demonstrated by cross-section analysis to produce features that span the entire BCP film thickness and the introduction of nitrogen into the guide line provides new evidence for the nature of the interaction between the guide lines and the BCP(Figure b). We have also reported the DSA and pattern transfer of poly(5-vinyl-1,3-benzodioxole-block-pentamethyldisilylstyrene) (PVBD-b-PDSS) at 10 nm full pitch. However, in this case, the DSA involved a trade-off between perpendicularity and dislocation defects [4]. Improved brush materials that selectively graft to an etched Cr surface rather than etched imprint resist provide oriented and aligned 5 nm line-and-space patterns that cleanly traverse the full film thickness thickness (Figure c). 1. Bates C. M., et al. Science (2012), 338 (6108), 775. 2. Azarnouchea, L., et al. J. Vac. Sci. Technol. B (2016) 34 (6), 061602/1-061602/10. 3. Blachut, G., et al. Chem. Mater (2016), 28 (24), 8951-8961. 4. Lane A. P., et al. ACS Nano (2017), 11 (8), 7656-i7665.

Proceedings Article | 19 March 2015 Paper

Imprint directed self-assembly of cylinder-forming Si-containing block copolymer for 6nm half-pitch line patterning

Shuaigang Xiao, XiaoMin Yang, Yautzong Hsu, Kim Lee, David Kuo

Proceedings Volume 9423, 94230O (2015) https://doi.org/10.1117/12.2085986

KEYWORDS: Picosecond phenomena, Oxygen, Reactive ion etching, Optical lithography, Nanoimprint lithography, Etching, Plasma, Polymers, Plasma etching, Directed self assembly

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SPIE Journal Paper | 12 August 2014 Open Access

Fabrication of servo-integrated template for 1.5 Teradot/inch² bit patterned media with block copolymer directed assembly

XiaoMin Yang, Shuaigang Xiao, Yautzong Hsu, HongYing Wang, Justin Hwu, Philip Steiner, Koichi Wago, Kim Lee, David Kuo

JM3, Vol. 13, Issue 03, 031307, (August 2014) https://doi.org/10.1117/12.10.1117/1.JMM.13.3.031307

KEYWORDS: Servomechanisms, Beam propagation method, Scanning electron microscopy, Quartz, Magnetism, Nanoimprint lithography, Etching, Optical lithography, Lithography, Directed self assembly

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SPIE Journal Paper | 2 August 2013 Open Access

Directed self-assembly for high-density bit-patterned media fabrication using spherical block copolymers

Shuaigang Xiao, XiaoMin Yang, Kim Lee, Justin Hwu, Koichi Wago, David Kuo

JM3, Vol. 12, Issue 03, 031110, (August 2013) https://doi.org/10.1117/12.10.1117/1.JMM.12.3.031110

KEYWORDS: Spherical lenses, Magnetism, Picosecond phenomena, Servomechanisms, Quartz, Beam propagation method, Lithography, Nanoimprint lithography, Reactive ion etching, Directed self assembly

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Proceedings Article | 11 July 2007 Paper

Heat assisted magnetic recording with a fully integrated recording head

Michael Seigler, William Challener, Edward Gage, Nils Gokemeijer, Bin Lu, Kalman Pelhos, Chubing Peng, Robert Rottmayer, Xiaomin Yang, Hua Zhou, Xiaobin Zhu, Tim Rausch

Proceedings Volume 6620, 66200P (2007) https://doi.org/10.1117/12.738903

KEYWORDS: Magnetism, Head, Near field scanning optical microscopy, Anisotropy, Integrated optics, Near field optics, Waveguides, Cladding, Scanning electron microscopy, Iron

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Proceedings Article | 24 March 2006 Paper

Electron beam lithography for high aspect-ratio trench patterning in thick resist: Experimental and simulation results

Jianyun Zhou, Shuaigang Xiao, Werner Scholz, XiaoMin Yang

Proceedings Volume 6151, 61513E (2006) https://doi.org/10.1117/12.656516

KEYWORDS: Electron beam lithography, Optical simulations, Magnetism, Scattering, Point spread functions, Electron beams, Laser scattering, Head, Photoresist processing, Monte Carlo methods

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Proceedings Article | 20 May 2004 Paper

Shrink assist film for enhanced resolution (SAFIER) process for printing of 20-nm trench with high aspect ratio

