Category Archives: Packaging Materials

As silicon-based semiconductors reach their performance limits, gallium nitride (GaN) is becoming the next go-to material to advance light-emitting diode (LED) technologies, high-frequency transistors and photovoltaic devices. Holding GaN back, however, is its high numbers of defects.

This material degradation is due to dislocations — when atoms become displaced in the crystal lattice structure. When multiple dislocations simultaneously move from shear force, bonds along the lattice planes stretch and eventually break. As the atoms rearrange themselves to reform their bonds, some planes stay intact while others become permanently deformed, with only half planes in place. If the shear force is great enough, the dislocation will end up along the edge of the material.

As silicon-based semiconductors reach performance limits, gallium nitride is becoming the next go-to material for several technologies. Holding GaN back, however, is its high numbers of defects. Better understanding how GaN defects form at the atomic level could improve the performance of the devices made using this material. Researchers have taken a significant step by examining and determining six core configurations of the GaN lattice. They present their findings in the Journal of Applied Physics. This image shoes the distribution of stresses per atom (a) and (b) of a-edge dislocations along the <1-100> direction in wurtzite GaN. Credit: Physics Department, Aristotle University of Thessaloniki

Layering GaN on substrates of different materials makes the problem that much worse because the lattice structures typically don’t align. This is why expanding our understanding of how GaN defects form at the atomic level could improve the performance of the devices made using this material.

A team of researchers has taken a significant step toward this goal by examining and determining six core configurations of the GaN lattice. They presented their findings in the Journal of Applied Physics, from AIP Publishing.

“The goal is to identify, process and characterize these dislocations to fully understand the impact of defects in GaN so we can find specific ways to optimize this material,” said Joseph Kioseoglou, a researcher at the Aristotle University of Thessaloniki and an author of the paper.

There are also problems that are intrinsic to the properties of GaN that result in unwanted effects like color shifts in the emission of GaN-based LEDs. According to Kioseoglou, this could potentially could be addressed by exploiting different growth orientations.

The researchers used computational analysis via molecular dynamics and density functional theory simulations to determine the structural and electronic properties of a-type basal edge dislocations along the <1-100> direction in GaN. Dislocations along this direction are common in semipolar growth orientations.

The study was based on three models with different core configurations. The first consisted of three nitrogen (N) atoms and one gallium (Ga) atom for the Ga polarity; the second had four N atoms and two Ga atoms; the third contained two N atoms and two Ga core-associated atoms. Molecular dynamic calculations were performed using approximately 15,000 atoms for each configuration.

The researchers found that the N polarity configurations exhibited significantly more states in the bandgap compared to the Ga polarity ones, with the N polar configurations presenting smaller bandgap values.

“There is a connection between the smaller bandgap values and the great number of states inside them,” said Kioseoglou. “These findings potentially demonstrate the role of nitrogen as a major contributor to dislocation-related effects in GaN-based devices.”

Gases and engineering company The Linde Group, a supplier of electronic materials, is investing in the expansion of existing products to improve business continuity planning (BCP), while adding new products with improved purity to meet the growing needs of sub-10nm semiconductor factories and advanced flat panel manufacturers.

Expanded capacity of fluorine/nitrogen mixtures
Linde has expanded capacity for fluorine/nitrogen mixtures at Medford, Oregon for etching and chamber cleaning applications.

  • This allows both low- and high-pressure fluorine and nitrogen mixture production.
  • On-site high-purity fluorine production minimizes third-party supply issues.
  • The product line is expanding to include fluorine/argon mixtures in place with tri-mix       capability(fluorine/argon/nitrogen) later in 2018.
  • This facility complements fluorine mixture production at the Linde Alpha, New Jersey facility.

New precursors to meet customer requirements
New elements of innovation continue to emerge in CVD, ALD, and ALE precursors such as high-volume supply capabilities, process solutions to deliver quality in our advanced precursors and an applications lab to support new materials development. Linde is developing deposition precursors and etch gases: silicon precursors, digermanium mixtures, high K and metal gate precursors, isotope gases and etch gases such as CF3I (trifluoroiodomethane) and custom fluorinated silane.

“Linde recognizes that our customers continue to make investments in new processes and technologies, and we are committed to investing with them for the materials they will require now and in the future,” states Matt Adams, Head of Sales and Marketing for Linde Electronics and Specialty Products.

Linde Electronics will be exhibiting at the SEMICON West tradeshow in San Francisco July 10-12. Its focus will be on the quality, expertise, commitment and environmental leadership that Linde Electronics brings to the semiconductor industry through such offerings as electronic specialty gases, on-site solutions, materials recycling and recovery and SPECTRA® nitrogen plants.

