Shifter Materials and Stack Explorations for $V_{t}$ Fine-Tunable Dual Dipole Multi-$V_{t}$ Gate Stacks Compatible with Low Thermal Budget CFET
H. Arimura, Leo Lukose, Jhuma Ganguly, Jacopo Franco, Hans W. Mertens, J. Stiers, J. G. Lai, Ankit Nalin Mehta, Matías Bejide, M. S. Kim, Naoto Horiguchi · 2025
We report ALD processes, shifter stack and materials for dual dipole multi-$\mathrm{V}_{\mathrm{t}}$gate stacks having a$\mathrm{V}_{\mathrm{t}}$fine tunability and compatibility with a low thermal budget RMG. EOT penalty of dipole-first stack is mitigated by the choice of ALD oxidant, q-time control and the use of a less hygroscopic shifter material. Based on the observed impact of silicate formation on La dipole magnitude and reported dipole models, fine tunable$\mathrm{n} / \mathrm{p}$-type dipole gate stacks are demonstrated via (a) buffer$\text{HfO}_{\mathrm{x}}$and (b)$\text{HfO}_{2}$and$\text{ZrO}_{2}$high-$k$shifters.