Hydrofluoric acid and Semiconductors

Ultra-high-purity hydrofluoric acid is used to clean wafers and etch oxide layers in every fab, and its supply runs from mostly Chinese fluorspar through a few mainly Japanese purifiers; Japan's 2019 curbs on Korea showed how a cheap chemical can become a lever over chipmaking.

Hydrofluoric acid (chemical) and Semiconductors (industry): 3 relationships.

How they are linked

1. Industry input

Physical flow · Strong · Hydrofluoric acid → wafer cleaning and etching

Hydrofluoric acid dissolves silicon oxide, so dilute and buffered grades are used to strip oxide and clean wafers between process steps; two enterprise types in semiconductors depend on it, rated 4 of 5 on criticality.

• 2 enterprise types that depend on it
• 4 of 5 highest criticality: wafer makers and electronic chemical suppliers

Silicon wafer makers use it for wafer cleaning and electronic chemical suppliers use it as the base for etching blends. USGS describes hydrofluoric acid as essential to cleaning and etching in semiconductor manufacturing. The electronic grade must be purified far beyond industrial acid and every change of material must be requalified by the fab, which is why criticality is rated high.

Enterprise types that depend on it:

• Silicon wafer makers: wafer cleaning (criticality 4 of 5)
• Electronic chemical and specialty gas suppliers: base for etching chemicals (criticality 4 of 5)

Sources: Material Insights; USGS

2. Japanese high-purity supply

Shared risk · Strong · Japanese purifiers → chipmakers elsewhere

A small number of Japanese firms, such as Morita Chemical and Stella Chemifa, have long supplied most of the high-purity hydrogen fluoride used by chipmakers, so a change in Japanese export licensing can disrupt fabs abroad.

• 80 to 90% share of the world high-purity hydrogen fluoride market held by Japanese firms, Korean press estimate, 2020
• 86% lower Korean imports of hydrogen fluoride from Japan in 2020 than in 2018

In July 2019 Japan tightened export licensing of hydrogen fluoride, photoresists and fluorinated polyimide for South Korea, which had sourced 44% of its etching gas imports from Japan in the first five months of that year; the first hydrogen fluoride shipment was approved only at the end of August 2019. Korean chipmakers turned to local purifiers such as Soulbrain and to other suppliers, so imports from Japan fell sharply, then rose 34% in 2021 as chip demand grew. Japan ended the curbs in 2023 and Korea withdrew its WTO complaint.

Sources: The Japan Times; Asia Economy; Asia Economy; AJOT (AFP); The Daily Star (Reuters)

3. Fluorspar upstream

Physical flow · Medium · Fluorspar → hydrogen fluoride → electronic-grade acid

All hydrofluoric acid is made by reacting acid-grade fluorspar with sulphuric acid, so the electronic grade inherits the concentration of fluorspar mining.

• about 60% China's share of world fluorspar mine output, 2025 (6.0 of 10 Mt)

Hydrofluoric acid production is by far the leading use of acid-grade fluorspar. Any electronic-grade supply chain, whether in Japan, Korea or India, therefore rests on fluorspar that is mostly Chinese; other sources include Mexico (about 1.5 Mt in 2025) and South Africa (about 0.4 Mt).

Sources: USGS

For investors

Key learnings

1. Electronic-grade hydrofluoric acid cannot be skipped and each supplier must be requalified by the fab, so purity and qualified supply matter more to chipmakers than price.
2. The 2019 Japan to Korea curbs showed that a supplier country can disrupt chipmaking through licensing alone, and that buyers respond by qualifying local purifiers: Korean imports from Japan were 86% lower by 2020.
3. About 60% of fluorspar mine output was Chinese in 2025, so high-purity acid makers outside China carry feedstock risk even when their purification is local.

What to track

• Fluorspar (acidspar) price and Chinese output: Feedstock cost and availability for all hydrofluoric acid (Quarterly · USGS Mineral Industry Surveys, Argus)
• Export licensing rules for fluorine chemicals in Japan and China: Risk of supply disruption to fabs (As announced · METI, China Ministry of Commerce)
• Semiconductor materials revenue by region: Demand for electronic-grade chemicals where new fabs open (Yearly · SEMI)

For policymakers

Key learnings

1. A fab programme needs a qualified local or diversified source of electronic-grade hydrofluoric acid, not only a chip plant.
2. Indian firms such as Tata Chemicals are scaling up high-purity etching and cleaning chemicals, which India has historically imported, mainly from Japan and the United States.
3. Korea's post-2019 localisation shows that purification capacity can be built within a few years when anchor customers commit to qualifying it.

What to track

• Imports of electronic-grade hydrofluoric acid by source: Dependence on Japan and other suppliers as Indian fabs start (Monthly · DGCI&S, Ministry of Commerce)
• Domestic qualification of high-purity acids at Indian fabs: Progress on local supply for the India Semiconductor Mission (Yearly · company announcements, MeitY)

India

India's fabs are still being built, and Indian firms such as Tata Chemicals are scaling up high-purity chemicals for etching and cleaning; these chemicals have so far been imported, mainly from Japan and the United States.

Sources

1. Semiconductors: materials, Material Insights (2026)
2. Mineral Commodity Summaries 2026: Fluorspar, USGS (2026)
3. Japan approves first export of hydrogen fluoride to South Korea since tightening rules, The Japan Times (2019)
4. Japan grants additional permission for hydrogen fluoride exports... what's behind it?, Asia Economy (2020)
5. 3 years of Japan's export restrictions: Korea's localisation efforts stagnant, Asia Economy (2022)
6. Japan ends curbs on exports of chip materials to South Korea, AJOT (AFP) (2023)
7. Indian chemical firms step up to fuel self-reliance in semiconductor manufacturing: report, The Tribune (ANI) (2025)
8. The high-tech trade dispute rooted in Japan's wartime history (Reuters explainer), The Daily Star (Reuters) (2019)