Ozone wafer cleaning substitutes for the sulfuric acid step in wet processing. Dissolved ozone water, DIO3, strips photoresist and removes organic residue where sulfuric acid and hydrogen peroxide mixtures have done the work since the 1970s. In Korea the technical case is mature enough that the commercial question dominates: who inside Samsung or SK hynix owns the decision, and what a foreign supplier has to clear to reach that person.
This page sits under the guide to Korea semiconductor market access and works the buying layer. Where ozone fits in the clean sequence, what removing sulfuric acid is worth to a Korean fab, who holds the supply position today, and what qualification looks like for an ozone generator or a DIO3 delivery system. Process selection, tool integration, and product specification route to Inquivix Technologies.
Where Does Ozone Sit in the Wafer Clean Sequence?
Ozone substitutes for the oxidizer, and in practice it targets one step. The RCA sequence that W. Kern and D. Puotinen published in RCA Review in 1970 still frames the vocabulary: SC-1, ammonium hydroxide with hydrogen peroxide and water, for organics and particles, and SC-2, hydrochloric acid with hydrogen peroxide, for metallic contamination. Sulfuric acid with hydrogen peroxide, known as SPM or piranha, sits above both for photoresist stripping and heavy organic removal.
A February 2019 outside-expert column on the SK hynix newsroom, by Professor Jin Jong-moon, notes that non-peroxide wet cleans applying ozone emerged to cut the volume of liquid chemistry the peroxide family consumes. Ozone is a volume and waste play at the resist strip and organic removal step. SC-1 and SC-2 keep the particle and metals work.
The step is large. That same column puts cleaning at about 15 percent of the 400 to 500 main process steps in semiconductor manufacture. Digital Daily reported in July 2023 that processes below 20 nanometres require more than 200 cleaning operations, more than double a legacy flow. Every added cleaning step multiplies chemical consumption, wastewater, and cost per wafer.
Ozone reaches the wafer as dissolved ozone water or as vapor phase in a humidified chamber, and the delivery choice drives the integration cost. Inquivix Technologies’ guide to ozone generators for semiconductor use covers that selection.
The engineering is current and published. Solid State Phenomena Volume 346, published August 2023, carries three consecutive papers on removing sulfuric acid from the strip and post-ash steps, one of them describing ozonated water and reclaimed SPM recycling already installed in high volume manufacturing fabs.
Why Do Korean Fabs Want the Sulfuric Acid Out?
Waste handling cost, chemical purchase volume, and Korean chemical law, in roughly that order.
The waste arithmetic is the clearest published case. KIPOST reported in December 2019 on ACM Research’s Ultra C Tahoe, a tool combining a batch SPM module with a single-wafer module, with a stated result of up to 80 percent less sulfuric acid waste than single-wafer SPM. The same article notes that Korea and Taiwan lack landfill capacity for sulfuric acid waste and treat it by high temperature purification, which consumes large amounts of energy and generates greenhouse gas emissions. Notably, ACM’s single-wafer module is configurable with SC-1, hydrofluoric acid, or DI-O3 at the customer’s request. Ozone is already a menu option on a commercial platform.
Korean tool makers are working the same seam from a different angle. Digital Daily reported in July 2023 that Zeus, selected as a materials, parts, and equipment leading company that March, sells a high temperature sulfuric acid tool that heats a plate instead of relying on the exothermic reaction between mixed chemicals, achieving the same effect on 30 percent of the previous chemical volume.
Then there is Korean law, which puts a step function at a concentration. The Ministry of Environment’s own guidance on classifying hazardous chemicals, published through its regional office in March 2018, works sulfuric acid as a specific example: substance number 97-1-405 is listed both as a toxic substance and as an accident preparedness substance for sulfuric acid and mixtures containing 10 percent or more. Below 10 percent it falls out of the hazardous chemical definition entirely. SPM runs far above that line, which pulls a fab into the Chemical Substances Control Act regime of business permits, handling facility installation and periodic inspection, and chemical accident prevention planning. The regulator has since written semiconductor-specific rules for that regime: the National Institute of Chemical Safety notice on installation and management of hazardous chemical handling facilities in the semiconductor manufacturing industry, notice 2022-20, took effect on 15 December 2022.
Ozone changes the shape of that exposure because it is generated on site from oxygen and decomposes back to oxygen. There is no bulk tank of a listed accident preparedness substance to permit, inspect, and evacuate around.
The honest counterweight belongs in the same conversation. Ozone moves load onto the ultrapure water plant and onto generator power, so a fab evaluating DIO3 is trading a chemical purchase and a waste stream for water demand and electricity. The scale of the water side is set out in the guide to the ultrapure water semiconductor market in Korea, and any credible ozone proposal to a Korean fab needs both halves of that ledger.
Who Holds the Ozone Supply Position in Korea Today?
