Beyond Moore’s law
ALD powers vertical innovation
Julien Arcamone, Corporate Vice President and Head of the Thermal ALD Business Unit at ASM, shares how ASM’s ALD technology is a major driver for the transition of the semiconductor industry to 3D architectures.
For decades, Moore’s Law has been the guiding principle of the semiconductor industry. But as traditional planar scaling reaches its physical and economic limits, the industry is entering a new phase where progress is defined by mastering complexity in three dimensions.
At the heart of this transition lies atomic layer deposition (ALD) that enables device scaling to smaller dimensions while reducing transistor power consumption, supporting the industry’s ability to continue along Moore’s Law and create smaller, more powerful semiconductors.
Expanding ALD applications
As device architectures evolve, many new applications are emerging where ALD is the technology of choice. In some cases, it is the only solution capable of meeting increasingly challenging technology requirements. One example is the use of ALD high‑k gate oxides, which are now in production for advanced logic transistors, and for high‑performance DRAM Peri devices as well. With each new technology node, customers are adopting more ALD applications, driving strong growth in the ALD equipment market.
These applications include high‑k metal gate oxides for gate‑all‑around (GAA) transistors, high aspect ratio gap‑fill, underlayers for EUV lithography, metal ALD, selective ALD, and others. In memory devices, ALD has also seen increased use for gap‑fill applications. With TENZA ALD technology, ASM can gap‑fill structures with aspect ratios greater than 100:1, and this technology has been selected for use in several 3D-NAND applications.
Process innovation at ASM
ASM supports this broad range of applications with the industry’s most extensive ALD product portfolio for thermal and plasma-based ALD, relying on innovative reactor designs.
Our products have been optimized and tailored for specific use cases. For metal oxides, ASM has developed a reactor with the flexibility to deposit five, six, or even seven elements. The ability to combine different precursors enables the development of new materials and has been an important factor in enabling new ALD applications, including those for GAA and selective ALD.
For metal ALD applications, ASM has further developed and optimized surface clean (SC) technology. SC reactors are integrated on the same platform as the metal ALD reactors, eliminating the need to break vacuum. These reactors remove impurities and moisture from the wafer surface prior to metal ALD deposition, improving productivity and reducing cost of ownership.
Why ALD matters now
At ASM, we believe that as demand for semiconductors continues to grow, Moore’s Law, or at least a generalized version of it, will continue. Scaling the smallest dimension through lithography alone is no longer sufficient to increase density and reduce cost per function. It is complemented by a move to the vertical dimension.
One example of this transition is gate-all-around that stacks up to four channels vertically, significantly increasing the current a transistor can carry while improving control.
Three‑dimensional integration is also visible at the package level, where chips are stacked vertically to reduce package size and shorten connection lengths. For example, high‑bandwidth DRAM devices integrate a logic chip with multiple vertically stacked memory arrays in a single package.
Due to its ability to deposit ultra-conformal, uniform, high‑quality layers of complex materials over three‑dimensional structures at relatively low temperatures, the share of ALD is expected to grow further significantly as the industry continues its transition toward 3D architectures.
At the same time, new ALD processes enable changes in device architecture that are not possible with other deposition technologies. New materials, such as improved conductors and insulators, are required to maintain and/or improve electrical performance.
By enabling atomic‑scale control over increasingly complex 3D structures, ALD is shaping the possibilities of tomorrow’s devices. As scaling moves upward and inward, it will continue to play a defining role in how the semiconductor industry innovates, performs, and progresses.
