Advanced Metal Gate Electrode Options Compatible with ALD and AVD® HfSiOx-Based Gate Dielectrics

We have investigated metal gate electrodes for use with high k HfSiOx gate dielectric films using AVD® and ALD technology. First, we report on the characterization of the AVD® and ALD deposition techniques where both HfO2 and SiO2 are combined for the formation of HfSiOx. Nitrogen is then incorporated using both in-situ and ex-situ methods to form HfSiON and the resulting film properties are compared. Using an AVD process a work-function of >4.7eV for Ru and RuO2 gate electrode metals in combination with HfSiOx was obtained. A TaN-based metal gate was also characterized to target a promising pMOS solution using different compositions. Together with its high flexibility and composition control, both ALD and AVD® can become key processes for advanced high-k dielectrics as well as compatible CMOS metal electrodes.