SEMICON West is the annual tradeshow for the micro-electronics manufacturing industry. All visitors are welcome to visit Linde in booth number 5644 in the North hall in the Moscone Center in San Francisco.

Researchers at Tokyo Institute of Technology have developed flexible terahertz imagers based on chemically “tunable” carbon nanotube materials. The findings expand the scope of terahertz applications to include wrap-around, wearable technologies as well as large-area photonic devices.

Carbon nanotubes (CNTs) are beginning to take the electronics world by storm, and now their use in terahertz (THz) technologies has taken a big step forward.

The CNT THz imager enabled clear, non-destructive visualization of a metal paper clip inside an envelope. Credit: ACS Applied Nano Materials

Due to their excellent conductivity and unique physical properties, CNTs are an attractive option for next-generation electronic devices. One of the most promising developments is their application in THz devices. Increasingly, THz imagers are emerging as a safe and viable alternative to conventional imaging systems across a wide range of applications, from airport security, food inspection and art authentication to medical and environmental sensing technologies.

The demand for THz detectors that can deliver real-time imaging for a broad range of industrial applications has spurred research into low-cost, flexible THz imaging systems. Yukio Kawano of the Laboratory for Future Interdisciplinary Research of Science and Technology, Tokyo Institute of Technology (Tokyo Tech), is a world-renowned expert in this field. In 2016, for example, he announced the development of wearable terahertz technologies based on multiarrayed carbon nanotubes.

Kawano and his team have since been investigating THz detection performance for various types of CNT materials, in recognition of the fact that there is plenty of room for improvement to meet the needs of industrial-scale applications.

Now, they report the development of flexible THz imagers for CNT films that can be fine-tuned to maximize THz detector performance.

Publishing their findings in ACS Applied Nano Materials, the new THz imagers are based on chemically adjustable semiconducting CNT films.

By making use of a technology known as ionic liquid gating[1], the researchers demonstrated that they could obtain a high degree of control over key factors related to THz detector performance for a CNT film with a thickness of 30 micrometers. This level of thickness was important to ensure that the imagers would maintain their free-standing shape and flexibility, as shown in Figure 1.

“Additionally,” the team says, “we developed gate-free Fermi-level[2] tuning based on variable-concentration dopant solutions and fabricated a Fermi-level-tuned p?n junction[3] CNT THz imager.” In experiments using this new type of imager, the researchers achieved successful visualization of a metal paper clip inside a standard envelope (see Figure 2.)

The bendability of the new THz imager and the possibility of even further fine-tuning will expand the range of CNT-based devices that could be developed in the near future.

Moreover, low-cost fabrication methods such as inkjet coating could make large-area THz imaging devices more readily available.

SEMI today announced the formation of the SEMI Electronic Materials Group (EMG), a new collaborative technology community that combines the former Chemical & Gas Manufacturers Group (CGMG), the Silicon Manufacturers Group (SMG) and other SEMI member segments to better serve the interests of the electronics materials industry. The group is open to SEMI Members involved in materials manufacture, distribution and services throughout the microelectronics industry.

“Materials companies are the linchpin of innovation – enabling advances in technology across the microelectronics value chain – from sand to smartphones,” said Bart Pitcock, vice president and general manager, North America for KMG Electronic Chemicals and chair of the EMG Americas Chapter. “We are pleased to build out this SEMI platform to drive program collaboration, information exchange, issues management and communication to materials industry stakeholders including customers and policymakers.”

Electronic materials have played an increasingly important role in technology innovation as electronics move from IT-centric to ubiquitous computing across consumer, industrial and data management markets. The market size for wafer fabrication materials (US$ 28 billion), semiconductor packaging materials (US$ 19 billion), and electronics assembly materials (US$ 20 billion) reflects the critical importance of materials to the growth and expansion of the worldwide electronic manufacturing ecosystem.

To help manage growing interdependencies across the microelectronics supply chain, the EMG now represents all materials makers, aligning with the SEMI mission to serve members across the microelectronics design and manufacturing industries.

As the first SEMI technology community, the Silicon Manufacturers’ Group was instrumental in the evolution of SEMI and the industry, defining standards for silicon wafers, the substrate on which semiconductors are built.

