Hey everyone! Today, we’re talking about a chemical that’s absolutely essential for making semiconductors, but its name might be a little unfamiliar: ‘photoresist.’ Ever heard of it? It’s a fascinating topic because Japanese companies control nearly 90% of this market. That’s almost a complete monopoly.
So today, we’re going to dig deep into how photoresist technology evolved and how Japanese firms reached their current position, exploring everything from the history and strategy to the geopolitical context. I’ll break it all down so you can grasp this complex story quickly and thoroughly! π
So, What Exactly Is Photoresist? π€
Simply put, it’s a light-sensitive liquid used to etch microscopic circuit patterns onto a semiconductor wafer. It reacts to light, much like the film used in photography. Without it, even the most expensive, state-of-the-art lithography equipment would be nothing more than a giant paperweight. Think of it this way: no matter how great your printer is, it’s useless without ink. Photoresist acts as that crucial ink or the stencil for creating the patterns.
The name itself is a hint: ‘Photo’ means light, and ‘resist’ means to withstand. In other words, it’s a material that ‘resists’ certain processes after being exposed to light. The entire process of drawing circuits on a wafer using this principle is called ‘photolithography’.
The 5 Steps of Photolithography at a Glance
- Coating: A thin, uniform layer of liquid photoresist is applied to the wafer. (Spin-coating)
- Exposure: A mask with the circuit blueprint is placed over the wafer, which is then exposed to ultraviolet (UV) light.
- Development: A developer solution selectively dissolves either the exposed or unexposed parts of the photoresist to create the pattern.
- Etching: The remaining photoresist acts as a protective barrier while the underlying layer is carved away.
- Stripping: Finally, the remaining photoresist is removed, leaving the finished circuit pattern.
Photoresists come in two types: ‘positive-tone,’ which dissolves when exposed to light, and ‘negative-tone,’ which hardens. While negative-tone was developed first, it had an issue where it would slightly swell during the hardening process, which reduced precision in ultra-fine circuits. In contrast, positive-tone resists don't have this problem, allowing for much more precise patterns. That’s why almost all modern processes use positive-tone photoresists.
From Asphalt to Advanced Materials: The History of Photoresist π
Amazingly, the origins of this technology date back to the 1820s in France. An inventor named NicΓ©phore NiΓ©pce used a substance similar to asphalt, ‘Bitumen of Judea,’ which hardens when exposed to light, to create the world’s first photograph. This technique was adapted for semiconductors in the 1950s, thanks to a suggestion by William Shockley at Bell Labs, the inventor of the transistor.
Early photographic materials couldn’t withstand the harsh chemicals (like hydrofluoric acid) used in chip manufacturing. So, Kodak, famous for its camera film, stepped in to develop ‘KPR,’ a chemically resistant negative resist, and later ‘KTFR,’ which had better adhesion. KTFR became the industry standard for over 15 years.
But the real breakthrough was the arrival of positive-tone resist. The key was the ‘DNQ-Novolac’ system, originating from German blueprinting technology, which made much finer circuits possible. This tech spread to the US semiconductor industry, supposedly because a German company's American subsidiary was coincidentally located in the same New Jersey town as Bell Labs, leading to US and European firms dominating the market in the 1970s.
TOK moved incredibly fast. In 1979, it launched its decisive product: ‘OPR-800.’ While its performance was excellent, its true secret to success was its competitive price and the fact that it left less residue on wafers after use. This was a perfect match for the needs of Japan’s booming DRAM companies. They adopted OPR-800 en masse, allowing TOK to capture over 80% of the Japanese market. In a way, OPR-800 was the unsung hero behind Japan’s 1980s DRAM miracle.
The Rise of JSR and the Next Tech Leap π
While TOK dominated the market, another powerhouse quietly emerged: JSR. Originally a government-backed company making synthetic rubber for tires, JSR pivoted to electronic materials after the oil shock created a crisis. But JSR’s strategy was different.
JSR's Secret Sauce: Open Innovation and Global Strategy
The 1990s shift to DUV was a game-changer, and the solution was IBM’s ‘Chemically Amplified Resist (CAR).’ However, the technology was too sensitive for easy commercialization. Instead of hoarding it, IBM chose ‘open innovation,’ seeking collaboration with firms like JSR and TOK.
For JSR, this was a golden opportunity. At a time when Japan's semiconductor industry was slowing down, JSR used the partnership with IBM as a springboard to get ahead in the race to commercialize ArF photoresist. Building on this collaboration, JSR expanded its portfolio all the way to EUV and secured top-tier overseas clients like Samsung and Intel. By the early 2000s, it had become a true global player, with 70% of its revenue coming from international sales. Boldly leveraging technological partnership to conquer the global market was the core of JSR’s success story.
Photoresist at the Center of Geopolitics: The 2019 Japan-Korea Trade Dispute π
The strategic importance of photoresist was thrust onto the world stage during the July 2019 trade dispute between Japan and South Korea. Let’s take a closer, neutral look at what happened.
The Dispute and the Stated Positions
- Japan's Action: In July 2019, the Japanese government tightened export procedures for three materials to South Korea: EUV photoresist, high-purity hydrogen fluoride (HF), and fluorinated polyimides (PI).
- Japan's Official Stance: The stated reason was national security, citing concerns that these strategic materials could be diverted for military use and that South Korea's export control systems were inadequate.
- South Korea's Official Stance: It strongly protested the move, framing it as ‘economic retaliation’ for a 2018 South Korean Supreme Court ruling regarding compensation for wartime forced laborers.
So, what was the actual impact on the semiconductor industry? Ultimately, the feared worst-case scenario of a ‘production line shutdown’ never happened.
