Ajinomoto build-up film (ABF) substrate has been a key component in chip manufacturing since its introduction shortly before the turn of the millennium. Substrates made with Ajinomoto build-up film – an electrical insulator designed for complex circuits – are found in PCs, routers, base stations, and servers.
Looking ahead, the ABF substrate market will continue to grow, with revenue up last year due to the strong demand for 5G, high-performance computing (HPC), servers and graphic processing units (GPU), as well as from the automotive industry. According to Goldman Sachs, the total demand for the ABF market should maintain a CAGR of 28% from 2022 to 2025. Like so many other essential components in the global supply chain, there is a shortage of ABF substrates.
But rising demand and supply chain issues aren’t the only factors contributing to the shortage of ABF substrates. Larger package sizes and an increasing number of layers for these high-technology products also play a part; after all, these larger packaging sizes result in fewer packages per ABF substrate. And since the manufacturing of ABF substrate is a build-up layer process, a defect in any one layer can hamper the final yield of the entire substrate. Given these factors facing the ABF substrate market, yield control becomes even more important than it was before.
As 3D NAND continues to scale vertically — all in the name of increasing capacity and speed and reducing inefficiency and cost — maintaining channel hole critical dimension (CD) and shape uniformity becomes even more challenging. Faced with rising high-aspect ratios, addressing these challenges requires new inline non-destructive metrology to provide real-time process control. Infrared critical dimension metrology (IRCD) is one solution.
But while IRCD can be used to measure high-aspect ratio structures like the amorphous carbon hardmask and channel hole profile in 3D NAND, the mid-IR wavelength range can be used to measure non-memory devices like logic and CIS. In particular, IRCD can be a powerful metrology resource when it comes to detecting fluorinated polymer residue after cleans in advanced logic devices and measuring vertical doping concentration profiles after plasma doping in CIS.
The new year is always a wonderful time to take a deep breath, hold it and reflect on the past 12 months while planning for the year ahead. In the semiconductor industry, we have never seen a year like 2021, one with so many surprises combined with so much growth.
In 2021 we saw semiconductor manufacturing expansions accelerate across the value chain. Advanced logic was especially pronounced, with leaders seeing the opportunity to serve the growing market for high-performance compute or hyperscalers to power artificial intelligence (AI) engines in a wide range of applications. But 2021 will be remembered for broad demand growth, with 5G adoption in mobile handsets and base stations continuing to double each year. This drove a strong surge in the introduction rate of next-generation mobile handsets, which ushered in higher demand for camera chips, power, and memory.
In addition, the industry managed through national concerns about semiconductor technology challenges from the ongoing pandemic, and, as a result of the sharp increase in demand, a worldwide supply chain shortage of chips compounded by logistics challenges around the globe.
Against this backdrop, companies like Onto Innovation will see a growth of 40% year over year, and demand is continuing to rise in 2022. All the drivers are the same for the new year as in 2021, but we also see an increased focus on compound semiconductor devices, particularly for power devices supporting the global emphasis on transitioning from the 130-year-old combustion engine to electric vehicles (EVs) and the world’s critical need for smarter power grids that allow more renewable energy sources to come online. Along with that, we project higher levels of investment in heterogeneous packaging technology for 2022 to support the next generation of AI engines and high-performance integrated modules, such as those for 5G communication.
The ability to trace the genealogy of all the components in an electronic device has been getting more complex for decades. For many industries — automotive, defense, medical and others — the need to locate the source of a problem in near real-time is paramount to gauging the extent of that problem. The extreme case is when the issue occurs with a product that already has been distributed and used in the field. Complicating matters is the fact that the current chip shortage is pushing chip designers to second- and third-tier suppliers for their inventory.
Tracking information is not easily done given the number of times material can change hands during the manufacturing life cycle. Designs can incorporate IP modules from Parties No. 1, No. 2, and No. 3 (figure 1). These designs are blended into a singular chip by the device’s Design House. This chip is then built at Front-end Foundries No. 1 or No. 2. The completed chip can be tested and partially assembled at OSAT A, B, or C. Finished assembly into a multi-chip module (MCM) or printed circuit board (PCB) can take place at Assembly House No. 1 or No. 2 (or happen at Customer A if they provide the IP for a design for a device that can be assembled by Finished Goods Maker No. 1) before it is finally sold by the Design House to the End User or Final Goods Manufacturer A, B, C, D and more for insertion in their end product, after which it is again tested before being sold to the end customer.
This is a very simplified example of how complex a supply chain can be, but it is illustrative nonetheless.
Virtual v. physical traceability
At some point in the supply chain, units receive a physical marker that enables traceability as it progresses through the remaining chain of manufacturing agents. Prior to the application of a marker, reliance on a part’s origin is a function of accounting and accurate recordkeeping. Although this seems simple enough, it is complicated by the transition of “ownership” of the chip as it moves through the supply chain.
Tracing a chip’s origin includes its transformation through multiple physical form factors. These material changes frequently include moving from a lot/wafer/die physical structure to a singulated die on a piece of tape or reel to an assembled die in a package, or in a tray, or as an inserted chip in a multi-chip module or PCB — ultimately ending with the PCB being inserted into a larger form factor, such as an automobile or a computer server. Each time the physical form factor is updated, there is a chance to break traceability in the supply chain if incoming and outgoing product labels are not meticulously documented. This is exacerbated by a lack of standardized data formats and communication frameworks throughout the supply chain. All too often, there is a gap in a unit’s back mapping. Once this occurs, any chance to trace a problem to a source is jeopardized.
In the leading high-volume manufacturing (HVM) process flows, materials-enabled scaling has increased inline applications for compositional metrology.
A previous blog discussed how Fourier transform infrared (FTIR) spectroscopy was used for inline composition measurements. These measurements informed advanced process control for the wafer-level processing of selectively etched 3D NAND wordlines and DRAM capacitor profiles.
FTIR metrology has further HVM applications, including incoming substrate quality assurance, hardmask selectivity qualifications in the middle of the line, and verification of Low-K porogen evolution during interlayer dielectric (ILD) depositions on the back end of the line. These examples illustrate how FTIR modeling delivers metrics based on materials’ bond types for compositional process control.
It may surprise you, but when it comes to chips in electronic braking systems, airbag control units, and more, automotive manufacturers are still using 10-year-old technology — and with good reason.
For the automotive industry, the reliability, stability, and robustness of electronic components are critical, especially when it comes to meeting the stringent Automotive Electronics Council (AEC) Q100 standards that fabs need to follow. Some in the industry would not only rather keep using proven older chips over new ones, but they might even call for the construction of new fabs for older chips. In other words, tried and true is better than new and improved.