Category Archives: Materials and Equipment

by Chi-I Lang, VP of workflow products and applications, Intermolecular Inc.

June 29, 2011 – The American Vacuum Society’s 2011 Atomic Level Deposition Conference in Cambridge, MA, logged an excellent second day, with the focus shifting towards ALD manufacturability, and a number of sessions that could only be described as "cool."

For semiconductor veterans, the ALD Conference is reminiscent of SEMICON West shows in the 1970s and 1980s: lots of ambitious competitors pursing a new and expanding market — with actual hardware on display — and a sense that everyone at the show was witnessing the real-time development of new production technologies. It’s an exciting feeling, and suggests that ALD has a very bright future ahead in a wide range of applications, with its outstanding film quality, wide range of precursors, and excellent step coverage (one presenter showed coatings on carbon nanotubes with an amazing 2000:1 aspect ratio).

Atomic Level Deposition Conference 2011
Day 1: Interface engineering, rabbit ears and Roy Gordon
Day 2: Manufacturability takes center stage
Day 3: Precursor needs, spatial ALD, and butterfly wings

A number of presenters discussed alternative approaches to ALD processing, breaking away from the traditional wafer-in-chamber model in search of higher throughput, the ability to deposit on a wider range of substrates, and more process flexibility.

Dutch equipment developer Levitech NV, one of the few suppliers able to show video of its equipment up and running, impressed the audience with their stated throughput of 3600 wafers/hour performing aluminum oxide passivation layer deposition on a solar cell production line. The spatial ALD system utilizes a continuous flow approach with no pulsing. A belt carries six-inch substrates past precursor dispensing stations; the belt’s speed is the controlling factor for deposition, in a process somewhat analogous to how an ion implanter achieves dose control.

Eastman Kodak’s David Levy provided another intriguing take, presenting a unique open-air spatial ALD approach to ALD on plastic. More than one attendee had to ask why Kodak is interested in ALD — the company is making a serious push in flexible substrates, and believes that it can use ALD as a patterning step in production of zinc oxide thin film transistors on plastic. The roll-to-roll process offers extremely high throughput and low cost. One challenge is the need to maintain very tight spacing (on the order of 100

June 28, 2011 – BUSINESS WIRE — NEXX Systems, advanced packaging equipment maker, completed a joint evaluation program with a principal Korean integrated device manufacturer (IDM), installing 2 300mm Stratus electrochemical deposition (ECD) systems. The IDM will use its Stratus ECD tools for wafer-level packaging (WLP) metallization processes for cutting-edge mobile products.

The manufacturer needed packaging tools that could handle high-volume manufacturing for advanced mobile devices, noted Rezwan Lateef, VP of business development and customer operations, NEXX Systems.

NEXX Systems opened a Korea subsidiary in collaboration with its sales and service agency in the region, Global Zeus. Bioh Kim is NEXX Systems’ Korea director and GM.

The Stratus production plating tool has 20 wafer plating positions. Its vertical processing technology and single, linear cell configuration enable dual-sided production plating on wafers from 50 to 200

by Chi-I Lang, VP of workflow products and applications, Intermolecular Inc.

June 28, 2011 – Greetings from the American Vacuum Society’s Atomic Level Deposition Conference in Cambridge, MA, where over 400 international attendees have gathered for an in-depth look at ALD and its emergence as an enabling technology not just in microelectronics, but also in nanostructures, energy, lighting, and other applications.

One interesting overall theme so far has been the attention paid to interface engineering. Several presenters have noted that achieving control of the interface between the substrate and the ALD layer is, arguably, more important than the ALD process itself in terms of obtaining the desired characteristics in the finished device. As a result, there has been significant discussion of supporting processes like cleaning and surface treatment.

Atomic Level Deposition Conference 2011
Day 1: Interface engineering, rabbit ears and Roy Gordon
Day 2: Manufacturability takes center stage
Day 3: Precursor needs, spatial ALD, and butterfly wings

A Sunday workshop session offered four long-form presentations, including one from A.C. Kummel of the University of California/San Diego on the novel use of in-situ scanning-tunneling electron microscopy for monitoring of ALD gate oxide deposition. He showed very good results, with evidence of the importance of interface engineering for III-V oxide processes. Even on simple precursor and water processes, interface quality has a big effect on electrical performance.

Also notable was a workshop session by Harvard’s Roy Gordon, who offered an excellent high-level survey of ALD chemistry, including precursor materials. He noted that there is a huge range of potential precursors and oxidizers beyond the commonly available choices, and a variety of processing parameters to play with, all of which play into film quality and electrical performance. Gordon is a star at the conference — many of his former students, including conference chair Jill Becker of Cambridge NanoTech, are in attendance — and Gordon was awarded the first ALD Innovation Award in recognition of his groundbreaking work and wide influence on the field.