The regulations were narrowly focused on EUV photoresist, a cutting-edge technology at the time. Both Samsung and SK Hynix were still in the early stages of adopting EUV, so they didn't require large volumes for mass production immediately. Furthermore, suppliers like JSR had alternative supply routes through joint ventures, such as with IMEC in Belgium, preventing a complete supply chain collapse. The restrictions were eventually lifted in 2023 as relations between the two countries improved.
How Does Japan Dominate the Market? π―π΅
The dispute is over, but a fundamental question remains: even in the EUV era, how does Japan maintain its absolute leadership in photoresist? The secret isn’t just one thing but a combination of five powerful factors.
| Japan's 5 Keys to Photoresist Success | |
|---|---|
| 1. Manufacturing Clusters | Key players like TOK and JSR are geographically concentrated, creating a hotbed of innovation through the exchange of talent, tech, and information. This environment of competition and cooperation accelerates development. |
| 2. Open Innovation | They masterfully adopted external technologies, like IBM's CAR, and evolved from being mere adopters to indispensable co-development partners, fully internalizing the tech. |
| 3. Customer Co-Development | Advanced photoresists are not off-the-shelf products. They are custom-tailored solutions developed jointly with clients like Samsung and TSMC, creating a powerful barrier to entry due to massive switching costs. |
| 4. Long-Term Relationships | A business culture that prioritizes long-term trust and sustainable partnerships over short-term profits has built incredible stability and customer loyalty. |
| 5. Extreme Quality Control | The purity required is astounding—akin to allowing only one drop of impurity in two Olympic-sized swimming pools. This level of quality, built on decades of know-how, is nearly impossible to replicate quickly. |
Despite its strategic importance, the photoresist market is tiny compared to the overall semiconductor industry (around $2 billion), and profit margins are not high (JSR ~3.8%, TOK ~7.8%). This creates a ‘high-risk, low-return’ structure, making it vulnerable to outside acquisition attempts. A former JSR chairman once joked that it was ‘smaller than the ramen market in Japan.’
A National Asset: The Meaning of the JSR Takeover π’
This structural vulnerability eventually became a reality. After a failed acquisition attempt of JSR by Germany’s Merck in 2022 and continued pressure from activist funds, the Japanese government made an unprecedented move in 2023.
A government-backed fund (JIC) invested approximately $6 billion to acquire JSR, a healthy, profitable private company, and take it private. This was not a bailout; it was a clear declaration that Japan considers photoresist technology a core national asset essential for economic security and sovereignty, and that it would shield it from foreign threats.
The Photoresist Story: Key Takeaways
Frequently Asked Questions ❓
Talent exchange in Japan's photoresist industry is centered around building an ‘Open Innovation Ecosystem.’ Its key feature is the active use of global hubs rather than being confined to a specific region.
1. Global Collaboration at Albany NanoTech Complex: Scientists and engineers from Rapidus collaborate on next-gen technology with global firms like IBM, Samsung Electronics, JSR, and universities at the Albany NanoTech Complex in New York.
2. Rapidus-IBM Partnership: Rapidus is sending over 100 engineers to IBM's facilities to master Gate-All-Around (GAA) technology, crucial for the 2nm process, while also actively recruiting veteran semiconductor engineers within Japan.
3. Research Collaboration with IMEC in Belgium: They leverage international open innovation research hubs by collaborating with world-renowned semiconductor research center IMEC in Belgium.
Yes, the most prominent success story is the co-development of EUV photoresist between Dongjin Semichem and Samsung Electronics.
1. Domestic Success: They succeeded in developing EUV photoresist, one of the three items restricted by Japan in 2019, marking a major milestone in technological self-sufficiency.
2. Rapid Implementation: Samsung applied Dongjin Semichem's EUV PR to its mass production lines less than a year after it passed reliability tests, showcasing the success of their close collaboration.
3. Infrastructure and Global Collaboration: Dongjin Semichem made bold investments in its own lithography equipment and forged a partnership with IMEC in Belgium. Building on this, it has become the world's No. 1 supplier of PR for 3D NAND flash, with over 35% market share.
[Features of Japan's Open Innovation Model]
1. Consortium-Based Collaboration: ‘Rapidus,’ established in August 2022 with backing from eight major corporations including Toyota and Sony, aims to develop 2nm process technology by 2027, serving as a prime example of a national-level collaborative model.
2. Public-Private Partnership: Since 2021, the Japanese government has used large-scale subsidies to attract global giants like TSMC and Micron while also supporting domestic firms like Kioxia, rapidly restoring its domestic production base.
[Application for Korea]
1. National Strategic Approach: Korea must also recognize the semiconductor industry as a ‘survival strategy’ essential for economic security and move beyond short-term tax credits to establish a robust, long-term financial support system including subsidies, loans, and infrastructure.
2. Fostering Open Innovation: To truly succeed in domesticating materials and equipment, it's crucial to strengthen the quality of private-sector companies to a level that surpasses foreign leaders. This should be an opportunity to advance technological capabilities through open innovation, independent of external policies.
3. A Korean-Style CREATE Model: A six-point CREATE policy is proposed to make Korea a leader in open innovation where the creativity of startups and the global competitiveness of large corporations create synergy. This includes expanding funding for Proof-of-Concept (PoC) and matching funds, and increasing deal-sourcing opportunities.
And that’s a wrap! The story of how the liquid in a tiny bottle is shaping global geopolitics is pretty incredible, isn’t it? It will be fascinating to see how other small but strategically vital industries evolve in the future. If you have any more questions, feel free to ask in the comments! π
