1. What Hydrofluoric Acid Is and What It Does
Hydrofluoric acid is element 9 in liquid form — fluorine dissolved in water (or, in its anhydrous form, pure hydrogen fluoride without water). It is one of the most reactive substances in industrial use, capable of dissolving silicon dioxide — the material that glass is made of and the material that insulating layers in semiconductor devices are made of — at room temperature. That property is the reason it is irreplaceable in chip manufacturing. Nothing else dissolves silicon dioxide with the precision and selectivity that semiconductor fabrication requires.
Before getting to the semiconductor application, the grade distinction matters because it changes everything about the supply chain analysis.
Industrial grade HF covers a wide range of applications where purity is measured in percentage points: fluorochemical production (refrigerants, fluoropolymers like PTFE — polytetrafluoroethylene, the material better known by the DuPont trade name Teflon), oil refinery alkylation (a process that uses HF as a catalyst to produce high-octane gasoline blending components), metal surface treatment, glass etching, and mineral processing. Industrial HF purity is typically 70%+ concentration, with acceptable impurity levels measured in hundreds or thousands of parts per million. The China domestic price of approximately $1,771/MT reflects industrial grade.
Electronic grade HF — EG-HF — is a different product manufactured to fundamentally different specifications. Semiconductor fabrication requires HF at 99.9999%+ purity (six-nines purity, meaning less than one part per million of total metallic impurities). A single sodium ion, a single iron atom, a single calcium particle in the wrong place on a silicon wafer can destroy a transistor or create a defect that propagates through an entire chip layer. The purity requirements are not a preference — they are a physical constraint imposed by the dimensions of modern transistor structures, which are measured in nanometers and cannot tolerate contamination at scales invisible to any conventional measurement.
EG-HF commands a significant price premium above industrial HF. The production requires specialized distillation equipment, ultra-clean handling systems, contamination-controlled packaging, and analytical verification at every stage. A handful of companies globally produce EG-HF to the purity levels required by leading-edge semiconductor fabs. Stella Chemifa and Morita Chemical Industries in Japan are among the most established. The supply chain for semiconductor-grade HF is thin, technically demanding, and geographically concentrated in Japan, South Korea, and, increasingly, China.
Plain English
HF dissolves silicon dioxide — the insulating material inside every chip. Industrial HF is used in dozens of applications. Electronic grade HF is the same chemical at million-times-higher purity, used in semiconductor fabs. You cannot make a chip without it at either grade, but the semiconductor application needs a level of purity that only a handful of companies in the world can achieve. China dominates the industrial grade. Japan dominates the semiconductor grade. The feedstock for both comes primarily from China.
2. The Fluorspar Connection
Hydrofluoric acid is made from two ingredients: fluorspar and sulfuric acid.
The reaction is precise: calcium fluoride (CaF₂, the chemical name for fluorspar — a mineral mined primarily in China, Mexico, South Africa, and Mongolia that is the primary commercial source of fluorine) plus sulfuric acid (H₂SO₄) produces hydrogen fluoride (2HF) plus calcium sulfate (CaSO₄, a byproduct commonly known as synthetic gypsum). Written as a chemical equation: CaF₂ + H₂SO₄ → 2HF + CaSO₄.
The reaction is simple. The feedstock supply is not.
China accounts for approximately 62% of global fluorspar output — roughly 5.8 million tonnes annually (USGS, 2024–2025 data). Acid-grade fluorspar (calcium fluoride concentrate at 97%+ purity, the grade required for HF production — distinguished from metallurgical-grade fluorspar used as a flux in steel production) is the input that determines who can make HF and at what cost. Controlling the fluorspar means controlling the upstream economics of HF production globally.
The second ingredient — sulfuric acid — connects this page directly to the sulfuric acid page on this site. China also produces sulfuric acid at lower domestic cost than international markets, for the structural reasons documented there: byproduct acid from copper and zinc smelting produces cheap domestic supply. The HF production feedstock chain — Chinese fluorspar combined with cheap Chinese sulfuric acid — gives Chinese HF manufacturers a cost structure that Western producers cannot replicate without access to both inputs at comparable cost.
The United States has no domestic fluorspar production whatsoever, and relies entirely on imports for its estimated 400,000–500,000 tonnes of annual consumption. Every HF facility in the United States depends on imported fluorspar — primarily from Mexico, which holds approximately 20% of global production and where Orbia operates significant mining capacity. The CHIPS Act is building new fabs in America that will need American HF made from feedstock America does not produce.
