Plasma exposure during etch and ash steps strips carbon from the organosilicate matrix of porous low k films, a process known as carbon depletion. The loss of carbon leaves the film more hydrophilic and structurally porous, which raises its dielectric constant (k value) and increases leakage current between interconnects. This is why the patent literature in this space pairs damage-mode claims with repair-process claims, since restoring the film’s hydrophobicity is treated as inseparable from characterizing the damage itself.

The assignee ranking in this dataset is heavily concentrated, with the top-ranked company holding 91 records against a fifth-place count of 7 and a tenth-place count of 4 across 36 ranked companies. That leader’s portfolio centers on ultraviolet and thermal treatments for sealing porous low k surfaces. Beyond the leader, activity drops off quickly into a long tail of companies with only a handful of filings each, rather than a cluster of comparably sized competitors.

Filings peaked at 22 in 2021 and fell to 1 by 2024, a decline of about 95% over that span, based on filings that have already been published and are old enough not to be affected by publication lag. This pattern is consistent with a technology area where the core repair mechanisms — UV curing, silylation, sidewall treatment — were claimed early and thoroughly, leaving less room for new foundational filings. It does not necessarily mean the underlying manufacturing techniques have stopped being used industrially.