XiaoMin Yang, Harold Gentile

Proceedings Volume 5374, (2004) https://doi.org/10.1117/12.535647

KEYWORDS: Photoresist processing, Critical dimension metrology, Line edge roughness, Image processing, Semiconducting wafers, Scanning electron microscopy, Cadmium, Printing, Coating, Electron beams

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Proceedings Article | 14 May 2004 Paper

E-beam proximity effect parameters for sub-100nm features

Keith Mountfield, Andrew Eckert, XiaoMin Yang, Earl Johns

Proceedings Volume 5376, (2004) https://doi.org/10.1117/12.535766

KEYWORDS: Neck, Magnetism, Scattering, Semiconducting wafers, Head, Electrons, Tantalum, Computer aided design, Compact discs, Glasses

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Proceedings Article | 16 June 2003 Paper

Three-dimensional imaging of isolated lines of negative e-beam resist

Andrew Eckert, Harold Gentile, Keith Mountfield, Carl Seiler, XiaoMin Yang, Earl Johns

Proceedings Volume 5037, (2003) https://doi.org/10.1117/12.482323

KEYWORDS: 3D metrology, Critical dimension metrology, Neck, 3D image processing, Stereoscopy, Semiconducting wafers, Metrology, Electron beam lithography, Scanning electron microscopy, Lithography

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We have implemented traditional CD-SEM metrology complimented with the 3D imaging capability of the VERASEM 3D CD-SEM from Applied Materials. 3D imaging is performed by tilting the SEM beam to capture images at two unique angles. Reconstruction of these images allows for the determination of resist thickness and sidewall angle at the same point the critical dimension, CD, is measured. These three output parameters provide the user with automated multi-metric lithographic process control. We have used these techniques to characterize e-beam lithography of isolated lines in ~0.6μm of negative resist at CDs between ~50 and ~100 nm. The flexibility of our e-beam lithography system allows us to expose an array of identical features with 30 distinct dose values over a small area of a wafer. We have characterized the resist CD and thickness as a function of small incremental decreases in dose. As the dose decreases so does the CD of the isolated resist line at a rate of ~1 nm per 1μC/cm² of area exposure. At a nominally high dose where the isolated line CD is ~100 nm the resist is measured by 3D imaging to be close to full thickness. The main observation is that the resist thickness erodes at a rate of ~5 nm in height per every 1nm decrease in CD down to the resolution limit of 50-60 nm. As the dose is further lowered the resist is then completely washed away. This subtle but significant loss in resist etch mask integrity could not have been observed by traditional top-down CD-SEM metrology alone. This also demonstrates the tilt capability of the VERASEM 3D to measure very thin resist films of ~100 nm. Additionally, we have successfully used this methodology to characterize this effect as a function of isolated line length from ~0.5-2.0μm, and resist thickness from ~0.25-0.6 μm. The CD is strongly correlated with the total isolated line length due to the e-beam proximity effect, while the resist erosion rate remains fairly constant. The resist erosion rate is also similar for the resist films regardless of initial thickness. However, we also confirm the trend that identical area doses produce larger CDs for thicker resist films with some subtle effects for the thinner films.

Proceedings Article | 16 June 2003 Paper

Electron-beam lithography method for sub-50-nm isolated trench with high aspect ratio

XiaoMin Yang, Andrew Eckert, Keith Mountfield, Harold Gentile, Carl Seiler, Stanko Brankovic, Robert Harris, Earl Johns

Proceedings Volume 5037, (2003) https://doi.org/10.1117/12.482343

KEYWORDS: Photoresist processing, Scanning electron microscopy, Magnetism, Plating, Real-time computing, Semiconducting wafers, Electron beam lithography, Thin films, Lithography, Atomic force microscopy

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Proceedings Article | 1 July 2002 Paper

Electron-beam lithography of isolated trenches with chemically amplified positive resist

Andrew Eckert, Richard Bojko, Harold Gentile, Robert Harris, Jay Jayashankar, Earl Johns, Kevin Minor, Keith Mountfield, Carl Seiler, XiaoMin Yang

Proceedings Volume 4688, (2002) https://doi.org/10.1117/12.472361

KEYWORDS: Semiconducting wafers, Plating, Critical dimension metrology, Lithography, Electron beam lithography, Scanning electron microscopy, Computer aided design, Thin film coatings, Scattering, Chemically amplified resists

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Showing 5 of 13 publications

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