Plain English
HF requires fluorspar plus sulfuric acid. China produces 62% of the world's fluorspar. China also produces cheap domestic sulfuric acid. Western HF producers pay more for both inputs. The US produces no fluorspar at all — it imports everything. The CHIPS Act is building American fabs that will need American HF from a supply chain that starts with imported raw material at every step.
3. The Semiconductor Dependency
No semiconductor can be fabricated without hydrofluoric acid. This is not a figure of speech or a supply chain risk framing — it is a physical fact about how silicon-based chips are manufactured.
The fabrication of a modern semiconductor device involves hundreds of individual process steps — deposition (adding thin layers of material), lithography (printing circuit patterns using light), etching (removing material with precision), implantation (introducing dopants), and cleaning (removing contamination and residues). HF is required at more than 60% of all process steps in a typical semiconductor fabrication sequence.
The two most fundamental HF applications in chip manufacturing are silicon wafer cleaning and silicon dioxide etching.
Silicon wafer cleaning: every wafer that enters a fab must be cleaned to remove organic contamination, metallic particles, and native oxide (the thin layer of silicon dioxide that forms spontaneously when silicon is exposed to oxygen in air) before any process step that requires a clean silicon surface. HF cleaning removes the native oxide and leaves a hydrogen-terminated silicon surface that is stable against re-oxidation long enough to proceed to the next process step. This cleaning step is performed repeatedly throughout the fabrication sequence — before deposition, before implantation, before certain lithography steps. Every cycle requires HF.
Silicon dioxide etching: modern transistors are built in a three-dimensional structure that requires selective removal of silicon dioxide insulating layers with angstrom-level precision. HF etches silicon dioxide but does not significantly attack silicon — this selectivity is the chemical property that makes it irreplaceable. Buffered HF solutions (BHF — a mixture of HF and ammonium fluoride that controls the etch rate for precise process control) are used for wet etching of oxide layers throughout the device structure. Vapor phase HF is used for more delicate applications where liquid contact would damage fragile structures.
There is no substitute for HF in these applications. Attempts to replace HF with alternative chemistries have been investigated for decades — motivated precisely by the hazardous nature of the chemical and the supply chain concentration concerns. None has achieved comparable selectivity and process compatibility for silicon dioxide removal at the dimensions required by modern devices. The semiconductor industry is locked into HF by chemistry, not by inertia.
Plain English
Chip fabs use HF at more than 60% of all process steps. It cleans silicon wafers by removing the oxide layer that forms when silicon touches air. It etches the insulating layers inside transistor structures with precision nothing else matches. Every chip — every AI GPU, every processor, every memory chip in a data center — was made using hydrofluoric acid. There is no substitute. The supply chain built $52 billion of new fabs without first building the domestic HF supply those fabs will need.
4. The CHIPS Act Problem
The CHIPS and Science Act of 2022 committed approximately $52 billion to semiconductor manufacturing incentives in the United States. The construction it has triggered is real and substantial: TSMC's Arizona fabs, Intel's Ohio campus, Samsung's Taylor facility, Micron's Idaho expansion. American semiconductor manufacturing capacity is being rebuilt after decades of offshoring.
The CHIPS Act investments address the manufacturing capacity gap. They do not address the materials supply chain gap.
TSMC's Arizona fab requires EG-HF at six-nines purity for wafer cleaning and oxide etching. The supply of EG-HF to TSMC Arizona will need to meet TSMC's exacting specifications — the same specifications its Taiwan facilities meet, which have been refined over decades of working with Japanese EG-HF specialists. There is no domestic US EG-HF supplier currently qualified to supply TSMC Arizona at the purity levels and volumes required for leading-edge production. The qualification process for a new EG-HF supplier at a leading-edge fab is measured in years, not months.
The same gap applies to every other new CHIPS Act fab. Intel Ohio, Samsung Taylor, Micron Idaho — all require EG-HF supply chains that do not currently exist at the required scale and qualification status for domestic US sourcing.
The CHIPS Act also requires recipients to not expand leading-edge semiconductor manufacturing in China for ten years. This guardrail is designed to reduce Chinese supply chain dependence. But the HF feedstock supply chain — fluorspar from China, converted to HF with Chinese sulfuric acid — runs directly through the supply chain the guardrail is trying to reduce dependence on. The US has no domestic fluorspar production. American HF production uses imported feedstock. Building new fabs in America without building new domestic HF supply chains is building half the solution.
