Chemicals, Gases and Photoresist

A modern fab is a chemical plant with lithography attached. Air Liquide alone supplies more than 200 molecules and roughly 50,000 cylinders a year^[1]. A shortage of any one of them can stop a fab.

How it works

The resist has to change only where the light lands, and change fast enough that the scanner, the machine that projects the pattern, can expose each patch of the wafer in milliseconds. Since the 1990s the standard resist has been the chemically amplified resist. At 248 nm and 193 nm, a photon absorbed in the film can free an acid molecule, and nothing more happens until the wafer is baked. In the bake, each acid molecule sets off hundreds of reactions around itself that turn the film soluble, so a little light does a lot of chemistry. The wash then takes away the exposed film and leaves the rest. The light comes at 248 nm from a krypton fluoride laser or 193 nm from an argon fluoride laser shining through a layer of water, which sharpens the image.

That chemistry works less well with extreme ultraviolet (see Lithography). An absorbed extreme ultraviolet photon instead knocks electrons loose, and a cascade of lower-energy secondary electrons makes the chemical changes in the resist^[3]. A 13.5 nm photon carries about fourteen times the energy of a 193 nm one, so the same dose of light arrives as far fewer photons. With fewer photons, where each one happens to land matters, and that randomness shows up as ragged line edges and missing contact holes, the small wells that join one layer of wiring to the next. Resist makers answered with metal-oxide resists, built on clusters with a tin-oxide core, which absorb more of the extreme ultraviolet light than chemically amplified resists^[4]. In 2021 JSR agreed to buy Inpria, an Oregon maker of these resists^[5].

Everything else puts material on the wafer, takes it off, or keeps it clean. Bulk gases arrive by the metric ton, specialty gases in grams. Silane carries silicon into the chamber for deposition. A plasma tears nitrogen trifluoride into charged fragments, which scrub the chamber walls clean between wafers. Hydrofluoric acid cleans the wafer itself. Polishing slurries grind each new layer flat before the next goes on. Sputtering targets are slabs of pure metal; a plasma knocks atoms off them, and the atoms settle on the wafer as thin metal films, including the barrier and seed layers for copper wiring^[6]. The copper wiring itself is then filled in by electroplating^[7]. Filters and carriers keep contamination out.

Variants and trade-offs

Each resist class is specific to one kind of lithography, such as EUV, ArF immersion, ArF, KrF or i-line^[8].

Who makes it

CSET's January 2021 brief, citing a 2019 estimate, gave Japan 90 percent of the semiconductor photoresist market, with the rest largely held by US and South Korean firms^[8]. A separate Fuji Keizai survey, relayed in the December 2025 strategy deck of Japan's Ministry of Economy, Trade and Industry, measures sales by company nationality and puts Japanese companies at 77 percent in 2021 and 78 percent in 2023, with American and South Korean companies next^[2].

Photoresist sales share by company nationality, 2023%

Japanese companies78%US, South Korean and other companies22%

Source: METI, December 2025, from Fuji Keizai data

CSET's January 2021 brief lists JSR, Tokyo Ohka Kogyo, Shin-Etsu Chemical, Fujifilm and Sumitomo Chemical of Japan as resist makers, along with Dongjin of South Korea, the American firms DuPont, EMD Performance Materials and Inpria, and four Chinese firms^[8]. Qnity Electronics, the former DuPont electronics business, says in its 2025 annual report that it offers lithography materials for every wavelength, including extreme ultraviolet^[9]. In its 2025 annual report summary, the Chinese firm Hubei Dinglong said China had yet to reach large-scale production of advanced resist for 248 nm, 193 nm or extreme-ultraviolet printing, though three of its own resists for 248 nm and 193 nm printing had moved into stable volume supply^[10].

A vehicle of Japan Investment Corporation, a state-backed fund, took 84.36 percent of JSR's shares at ¥4,350 each in a tender offer that closed on 16 April 2024^[11]. JSR's shares were delisted from the Tokyo Stock Exchange on 25 June 2024^[12].

Tokyo Ohka Kogyo sold ¥139,668 million in the first half of fiscal 2026, up 25.1 percent, as strong demand for AI servers in data centers raised demand for chips^[13]. Fujifilm planned to raise its polishing-slurry capacity at Kumamoto by about 30 percent from January 2025^[14]. It also scheduled new production and quality-evaluation equipment for extreme-ultraviolet resist at Shizuoka and Pyeongtaek to start in October 2025^[15].

Wafer fabrication materials sold $45.8 billion in 2025 and packaging materials $27.4 billion^[16].

In electronic gases, CSET named Merck, Air Products and Air Liquide as the market leaders in January 2021^[8]. Air Liquide's electronics arm alone sold €2,465 million in 2025, 9.1 percent of group revenue^[1]. Smaller firms specialize in single molecules: SK Materials in nitrogen trifluoride, Kanto Denka in fluorine chemistry, Stella Chemifa and Morita in ultra-high-purity hydrofluoric acid.

