Quantitative Analysis of La and Al Additives Role on Dipole Magnitude Inducing Vt Shift in High-K/Metal Gate Stack

Voltage drop induced by an electrical dipole layer after the incorporation of La or Al in high-k/metal gate-stack has been measured on nominal and beveled-SiOx devices and linearly correlated to the effective La/Al dose into the high-k/SiOx stack determined through X-ray fluorescence spectroscopy. Electrical dipoles were experimentally estimated to be around -55 and +40 meV for each 1×10 ¹⁴ at/cm ² of effective La and Al dose, respectively.