The assignee ranking covers 45 companies across the 83 records in scope, and it is led by a single company with 11 records, with the field concentrating further so that the top 5 assignees together hold 47.0% of all records. Below fifth place the count drops quickly, to 6 records at fifth place and just 2 at tenth, meaning most of the ranked companies hold only one or two filings. That shape — a dense top and a long single-filing tail — is typical of a technology area that is still attracting new entrants rather than having consolidated around a handful of dominant players.

The interface between the silicon carbide surface and the gate oxide governs threshold voltage stability, channel mobility and long-term reliability under the high electric fields SiC devices are designed to operate at. Interface trap density at this boundary has historically been higher in SiC than in silicon, which depresses channel mobility and can shift threshold voltage under stress. That is why the bulk of the patent activity in this dataset — 89.2% of the 83 records carrying an H01L classification — sits on oxide growth, passivation and post-oxidation treatment claims rather than on the broader device architecture.

Filing activity grew sharply through the period covered, rising from 7 records in 2021 to a peak of 20 in 2024, a +186% increase over that span. Because patent publication typically lags filing by around 18 months, the apparent figures for 2025 and 2026 are still incomplete and should not be read as a slowdown. Treat 2024 as the most recent year with a reasonably complete count.

China leads by receiving office with 39 of the 83 tracked records, ahead of Japan at 15 and the United States at 8, with Europe, India and Sweden each contributing single-digit counts. Several of the closest co-assignee pairings in the dataset link Chinese research institutes with industry partners, which points to coordinated national-level filing programmes rather than purely independent competitive activity. This geographic skew is worth checking against where a company actually intends to manufacture or sell, since receiving-office counts do not equal enforceable coverage in every market.

EP3753052B1 is a granted European patent held by Hitachi Energy Switzerland, with a priority date of 2021-07-28, claiming a silicon carbide power device that combines a MOS gate structure with a stressor element to manage mechanical stress at the gate interface. It represents a structural approach to interface stability, distinct from the oxide-treatment and passivation routes that make up most of the dataset. Anyone designing a gate stack that manages interface stress mechanically, rather than purely chemically, should review this claim set closely before finalising an architecture.