The deposition and etch tools that form gate-all-around transistors on the newest logic chips. They sit in the wafer fabrication toolchain ahead of high-volume production, and the balance tightens when demand for leading-edge logic ramps outpaces the availability of these process tools.
A sustained tight read means installed capacity of the deposition and etch tools that build gate-all-around transistors is short of what leading-edge logic ramps require, so fabs can wait on tool delivery and qualification even when lithography is available. Additional supply requires tool makers to expand and qualify capacity, so relief arrives only as new tools are built and brought online over successive quarters rather than within a single order cycle.