Japanese and Western generator makers at the equipment layer, and the wet-clean tool maker at the fab interface. Those are two different sales, and an entrant who runs one playbook for both loses the first year to the wrong meetings.
At the generation layer, incumbency is long. Sumitomo Precision Products states on its ozone business page that it has extended ozone from wastewater treatment into manufacturing processes for pharmaceuticals, semiconductors, and flat panel displays, and it sells ozone generators alongside ozone-added ultrapure water production systems. Meidensha’s pure ozone generator liquefies and stores ozone gas to supply high-purity ozone continuously, is described as an oxygen radical source for semiconductor processes, was jointly developed with Japan’s National Institute of Advanced Industrial Science and Technology, and is published as conforming to SEMI S2, UL, NFPA, and CE. That last detail sets the documentation bar a challenger has to match.
At the tool layer sit the companies that own the fab relationship. Japanese makers lead batch wet cleaning, Tokyo Electron among them, per Digital Daily’s July 2023 account of Zeus competing in that segment. Zeus builds both single and batch tools, acquired Japan’s JET in 2009, established batch cleaning production through JET in 2020, and supplies Samsung and SK hynix. ACM Research configures DI-O3 into its single-wafer module. SEMES, Samsung Electronics’ equipment subsidiary, localized cleaning early and sells those tools mainly to Samsung, per The Elec in April 2026.
For a foreign ozone supplier the practical consequence is structural. Wet chemistry is configured into the tool. ACM Research places SC-1, hydrofluoric acid, or DI-O3 in its single-wafer module at the customer’s request, and MKS supplied LIQUOZON dissolved ozone systems into SEZ AG’s single wafer processors, per Semiconductor Online in July 2007. An ozone generator or DIO3 skid therefore usually reaches a Korean wafer line inside a tool maker’s bill of materials or as a central fab utility feeding those tools. Selling a standalone box into a fab that has not decided to change its clean chemistry is the slowest version of this sale.
Three functions have to align before an ozone system moves, and Samsung’s DS division recruiting site, accessed September 2026, names them. Semiconductor process engineering develops and standardizes the eight process technologies, Clean among them, so it owns the recipe and is the only group that can change the chemistry at all. Equipment engineering owns the wet bench and its pumps, chillers, and scrubbers, and with them the tool maker relationship. Infrastructure engineering runs the gas and chemical system, sets supply conditions of temperature, pressure, flow, and concentration for each process step, and applies Korean chemical law on the floor. Its facility and construction arm plans the fab utilities, so a central ozone loop, its oxygen feed, and its destruct and exhaust tie-in put the EPC contractor inside the decision on a new line. Purchasing issues the order after those groups have agreed. On a central utility, how the buying centers split between engineering, construction, and operations follows the pattern mapped in the ultrapure water guide.
What Does Korea’s Domestic Position Change?
It raises the cost of competing as a complete cleaning tool and leaves the generation and delivery layer open.
Korea’s government designated SEMES’s semiconductor cleaning process technology a National Core Technology in July 2025, following review by the Ministry of Trade, Industry and Energy and the Korea Industrial Technology Protection Association, as DigiTimes reported on 10 July 2025 citing Korean coverage. The designation covers technology for sub-30nm DRAM, foundry, and 3D NAND at 64 layers and above, and it carries legal penalties for leakage. DigiTimes notes SEMES responded by tightening access to technical data and its collaboration protocols with partner companies. SEMES had already had a supercritical drying process designated in 2022.
Read that as two signals at once. Korea considers advanced cleaning a protected national capability, which tells a foreign supplier how much of this category is genuinely contestable. And a foreign component supplier working inside a SEMES platform will meet tighter data handling, documentation, and partner qualification requirements than the same company would face elsewhere.
The policy money points the same way. Zeus received leading-company status in cleaning equipment with up to KRW 25 billion of research funding over five years under the Ministry of Trade, Industry and Energy programme, per Digital Daily in July 2023. The wider self-sufficiency target and what it does to a foreign supplier’s addressable estimate are covered in the guide to the Korea semiconductor equipment market.
The same policy pays a supplier that localizes. Korea’s facility investment tax credit for national strategic technologies has run since 1 April 2025 at 20 percent for large and mid-sized companies and 30 percent for SMEs, per the UNCTAD Investment Policy Monitor, and it is claimable only by a Korean enterprise investing in a facility the finance and industry ministers have jointly recognized as commercializing a national strategic technology. Until that recognition lands, a Korean sales or service subsidiary draws the ordinary integrated investment rate instead, as the guide to the K-Chips Act and Korea’s semiconductor incentives sets out. Locally produced supply also counts toward the resilience Korea is buying.
The conclusion for an ozone company is specific. Competing as a complete cleaning tool means bidding against funded and protected domestic capability. Selling ozone generation, dissolution, delivery, monitoring, and destruct as a qualified subsystem inside those tools means selling to that capability.
