Silicon Carbide Boule Growth Patents: Top Companies & Trends 2026
- 40.0% concentration. The top 5 assignees hold 586 of 1,464 records in scope — filing here is already concentrated at the top, not wide open.
- Filings cooled after 2021. Annual filings fell from 124 in 2021 to 50 in 2024, a -60% swing over that span, even as the field's peak year (2020, 126) is still recent history.
- Crystal growth dominates the claims. C30B covers 62.6% of all records and H01L 56.4%, meaning most protection sits on core growth methods and device integration rather than downstream branches.
Filing growth compares 2021 (124 records) with 2024 (50) — 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 1,464 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Silicon carbide boule growth sits at the front end of the SiC substrate supply chain: pulling large-diameter single crystals by physical vapor transport, controlling polytype, and managing defects such as micropipes and basal plane dislocations before a wafer is ever sliced. This landscape draws on 1,464 published records filed between 2015 and the 2026 data cut-off, searched against language specific to boule growth, seed preparation, growth rate limits and crystal diameter expansion rather than SiC devices generally.
Because publication lags filing by roughly 18 months, the most recent one to two years in any trend understate real filing activity — 2024 is the last year that can be read as a complete picture, and 2025-2026 figures will keep rising as those applications publish.
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Filing trends and technology composition
Two views of the same 1,464-record dataset: how filing volume has moved year over year, and which IPC subclasses the claims actually sit in.
A 2020 peak followed by a real pullback
Filings rose from 30 in 2017 to a peak of 126 in 2020, then declined; the 2021-to-2024 window alone shows a -60% drop, from 124 to 50 filings. Given the 18-month publication lag, 2025 and 2026 figures are still incomplete and should not yet be read as a continuation of that decline.
Growth and integration classes carry the weight
C30B (crystal growth) appears on 62.6% of the 1,464 records and H01L (semiconductor devices) on 56.4%, confirming that most filings claim either the growth process itself or its direct device integration. Smaller shares in C23C, C01B, C04B and G01N mark adjacent surface-treatment, chemistry and characterization work that is filed far less often.
Shares are the percentage of the 1,464 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Silicon Carbide Boule Growth with Eureka
This page is one run against one query. Ask Eureka your own question about silicon carbide boule growth and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited prior art in this space
US9337277B2 — High voltage power semiconductor device on SiC
Filed by SK Siltron CSS, this patent covers 4H-SiC epiwafers grown on 4-degree off-axis substrates at 50-100 μm thickness, with surface morphological defect density of 2-6 per cm2, carrier lifetimes of 2-3 μs, and basal plane dislocation density held below 10 per cm2. Diodes fabricated on these epiwafers demonstrated blocking voltages near theoretical limits for 4H-SiC, up to 8 kV on 50 μm films.Numbers as stated in the patent abstract; not independently verified against later art.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US6734461B1 | SiC wafer, SiC semiconductor device, and production method of SiC wafer | 503 |
| 2 | US7226805B2 | Sequential lithographic methods to reduce stacking fault nucleation sites | 236 |
| 3 | US7314520B2 | Low 1c screw dislocation 3 inch silicon carbide wafer | 166 |
| 4 | US20040000266A1 | Method for reducing defect concentrations in crystals | 136 |
| 5 | US20120103249A1 | Sic single crystal sublimation growth method and apparatus | 104 |
| 6 | US20060096521A1 | Method for reducing defect concentration in crystals | 104 |
| 7 | US7175704B2 | Method for reducing defect concentrations in crystals | 103 |
| 8 | US20170321345A1 | Large Diameter Silicon Carbide Single Crystals and Apparatus and Method of Manufacture Thereof | 97 |
| 9 | US20050126471A1 | One hundred millimeter high purity semi-insulating single crystal silicon carbide wafer | 94 |
| 10 | US20130280466A1 | Large Diameter, High Quality SiC Single Crystals, Method and Apparatus | 81 |
Citation counts inside a searched corpus favor older filings; treat them as a signal of influence on later work, not as a measure of current commercial relevance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the filing pattern tells a decision-maker
Three findings that shape where a new filing or licensing conversation should start.
Ownership is already concentrated at the top
The five leading assignees together hold 586 of the 1,464 records in scope, and the top 10 extend that to 792 records, 54.1% of the field. A new entrant is filing into a space where a handful of players already hold dense, overlapping claim coverage on core growth methods.
Filing volume has pulled back from its 2020 peak
After peaking at 126 filings in 2020, volume fell from 124 in 2021 to 50 in 2024. That decline predates the publication-lag window, so it reflects a genuine slowdown in new filing activity rather than an artifact of recent data still filling in.
