SiC Dislocation Patents: Top Companies & Filing Trends 2026
- Filing peaked in 2017 at 18 records and has run flat-to-declining since, with the 2022 midpoint at 13 — this is a maturing claim space, not a growing one.
- The top 5 assignees hold 44.3% of all 183 records in scope, and the top 10 hold 62.8% — a genuinely concentrated field with a long tail below it.
- C30B crystal growth claims dominate at 65.0% of records, well ahead of H01L device claims at 56.3%, showing the contest is mostly won or lost at the boule and epitaxy stage.
Filing growth compares 2021 (11 records) with 2024 (7) — 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 183 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Basal plane dislocations (BPDs) propagate from seed crystal into epitaxial layers and device structures, degrading forward voltage stability in bipolar SiC devices. This landscape tracks patent activity on reducing BPD density and converting BPDs into less harmful threading edge dislocations, spanning seed preparation, thermomechanical stress control during growth, and epitaxial conversion techniques. The dataset covers 183 published records filed between 2015 and mid-2026, drawn from applicants spanning crystal growers, device makers and research institutes.
Because publication lags filing by roughly 18 months, the 2025-2026 counts in the trend chart understate actual filing activity for those years; the shape of the curve up to 2023-2024 is the more reliable signal.
Let an AI agent run this analysis on your own technology
Pick a task. Every answer cites the patents behind it.
Filing trends and technology composition
Two views of the same 183 records: how filing volume has moved year over year, and which IPC subclasses the claims sit in.
A field past its filing peak
Annual filings rose to a peak of 18 records in 2017, then softened. The 2022 midpoint of 13 records confirms the trend is flat or declining rather than recovering, and the partial 2026 count (1 record so far) reflects reporting lag rather than a sudden stop.
Growth-stage claims outweigh device-stage claims
C30B (crystal growth) appears in 65.0% of the 183 records, ahead of H01L (semiconductor devices) at 56.3%. H10P and H10D each cover roughly a fifth of records, while coating (C23C), inorganic materials (C01B), testing (G01N) and laminates (B32B) are minor branches — each under 5% and together suggesting most of the unclaimed room sits away from bulk crystal growth.
Shares are the percentage of the 183 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Basal Plane Dislocation Reduction in SiC Crystals with Eureka
This page is one run against one query. Ask Eureka your own question about basal plane dislocation reduction in sic crystals and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited prior art in this space
Reducing SiC epitaxial basal plane dislocation density via composite buffer layers
The method epitaxially grows a high-low doping concentration composite buffer layer with multiple cycles on an SiC substrate, applies interfacial high-temperature hydrogen etching to each buffer sub-layer, and uses interfacial doping induction together with interfacial image force to convert basal plane dislocation (BPD) defects into threading edge dislocation (TED) defects. The approach is aimed at reducing BPD defects that would otherwise propagate into the active epitaxial layer.Filed by China Electronics Technology Group Corporation No. 55 Research Institute, published as EP3547349A1.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20070290211A1 | Bipolar Semiconductor Device and Process for Producing the Same | 67 |
| 2 | US7279115B1 | Method to reduce stacking fault nucleation sites and reduce V<sub>f </sub> drift in bipolar devices | 52 |
| 3 | US20060075958A1 | Low basal plane dislocation bulk grown SiC wafers | 49 |
| 4 | US20050064723A1 | Method To Reduce Stacking Fault Nucleation Sites And Reduce Forward Voltage Drift In Bipolar Devices | 48 |
| 5 | CN107068539A | 降低碳化硅外延基平面位错密度的方法 | 40 |
| 6 | US20150168311A1 | Defect classifying method and inspection apparatus | 40 |
| 7 | US20090114148A1 | Method of producing epitaxial layers with low basal plane dislocation concentrations | 40 |
| 8 | WO2017057742A1 | Sic single crystal ingot | 39 |
| 9 | US20130071643A1 | Silicon carbide substrate and method of manufacturing the same | 39 |
| 10 | US7294324B2 | Low basal plane dislocation bulk grown SiC wafers | 35 |
Citation counts reflect influence within the searched corpus and skew toward older filings; treat them as a map of foundational art, not current commercial relevance.
Patent titles are shown in the language they were filed in, not translated, so that each record stays verifiable against the original filing — a translated title will not match in Eureka or in any national register. Each row carries its publication number; clicking a row searches Eureka by that number.
Put your own technology through the same analysis
Eureka on the web
When you want the answer in the next five minutes.
The agent works the prompt against patents and technical literature, citing every source.
Run your analysis now →MCP server & REST API
When it has to run inside your own pipeline.
Patent search, landscape analysis and assignee resolution as MCP tools. Drop them into any agent framework, or call REST directly.
Browse MCP servers →What the numbers mean for a filing strategy
Read together, the trend, concentration and citation data point to a field where the foundational conversion mechanisms are already staked out, and the remaining room is at the margins.
A crowded top, then a long tail
With the leader alone at 24 records and the field dropping to 11 by fifth place, new entrants are filing into a space where a handful of players already hold a large share of the priority art. The tail below tenth place (6 records) is thin and fragmented across single-digit filers.
Past the peak, not at a plateau
The 2022 midpoint of 13 filings shows the decline from the 2017 peak is not a blip; several of the most active historical filers show 0 filings in the latest year, including year-over-year declines of -100% for some. That is consistent with a technology where the core conversion mechanisms are patented and refinement has slowed.
