From metrology to control: a comprehensive overlay solution for IC manufacturing and packaging challenges

As semiconductor end markets diversified from computers and Internet to mobile and social media, computing demand increased from hundreds of millions to billions of units. With the advent of AI, and big data end markets further diversified to IOT, communications, self-driving cars, power, and sensors, resulting in demand for computing that ski-rocketed to the trillions. To fuel this growth PPACt :Power, Performance, Area-cost and time-to-market needed to accelerate. This acceleration is enabled by new architectures, 3D structures, new materials, new ways to shrink, and advanced packaging. An obstacle limiting this growth was identified as loss of correlation between the new aforementioned semiconductor device structures, and the measurements conventional optical workhorse metrology provided. This was not a one-time calibration event. Optical metrology increased reliance on accuracy check, ground truth and calibration is a result of increasing optical metrology accuracy gaps over time, causing inflating edge placement error budgets, instability in litho to etch bias and non-zero offset over time. A paradigm shift in overlay, CDU, and edge placement error patterning control metrology was sought to accelerate PPACt at needed yield. This talk tells the story of how to introduce a new standard to a needing industry. We start with addressing the need for a new technology enabling a fast non-destructive accurate inline metrology, we then validate its accuracy overtime using two different industry standard reference metrologies. And we conclude with testimonies of chipmakers showcasing the use of the new industry standard of patterning control. To enable high throughput accuracy in overlay, EPE, and NZO metrology a highly efficient BSE see-through ebeam technology was introduced and benchmarked against optical metrology. Showing reduced non zero offset residuals on device, with the capability to accurately gauge litho-to-etch bias. As a good engineering practice STEM and Delayer techniques validated the accuracy of the inline ebeam technology so it could become the new workhorse to assume the role of HVM overlay metrology. We conclude with three chipmakers case studies of how the use of the new workhorse ebeam metrology accelerated cycles of development, reduced reliance on destructive metrology enabling faster process splits in fabrication of three dimensional nanosheet transistors, faster ramp of semiconductor manufacturing and better yield by better on device overlay and NZO at HVM.

Fish and other seafood products are an integral and valuable part of human diets. In advanced nations, the transportation of fish and other seafood products to customers requires packaging and display. Due to their intrinsic physicochemical properties, seafood products are particularly susceptible to microbial growth, resulting in shorter shelf lives and higher spoilage rates compared to other animal-derived proteins, such as meat. To prevent microbial spoilage and preserve the freshness and quality of fish and other seafood products, petroleum-based plastic materials are commonly used in combination with packaging technologies, such as vacuum packaging and modified atmosphere packaging. However, as these fossil fuel-based materials are non-biodegradable, non-recyclable, and associated with damaging environmental footprints, there is a clear need to develop advanced and smart sustainable packaging solutions that can meet environmental and climate demand while being able to extend the shelf-life of seafood products beyond current expectations. Various biopolymers, including polylactic acid, polyvinyl alcohol, chitosan, and polyethylene glycol, have been widely utilised in the development of advanced, sustainable, and biodegradable packaging materials for seafood. However, most of these biopolymers inherently lack antimicrobial properties, limiting their ability to effectively extend the shelf-life of seafood products. Recent studies have shown that incorporating natural antimicrobial materials into biopolymers significantly enhances their antimicrobial properties. As a result, the development of active packaging materials for seafood preservation has emerged as a growing area of research. In this review, we examine approaches that have been used in this area with an emphasis on active antimicrobial-containing systems based on non-fossil fuel plastics. This work will centre on reviewing the literature to understand and analyse the techniques used to create these advanced active biodegradable and sustainable packaging materials.

The tremendous growth in smartphones and tablets has been fueled by consumer demand for increased mobility, functionality, and ease of use. This, in turn, has been driving an increase in functional convergence and 3D integration of integrated circuit (IC) devices, resulting in the need for more advanced and sophisticated packaging techniques. In particular, the integration of the application processor (AP) and dedicated memory has become increasingly complex. Smartphones and tablets have become virtual streaming devices requiring low power, high bandwidth memory (HBM). For quality, high-speed video and multi-tasking applications, the memory interface to the AP must have superior signal integrity to minimize crosstalk and insertion/return losses. In addition, the thermal management of the processor must allow the maximum clock speed and duty cycle for high-performance applications. Finally, to conserve battery life for the mobility device, the power distribution to the processor must be as efficient as possible. This creates a significant challenge for the semiconductor packaging industry to meet these demanding requirements for smartphone and tablet products. This paper introduces a leading-edge high-density fan-out (HD-FO) semiconductor packaging technology that addresses the need for higher levels of integration and improved electrical and thermal performance for mobile applications. This new innovative technique, called Silicon Wafer Integrated Fan-out Technology (SWIFT™) packaging, leverages the fine feature size and thin-film circuit patterning capabilities of wafer-level packaging. In addition, thin-film dielectric photolithography and pattern plating provides a significant reduction in package z-height, which is critical for advanced mobile devices. By incorporating a redistribution layer (RDL)-first/chip-last process flow, there is also an opportunity for yield optimization and cycle-time reduction. This work compares the electrical and thermal modeling results between a conventional Package-on-Package (PoP) and HD-FO SWIFT devices. The results reveal a highly integrated PoP structure with exceptional electrical, mechanical, and thermal performance benefits – compared to conventional organic laminate-based technologies – to meet the growing need for high-performance mobile applications.

