Fastest
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 →https://www.patsnap.com/resources/blog/rd-blog/phase-change-memory-materials-patent-landscape/ · Patsnap · data cut-off 2026-07-31 · downloaded from the live page
Patent Landscape · Emerging MemoryPhase Change Memory Materials Patents: Concentration at the Top, a Long Tail Below
- 45.9% of all filings sit with five assignees. 1,899 of the 4,140 records in scope belong to the top five, so most of the claim space in this field was staked out early by a small group.
- Filing activity peaked in 2019 at 170 records. Volume from 2021 to 2024 fell 71% (149 to 43), though 2025-2026 figures are still filling in given the roughly 18-month publication lag.
- H01L and G11C cover more than half the field. 54.9% of records touch semiconductor device claims and 51.6% touch static/digital memory claims, leaving manufacturing- and integration-specific subclasses comparatively thin.
4,140
Published Records
46%
Top-5 Share of All Records
-71%
Filing Growth 2021→2024
US
Leading Jurisdiction
Filing growth compares 2021 (149 records) with 2024 (43) — 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 4,140 records in scope (CR5), not by the ranked leaders only.
Published byPatsnap Research··7 min readSourced from Patsnap Eureka
Overview
What this landscape covers
Phase change memory stores data by switching a chalcogenide material between crystalline and amorphous states, and the claim activity tracked here runs from the earliest resistance-drift and reset-current fixes through to multilevel storage and ovonic threshold switch selector designs. The dataset spans 4,140 published records filed or published between 2015 and mid-2026, searched against terms that pair the memory element itself ("phase change memory", "chalcogenide material", "ovonic threshold switch") with the operating problems that define the field's hard engineering questions: crystallization speed, drift of resistance, reset current, elemental segregation, thermal disturb, multilevel storage.
Because publication trails filing by roughly a year and a half, the last one to two years in any chart will look thinner than they will eventually turn out to be. Treat 2024 as the most recent year with a reasonably complete picture, and treat everything after it as provisional.
Filing activity and technology composition, 2015-2026
Source: Patsnap Eureka. Assignee ranking and totals. Derived from a Patsnap search on Phase Change Memory Materials 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 Numbers
Filing trend and technology composition
Two views of the same 4,140 records: how filing volume has moved year over year, and which IPC subclasses the claims actually sit in.
Filing trend, 2017-2026
Activity rose from 143 records in 2017 to a peak of 170 in 2019, then eased. The 2021-to-2024 window shows a 71% decline (149 to 43) — a real contraction, not a data artifact, though 2025 and 2026 are undercounted by design given publication lag.
IPC subclass composition
H01L (semiconductor devices) and G11C (static and digital memories) each cover roughly half the record set, reflecting how tightly phase change memory claims are written into standard device and memory architecture language. H10N, H10B and H10D — device structure, manufacture and general semiconductor claims — sit well behind at 26.4%, 18.8% and 14.1% respectively, and G06F and G11B barely register at 3.2% and 2.9%, marking the system- and storage-integration side of the field as comparatively open.
Shares are the percentage of the 4,140 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 Phase Change Memory Materials covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.
Go deeper on Phase Change Memory Materials with Eureka
This page is one run against one query. Ask Eureka your own question about phase change memory materials and every answer comes back with the patent numbers behind it.
Try EurekaKey Patents
The most-cited prior art in this field
Representative Filing
US11101326B2 — Methods of forming a phase change memory with vertical cross-point structure
SANDISK TECHNOLOGIES LLC
A non-volatile memory uses phase change memory (PCM) cells in a three dimensional vertical cross-point structure, in which multiple layers of word lines run in a horizontal direction and bit lines run in a vertical direction. The memory cells are located in a recessed region of the word lines and are separated from the bit line by an ovonic threshold switch. A surfactant lining of the word line recess in which the phase change memory material is placed improves stability of the resistance state of the memory cells, allowing for improved multi-state operation.Filed by SanDisk Technologies, granted 2021-08-24 — a 3D vertical cross-point structure combining a PCM cell, an ovonic threshold switch selector and a surfactant lining aimed squarely at resistance-state stability for multi-state operation.
Most-cited records
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5687112A | Multibit single cell memory element having tapered contact | 1,058 |
| 2 | US6087674A | Memory element with memory material comprising phase-change material and dielectric material | 890 |
| 3 | US5912839A | Universal memory element and method of programming same | 689 |
| 4 | US5534712A | Electrically erasable memory elements characterized by reduced current and improved thermal stability | 666 |
| 5 | US5825046A | Composite memory material comprising a mixture of phase-change memory material and dielectric material | 644 |
| 6 | US5933365A | Memory element with energy control mechanism | 634 |
| 7 | US5536947A | Electrically erasable, directly overwritable, multibit single cell memory element and arrays fabricated there… | 579 |
| 8 | US5714768A | Second-layer phase change memory array on top of a logic device | 558 |
| 9 | US5596522A | Homogeneous compositions of microcrystalline semiconductor material, semiconductor devices and directly overw… | 519 |
| 10 | US20050029502A1 | Processing phase change material to improve programming speed | 505 |
Citation counts are drawn from within the searched corpus and skew toward older filings simply because they have had more time to accumulate citations — treat this as a measure of influence, not of present-day relevance.
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 Phase Change Memory Materials 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
Run it yourself
Put your own technology through the same analysis
Where to run it
For builders
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 →Insights
What the data says about this field
Three findings that shape how a freedom-to-operate or whitespace review should be scoped in phase change memory materials.
Concentration
45.9%
of 4,140 records
Five assignees hold nearly half the field
The leader alone accounts for 516 records, and the top five combined reach 1,899 of the 4,140 records in scope. Anything filed close to core chalcogenide composition or reset-current reduction claims is likely to run into this group's prior art first.
