Interfacial Properties of nMOSFETs With Different Al2O3 Capping Layer Thickness and TiN Gate Stacks

In this article, the interfacial properties of nMOSFETs with different thickness high-
$\kappa $
Al
₂
O
₃
capping layer on an 8-nm SiO
₂
and TiN gate stacks have been investigated using electrical measurement and low-frequency noise at room temperature. It is shown that the predominant 1/
${f}$
noise is governed by the number fluctuations mechanism. It is indicated that: 1) presence of an Al
₂
O
₃
capping layer increases the noise power spectral density and, hence, the oxide trap density has an influence on the low-field mobility further and 2) effective work-function and the threshold voltage of nMOSFET should be modulated using the high-
$\kappa $
Al
₂
O
₃
capping layers.