Driven by artificial intelligence, edge computing, and smart device performance upgrades, the semiconductor industry is undergoing unprecedented technological changes. In 2024, the global production of semiconductor chips will exceed a staggering 1 trillion, but behind this number, the industry is urgently pushing the physical limits to meet the needs of high-performance computing. Among them, the innovation of metallization process in chip manufacturing has become a key breakthrough, and molybdenum, as a new generation of metal materials, is leading this manufacturing revolution.
ⅠThe bottleneck of the chip metallization process and the breakthrough of molybdenum
Among the seven core steps of chip manufacturing, metallization is responsible for depositing metal layers on chips to form electrical signal pathways, and its importance increases significantly with the increase of 3D NAND stacking layers and the shrinking linewidth of logic chips. Over the past 25 years, tungsten has been the workhorse of interconnect processes, but its limitations have become increasingly prominent in advanced processes in the AI era:
Resistance bottleneck: At the nanoscale, the high resistivity of tungsten leads to increased signal delay, especially in the wordline connection of 3D NAND, and the resistance problem is a major obstacle to performance improvement.
Process complexity: Tungsten interconnects require an additional barrier layer to prevent metal diffusion, increasing manufacturing steps and costs.
Limited scalability: As device sizes shrink and stack layers increase, tungsten deposition uniformity and reliability struggle to meet next-generation chip demands.
Molybdenum's three core advantages make it an ideal alternative:
1. Lower nanoscale resistivity: The resistivity of molybdenum is more than 30% lower than that of tungsten at advanced process nodes, which can significantly improve the signal transmission speed.
2. No barrier process: The compatibility of molybdenum with semiconductor materials does not require additional barrier layers, simplifying the process flow and reducing the defect rate.
3. Excellent scalability: It is suitable for multi-layer stacking and fine interconnection of 3D NAND, DRAM and logic chips to cope with more complex device structures in the future.
Figure: Molybdenum: a key metal for the leap in chip manufacturing in the AI era
Ⅱ. Breakthrough in the industrialization of molybdenum process: from technology to mass production
For a long time, the core challenge of molybdenum failure to be applied to the metallization process was the bottleneck of atomic layer deposition (ALD) technology. Traditional ALDs are difficult to process the solid precursor of molybdenum, and need to meet the differentiated needs of different chip types (such as vertical/horizontal lines of NAND and low-temperature deposition of logic chips).
Lam Research's ALTUS® Halo device breaks the ice:
The world's first molybdenum ALD tool: Atomic-level precision deposition through a solid-state precursor delivery system and advanced hardware design.
Performance Leap: Compared to the tungsten process, molybdenum interconnects reduce the wire resistance by more than 50%, while improving deposition uniformity and yield.
Mass production: ALTUS Halo has been used in high-capacity 3D NAND and advanced logic chip factories, and industry giants® such as Micron have taken the lead in adopting it to produce next-generation NAND products, and application research and development in the DRAM field is also advancing.
Ⅲ. The strategic significance of molybdenum to the semiconductor industry
1. A double breakthrough in performance and economy
For terminal products, molybdenum interconnection chips can improve AI inference speed, reduce power consumption of edge devices, and directly empower scenarios such as autonomous driving and intelligent terminals.
On the manufacturing side, simplified processes and higher yields can reduce the cost per chip, and the industry predicts that the popularity of the molybdenum process in 3D NAND is expected to reduce the cost per Gb of memory by 10-15%.
2. Material innovation drives industrial transformation
With the slowdown of Moore's Law, "material substitution" has become the core path to continue the performance improvement of chips. As Counterpoint points out, "The application of molybdenum is not only an upgrade of materials, but also a turning point in the performance and economy of advanced chip manufacturing." Through technological breakthroughs, companies such as Lam Research are turning this turning point into real productivity, pushing the semiconductor industry toward a "post-Moore era."
Ⅳ. Future prospects: the symbiotic evolution of molybdenum and AI chips
The explosive growth of AI computing power demand is forcing chip manufacturing to shift from "shrinking line width" to "architecture and material innovation". As a metal material with both high performance and scalability, the industrialization process of molybdenum will accelerate the following trends:
3D chip stacking is ubiquitous: In 3D NAND and storage-computing architectures with more than 100 layers, molybdenum interconnect will become standard.
Convergence of advanced packaging technologies: Combined with fan-out packaging and system-in-package (SiP), the chip integration is further improved.
Expansion of emerging applications: In cutting-edge fields such as quantum computing and photonic chips, the low resistance and high thermal stability of molybdenum may open up new application scenarios.
Conclusion
From silicon-based semiconductors to third-generation semiconductors, material innovation has always been the underlying driving force for industry progress. The rise of molybdenum marks the strategic shift of semiconductor manufacturing from "size reduction" to "material innovation".