Monday’s keynote was given by MIT professor Robert Langer, a brilliant biotechnologist and entertaining speaker, who provided an inspiring review of his work developing drug delivery systems and other treatment technologies that combine biology, chemistry, and electronics. His current work involves cartilage tissue engineering, including the remarkable accomplishment of growing an ear-shaped structure on a rabbit, and also the re-growth of spinal tissues in animals. He encouraged the audience to persevere, noting that in his early days of work, "no one believed in what I was doing," and predicted that ALD will become a mainstream technology with wide applicability.

Langer also gave an endorsement to high-throughput experimentation techniques (which my Intermolecular colleague, Russell Kempt, and I were gratified to hear). In response to an audience question, he said high-throughput techniques are ideal for addressing challenging problems when fundamental understanding is lacking, and new materials candidates need to be identified.

Another strong presentation came from Martyn Pemble of Tyndall National Institute in Ireland, highlighting the use of interface control layers, primarily nanometer-scale Al2O3, to boost performance of high-k gate oxides in InGaAs devices. III-V materials have great electrical properties, and high mobility, but the interface is very tricky. Pemble noted that cleaning and surface treatment are critical to ultimate success.

Also looking at better control was Shaista Babar from the U. of Illinois at Urbana Champaign, who discussed nucleation enhancement for the improvement of uniformity in ALD layers, which can experience roughness if the nucleation "islands" form in different sizes. Chemical or plasma surface activation are possible, but both have issues; Babar’s approach uses inhibitors to decrease the growth rate of the islands, helping to create continuous nucleation on the bare surface (with control of the interface again being called out as a critical factor).

K.H. Lee of South Korean equipment developer Wonik IPS Co. described an interesting mini-batch ALD system that targets higher throughput and lower cost-of-ownership. It utilizes rotating wafer stages that spin at 10-40rpm to provide better manufacturability using water, ozone, and metal precursors that are suitable for nanostructures.

Sunday night’s reception at the nearby Museum of Science was a fantastic opportunity for networking and conversation; we look forward to tonight’s poster session, and many more presentations tomorrow.

June 24, 2011 — Heidelberg Instruments (Germany) optioned University of Colorado (CU) Boulder’s technique for shrinking copper circuits by zapping a substrate with two separate colors of light beams. The shrinking technology could miniaturize circuits in semiconductors, nanomechanical devices, and photovoltaics.

The technique involves etching lines and dots in nm widths with a tightly focused beam of blue light, creating a lithography pattern on a substrate, commonly silicon. An ultraviolet light is then used to "erase" the edges of the pattern, shrinking the structure sizes.

The CU technology was developed by Associate Professor Robert McLeod of the electrical, computer and energy engineering department, Visiting Assistant Professor Tim Scott of the chemical and biological engineering department and Professor Christopher Bowman of the chemical and biological engineering department, with graduate students Benjamin Kowalski and Amy Sullivan (Sullivan is now a faculty member at Agnes Scott College in Decatur, GA). The technique was licensed to Heidelberg Instruments by the University of Colorado Technology Transfer Office.

McLeod and his colleagues used a tabletop laser to project tightly focused beams of visible blue light onto liquid monomer molecules. A chemical reaction initiated a bonding of the monomers into a plastic-like polymer solid. Focusing the blue beam in one place inscribed a small, solid dot. If the beam moved the focus across the material, it created a thin thread. An ultraviolet laser, focused into a halo, surrounded the blue light. The special monomer formulation was designed to be inhibited by the UV light, shutting down its transformation from a liquid to a solid. This prevented the edges of the spot or line from developing, resulting in a much finer final structure. The researchers refer to the light beam structure as the "halo of inhibition." Research on the project was funded by the National Science Foundation and through the University of Colorado Innovative Seed Program.

The CU Technology Transfer Office pursues, protects, packages and licenses the intellectual property generated from research at CU to businesses. For more information, visit www.cu.edu/techtransfer.

Heidelberg Instruments makes high-precision lithography systems. Learn more at http://www.himt.de/en/home/

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June 24, 2011 — SouthWest NanoTechnologies’ (SWeNT) single-wall carbon nanotubes (SWCNTs) demonstrated absorption of indocyanine green (ICG) — a functional dye with unique photomechanical, photochemical, and photobiological properties — in recent research. The CNTs could contribute to future cancer therapies due to this property.

