14nm FinFET

Device Context and Integration Logic

The FCT CSOH Oxide Deposition step is inserted immediately after the fin hard-mask stack etch sequence to introduce a conformal oxide layer that stabilizes fin sidewalls and defines an intermediate dielectric interface before fin-cut patterning, which is essential for maintaining fin dimensional fidelity during subsequent pattern transfer [P1].This oxide acts as a chemically distinct buffer between the etched silicon fins and the upcoming SiON deposition…

• [High] Non-uniform Conformality in Fin Trenches: Incomplete surface saturation or precursor depletion in high-aspect-ratio fin-cut regions can lead to thinner oxide at trench bottoms, reducing etch protection and causing fin footing during subsequent fin-cut etch, following the conformality limitations described for ALD-like processes [P1].- [Medium] Plasma-Induced Interface Damage: Excessive ion energy during plasma-assisted deposition can create interface states or fixed charges at t…