The semiconductor HF market is growing at 11–16% CAGR through 2035, driven by AI chip demand and the CHIPS Act buildout. That demand growth will need to be met by a supply chain that has not been built yet at the scale required.
Plain English
The US committed $52 billion to build new chip fabs. The fabs are being built. The domestic HF supply chain those fabs need does not exist at the required scale or purity level. No US supplier is qualified for leading-edge production. The US has no domestic fluorspar production — the feedstock for HF must be imported. The CHIPS Act built the factory without building the chemistry. The manufacturing investment arrived before the materials supply chain.
5. The Supply Structure
The HF supply chain outside China is real but structurally exposed to Chinese feedstock.
Honeywell is the largest US HF producer, operating facilities that produce both industrial and specialty HF grades. Honeywell's fluorine chemistry operations have deep roots in refrigerant and fluoropolymer production — the industrial HF applications that precede the semiconductor market by decades. Honeywell has capabilities in high-purity HF but has not historically been the primary EG-HF supplier for leading-edge Asian fabs.
Solvay in Belgium is the primary European HF producer, with fluorochemical operations supplying industrial and specialty markets. European HF supply is concentrated in a small number of producers serving a mix of industrial and semiconductor customers.
Orbia (formerly Mexichem) operates the San Luis Potosí facility in Mexico, benefiting from Mexican fluorspar deposits — one of the few HF production facilities in the Western Hemisphere with meaningful feedstock independence from Chinese fluorspar. Mexico holds approximately 20% of global fluorspar production. The geographic proximity to the United States and the domestic fluorspar supply makes Orbia's operations relevant to North American HF supply chain resilience.
The Japanese EG-HF specialists — Stella Chemifa and Morita Chemical Industries — represent the highest point of the EG-HF supply chain. Both companies have decades of experience producing ultra-high purity HF for TSMC, Samsung, and other leading-edge fabs. Their qualification at leading-edge nodes is deep and well-established.
The 2019 Japan-Korea trade dispute demonstrated how thin this supply chain is. Japan restricted exports of HF (along with photoresists and fluorinated polyimide) to South Korea as part of a bilateral trade dispute. Samsung and SK Hynix — whose fabs depend on Japanese EG-HF — spent weeks managing emergency inventory and accelerating qualification of alternative suppliers. The disruption lasted months before diplomatic resolution. The structural fragility has not been fundamentally addressed since.
The CHIPS Act construction is adding demand to this supply chain without proportionally adding supply. New US fabs that cannot source domestic EG-HF will source it from Japan — deepening the concentration in a supply chain that was already concentrated before the buildout began.
Plain English
Western HF producers exist but their industrial HF is not the same product as the EG-HF that leading-edge fabs need. Japan's Stella Chemifa and Morita are the EG-HF specialists fabs actually depend on. The 2019 Japan-Korea dispute showed what happens when that thin supply chain gets disrupted — Samsung and SK Hynix scrambled for months. The CHIPS Act is adding new fabs to a supply chain that was already thin. The feedstock for all of it flows through Chinese fluorspar.
6. Why It Belongs in the Reagent Layer
The Reagent Layer exists on this site because the supply chain doesn't end at the mineral. Hydrofluoric acid belongs in the Reagent Layer for the most direct reason of any entry in this section: it is present at more than 60% of all semiconductor fabrication steps, woven continuously through the process of making the chips that run the digital economy.
The fluorspar connection closes the loop between this page and the broader ScarceEarth thesis. China controls 62% of the fluorspar that produces the HF that cleans the wafers and etches the transistors in every chip made anywhere in the world. The US has no domestic fluorspar. The CHIPS Act is building fabs without solving that dependency.
The chemistry is the supply chain. The feedstock for the chemistry is the supply chain before the supply chain. Hydrofluoric acid is the layer between the fluorspar mine and the silicon wafer — the step that is invisible in the finished chip but present at every step of making it.
That is the same structure as every rare earth page on this site. Different chemical, different layer, same physical floor. The digital economy runs on chips. The chips are made with HF. The HF is made from Chinese fluorspar. The physical floor of the digital economy runs through this reagent.
Plain English
Every chip is made using HF at more than 60% of its manufacturing steps. China controls 62% of the fluorspar that makes HF. The US produces none of it domestically. The CHIPS Act built the fabs without solving this. The reagent that makes the chip is made from the mineral China controls. That's why it belongs in the Reagent Layer.