“Members of the former Silicon Manufacturers’ Group are pleased to join forces with other companies that provide the critical materials that enable the worldwide electronics manufacturing industries,” said Neil Weaver, director, Product Development and Applications Engineering of Shin-Etsu Handotai America. “We see great value and mutual purpose in working with others in the electronics materials community to advance our common interests.”

The EMG will continue its mission to facilitate collective efforts on issues related to the microelectronics materials industry that are more effectively addressed by an industry association than by individual companies.

“We are pleased with the unanimous affirmation of the new community by SEMI regions and member segments worldwide,” said Tom Salmon, vice president of Collaborative Technology Platforms at SEMI.

Entegris, Inc. (NASDAQ: ENTG), a developer of specialty chemicals and advanced materials solutions for the microelectronics industry, announced today that it acquired Flex Concepts, Inc., a technology company focused on bioprocessing single-use bags, and fluid transfer solutions for the life sciences industry. Flex Concepts’ quick-turn, custom-configured, single-use product technology is a complement to Entegris existing single-use bag product line. With this combination, Entegris is now able to provide customers with a comprehensive solution set to meet emerging bioprocessing requirements.

Regulatory-driven process and production changes to pharmaceutical products are bringing incredible advancements to this industry.  However, these advancements often require organizations to have highly-customized process solutions that can be delivered with speed to meet tight development timelines.  With the technology from Flex Concepts, Entegris is able to better equip its customers to deliver the next healthcare treatment or disease prevention tool with the speed and flexibility they need to succeed in the market.

“In the pharma development pipeline, the quicker a potential process is developed, the faster life-saving treatments can be made available to patients” says Eric Isberg director of Life Sciences, Entegris. “The addition of Flex Concepts capabilities will allow us to enrich our solutions set for fast growing single use bioprocessing applications.”

Neither the purchase price nor Flex Concepts financial results are material to Entegris overall financial statements.

TowerJazz, the global specialty foundry, today announced a ramp for its radio frequency silicon-on-insulator (RF SOI) 65nm process in its 300mm Uozu, Japan fab. TowerJazz has signed a contract with long-term partner, SOITEC, a semiconductor materials supplier to guarantee a supply of tens of thousands of 300mm SOI silicon wafers, securing wafer prices for the next years and ensuring supply to its customers, despite a very tight SOI wafer market.

With best in class metrics, TowerJazz’s 65nm RF SOI process enables the combination of low insertion loss and high power handling RF switches with options for high-performance low-noise amplifiers as well as digital integration. The process can reduce losses in an RF switch improving battery life and boosting data rates in handsets and IoT terminals.

According to Mobile Experts, LLC, a market research firm for mobile communications, the mobile RF front-end market is estimated to reach $22 billion in 2022 from an estimated $16 billion in 2018. TowerJazz’s breakthrough RF SOI technology continues to support this high-growth market and is well-poised to take advantage of next-generation 5G standards which will boost data rates and provide further content growth opportunities in the coming years.

TowerJazz is also proud to announce its relationship with Maxscend, a provider of RF components and IoT integrated circuits, ramping in this new technology.

“We chose TowerJazz for its advanced technology capabilities and its ability to deliver in high volume while continuously innovating with a strong roadmap. We specifically selected its 300mm 65nm RF SOI platform for our next-generation product line due to its superior performance, enabling low insertion loss and high power handling,” said Zhihan Xu, Maxscend Chief Executive Officer.

“We are delighted to see the strong adoption of 300mm RF SOI through this large capacity and supply agreement with TowerJazz to augment our already significant 200mm RF SOI partnership.  TowerJazz was the first foundry to ramp our RFeSI products to high volume production in 200mm and continues as one of the industry leaders in innovation in this exciting RF market with advanced and differentiated offerings,” said Paul Boudre, SOITEC Chief Executive Officer.

“We are thrilled about our continued partnership with Maxscend as they bring breakthrough products to market, manufactured using our latest 300mm 65nm RF SOI platform. Also, we are very pleased with our SOITEC partnership to secure tens of thousands of 300mm RF SOI wafers to feed the strong demand in our 300mm Japan factory,” said Russell Ellwanger, TowerJazz Chief Executive Officer.

For more information on TowerJazz’s 65nm RF SOI technology, please visit: http://www.towerjazz.com/sige-bicmos_rf-cmos.html.

Virginia Commonwealth University researchers have discovered a novel strategy for creating superatoms — combinations of atoms that can mimic the properties of more than one group of elements of the periodic table. These superatoms could be used to create new materials, including more efficient batteries and better semiconductors; a core component of microchips, transistors and most computerized devices.

