Measurement of Dipoles/Roll-Off /Work Functions by Coupling CV and IPE and Study of Their Dependence on Fabrication Process

We study the effective metal gate work function (WF
_Meff
) of different metal/high-κ gate stacks. Both capacitance versus voltage measurement and internal photo emission measurement were used, leading to a better understanding of the WF
_Meff
variations. We demonstrate that these variations are related to two main process dependent parameters, a voltage drop at the high- κ/SiO
₂
interface and the metal work function. These two parameters are studied for various process conditions.