III. The function of a photomask lithography machine

The function of a photomask lithography machine is to create photomasks, which are essential tools in the manufacturing process of integrated circuits. Photomasks are typically made using laser lithography machines or electron beam (e-beam) lithography machines. Laser lithography machines are more versatile and commonly used, while e-beam lithography machines are employed for producing critical photomasks in advanced process nodes. E-beam lithography machines can generate smaller feature sizes compared to traditional laser lithography machines, but they are slower and more expensive, as well as larger in size.

In the manufacturing process of advanced integrated circuits, the bottom layers (referred to as layers 1 to 2) require precise photolithography, and therefore more sophisticated photomasks produced using e-beam lithography machines are commonly used. For the upper layers, manufacturers prefer to use cheaper and more efficient laser lithography machines.

Each photomask is unique, and the time required to pattern a photomask can vary from short for simple patterns to long for complex ones. Therefore, the "write time" is crucial when using e-beam photomask lithography machines as it directly affects the lithography efficiency.

Currently, there are only a few global manufacturers capable of producing multi-beam photomask lithography machines. The main companies are JEOL and Nuflare from Japan, Vistec from Germany, and IMS from Austria. Among these four, Nuflare holds the highest market share, accounting for 90% globally and being the first company with the capability to manufacture photomasks for the 3nm process node.

IMS was founded in Vienna in 1985. In 2009, Intel invested in IMS due to the potential development prospects of its multi-beam programmable e-beam lithography system. In 2015, Intel acquired IMS, leading to rapid growth in employee numbers and production capacity, as well as the introduction of three new generations of products. TSMC has been collaborating with IMS since 2012 to develop multi-beam photomask lithography machines for advanced process technology. In 2016, IMS released its first commercially available multi-beam photomask lithography machine, which is applicable to all process technologies beyond 7nm. In 2019, the company delivered its second-generation product, the MBMW-201, for 5nm process technology.

In recent years, IMS considers Nuflare its primary competitor in the industry. IMS believes that Nuflare's lithography machines are not precise enough and relatively slow. Furthermore, Nuflare's multi-beam photomask lithography machines entered the market several years after IMS. IMS states that over 98% of EUV photomasks are manufactured using their multi-beam lithography machines.

With the development of lithography technology, particularly the continuous updates of EUV lithography machines by ASML, there are higher requirements for corresponding products and equipment, including photomask lithography machines.

Based on current technological advancements, a technique called Curvilinear masking offers an opportunity to improve sub-resolution assist features (SRAF) and extend the process window. Curvilinear masking can provide better wafer lithography effects. As long as the photomask can be accurately written within a reasonable time/cost, multi-beam lithography machines can write any shape in a constant time using a given resist and writing method. Mask-wafer co-optimization (MWCO), combined with overlapping deformable shape beams (DSB), can generate better wafer lithography quality with fewer lenses through dual simulation evaluation of injection positions based on mask-wafer. It outperforms traditional optical proximity correction (OPC) techniques.

The commercialization and maturity of multi-beam photomask lithography machines have facilitated the adoption of Curvilinear masking technology, breaking the long-standing cost paradigm associated with shot count for photomasks. Although there is an increased cost for Curvilinear masking compared to traditional methods, it is still relatively small compared to the investment in EUV lithography machines.

As EUV enters high-volume production (HVM) stages, the adoption of multi-beam photomask lithography machines is significantly increasing. At present, almost all EUV photomasks are written using multi-beam lithography machines to transfer integrated circuit information.

Conclusion

From the above introduction, we can see that TSMC's investment in IMS and its acquisition by Intel in earlier years are significant. As the progress of advanced processes becomes increasingly slow in the future, it requires various advanced technologies support in the semiconductor equipment, materials, packaging, and other sectors of the industry chain to maintain a competitive position in the advanced process market.

After focusing on the development of the photomask industry chain in which IMS is invested, let's briefly analyze the investment in Arm. After all, as a global leader in processor IP, Arm has a great influence on the industry. Moreover, on September 15th, Arm officially went public on Nasdaq, with a market value of $65.2 billion on that day.

TSMC stated that participating in Arm's IPO is a strategic investment that can put TSMC in an advantageous position in future collaborations with suppliers and partners.

Renowned analyst Guo Mingqi believes that the main purpose of these two investments by TSMC is to enhance vertical integration capabilities, ensuring a smooth transition from the current 3nm FinFET technology to 2nm GAA technology.

Guo Mingqi also mentioned that Intel plans to produce Arm chips using the 18A process (approximately equivalent to TSMC's 2nm), which could be one of the reasons why TSMC is more actively investing in Arm. Through this move, TSMC can form closer cooperation with Arm (such as DTCO and STCO), which helps optimize Arm IP on TSMC's advanced process and packaging technology.

Guo Mingqi believes that Apple and NVIDIA will be the first to use 2nm process technology to produce next-generation AI chips in 2026 (iPhone processors and B100, respectively) because these two potential 2nm customers have also invested in Arm. TSMC's investment in Arm is beneficial for strengthening cooperation with Apple and NVIDIA, as well as competing for 2nm orders.

Guo Mingqi also mentioned that investing in IMS can ensure the technical development and supply of critical equipment to meet the commercialization requirements of the 2nm process.

In the coming years, there will still only be three players in the manufacturing of advanced process (below 7nm) chips: TSMC, Intel, and Samsung Electronics. With Intel formally joining the foundry competition, the competition will become more intense, and the relationship between cooperation and competition will become more complex. In earlier years, when Intel faced difficulties with its 10nm process, it had to rely on Samsung Electronics for chip production. Currently, TSMC is also responsible for producing various non-core products for Intel. Additionally, Intel has formed both cooperative and competitive relationships with TSMC in the upstream of the industry chain, such as investment in ASML and jointly owning IMS shares. Both giants will face more competition in terms of controlling Arm and future production of Arm-based chips in a few years.