The precise control of ion implants for threshold voltage adjustment requires formation of ultra‐shallow electrically active carrier profiles, which begin at the Si–SiO2interface. Obtaining accurate and precise carrier density profiles near the interface with metal–oxide–semiconductor capactiance–voltage (MOSC–V) requires special data acquisition, numerical analysis, and surface corrections. These methods, when applied toC–Vdata collected with a unique, highly repeatable mercury (Hg) probe, provide rapid data acquisition and analysis for threshold adjust implant control in a production environment. Pulsed MOSC–Vmeasurements were used to profile implanted layers with peak carrier densities of ∼1017cm−3, located 15 nm from the Si–SiO2interface.