Experimental investigation on growth mechanism of GeOx layer formed by plasma post oxidation based on angle resolved X-ray photoelectron spectroscopy

The growth mechanism of GeO_x layer formed by plasma post oxidation at room temperature (RT PPO) is investigated based on angle resolved X-ray photoelectron spectroscopy (AR-XPS). The experimental results show that the GeOx grown by RT PPO does not obey layer-by-layer growth mode. And the distribution of Ge oxidation states is random during RT PPO. These findings are helpful to the optimization of the Ge based gate stacks for future CMOSFET devices.