The ranked leaders in this 645-record dataset include a university research program, GaN materials and equipment suppliers, and device IDMs, with the top assignee holding 51 records. Concentration is moderate rather than extreme: the top five hold 24.5% of all records in scope and the top ten hold 36.7%, leaving most filings spread across a long tail of smaller filers. This means competitive monitoring should extend well beyond the handful of largest names.

Filing activity peaked in 2018 at 48 records and has declined since, falling to 12 by 2026, though that most recent year is still partial and publication lag of roughly 18 months means it will revise upward. The 2022 midpoint of 27 filings confirms this is a genuine multi-year slowdown rather than a single-year dip. Recent-year momentum data shows most previously active assignees recording no filings in the latest tracked year, suggesting the core buffer-engineering approaches may be reaching claim saturation.

Carbon doping is used to control trap states and increase the resistivity of buffer layers, which supports higher vertical breakdown voltage without introducing additional dislocations. A representative record, US9608103B2, claims a HEMT built from alternating undoped and periodically carbon-doped GaN layers within the channel stack beneath a barrier layer. Because carbon doping appears as a named search criterion in this dataset, it is a well-represented but specific mechanism, and claim language tends to focus on the doping periodicity and layer arrangement rather than the doping chemistry alone.

The IPC composition shows H01L device claims dominating at 83.7% of the 645 records, while process-oriented classes like C30B crystal growth (16.3%) and C23C coating and deposition (5.9%) are comparatively thinner. Specific sub-areas such as crack-free thickness thresholds, wafer bow compensation for larger-diameter silicon, and composition-graded AlGaN transition schemes show less density than core device claims. These are reasonable starting points for a novelty search before drafting, though a thin IPC share is not proof of an open claim — it needs confirming against the actual prior art.

The United States receives the largest share by a wide margin at 332 records, followed by the European Patent Office at 80, WIPO under the PCT route at 68, China at 56, India at 31, and Singapore at 20. This distribution reflects where GaN power and RF device manufacturing and enforcement activity are concentrated. A filer targeting global coverage should expect the US and PCT routes to carry the densest prior art to search against.