Batteries and semiconductors rely on the movement of charges from one group of atoms to another. During this process, electrons are transferred from donor atoms to acceptor atoms. Forming superatoms that can supply or accept multiple electrons while maintaining structural stability is a key requirement for creating better batteries or semiconductors, said Shiv Khanna, Ph.D., Commonwealth Professor and chair of the Department of Physics in the College of Humanities and Sciences. The ability of superatoms to effectively move charges while staying intact is attributed to how they mimic the properties of multiple groups of elements.

“We have devised a new approach in which one can synthesize such metal-based superatoms,” Khanna said.

In a paper published in Nature Communications last week, Khanna theoretically proved a method of building superatoms that could result in the creation of more effective energetic materials. The work was funded by the Air Force Office of Scientific Research.

“Semiconductors are used in every sphere of life,” Khanna said. “Superatoms that could substantially enhance electron donation would be a significant societal benefit.”

Currently, alkali atoms, which form the first column of the periodic table, are optimal for donating electrons. These naturally occurring atoms require a low amount of energy to donate an electron. However, donating more than one electron requires a prohibitively high amount of energy.

Khanna and colleagues Arthur Reber, associate professor of physics, and Vikas Chauhan, a postdoctoral fellow in the Department of Physics, have created a process by which clusters of atoms can donate or receive multiple electrons using low levels of energy.

“The possibility of having these building blocks that can accept multiple charges or donate multiple charges would eventually have wide-ranging applications in electronics,” Khanna said.

While such superatoms already have been made, there has never been a guiding theory for doing so effectively. Khanna and his colleagues theorize that organic ligands — molecules that bind metal atoms to protect and stabilize them — can improve the exchange of electrons without compromising energy levels.

They considered this theory using groups of aluminum clusters mixed with boron, carbon, silicon and phosphorous, paired with organic ligands. Using computational analysis, they demonstrated the cluster would use even less energy to donate an electron than francium, the strongest naturally occurring alkali electron donor.

“We could use ligands to take any cluster of atoms and turn it into either a donor or acceptor of electrons,” Khanna said. “We could form electron donors that are stronger than any element found on the periodic table.”

Researchers at Chalmers University of Technology, Sweden, have developed a graphene assembled film that has over 60 percent higher thermal conductivity than graphite film – despite the fact that graphite simply consists of many layers of graphene. The graphene film shows great potential as a novel heat spreading material for form-factor driven electronics and other high power-driven systems.

Until now, scientists in the graphene research community have assumed that graphene assembled film cannot have higher thermal conductivity than graphite film. Single layer graphene has a thermal conductivity between 3500 and 5000 W/mK. If you put two graphene layers together, then it theoretically becomes graphite, as graphene is only one layer of graphite.

Today, graphite films, which are practically useful for heat dissipation and spreading in mobile phones and other power devices, have a thermal conductivity of up to 1950 W/mK. Therefore, the graphene-assembled film should not have higher thermal conductivity than this.

Research scientists at Chalmers University of Technology have recently changed this situation. They discovered that the thermal conductivity of graphene assembled film can reach up to 3200 W/mK, which is over 60 percent higher than the best graphite films.

In the graphene film, phonons — quantum particles that describe thermal conductivity — can move faster in the graphene layers rather than interact between the layers, thereby leading to higher thermal conductivity. Credit: Chalmers University of Technology/Krantz Nanoart

Professor Johan Liu and his research team have done this through careful control of both grain size and the stacking orders of graphene layers. The high thermal conductivity is a result of large grain size, high flatness, and weak interlayer binding energy of the graphene layers. With these important features, phonons, whose movement and vibration determine the thermal performance, can move faster in the graphene layers rather than interact between the layers, thereby leading to higher thermal conductivity.

“This is indeed a great scientific break-through, and it can have a large impact on the transformation of the existing graphite film manufacturing industry”, says Johan Liu.

Furthermore, the researchers discovered that the graphene film has almost three times higher mechanical tensile strength than graphite film, reaching 70 MPa.

“With the advantages of ultra-high thermal conductivity, and thin, flexible, and robust structures, the developed graphene film shows great potential as a novel heat spreading material for thermal management of form-factor driven electronics and other high power-driven systems”, says Johan Liu.

As a consequence of never-ending miniaturisation and integration, the performance and reliability of modern electronic devices and many other high-power systems are greatly threatened by severe thermal dissipation issues.