The ICG-SWNT complexes are sensitive to a broad spectrum of light, ultraviolet (UV) to near infrared (NIR), which may make it integral to new photothermal cancer therapies. According to the study, published in Journal of X-Ray Science and Technology, researchers in China showed that "an effective phototherapy is not limited to a single light source." Future photothermal therapies could be demonstrated in the visible light spectrum.

Photothermal therapies typically involve a laser with a single wavelength (808, 980, 1064 and 658nm) that, when coupled with nanoparticles, cause irreversible damage to tumors. "In previous experiments, the absorption of surfactants and dissolved SWNTs had an additive effect," said Xiaohui Zhen, lead author of the paper. "Our results show with increased concentrations of SWCNTs, typical absorption peaks of ICG monomer (at 700nm to 780nm) were decreased and typical absorption peak of SWNTs (at 1030nm) was increased."

The research is supported by the National Basic Research Program of China, the Program for Changjiang Scholars and Innovative Research Team in University and the National Natural Science Foundation of China.

Access the study in the Journal of X–Ray Science and Technology, http://www.sciencedirect.com/science/journal/08953996
"Direct Imaging the Subcellular Localization of Single-Walled Carbon Nanotubes," Biophotonics and Immune Responses, Xiaohui Zheng and Feifan Zhou, MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, China

SouthWest NanoTechnologies Inc. (SWeNT) is a specialty chemical company that manufactures high quality single-wall and specialty multi-wall (SMW) carbon nanotubes, printable inks and CNT-coated fabrics. For more information, visit www.swentnano.com

June 21, 2011 – KLA-Tencor has joined SEMATECH’s lithography defect reduction program, housed at the U. of Albany’s College of Nanoscale Science and Engineering (CNSE), to collaborate on several areas of EUV lithography.

Areas of work are expected to include: defect source identification and elimination using leading-edge metrology; printability; and characterization methods to advance mask metrology infrastructure and metrology source development. Also addressed will be overall EUV manufacturability and extendibility.

EUV is believed to be the replacement-in-waiting for optical lithography — and it’s been that way for a couple of technology nodes now, as R&D keeps getting the kinks worked out and optical keeps getting extended (with things like immersion and multipatterning). Part of the problem with EUV is source power, but another problem is that the ability to identify and manage defects is "massively behind," as Rice recently said at a SEMI meeting in NY.

"KLA Tencor is embarking on an ambitious program to create the next generation of patterned mask inspection using an actinic (i.e. EUV) wavelength of light," said SEMATECH lithography director Bryan Rice, in an additional comment to Solid State Technology. "Since such an effort is necessarily complex, SEMATECH and KLA-Tencor will be partnering to investigate key aspects of the underlying technology to insure they are ready when needed."

Execs from KLA-Tencor, SEMATECH, and CNSE all lauded the combination of KLAC’s litho inspection tools and measurement know-how with SEMATECH’s industrywide collaboration and EUV R&D background. "We are excited to partner with SEMATECH to develop new metrology capabilities that address the fundamental defect detection and reduction processes that are critical for EUV infrastructure," noted Rick Wallace, KLA-Tencor’s president and CEO, in a statement.

June 20, 2011 — University-led consortium Semiconductor Research Corporation (SRC), SEMATECH, and The University of Texas at Dallas removed potentially toxic nano contaminants from a type of single-walled carbon nanotubes (SWCNTs).

Image. A single cell overlayed with the distribution in the cell of purified carboxylated single-walled carbon nanotubes (shown in yellow) as determined by laser scanning confocal Raman microscopy. Other experiments demonstrated that there was no apparent effect of the purified nanotubes inside cells on the ability of the cells to grow, whereas unpurified nanotubes inside cells inhibited growth by 60%.

SWCNTs are used in advanced nanoelectronics, as well as other industries that benefit from carbon nanotubes’ unique nano properties. The research team found that one functionalized SWCNT family, carboxylated single-walled carbon nanotubes (CSWNTs), reduced the ability of mammalian cells to grow in culture. This could signal toxicity. While small oxidized carbon fragments have been observed in prior research, this is the first suggestion that the fragments may be toxic.

Standard separation techniques removed the contaminating material, indicating that the purified nanotubes were not toxic, say researchers. The data suggests that specific organic impurities in CSWNTs may be responsible for much of the concern associated with the nano material. Continuing research will test this theory.

Removing the nano contaminants is "relatively easy," and practical to integrate to a semiconductor manufacturing facility, said Rockford Draper, Professor, Departments of Molecular & Biology and Chemistry at UT Dallas, adding that the contamination research could better inform companies buying and using CNTs.

