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Run your analysis now →https://www.patsnap.com/resources/blog/rd-blog/wet-etching-and-selectivity-control-patent-landscape/ · Patsnap · data cut-off 2026-07-31 · downloaded from the live page
Patent Landscape · Wet Etching & Selectivity ControlWet Etching and Selectivity Control Patents: Who Holds the Ground
- 29.7% concentration at the top. The five leading assignees hold 2,857 of 9,618 records in scope, but that still leaves a long tail of single- and low-filing entrants below tenth place.
- Filing cooled through the early 2020s. From a 2020 peak of 485 records, filings fell from 452 in 2021 to 250 in 2024 — a 45% drop over that three-year span, before the most recent, still-incomplete years.
- Claims cluster hard in semiconductor devices. H01L accounts for 51.8% of all records in scope, meaning selectivity and etch-rate claims are overwhelmingly filed as device or process steps rather than as standalone chemistry.
9,618
Published Records
30%
Top-5 Share of All Records
-45%
Filing Growth 2021→2024
US
Leading Jurisdiction
Filing growth compares 2021 (452 records) with 2024 (250) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 9,618 records in scope (CR5), not by the ranked leaders only.
Published byPatsnap Research··7 min readSourced from Patsnap Eureka
Overview
What this landscape covers
Wet etching and selectivity control sits at the intersection of process chemistry and device fabrication: hot phosphoric acid baths, nitride-to-oxide selectivity, bath aging, and temperature control at point of use are the recurring technical anchors in this dataset. The search captures records where etch-rate uniformity and silicon loss are treated as engineering variables to be measured and controlled, not just described. 9,618 records are in scope from 2015 through the 2026 data cut-off, spanning semiconductor fabrication, materials characterization, and adjacent lab-apparatus filings.
Because publication trails filing by roughly 18 months, the most recent one to two years in any trend understate real filing activity. The 2024 figures are the last that can be read as materially complete; 2025 and 2026 will continue to fill in as those applications publish.
Filing activity and technology composition, 2017–2026
Source: Patsnap Eureka. Assignee ranking and totals. Derived from a Patsnap search on Wet Etching and Selectivity Control covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
The Data
Filing trends and technology composition
The two views below — filing volume over time and IPC subclass composition — are the two questions worth asking before drafting any claim in this space: is the field growing or contracting, and where does prior art actually sit.
Filing trend, 2017–2026
Filings rose to a peak of 485 records in 2020, then declined from 452 in 2021 to 250 in 2024 — a 45% fall over that three-year window. Treat 2025 and 2026 figures as provisional given publication lag; they are not evidence of a further slowdown.
IPC subclass composition
H01L (semiconductor devices) covers 51.8% of the 9,618 records in scope, with H10P at 22.2% and G01N (material analysis and testing) at 10.7%. Because records can carry multiple IPC classes, these shares sum to well over 100% and should be read as overlap, not as a partition of the field.
Shares are the percentage of the 9,618 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Source: Patsnap Eureka. Filing trend and technology composition. Derived from a Patsnap search on Wet Etching and Selectivity Control covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.
Go deeper on Wet Etching and Selectivity Control with Eureka
This page is one run against one query. Ask Eureka your own question about wet etching and selectivity control and every answer comes back with the patent numbers behind it.
Try EurekaKey Patents
A representative early filing
Representative Filing
EP0474482A1 — hot phosphoric acid etch temperature control (Fujitsu, 1992)
FUJITSU LIMITED
A method of fabricating a semiconductor device by etching a silicon nitride layer in a hot phosphoric acid solution, where a low-concentration phosphoric acid supply is triggered once the bath temperature crosses a first threshold and a set time has elapsed — an early instance of closed-loop bath composition control rather than fixed-recipe etching.Filed by Fujitsu, published 1992 — predates the bulk of the dataset and anchors the temperature/concentration control lineage that later filings build on.
Most-cited records in scope
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | WO2007123744A2 | Systems and devices for sequence by synthesis analysis | 2,073 |
| 2 | US6573030B1 | Method for depositing an amorphous carbon layer | 1,381 |
| 3 | US20100111768A1 | Systems and devices for sequence by synthesis analysis | 1,242 |
| 4 | US6379929B1 | Chip-based isothermal amplification devices and methods | 906 |
| 5 | US20050287771A1 | Liquid precursors for the CVD deposition of amorphous carbon films | 855 |
| 6 | US20110061810A1 | Apparatus and Methods for Cyclical Oxidation and Etching | 842 |
| 7 | US20030091938A1 | Method of depositing an amorphous carbon layer | 832 |
| 8 | US20150270140A1 | Atomic layer or cyclic plasma etching chemistries and processes | 812 |
| 9 | US20050023656A1 | Vertical system integration | 785 |
| 10 | US20120009802A1 | Plasma activated conformal dielectric film deposition | 759 |
Citation counts favor older records simply because they have had more time to accumulate them — read this table as a map of influence within the searched corpus, not as a ranking of current importance.
Each row carries its publication number; clicking a row searches Eureka by that number.
Source: Patsnap Eureka. Citation counts and representative records. Derived from a Patsnap search on Wet Etching and Selectivity Control covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
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Reading the concentration and momentum data together
Three figures matter more than the rest of the dataset for deciding where to file and who to watch.
Concentration
29.7%
of 9,618 records held by top 5
The top of the field is dense, the rest is thin
Five assignees hold 2,857 of the 9,618 records in scope, and the top ten hold 3,764 (39.1%). That leaves the ranked leaders' remaining 90 positions splitting a much smaller share, which is the profile of a field with a small set of process-tool incumbents and a wide field of device makers filing incidentally.