Most protection sits on crystal growth, not on characterization
C30B and H01L together dominate the classification mix, while G01N (material analysis and testing) appears on only 3.9% of records. Defect-measurement and inspection methods are claimed far less often than the growth processes they support.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to silicon carbide boule growth, with the prior art for and against each one.
| Assignee | Co-assignee | Shared families |
|---|---|---|
| Kwansei Gakuin Educational Foundation | Toyota Tsusho Corporation | 74 |
| Sumitomo Electric Industries, Ltd. | SK Siltron CSS, LLC | 11 |
| Sumitomo Electric Industries, Ltd. | Mitsubishi Corporation | 11 |
| II-VI Incorporated | ZWIEBACK ILYA | 10 |
| Resonac Holdings Corporation | Denso Corporation | 9 |
| II-VI Incorporated | SEMENAS EDWARD | 8 |
| II-VI Incorporated | GUPTA AVINASH K | 7 |
| Wolfspeed, Inc. | POWELL ADRIAN | 6 |
Only 10 co-assignee pairs appear across the dataset, and the strongest pairing accounts for 74 shared records — most applicants in this field file alone rather than through joint ventures or research partnerships.
Who holds the ground, and what is still open
The ranked leaders account for just over half of all filings between them; everyone else is working around already-dense claim territory.
One filer sits well ahead of the field
The top assignee holds 217 records, more than double the fifth-ranked filer at 70. That gap suggests a single company has built sustained, multi-year coverage rather than a one-time filing push.
A steep drop-off after the top ten
Filing counts fall from 70 at fifth place to 33 at tenth, and the ranking runs to 100 companies in total. Beyond the leading names, coverage thins quickly into single- and low-digit filers.
Even active historical filers show a quiet latest year
Multiple assignees with substantial filing histories show zero filings in the latest tracked year, with year-over-year drops as steep as -100%. Given publication lag, this likely reflects pending applications not yet visible rather than an actual halt in R&D.
| Assignee | Recent year | YoY |
|---|---|---|
| Wolfspeed, Inc. | 0 | -100% |
| Sumitomo Electric Industries, Ltd. | 0 | — |
| Kwansei Gakuin Educational Foundation | 0 | -100% |
| Toyota Tsusho Corporation | 0 | -100% |
| II-VI Incorporated | 0 | — |
| Dow Silicones Corporation | 0 | — |
| Resonac Holdings Corporation | 0 | — |
| NIPPON STEEL & SUMITOMO METAL CORP | 0 | — |
Where to take this
The dataset points to where claim density is heaviest and where it thins out — the next step is testing a specific claim idea against that map.
Check freedom-to-operate before drafting
With 40.0% of records held by five assignees, a new filing on core boule growth methods is likely to sit close to existing claims. Screening against the leading assignees' portfolios before drafting saves rework later.
Run a claim check in EurekaExplore the under-claimed branches
In-situ metrology and seed preparation carry far lower filing density than crystal growth itself. These are places where a first, well-drafted claim can still stake meaningful ground.
Explore white space in EurekaCommon questions about this landscape
One assignee leads the ranked field with 217 records, well ahead of the fifth-ranked company at 70. The top five assignees combined hold 586 of the 1,464 records in scope, or 40.0% of the field, showing that filing activity is concentrated rather than evenly spread. Beyond the top ten, which together hold 54.1% of records, coverage drops off quickly across the remaining ranked companies.
Filing peaked in 2020 at 126 records and then declined, falling from 124 in 2021 to 50 in 2024, a -60% drop over that span. That decline covers only complete years; 2025 and 2026 figures will rise as pending applications publish, given the roughly 18-month lag between filing and publication. Based on complete-year data, the field has cooled from its 2020 high rather than continuing to accelerate.
Micropipe density is one of the defect metrics used throughout the search terms defining this dataset, alongside basal plane dislocation and polytype control, because it directly affects wafer yield from a grown boule. Patents addressing growth conditions, seed preparation and diameter expansion frequently claim defect-density outcomes as evidence the method works. It functions less as its own filing category and more as a performance claim attached to growth-process patents.
In-situ defect metrology during growth and seed crystal surface preparation both show comparatively thin filing density next to the dominant crystal-growth classes, C30B at 62.6% and H01L at 56.4% of the 1,464 records. G01N, covering material analysis and testing, appears on only 3.9% of records despite defect characterization being central to the field. These gaps suggest technical territory that has not been heavily claimed relative to core growth methods.
US9337277B2, assigned to SK Siltron CSS, claims 4H-SiC epiwafers grown on 4-degree off-axis substrates with specific thickness, defect-density and carrier-lifetime ranges, plus diodes fabricated on them reaching blocking voltages near theoretical limits. Anyone working with similar off-axis growth parameters and defect-density targets should review its claim scope carefully before finalizing a process. It is one of the more heavily cited records in this dataset, meaning later filings have frequently built on or distinguished themselves from it.
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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.