Growth-stage claims crowd out device-stage ones
Nearly two-thirds of records touch crystal growth (C30B), while device-level classes such as H10P and H10D sit at roughly a quarter and a fifth respectively. That gap suggests device integration and packaging claims building on BPD-reduced material are comparatively less contested.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to basal plane dislocation reduction in sic crystals, with the prior art for and against each one.
| Assignee | Co-assignee | Shared families |
|---|---|---|
| Wolfspeed Semiconductor Co., Ltd. | SUMAKERIS JOSEPH JOHN | 2 |
| NIPPON STEEL & SUMITOMO METAL CORP | Nippon Steel Corporation | 2 |
| Wolfspeed Semiconductor Co., Ltd. | TSVETKOV VALERI F | 1 |
| Wolfspeed Semiconductor Co., Ltd. | POWELL ADRIAN | 1 |
| Wolfspeed Semiconductor Co., Ltd. | BRADY MARK | 1 |
| Resonac Holdings Corporation | Central Research Institute of Electric Power Industry | 1 |
| Resonac Holdings Corporation | Denso Corporation | 1 |
| Nippon Steel & Sumikin Materials Co., Ltd. | Nippon Steel & Sumikin Materials Co., Ltd. | 1 |
Only 8 co-assignee pairs appear across the dataset, and the strongest pairings link a single company to individual named inventors rather than to other corporate assignees — this is a field of solo corporate filers, not joint ventures.
Who holds the claims, and where the gate sits
The leader holds 24 of the 183 records, more than double the fifth-place filer at 11, and the ranked list of 53 companies thins quickly past the top ten.
A clear front-runner
The top-ranked assignee's filing volume is more than double the fifth-place company's, giving it the deepest coverage of conversion and seed-preparation claims in the dataset.
A compact second tier
Places two through five cluster in a band that together with the leader accounts for 44.3% of all 183 records — a group worth tracking for freedom-to-operate before filing into crystal growth claims.
Fragmentation below the top ten
By tenth place volume has dropped to 6 records, and the remaining 43 ranked companies split the balance of the field, many with only one or two filings each.
| Assignee | Recent year | YoY |
|---|---|---|
| Wolfspeed Semiconductor Co., Ltd. | 0 | — |
| China Electronics Technology Group Corporation No. 55 Research Institute | 0 | — |
| GlobalWafers Co., Ltd. | 0 | -100% |
| Ricoh Co., Ltd. | 0 | — |
| Proterial, Ltd. | 0 | — |
| Resonac Corporation | 0 | -100% |
| Resonac Holdings Corporation | 0 | — |
| Nippon Steel & Sumikin Materials Co., Ltd. | 0 | — |
Where to take this analysis
The dataset points to a field with occupied core claims and a thinning tail — the next steps depend on whether you are filing, licensing, or clearing a design.
Map freedom-to-operate against the top 10
With 62.8% of records held by ten assignees, a targeted FTO review against that group is more efficient than screening all 53 ranked companies.
Run an FTO screen in EurekaTrack the conversion-mechanism claims specifically
Because C30B crystal growth claims cover 65.0% of records, any new filing on BPD-to-TED conversion should be checked against this subclass first.
Search C30B prior art in EurekaWatch for renewed filing activity
Flat-to-declining filings since 2017 could reverse if wafer-diameter scaling drives new seed-preparation art; monitoring the leader's and mid-field's activity catches that shift early.
Set up assignee alerts in EurekaCommon questions on this landscape
A basal plane dislocation (BPD) is a crystal defect that lies in the basal plane of a SiC boule and can propagate into epitaxial layers grown on top of it. In bipolar SiC devices, BPDs act as nucleation sites for stacking faults that expand under current flow, causing forward voltage drift and long-term reliability failures. Reducing BPD density, or converting BPDs into threading edge dislocations (TEDs) that do not expand the same way, is the central goal of the patent activity tracked in this landscape.
The ranked assignee list covers 53 companies, with the leader holding 24 of the 183 records in scope and the field narrowing to 11 records by fifth place. Filing is concentrated: the top 5 assignees together hold 44.3% of all records, and the top 10 hold 62.8%. Below the top ten the field fragments quickly into single- and double-digit filers, so the practical competitive set for freedom-to-operate purposes is small even though the full ranked list is long.
No. Filing peaked in 2017 at 18 records and has since run flat or declined, with the 2022 midpoint at 13 records confirming the softer trend rather than a temporary dip. Several previously active filers show zero filings in the most recent reporting year, including year-over-year drops of -100% for some assignees. Because publication lags filing by around 18 months, the last one to two years in any count will always look lower than the true filing rate, but the multi-year decline predates that lag effect.
Crystal growth methods classified under C30B appear in 65.0% of the 183 records, making growth-stage intervention — seed preparation, thermomechanical stress control during boule growth, and epitaxial buffer layers — the most heavily claimed route. Semiconductor device claims under H01L follow at 56.3%, often covering how BPD-reduced material is used in bipolar device structures. Narrower branches such as coating and surface deposition (C23C), inorganic materials (C01B) and material testing (G01N) each cover under 5% of records, indicating comparatively open claim space in those adjacent areas.
EP3547349A1, filed by China Electronics Technology Group Corporation No. 55 Research Institute and published in 2019, discloses a method for reducing SiC epitaxial basal plane dislocation density using a multi-cycle composite buffer layer with alternating high-low doping concentrations. Each buffer sub-layer undergoes interfacial high-temperature hydrogen etching, and the method uses interfacial doping induction together with interfacial image force to convert BPD defects into threading edge dislocation (TED) defects. Anyone developing a buffer-layer or interfacial-etching approach to BPD conversion should review this filing's specific claim scope before finalising a process design.
Research Basal Plane Dislocation Reduction in SiC Crystals in depth with Eureka
Go past this page: query the whole basal plane dislocation reduction in sic crystals corpus yourself, in your own scope.
Every answer comes back with patent numbers you can open.
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.