“To address the problem, heat spreading materials must get better properties when it comes to thermal conductivity, thickness, flexibility and robustness, to match the complex and highly integrated nature of power systems”, says Johan Liu. “Commercially available thermal conductivity materials, like copper, aluminum, and artificial graphite film, will no longer meet and satisfy these demands.”

The IP of the high-quality manufacturing process for the graphene film belongs to SHT Smart High Tech AB, a spin-off company from Chalmers, which is going to focus on the commercialisation of the technology.

Scientists of the Far Eastern Federal University (FEFU) in cooperation with colleagues from the Russian Academy of Sciences (RAS), Australian and Lithuanian Universities have improved the technique of ultrasensitive nonperturbing spectroscopic identification of molecular fingerprints.

A group of physicists experimentally confirmed that molecular fingerprints of toxic, explosive, polluting and other dangerous substances could be reliably detected and identified by surface-enhanced Raman spectroscopy (SERS) using black silicon (b-Si) substrate. The results of the work are published in the authoritative scientific journal Nanoscale.

The needle-shaped surface structure of black silicon where needles are made of single-crystal silicon. The nanomaterial is absolutely chemically inert, non-invasive, and could support a strong and non-distorted signal Credit: FEFU press office

“When detecting the smallest molecules using SERS spectroscopy their interaction with the nanostructured substrate – the platform allowing ultrasensitive identification – is crucial”, the head of research team Alexander Kuchmizhak, Ph.D., reported. Alexander is a researcher of the Department of Theoretical and Nuclear Physics of the School of Natural Sciences of the FEFU. He also added: “Currently noble metals-based substrates are chemically active and as a result, they distort the characteristic molecules signals.”

“Due to its’ special morphology black silicon significantly enhances the signal from the molecules wanted. This nanomaterial doesn’t support catalytic conversion of the analyte as it could be in the case of the metal-based substrates applying. The ‘black silicon’- based substrate is unique: being absolutely chemically inert and non-invasive it could support a strong and non-distorted signal,” told Alexander Kuchmizhak.

The substrate can be fabricated by using the easy-to-implement scalable technology of plasma etching, thus has good prospects for commercial implementation. Such inexpensive non-metallic substrates with high accuracy of detection can be promising for routine SERS applications, where the non-invasiveness is of high importance.

Valuable properties of black silicon were discovered thanks to extensive scientific cooperation. Samples of the material were developed and provided by Australian colleagues, experimental work was carried out in the laboratories of the Institute of Chemistry and the Institute of Automation and Control Processes of the Far Eastern Branch of the RAS, as well as in the Scientific and Educational Center “Nanotechnologies” of the Engineering School of the FEFU.

The way that electrons paired as composite particles or arranged in lines interact with each other within a semiconductor provides new design opportunities for electronics, according to recent findings in Nature Communications.

What this means for semiconductor components, such as those that send information throughout electronic devices, is not yet clear, but hydrostatic pressure can be used to tune the interaction so that electrons paired as composite particles switch between paired, or “superconductor-like,” and lined-up, or “nematic,” phases. Forcing these phases to interact also suggests that they can influence each other’s properties, like stability – opening up possibilities for manipulation in electronic devices and quantum computing.

Two different kinds of electron arrangements in a semiconductor, paired as composite particles or lined-up, can interact with and tweak each other in the presence of hydrostatic pressure. Credit: Purdue University image/Gábor Csáthy

“You can literally have hundreds of different phases of electrons organizing themselves in different ways in a semiconductor,” said Gábor Csáthy, Purdue professor of physics and astronomy. “We found that two in particular can actually talk to each other in the presence of hydrostatic pressure.”

Csáthy’s group discovered that hydrostatic pressure, which is 10,000 times stronger than ambient pressure, compresses the lattice of atoms in a semiconductor and, therefore, influences the electron arrangement within a two-dimensional electron gas hosted by the semiconductor. The strength of the pressure determines which arrangement is favored and tunes the transition between the paired and lined-up phases, making them more tailorable for an application. Of the two phases, the paired phase may support a certain type of quantum computing.

“We can also tune the interaction by engineering the semiconductor,” Csáthy said. “Say, for example, we grew a semiconductor with a particular width and electron density that we estimated could stabilize the nematic phase. Then we’ve tuned the electron-electron interaction as a result.”

Michael Manfra, Purdue professor of physics and astronomy, electrical and computer engineering and materials engineering, and researchers Loren Pfeiffer and Kenneth West at Princeton University grew the semiconductor samples for this study. Yuli Lyanda-Geller, Purdue associate professor of physics and astronomy, provided theoretical support for the understanding on how these electron-electron interactions took place.