As a global leader in three-dimensional stacking (3D-IC) and chiplet integration technologies, which are driving performance improvements in next-generation semiconductors, our laboratory has spearheaded research in chip-to-wafer type three-dimensional integration for over 20 years. Utilizing unique technologies, including "self-alignment packaging" that leverages the surface tension of droplets, we have tackled the challenging trade-off between positional accuracy and throughput, contributing to the realization of ultra-high-speed, low-power AI chip systems.
Furthermore, we have developed "dilet" technology, which miniaturizes silicon chips and embeds them in flexible substrates, establishing a platform that enables high-performance device mounting on curved surfaces. This has made significant contributions to the integration and applied research of flexible devices, such as wearable systems that naturally fit the arm, blood vessel visualization sheets, and low-power phototherapy devices that integrate chips and fine wiring into hydrogels primarily composed of water.

From basic research to social implementation utilizing GINTI, we are promoting consistent technological development and opening up new possibilities in semiconductor integration technology.

Compared to conventional planar mounting, vertical stacking of chips (3D-IC) shortens wiring length and dramatically improves signal transmission capability and energy efficiency. Furthermore, self-alignment enables the simultaneous placement of tens of thousands of tiny chips at ultra-high speed and precision

• At IEDM2005, we demonstrated the world's first chip-to-wafer 3D stacking, and since then, we have continued to showcase our achievements at IEDM, leading the way in industrial applications. By using the surface tension of droplets for self-alignment, we have achieved both nano-precision and high throughput, and have established dielet technology that conforms to flexible substrates, as well as die-level 3D-ICs utilizing existing ICs. Furthermore, through collaboration with GINTI and venture companies, we are promoting high-speed prototyping and social implementation.

Applications are envisioned in areas such as HPC, edge AI, and medical devices. We anticipate collaboration with materials and equipment manufacturers to co-create new materials and processes, as well as design and fabless companies exploring innovative structures.

• Toward the ultimate performances of image sensors, advanced research activities are being conducted that cover a wide range of technology fields from cleanroom infrastructure, materials, process equipment, process, device, circuit, assembly, signal processing, measurement/evaluation and reliability. Following technologies have been successfully commercialized:
• A fast and accurate measurement technology of electrical characteristics for over 1 million transistors
• A wide dynamic range CMOS image sensor technology capturing images over five decade brightness ranges
• An ultra-fast CMOS image sensor technology with 10 million frames/sec

Followings are available for industry collaborators:
A. 200mm-diameter-wafer silicon device fabrication utilizing the ultra-clean facility including wafer mutual fabrication processing between device manufacturers.
B. Process technology development and various kinds of analyses.
C. Development of new image sensors.

The sea pineapple is the only animal that produces cellulose, and its shells, excluding the edible parts, are treated as industrial waste. By removing proteins and other components from the sea squirt shells and fibrillating them, cellulose nanofibers (CNFs) can be extracted. We have focused on the fact that CNFs derived from sea squirt shells have a higher degree of crystallinity and greater mechanical strength compared to those from wood, and we are exploring various applications of this material. Furthermore, since the material transforms into high-quality carbon upon calcination, we successfully developed "nano-blood carbon catalysts" by mixing it with dried blood powder and calcining the mixture. These catalysts are being applied in fuel cells, water electrolysis, and metal-air batteries.

CNFs derived from sea pineapple's shells have a higher degree of crystallinity compared to those from wood and provide longer fibers, resulting in high strength. When calcined, they transform into high-performance carbon.

• We are the only research laboratory that has consistently developed a process for the simple and large-scale purification of CNFs derived from sea pineapple's shells, along with the creation of film materials that leverage their unique properties (mechanical, engineering, surface science, electrical, and thermal characteristics), as well as the development of carbonized materials.

We offer materials derived from sea pineapples' shell CNFs, as well as their carbonized products and catalysts. Please feel free to consult us regarding material supply, carbonization processes, or the utilization of catalysts.

• Our research group has succeeded in synthesizing various metal oxide nanoparticles with controlled size and exposure crystal planes by using organic modifiers under supercritical water conditions. The oxygen storage/release capacity of those materials in the low-temperature region is very high, and the reforming reaction of oxidative hydrocarbon proceeds at a significant rate. Besides, by combining the supercritical CO2 drying method, we have succeeded in forming a complex in which oxide nanoparticles are dispersed at a high concentration on the surface of the porous material, realizing both high oxygen storage/release capability and stability.