Top 5 = 45.9% of all records in scope
Momentum
-71%
2021 to 2024
Filing volume has genuinely contracted, not just paused
Volume moved from 149 records in 2021 to 43 in 2024, a real three-year decline rather than a lag artifact, since 2024 is the last year with a largely complete publication picture. That contraction sits after a 2019 peak of 170 records.
149 (2021) to 43 (2024)
Composition
3.2% / 2.9%
G06F / G11B share
System- and storage-integration claims are thin
Device- and memory-architecture subclasses (H01L, G11C) dominate at over half the record set each, while digital-data-processing (G06F) and non-semiconductor storage (G11B) claims barely register. That gap points to where integration-level claims remain comparatively unclaimed.
H01L 54.9% vs G06F 3.2% of 4,140 records
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 phase change memory materials, with the prior art for and against each one.
Source: Patsnap Eureka. Co-assignee relationships and derived observations. Derived from a Patsnap search on Phase Change Memory Materials 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 the openings sit
The ranked leaders span integrated device makers, memory specialists and a research-heavy tail; recent-year momentum has cooled across almost all of them, which changes how a competitive read should be framed.
Leader
516
records
A single assignee anchors the field
The top-ranked assignee holds 516 records on its own, well ahead of fifth place at 187 and tenth place at 106 — a steep drop-off rather than a gradual one.
Leader vs 5th (187) vs 10th (106)
Momentum
0% to -100%
YoY, latest year
Recent-year activity has slowed across the board
Latest-year momentum among the most active assignees ranges from flat to a full year-over-year drop, consistent with the broader 2021-2024 contraction rather than any single company pulling back alone.
See recent-year momentum by assignee
Collaboration
10
co-assignee pairs
Co-filing is limited and concentrated
Only ten co-assignee pairs appear in the dataset, and the strongest pair — a co-filing relationship between two of the largest holders — is far ahead of the rest, suggesting collaboration here is the exception rather than the norm.
Strongest pair recorded at 67 co-filings
Recent-year momentum by assignee
| Assignee | Recent year | YoY |
|---|---|---|
| International Business Machines Corporation (IBM) | 1 | 0% |
| Micron Technology, Inc. | 0 | -100% |
| Samsung Electronics Co., Ltd. | 0 | — |
| Macronix International Co., Ltd. | 0 | — |
| Intel Corporation | 0 | — |
| SK Hynix Inc. | 0 | — |
| Ovonyx Memory Technology, LLC | 0 | — |
| Energy Conversion Devices, Inc. | 0 | — |
Source: Patsnap Eureka. Assignee-level momentum. Derived from a Patsnap search on Phase Change Memory Materials 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 analysis
The landscape points to where claim density is heavy and where it thins out; the next step is testing a specific concept against both.
Run a freedom-to-operate check
Screen a specific cell structure, selector design or composition claim against the top assignees' portfolios before committing engineering time to it.
Check claims in EurekaMap the white space in detail
Pressure-test the under-claimed branches identified here — integration-level and system-side claims in particular — against the full claim text, not just IPC codes.
Explore white space in EurekaTrack assignee momentum going forward
Set alerts on the leading assignees' recent filings to catch any reversal of the 2021-2024 contraction as 2025-2026 data fills in.
Set up tracking in EurekaSource: Patsnap Eureka. Forward-looking reading of the same dataset. Derived from a Patsnap search on Phase Change Memory Materials 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 about phase change memory patents
The ranked leader in this dataset holds 516 of the 4,140 records in scope, noticeably ahead of fifth place at 187 and tenth place at 106. Filing here is concentrated: the top five assignees together account for 45.9% of all records, and the top ten account for 63.2%. That leaves a long tail of smaller filers and single-patent entrants behind a steep drop-off from the leader.
Filing peaked in 2019 at 170 records and has since declined; the 2021-to-2024 window shows a 71% drop, from 149 records to 43. 2024 is the most recent year that can be treated as a reasonably complete picture, because publication typically lags filing by around 18 months. The 2025 and 2026 figures in any chart will look artificially low for that reason and should not be read as confirmation of a further slowdown.
US11101326B2, assigned to SanDisk Technologies and granted in August 2021, covers a three-dimensional vertical cross-point phase change memory structure where word lines run horizontally and bit lines vertically, with cells set in recessed word-line regions and separated from the bit line by an ovonic threshold switch selector. A distinguishing feature is a surfactant lining of the word-line recess that stabilizes the resistance state and supports multi-state (multilevel) operation. Anyone designing a similar 3D cross-point PCM cell with a selector and a lining or interface treatment for resistance stability needs to check this filing's specific claim scope closely.
IPC composition shows H01L and G11C — core semiconductor device and memory architecture classes — each covering roughly half of the 4,140 records, while G06F (digital data processing) and G11B (non-semiconductor storage) sit under 4% each. That gap suggests system- and integration-level claims, such as how PCM arrays interface with data-path logic or coexist with other storage tiers, are comparatively under-claimed relative to the cell and material chemistry itself. Sub-areas like surfactant-lined interfaces, 3D vertical cross-point integration and multilevel read-margin schemes are worth a closer independent claim-text review.
The United States dominates with 2,915 filings recorded, followed at a distance by the European Patent Office (361), WIPO under the PCT route (245), China (102), South Korea (95) and Germany (74). This distribution reflects where the largest holders in this dataset are headquartered and where they have historically sought the broadest protection, rather than where the underlying research necessarily originates.
Answers are grounded in the same dataset. Derived from a Patsnap search on Phase Change Memory Materials 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
Research Phase Change Memory Materials in depth with Eureka
Go past this page: query the whole phase change memory materials 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.