The research is directed by SRC through the Center for Environmentally Benign Semiconductor Manufacturing, which anticipates and addresses future industry needs, with additional funding by the National Institute of Environmental Health Sciences.  SRC’s Center supports a major effort to understand, assess and screen emerging materials for their potential impact on environment, human health, and safety (EHS) prior to fab-level use. SWCNTs, which are an "emerging research material" listed in the International Technology Roadmap for Semiconductors (ITRS), are a perfect candidate for screening at the Center.

For more information and details about the research, see the forthcoming manuscript "Cytotoxicity Screening of Single-Walled Carbon Nanotubes: Detection and Removal of Cytotoxic Contaminants from Carboxylated Carbon Nanotubes" by Wang et al, that has been recommended for publication in Molecular Pharmaceutics.

SRC defines industry needs, invests in and manages the research that gives its members a competitive advantage in the dynamic global marketplace. For more information, visit www.src.org.

June 16, 2011 — The global graphene-based product market value will grow to $67 million in 2015, and $675.1 million in 2020, according to BCC Research’s new report, "Graphene: Technologies, Applications, and Markets" (Report ID: AVM075A). That’s a 58.7% five-year compound annual growth rate (CAGR).

Click to Enlarge

Figure. Global market for graphene-based products, 2009-2020 ($ millions). SOURCE: BCC Research

Graphene-based capacitors: The largest product segment. 67.2% 5-year CAGR, from $26 million in 2015 to $340 million in 2020.

Structured materials: Second-largest segment. 39.1% 5-yr CAGR, from $17.5 million in 2015 to $91 million in 2020.

Graphene in displays: Shooting up from a negligible value in 2015, this segment will reach $43.8 million in 2020.

Graphene-based photovoltaics (PV): 36.1% 5-yr CAGR, from $7.5 million in 2015 to $35 million in 2020.

Thermal management graphene products: 8.4% CAGR, from $15 million in 2015 to $22.5 million in 2020.

Remaining graphene-using products will make up a $1 million industry in 2015, and should hit $142.8 million in 2020 (169.7% 5-yr CAGR).

The commercial market for graphene-based products was essentially nonexistent 2009-2010, but BCC expects commercially significant graphene sales to crop up before 2015.

The BCC report surveys emerging graphene technologies and applications, identifies significant commercial sales opportunities in the next 5-10 years, and shares quantitative estimates of potential sales.

For more information, contact BCC Research (http://www.bccresearch.com), 35 Walnut Street, Suite 100, Wellesley, MA; Telephone: 866-285-7215.

Graphene news:

June 15, 2011 — LORD Corporation, thermal management materials, adhesives, coatings and encapsulants supplier, launched the ME-555 underfill encapsulant for semiconductor packaging and assembly. LORD ME-555 is a high-purity, semiconductor-grade epoxy underfill for encapsulating flip chips.

The material was engineered to be lower-cost than competitive underfill materials, the company said in a statement, comparing it to underfills such as Henkel 4526.

The ME-555 is formulated to reduce flip chip die warpage and to withstand overmolding. It can be used under CSP/BGAs and small dies with stand-off heights as small as 25

June 14, 2011 — Metryx Limited, semiconductor metrology equipment company, joined the joint European Semiconductor Equipment Assessment Leveraging Innovation (SEAL) project to vet mass metrology for in-line production wafer monitoring. Metryx will work with IMEC and Intel to assess high-resolution mass metrology viability at 20nm and smaller nodes.

Mass metrology is valuable in the current-generation semiconductor manufacturing line, and pooled resources with IC manufacturers and research groups via SEAL will ensure mass metrology is an integral inspection tool as devices shrink, said Dr. Adrian Kiermasz, president and CEO of Metryx.

Yield changes from silicon loss, or substrate damage, resulting from high-dose implant resist stripping, and other expected metrology challenges, will be tested through SEAL. A method that can quantify silicon loss at this early stage of device production would improve fab yield and product quality, for example. Metryx’s platforms monitor wafer mass after a process step to quickly determine whether device manufacture process steps are operating consistently, using passive data collection (PDC) and normal distribution analysis.

SEAL exists to accelerate market availability of innovative wafer processing equipment, via cost-efficient equipment development. It unites equipment users and producers, materials manufacturers and IC manufacturers. 38 project partners — European semiconductor equipment manufacturers, materials manufacturers, major IC manufacturers, start-ups, and research institutes — started the joint EC-funded project SEAL on semiconductor equipment development and assessment. SEAL is a 3-year-long project with a total budget of more than EUR14m and funding of EUR9m.

Metryx mass measurement technology measures any mass change resulting from a process change with atomic level accuracy. Learn more at www.metryx.net.

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