Low-temperature reforming reaction of biomass wastes, heavy oils, and methane. In the future, it is expected to be a technology that will lead to the construction of a low-carbon society, including CO2-free complete recycling of waste plastics.

• Monoatomic layered materials of Graphene, Transition metal sulfide nanosheet, nanocrystalline active materials, nanoparticles and nanoporous materials are investigated for realizing high capacity, high power, high safety and low cost energy storage devices as a post- Lithium ion battery. Advanced chemistry of functional materials and device processes for All solid state battery, Magnesium battery, fuel cells, supercapacitor and wearable batteries are investigated.

Academia – Industry collaboration with manufacturing companies of functional materials, batteries, and also smart grid, renewable energy, electrical power companies are encouraged for developments of advanced energy materials and post-Lithium ion battery.

• The cold spray (CS) technique is known as a new technique not only for coating but also for thick depositions. It has many advantages, i.e. dense coating, high deposition rate, low oxidation, and no phase transformation. We have been carrying out establishment of innovative preparing and coating techniques using the CS, and maintenance of reliability and safety of the cold sprayed repairing parts and coatings. Moreover, in order to evaluate the compatibility between a substrate material and particles based on an adhesion mechanism and scientific basis, various adhesion conditions are examined a micro / nano-structure observation and a molecular simulation.

Our targets were mainly hot section parts of thermal power plants and reactor piping and tubes etc. Recently, it is possible to make a ceramic coating. Therefore, we accelerate the evolution of the other fields including the creation of the functionality materials in near future.

• Molecular-scale mechanism of solid-liquid affinity, wettability, thermal boundary resistance and molecular deposition are analyzed by molecular dynamics simulations toward its control. With a background of heat and mass transport and interfacial thermodynamics, transport phenomena of various scales ranging from spin coating of photoresist to SAM (self-assembled monolayer) and hydrophobic/hydrophilic treatment by attaching some molecular basis are studied. Futhermore, the molecular-scale mechanisms which determine thermophysical properties and the molecular structure that realizes desired thermophysical properties are studied. We can conduct effective collaboration and provide academic consultations to companies interested in our research.

• General metallic biomaterials, such as stainless steels and conventional CoCr alloys, show a high Young's modulus ten times higher than that of human bones. This is an unfavored feature because it causes the so-called "stress shielding effect" when they are used as implants. β-type Ti alloys have a relatively lower Young's modulus, but they come with a compromise of low wear resistance. The current novel CoCr-based alloys are a breakthrough; they exhibit both a low Young's modulus similar to human bones and a high wear and corrosion resistance. Moreover, they exhibit superelasticity with a huge recoverable strain over 17%, also showing promise as shape memory alloys.

It is the first time that a low Young's modulus, a high corrosion and wear resistance, and a superior superelastic behavior are simultaneously obtained in a single material. The current novel CoCr-based alloys are promising for biomedical applications such as total hip or knee joint replacements, bone plates, spinal fixation devices, and vascular stents.

• Intergranular degradation often results in decreased lifetime, reliability and economical efficiency of polycrystalline materials. In spite of persistent efforts to prevent such degradation, its complete suppression has not yet been achieved. Grain boundary studies have revealed that coincidence-site-lattice (CSL) boundaries have stronger resistance to intergranular degradations than random boundaries. The concept of ‘grain boundary design and control' has been refined as grain boundary engineering (GBE). GBEed materials which are characterized by high frequencies of CSL boundaries are resistant to intergranular degradations. Our group has achieved very high frequencies of CSL boundaries in commercial stainless steels by GBE. GBEed stainless steels showed significantly stronger resistance to intergranular corrosion (see Figs. 1 and 2), weld-decay, knife-line attack, stress corrosion cracking, liquid-metal embrittlement, radiation damage, etc. and much longer creep life (see Fig. 3) than the unGBEed ones.

By using this GBE processing, we expect to conduct effective collaborative research in related fields.

• The cold spray (CS) technique is known as a new technique not only for coating but also for thick depositions. It has many advantages, i.e. dense coating, high deposition rate, low oxidation, and no phase transformation. We have been carrying out establishment of innovative preparing and coating techniques using the CS, and maintenance of reliability and safety of the cold sprayed repairing parts and coatings. Moreover, in order to evaluate the compatibility between a substrate material and particles based on an adhesion mechanism and scientific basis, various adhesion conditions are examined a micro / nano-structure observation and a molecular simulation.

Our targets were mainly hot section parts of thermal power plants and reactor piping and tubes etc. Recently, it is possible to make a ceramic coating. Therefore, we accelerate the evolution of the other fields including the creation of the functionality materials in near future.