Integration of TmSiO/HfO2 Dielectric Stack in Sub-nm EOT High-k/Metal Gate CMOS Technology
2015 (English)In: IEEE Transactions on Electron Devices, ISSN 0018-9383, Vol. 62, no 3, 934-939 p.Article in journal (Refereed) Published
Integration of a high-k interfacial layer (IL) is a promising technological solution to improve the scalability of high-k/metal gate CMOS technology. We have previously demonstrated a CMOS-compatible integration scheme for thulium silicate (TmSiO) IL and shown excellent characteristics in terms of equivalent oxide thickness (EOT), interface state density, channel mobility, and threshold voltage control. Here, we report on optimized annealing conditions leading to gate leakage current density comparable with state-of-the-art SiOx/HfO2 nFETs (0.7 A/cm(2) at 1 V gate bias) at sub-nm EOT (as low as 0.6 nm), with near-symmetric threshold voltages (0.5 V for nFETs and -0.4 V for pFETs). We demonstrate an excellent performance benefit of the TmSiO/HfO2 stack, i.e., improved channel mobility over SiOx/HfO2 dielectric stacks, demonstrating high-field electron and hole mobility of 230 and 70 cm(2)/Vs, respectively, after forming gas anneal at EOT = 0.8 nm. Finally, the reliability of the TmSiO/HfO2/TiN gate stack is investigated, demonstrating 10-year expected life-times for both oxide integrity and threshold voltage stability at an operating voltage of 0.9 V.
Place, publisher, year, edition, pages
2015. Vol. 62, no 3, 934-939 p.
Bias temperature instability (BTI), CMOS, equivalent oxide thickness (EOT), HfO2, high-k, mobility, reliability, silicate, thulium, thulium silicate (TmSiO), time-dependent dielectric breakdown (TDDB)
Other Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-163458DOI: 10.1109/TED.2015.2391179ISI: 000350332000037ScopusID: 2-s2.0-84923644871OAI: oai:DiVA.org:kth-163458DiVA: diva2:800953
FunderEU, European Research Council, OSIRIS 228229Swedish Foundation for Strategic Research
QC 201504082015-04-082015-04-072015-04-08Bibliographically approved