6 - Thermal and mechanical tests for packages and materials

MXene confined in shape-stabilized phase change material combining enhanced electromagnetic interference shielding and thermal management capability

Biopolymer-based packaging materials are increasingly favored for their eco-friendly and biodegradable properties. Among the promising biopolymer materials, agar-based biodegradable films stand out since they are made from water and plasticizers like glycerol. However, they often suffer from reduced mechanical strength and higher moisture sensitivity compared to synthetic alternatives. To address these issues, this study explores the incorporation of silver nanoparticles (AgNPs) into agar-based films using Aloe vera gel as a green synthesis agent. The study demonstrates that Aloe vera gel effectively stabilizes AgNPs, resulting in nanoparticles with distinctive reddish-brown coloration. The agar-based films with AgNPs exhibited enhanced antioxidant activity, with inhibition rates up to 85.39%. These films also maintained smooth surfaces and evenly dispersed nanoparticles, ensuring both mechanical stability and bioactivity. The results suggest that Aloe vera gel not only facilitates the synthesis of AgNPs but also preserves their functional properties, offering a promising approach for developing advanced food packaging materials with improved antioxidant and antimicrobial characteristics.

The measurement of thermo-mechanical deformation in C4 interconnect and chip scale packages is a critical metrology problem for IC packaging. The ability to directly measure the deformation of the actual package, without applying special structures for metrology, is a major advantage of optical digital image correlation technology. Cutting edge automated digital image correlation technology allows in-plane deformation and strain to be measured directly at multiple locations on the bare cross-section or exterior surface of an IC package. In this paper the authors have shown the advantages of using digital image correlation based techniques for the measurement of advanced electronic packaging materials and components. The technique has moved on with the increasing power of computers which enable the required high intensity numerical calculations to be computed. The technique has been applied to the measurement of C4 based components. Highly accurate deformation measurements are possible with accuracy of 20 nm deformation resolution being possible. Minimal sample preparation was required with samples only requiring a minimal amount of roughening with silicon carbide paper. This compares favourably with comparable techniques such as moire interferometry which require a large amount of time-consuming sample conditioning and grating replication before any measurement can be made

The University of Arkansas established the interdisciplinary High Density Electronics Center (HiDEC) in 1991 to conduct research in advanced electronic packaging materials and technologies, with the primary focus being on thin film multichip module (MCM-D) packaging. To support this effort from an educational perspective, the offering of senior elective and graduate level courses in electronic packaging became necessary. Since an acceptable textbook was not available, ten faculty members from the University of Arkansas agreed to prepare discipline-specific material for the courses and to teach the portions of the courses for which they had prepared material. Using this approach, two senior/graduate courses were developed and taught by the ten faculty members during the 1994-95 academic year, and each academic year since then. Consequently, in these two courses, students from several engineering and basic science departments were subjected to technical subjects from a number of disciplines, each taught by a different instructor. Subsequent to the initial offering of the two courses, a decision was made to use the material which had been prepared for the two courses as the basis for a textbook on electronic packaging with emphasis on multichip modules. This paper discusses the organization of the two courses, the performance and comments of students who have completed the courses, the level of success of the courses as perceived by both the students and the instructors, and the contents and organizational philosophy of a textbook which resulted from the development of the two courses.

ABSTRACTThe accumulation of aluminium waste in landfills constitutes a significant environmental challenge due to its substantial presence as solid waste. Conventional disposal and recycling techniques have been employed to mitigate this issue; however, they often result in secondary environmental pollution. In this study, eco‐friendly and cost‐effective aluminium oxide nanoparticles (Al2O3‐NPs) were synthesized via a green synthesis approach utilizing date palm seed extract. Flexible polystyrene (FPS) was fabricated through in‐situ polymerization in the presence of varying concentrations of Al2O3‐NPs to develop active nanobiocomposite coatings. The physicochemical characteristics of the synthesized Al2O3 nanoparticles were comprehensively analysed using multiple advanced techniques, including dynamic light scattering (DLS), Brunauer–Emmett–Teller (BET) surface area analysis, X‐ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy‐dispersive X‐ray spectroscopy (EDX) and transmission electron microscopy (TEM). XRD analysis confirmed a rhombohedral crystal structure with an average particle size of 32 nm. Fourier transform infrared spectroscopy (FTIR) and X‐ray photoelectron spectroscopy (XPS) further validated the structural composition of the synthesized Al2O3 nanoparticles. Additionally, thermogravimetric analysis (TGA) was employed to assess the thermal stability of the FPS/Al2O3 bionanocomposite coating, revealing excellent thermal resistance withstanding temperatures ≥ 240°C. DLS measurements indicated a uniform particle size distribution with stable zeta potential, while BET analysis demonstrated a substantial surface area ranging between 62 and 147 m2/g. Furthermore, the antimicrobial efficacy of Al2O3 nanoparticles was investigated by determining their minimum inhibitory concentration (MIC) against both Gram‐positive and Gram‐negative bacteria. The antimicrobial assessment revealed that Gram‐negative bacteria exhibited greater resistance compared to Gram‐positive bacteria and yeast. Migration analysis demonstrated that the percentage of migrated material was within acceptable limits as per European Commission (EC) regulations. These findings suggest that the developed flexible nanobiocomposite‐coated paperboard holds significant potential as an advanced active packaging material.

