Relentless increase in the number of transistors accommodated on a single integrated circuit (IC) chip makes the well-recognized need for the consumed power lowering more and more acute with technology progressing from the
current node to the next one. The proposed solution includes combination of lower on-transistor voltages (down to 0.55 V by year 2033) and the on-chip power management allowing for de-activation of temporally unused IC
segments. Furthermore, even more dramatic on-device voltage downscaling (to about 100 mV) is required for metaloxide-semiconductor (MOS) IC periphery of quantum computers because of cooling power limitations. To meet these
challenges, MOS transistor fabrication technology allowing for the tight control of the threshold voltage Vt and possibility to integrate devices with multiple Vt-s on the same IC chip needs to be developed. The key technology enabling the Vt control allows one to avoid the additional variability caused by statistical
fluctuations in the number of doping atoms in the channel region scaled to few-nanometer dimensions. However, there is additional factor affecting stoichiometry of traditionally used metal electrode at interfaces with oxide
insulators, namely additional electrode oxidation due to the oxygen “scavenging” from the underlying oxide or direct interaction with oxidant molecules in the case of oxide deposition on top of electrode. This stoichiometry change may
have direct effect on effective work function (EWF). Obviously then, the degree of the electrode material oxidation at the interface should be tightly controlled and, if possible, suppressed to ensure the desirable EWF (and Vt) control.
To progress towards better understanding the physics and chemistry of the metal/oxide interface the practically relevant stacks used in charge trapping memory cells and in advanced logic and memory semiconductor devices
were studied using Hard X-ray photoelectron spectroscopy allowing to carry out in depth non-destructive chemical analysis of multilayered systems with high depth resolution. The most interesting examples will be presented in the
talk. We will specifically focusing on titanium dioxide/oxynitride interlayers (ILs) formation and on control of the amount of TiO2 enabling engineering of vacancy-mediated processes. The possibility of using ILs to limit oxygen redistribution at the metal/oxide interfaces will be also discussed. The work was supported by grant RSF No 18-72-00132.