Technology
An etch has to cut vertically without widening, remove one material while barely touching the one beneath it, and stop within a few atoms of a buried layer it cannot see. Doing all three at once, in holes tens or hundreds of times deeper than they are wide, is the hardest routine operation in a fab.
In one sentence
Plasma etch removes material from a wafer by exposing it to a reactive, electrically driven gas discharge in which ions are accelerated perpendicular to the surface, so that material is removed downwards rather than in every direction.
A wet chemical etch removes material equally in all directions, which rounds off any feature narrower than the film is thick. A plasma etch works because an electric field accelerates ions towards the wafer: the reaction proceeds where the ions land, so the floor of a feature is removed while its sidewalls are not. Everything else about the process — the gas mixture, the chamber pressure, the two separate power supplies that set plasma density and ion energy independently — exists to control that directionality.
Selectivity is the second requirement, and it works against the first. The process must remove one material quickly and the layer beneath it slowly, so that the over-etch needed to clear the slowest part of the wafer does not punch through elsewhere. The plasma's optical emission shifts when a new material is reached, and that shift is what tells the tool to stop. In high-aspect-ratio etch — the channel holes through a hundred or more stacked memory layers — neither requirement is comfortably met, and it is etch rather than lithography that limits how tall the stack can be.
The chemistry itself is isotropic; the anisotropy comes from ion bombardment and from deliberately depositing a thin passivating polymer on the sidewalls as the etch proceeds. The gas mixture is tuned so that the etch products redeposit on vertical surfaces and are cleared from horizontal ones. Getting that balance wrong shows up as a bowed profile, a tapered hole, or a feature that has widened enough to short against its neighbour.
Once a hole is fifty or more times deeper than it is wide, ions scatter on the way down, charge builds on the insulating sidewalls and deflects them, and etch products struggle to leave. The failure modes have their own names — bowing, twisting, incomplete clearing at the bottom — and the countermeasures are distinct too: very high bias energy, pulsed plasma, and cryogenic operation that changes how the passivating layer forms. This is the segment where equipment share is most concentrated.
Spacer-defined patterning sets the feature width by the thickness of a deposited film and then relies on etch to clear everything but the sidewall. Trim etches shrink a printed line after exposure. Selective removal takes one alloy out of a stack while leaving its neighbour, which is how the sheets in a gate-all-around transistor are released. In each case the final dimension is an etch result, which is why etch intensity per wafer has risen faster than exposure count.
1 of these is marked as a chokepoint: a handful of qualified suppliers, a multi-year lead time, or a single geography.
Fluorocarbons, chlorine, hydrogen bromide and nitrogen trifluoride are consumed continuously, come from a small supplier base, and several are subject to emissions regulation that constrains their use.
Specialty gasesEtch copies a pattern; it does not create one. Without a developed resist or hard mask defining where material should stay, a plasma etch simply thins the whole wafer.
PhotolithographyThe multi-patterning sequence that defines the smallest features depends on an atomic-layer film to etch back. The etch sets the profile, but the width comes from the deposition.
Atomic layer depositionThe stopping point is inferred from the plasma's emission spectrum, and the resulting profile measured by scatterometry or cross-section. Without both, a drifting chamber removes the layer beneath before anyone notices.
Metrology and testCorrosive process gases have to be delivered at controlled flow and then abated. Both the delivery line and the chamber parts it feeds are consumable items with their own qualification.
Ultrapure deliveryOther pages in this map that name Plasma etch as something they cannot do without.
What each company supplies at this step, and — where a public figure exists — its share of this specific market — with what that share measures, the period it covers and who published it. Some rows also show the company’s own reported revenue for the segment covering this step, which is a different thing: it says how much this business matters to that company, not how much of the market it holds. Not a ranking and not a recommendation.
Supplies conductor and dielectric etch across logic and memory, and is the established supplier for the deep high-aspect-ratio etches three-dimensional memory depends on.
System segment — 64.1% of Lam Research’s reported revenue ($14.9B)FY2026 · company filings · not a market share
Supplies conductor etch systems, and the selective removal processes that take one material out of a stack without attacking its neighbour.
Semiconductor Systems segment — 73.3% of Applied Materials’s reported revenue ($20.8B)FY2025 · company filings · not a market share
Supplies dielectric and conductor etch systems, and is the main alternative to the two American suppliers at most steps.
Supplies microwave plasma etch systems; a wholly owned unit of Hitachi rather than a separately traded company.
Supplies plasma etch systems qualified at advanced logic and memory nodes, and is China's principal domestic etch supplier.
Supplies etch systems alongside its deposition and cleaning lines to Chinese fabs.
Supplies plasma etch and deposition systems for compound semiconductor, photonics and specialty device production.
Supplies plasma etch and deposition systems for compound semiconductor, photonics and research-scale production.
Whether cryogenic and pulsed-plasma etch extend how deep one high-aspect-ratio etch can go, which sets how many layers a memory stack can hold before it has to be bonded from two.
Whether gate-all-around and backside power delivery raise the number of selective removal steps per wafer.
How far domestic Chinese etch suppliers qualify into leading-edge domestic fabs, since etch is the segment where they are closest to the incumbents.
Each page explains one technology in plain language, states what it depends on, and names companies by what they supply at that step. Company roles are described qualitatively and deliberately carry no market shares, revenue figures or rankings — those change faster than an explainer can, and a stale number is worse than none. Ticker links point at company pages on this site and are provided for reference only.
Nothing here is investment advice, a recommendation, or a forecast. A company named on a page about a technology is not thereby a good investment, and the chokepoints described are structural facts about supply chains rather than predictions about prices. Technology moves; where a page describes something as unresolved or in development, that was true when it was written.
Plutux is not an investment adviser. Market data and AI-generated analysis are for information and education only, not investment advice. Disclaimer