That route carries a condition. Samsung’s Responsible Business Alliance based Supplier Code of Conduct reaches past the first tier, with third-party audits covering 122 first-tier and 39 second-tier suppliers in its 2026 Sustainability Report, so a component vendor inside a SEMES bill of materials sits inside Samsung’s supplier management, as the guide to the Samsung and SK hynix supplier landscape sets out. Korean fabs also qualify a new foreign supplier as a second source more often than as a replacement, so in a category the government has named for localization, treat a funded domestic second source as a scheduled event rather than a risk.
How Does an Ozone System Get Qualified in Korea?
On two different clocks, depending on the route.
A subsystem entering an OEM platform runs the tool maker’s own supplier qualification first, and then enters the fab under the OEM’s tool qualification. A central ozone utility sold to the fab runs the full new-supplier path, typically 12 to 18 months or longer, laid out stage by stage in the guide to the fab qualification process in Korea.
One factor governs timing more than any other. Changing the clean chemistry is a process change, and changing a chemical formulation re-opens qualification of both the delivery system and the process, a lock-in SemiconductorX’s 2026 fab chemical delivery account extends to specialty cleaning chemistries. A live production loop leaves a new chemistry nowhere to be evaluated except a side stream or a test skid, which is why a construction phase is the practical opening. Samsung is bringing Pyeongtaek P4 into full operation during 2026 and started main construction on P5 in April 2026 for a 2028 production start, per Seoul Economic Daily, and SK hynix is building out four fabs at its Yongin semiconductor cluster over a ten-year program. An entry plan pinned to one of those milestones is more credible than one pinned to a sales quarter.
Compliance shifts with the chemistry. On-site generation from oxygen removes the bulk hazardous chemical inventory that drives the sulfuric acid regime, and moves the burden onto equipment safety certification, workplace exposure control, and gas handling. Expect KC certification questions on electrical equipment, SEMI S2 evidence of the kind Meidensha publishes, and Korean-language documentation for whatever chemistry remains on the tool. What the fabs ask for, and what Korean law requires in Korean, is set out in the guide to technical documentation for Korean fabs.
One acceptance criterion belongs to this category alone. Ozone decomposes back to oxygen in transit, so the fab writes DIO3 concentration and its stability into the supply condition at point of use, the way its infrastructure group specifies concentration for every other process chemical. The qualification argument then covers the whole loop: recirculation, materials compatibility, and dissolved ozone decay between the generator and the wafer. A generator datasheet on its own does not answer it.
Service closes the file. A DIO3 loop feeds a wet bench that gates wafer starts, and generator cells, dielectrics, oxygen supply, ozone destruct units, and leak monitoring all carry maintenance obligations. Korean buyers price that as Korean-speaking engineers, spares held in country, and response measured in hours around the clock, at the cost set out in the guide to after-sales service in Korean semiconductor procurement.
Frequently Asked Questions
Does ozone wafer cleaning replace RCA cleaning? Not as a whole sequence. Ozone chemistry mainly substitutes for the sulfuric acid and hydrogen peroxide step used for photoresist stripping and organic removal. A February 2019 column on the SK hynix newsroom describes ozone wet cleans as the non-peroxide branch that emerged to cut liquid chemical volume, while SC-1 and SC-2 continue to handle particles and metallic contamination.
Why do Korean fabs want to reduce sulfuric acid? Waste handling, cost, and Korean chemical law. KIPOST reported in December 2019 that Korea and Taiwan treat sulfuric acid waste by high temperature purification because landfill capacity is limited, consuming energy and producing emissions. Sulfuric acid at 10 percent or more is listed by the Ministry of Environment as both a toxic substance and an accident preparedness substance, which triggers permits, facility inspections, and accident planning.
Who makes ozone generators for semiconductor use? The established position sits with Japanese and Western equipment makers. Sumitomo Precision Products supplies ozone generators and ozone-added ultrapure water systems into semiconductor and flat panel manufacturing. Meidensha’s pure ozone generator, jointly developed with Japan’s National Institute of Advanced Industrial Science and Technology, is published as conforming to SEMI S2, UL, NFPA, and CE. On the Western side MKS Instruments supplies LIQUOZON dissolved ozone delivery systems. Wet-clean tool makers integrate these systems.
How does a foreign ozone supplier reach Samsung or SK hynix? Usually through a wet-clean tool maker’s bill of materials or as a central fab utility, with local representation carrying the account. Wet chemistry is configured into the tool, so the tool maker owns the fab interface. Korea’s designation of SEMES cleaning technology as a National Core Technology in July 2025 also tightens data handling for partner suppliers.
Inquivix Technologies represents global clean-process suppliers in Korea across hydrogen, ozone, and ultrapure water systems, covering distribution, technical localization, and fab-side coordination. Its guide to chemical free wafer cleaning and ozone-based alternatives takes the technical and product view. To discuss where your ozone technology fits against Korean fab demand, contact Joon K Lee at joon@joonklee.com.