Enhanced thermal conductivity of epoxy composites reinforced with oriented polydopamine-graphene foam complexed by metal ions

Miniaturization and higher functionality in electronics packaging require the use of advanced packages and small components. This trend has translated into the use of new package types such as Quad Flat Pack (QFP) no lead (also referred to as Leadless Plastic Packages), increased use of chip scale packages as well as increased component density and tighter PCB layouts. Advanced package innovations further complicate post assembly cleaning. It is often a challenge to clean flux residue from under these highly dense and advanced packages after reflow soldering. Uncleaned flux residue is a reliability issue. One example detailed in this paper is removal of flux residue from under low standoff (1.0-1.5 mil) SMD Chip capacitors. Flush mounted chip cap components result in these “caps” creating a flux dam under the component during reflow. Inline cleaning processes have been developed to address the cleaning needs of these high reliability Class III electronics assemblies. Coupled with the need to reduce cycle times, the cleaning process must provide for reliability through efficient cleaning and yet allow for optimum production throughput. As a result, the cleaning process is typically given only a short process window to penetrate, dissolve, and remove the flux residue from these complex electronic assemblies. To address this problem, upstream cleaning process conditions must be optimized. A designed experiment was performed to accomplish this task. The data generated from the designed experiment provided the basis for modifying the manufacturing process to meet the cleaning objectives. This paper will discuss in detail the work that supported and achieved these required cleaning objectives.

Interactions between nanoparticle-based food additives and other food ingredients: A review of current knowledge

The exceptional electronic, thermal, mechanical, and optical characteristics of carbon nanotubes offer significant improvement in diverse applications such as flexible electronics, energy conversion, and thermal management. We present an overview of recent research on the fabrication, characterization and modeling of carbon nanotube (CNT) networks or ensembles for three emerging applications: thin-film transistors for flexible electronics, interface materials for thermal management and transparent electrodes for organic photovoltaics or light emitting diodes. Results from experimental measurements and numerical simulations to determine the electrical and thermal transport properties and characteristics of carbon nanotube networks and arrays used in the above applications are presented. The roles heterogeneous networks of semiconducting and metallic CNTs play in defining electrical, thermal, and optical characteristics of CNT ensembles are presented. We conclude with discussions on future research directions for electronics and packaging materials based on CNT ensembles.

In the field of integrated circuits, as Moore’s Law approaches its limits, advanced packaging technologies have emerged as a key driver for enhancing circuit performance in the post-Moore era. However, the interfacial stability of advanced packaging materials—particularly photosensitive polyimide (PSPI)—is a critical factor in determining the reliability of integrated circuits’ internal chips and devices. Since the thickness of PSPI films prepared by spin-coating processes is typically controlled on the order of 10 μm or even smaller, research on the interfacial strength distribution and molecular-level interfacial bonding mechanisms at the heterointerface formed between PSPI and copper at the sub-micron scale faces significant challenges. Based on this, a study was conducted on the interfacial mechanical properties of the PSPI/Cu under loading. An in situ Transmission electron microscope (TEM) tensile testing platform was used to observe the PSPI/Cu interfacial fracture process in real time, revealing the dynamic evolution of interfacial delamination under load. The high-resolution imaging mode of Atomic Force Microscopy (AFM) was utilized to characterize the surface morphology and interfacial diffusion layer features. Simultaneously, nanoindentation technology was combined to obtain the gradient distribution of the elastic modulus in the interfacial transition zone between PSPI and Cu. Through in situ testing, AFM characterization, and nanoindentation techniques, the mechanical response mechanism at the PSPI/Cu interface was characterized, and its interfacial failure mechanism was revealed. By comparing sample data under different processing conditions, this work provides a scientific and effective theoretical basis for the optimization of advanced packaging materials and process improvements.

Soft-template-assisted bottom-up fabrication of tunable porosity monolithic copper film for interconnection in microelectronics