Effective work function of TiN films: Profound surface effect and controllable aging process

Titanium nitride (TiN), with its tunable work function, serves as an electrode metal in the scaling fin-type field-effect transistor and plays key role for low threshold operation. Measuring effective function of thin TiN films is desirable rapid evaluation before device fabrication. In this work, Kelvin probe force microscopy applied to study impact various factors on surface potential uncertainty below 30 mV. By scraping gauging evolvement different circumstances, it revealed that effect major obstacle determine as-deposited TiN. For thick films, drops over 530 mV a fresh relative aged one. thinner than 5 nm, changes by 290 due oxidation. This enables quantitative assessment well charge density films.