Assignee ranking, 100 companies
Momentum
-45%
filings, 2021 to 2024
Volume is off its 2020 peak
Filings peaked at 485 in 2020, then fell from 452 in 2021 to 250 in 2024. That is a real three-year contraction, not a publication-lag artefact, since 2024 is the last year that can be read as materially complete.
Filing trend, 2017-2026
Composition
51.8%
of records classed under H01L
Claims are filed as device steps, not standalone chemistry
Over half of all records in scope sit in H01L (semiconductor devices), with H10P and G01N as the next largest subclasses. Etch-selectivity and bath-control inventions are mostly claimed inside a larger device or process patent rather than as a freestanding wet-chemistry method.
IPC composition, 8 subclasses tracked
Eureka AI Agent
Looking for what nobody has claimed yet?
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to wet etching and selectivity control, with the prior art for and against each one.
Source: Patsnap Eureka. Co-assignee relationships and derived observations. Derived from a Patsnap search on Wet Etching and Selectivity Control covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
Players
Who is filing, and where activity is easing
The leader in this ranking holds 868 records against a fifth-place figure of 238 and a tenth-place figure of 123 — a steep drop-off that flattens quickly once you move past the first few names. Recent-year momentum by assignee shows the same pattern from the other direction: several of the largest holders posted sharp year-on-year declines in their latest-year counts, though those latest-year totals are still small and subject to publication lag.
Leader
868
records
A single process-tool incumbent leads by a wide margin
The top-ranked assignee's 868 records are more than triple the fifth-place total of 238, consistent with a company that treats wet-etch chemistry and equipment control as core claim territory rather than an incidental filing area.
Assignee ranking, position 1
Mid-field
123
records, 10th place
The drop-off from top five to top ten is steep
Combined, the top ten hold 39.1% of all 9,618 records, only 9.4 points above the top five's 29.7% — meaning positions six through ten each contribute comparatively little, and the real competitive contest is concentrated near the very top.
Assignee ranking, positions 6-10
Momentum
-85% to -94%
YoY, latest year
Several large holders slowed sharply in the latest year
Multiple assignees in the recent-momentum data posted year-on-year declines in the -80% to -94% range for their latest-year counts, and two of the tracked names show zero filings in the latest year. Given publication lag, this likely overstates the real slowdown, but it is the direction the visible data points.
Recent-year momentum by assignee
Recent-year filing momentum by assignee
| Assignee | Recent year | YoY |
|---|---|---|
| Lam Research Corp | 4 | -85% |
| Tokyo Electron Ltd | 2 | -89% |
| Applied Materials Inc | 1 | -94% |
| Entegris Inc | 1 | -80% |
| Inscripta Inc | 0 | — |
| The Regents of the University of California | 0 | — |
| Semiconductor Energy Laboratory Co., Ltd. | 0 | -100% |
| Taiwan Semiconductor Manufacturing Co., Ltd. | 0 | -100% |
Source: Patsnap Eureka. Assignee-level momentum. Derived from a Patsnap search on Wet Etching and Selectivity Control covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
What's Next
Where to take this next
The landscape points to two practical next steps: checking freedom to operate against the concentrated top of the ranking, and scoping claims into the under-claimed sub-areas before the field re-accelerates.
Map claim scope against the top holders
With 29.7% of records held by five assignees, any new filing in bath control or selectivity chemistry should be checked against that concentrated set before drafting.
Explore the assignee landscape in EurekaScope the under-claimed sub-areas
Real-time bath sensing and point-of-use dilution control sit outside the dense H01L/H10P cluster and are candidates for a first-claim position.
Run a white-space search in EurekaSource: Patsnap Eureka. Forward-looking reading of the same dataset. Derived from a Patsnap search on Wet Etching and Selectivity Control covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
FAQ
Common questions on this landscape
One assignee leads the ranking with 868 records, more than triple the fifth-place count of 238. The top five combined hold 2,857 of the 9,618 records in scope — 29.7% of the field — with a steep drop-off after that into a long tail of smaller filers. This concentration pattern is typical of a field anchored by process-tool and equipment suppliers rather than spread evenly across device makers.
Filings peaked at 485 records in 2020 and then declined from 452 in 2021 to 250 in 2024, a 45% drop over that three-year span. 2024 is the most recent year that can be read as materially complete because publication lags filing by roughly 18 months, so the apparent falls in 2025 and 2026 are partly an artefact of that lag rather than confirmed further decline. Read the 2021-2024 contraction as the reliable signal.
Just over half of all records in scope, 51.8%, carry an H01L semiconductor-devices classification, meaning most wet-etch and selectivity claims are filed inside a broader device or fabrication-process patent. H10P (22.2%) and G01N material analysis and testing (10.7%) are the next largest subclasses. Because a single record can carry multiple IPC codes, these shares overlap rather than sum to a whole field.
EP0474482A1, filed by Fujitsu and published in 1992, claims a method for etching silicon nitride in hot phosphoric acid where a low-concentration acid supply is triggered once bath temperature crosses a threshold after a set elapsed time. It is an early closed-loop temperature-and-concentration control method rather than a broad composition claim, so it constrains that specific triggering logic more than it blocks selectivity chemistry generally. Given its age, any enforceable term has long since lapsed in most jurisdictions, but it remains useful prior art to design around or cite against newer temperature-control claims.
The under-claimed areas sit adjacent to the dense H01L and H10P cluster rather than inside it: real-time bath composition sensing, point-of-use dilution control loops, and silicon-loss compensation algorithms show comparatively little claim density relative to the core etch-chemistry filings. These are candidates for a first-claim position, though any filing there should still be checked against the concentrated top-five assignees who hold nearly 30% of the whole field.
Answers are grounded in the same dataset. Derived from a Patsnap search on Wet Etching and Selectivity Control covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company's registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.