CSET's January 2021 brief, drawing on 2019 market reports, put five firms at more than 60 percent of wet chemicals and DuPont and Cabot Microelectronics at about 56 percent of a $790 million market in polishing slurries^[8]. The same Fuji Keizai survey that METI relayed counts sales by company nationality, and it puts Japanese companies at 51 percent of polishing-slurry sales and 59 percent of high-purity cleaning-liquid sales in 2023, up from 49 percent of each in 2021^[2]. Cabot Microelectronics renamed itself CMC Materials in October 2020^[17]. Entegris completed its purchase of CMC Materials on 6 July 2022^[18]. DuPont separated its electronics business into an independent company, Qnity Electronics, on 1 November 2025^[19]. Qnity sells polishing slurries and pads^[20]. In sputtering targets for semiconductors, JX Advanced Metals puts its own share of the world market at about 65 percent as of fiscal 2026^[21].

The chokepoint

Supply at this stage has been disrupted three times since 2019, twice by governments and once by a war.

In July 2019 Japan put photoresist, hydrogen fluoride and fluorinated polyimide under individual export licenses for South Korea. It had supplied more than 90 percent of Korean imports of two of the three, and hydrogen fluoride exports fell 87.9 percent^[22]. Japanese photoresist exports to Korea did not fall, possibly in part because Japan allowed three-year bulk licenses for some resist sales in December 2019^[22]. South Korea bought more hydrogen fluoride from the United States and Taiwan and more photoresist from Belgium, and production of all three chemicals rose inside the country^[22]. The same study found that Japanese hydrogen fluoride exports to the United States rose, which may mean some Japanese supply reached Korea by way of the United States^[22]. The rise in Korean output came both from Korean firms and from Japanese companies' affiliates in South Korea^[22]. Japan ended the individual licenses on 23 March 2023, when it put exports of the three chemicals to South Korea under its bulk export license system^[23].

In 2022 Russia invaded Ukraine, which supplied about 70 percent of the world's neon and 90 percent of the semiconductor-grade neon used by US industry^[24]. Many chipmakers had added to their gas stockpiles after Russia annexed Crimea in 2014, and Samsung, SK Hynix, Renesas and Rohm reported adequate neon supplies from China^[24].

China's export controls fall on the metals. Beijing announced export licenses for gallium and germanium on 3 July 2023, in force from 1 August^[25]. On 3 December 2024 it said it would in principle grant no licenses to export gallium, germanium, antimony or superhard materials to the United States^[26]. On 9 November 2025 it suspended that ban until 27 November 2026^[27]. Under a trade deal set out by the White House on 1 November 2025, China also agreed to issue general licenses for exports of gallium, germanium and antimony for the benefit of US end users and their suppliers^[28].

In the United States, germanium goes mainly into fiber optics, infrared optics, semiconductors and solar cells, and radiation detectors^[29]. Of the gallium used in the United States, 73 percent went into integrated circuits built on gallium arsenide or gallium nitride, and 26 percent into optoelectronic devices such as LEDs and laser diodes^[30]. Germanium metal averaged $4,100 a kilogram in 2025 against $1,392 in 2023, and US imports of the metal fell 67 percent in 2025 because of China's ban^[29]. The US Geological Survey estimated that a total Chinese ban on gallium and germanium exports could cut US GDP by $3.4 billion^[31].

Germanium metal, annual average price ($/kg). China licensed exports from August 2023, banned US shipments in December 2024 and suspended the ban from November 2025 to 27 November 2026$/kg

Germanium metal, annual average price ($/kg). China licensed exports from August 2023, banned US shipments in December 2024 and suspended the ban from November 2025 to 27 November 2026

2021	1,187 $/kg
2022	1,294 $/kg
2023	1,392 $/kg
2024	1,991 $/kg
2025	4,100 $/kg

Source: USGS Mineral Commodity Summaries, February 2026 (Argus Media prices)

The slower risk is the European Union's proposed restriction on PFAS, the long-lived fluorinated chemicals. The five national authorities behind it, from Denmark, Germany, the Netherlands, Norway and Sweden, evaluated more than 5,600 comments and updated the proposal, which ECHA, the EU chemicals agency, published on 20 August 2025^[32]. In March 2026 ECHA's two scientific committees backed an EU-wide restriction with targeted derogations, one in a final opinion and one in a draft, and their evaluation is due to finish by the end of 2026^[33]. These chemicals are everywhere in a fab: photoacid generators, etch gases, chamber liners, pump seals and filter membranes are all fluorinated. The updated proposal assessed options that would let electronics and semiconductor makers keep using PFAS where the risks can be controlled, and the European Commission will decide in consultation with the member states^[32].

Key evaluation criteria

• Purity, in parts per trillion of metallic contamination, a million times finer than parts per million, which is the spec that keeps entrants out.
• Qualification lock-in: a resist or slurry is approved for one layer of one product at one fab, so switching costs are counted in tape-outs.
• Photon efficiency for EUV resists: how much light the resist absorbs sets the dose, the dose sets how many wafers an hour the scanner prints, and too few photons per dose set the defect rate, which is the case for metal-oxide chemistry.
• Transportability: bulk gases are often made on site at the fab, while specialty gases travel in cylinders and can be embargoed.
• Byproduct exposure: gallium is recovered mostly as a byproduct of processing bauxite^[30]. Germanium comes from certain zinc ores and coal deposits, so supply of both depends on another industry's economics^[29].