I do not understand the full concept/theory of how dangling bonds pins the fermi levels in MOSFET which in turn affects the threshold voltage. Hydrogen atoms are deployed to passivate the dangling bond since oxidation is not enough, however is hydrogen annealing is not done, the excess dangling bond will pins the fermi level. I could not understand this term, can someone please explain to me please?
Dear Zhi Lin Sim,
Quite comprehensive explanation is presented in the article below:
https://www.researchgate.net/publication/3065559_Fermi-Level_Pinning_at_the_PolysiliconMetal_Oxide_Interface-Part_I
Fermi-Level Pinning at the Polysilicon/Metal Oxide Interface—Part I
- July 2004
- IEEE Transactions on Electron Devices 51(6):971 - 977
- DOI:
- 10.1109/TED.2004.829513
- Source
- IEEE Xplore
- Christopher C. Hobbs
- L. R. C. Fonseca
- A. A. Knizhnik
- Show all 20 authors
- Philip J. Tobin
IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 51, NO. 6, JUNE 2004 971Fermi-Level Pinning at the Polysilicon/Metal OxideInterface—Part I Christopher C. Hobbs, Leonardo R. C. Fonseca, Andrey Knizhnik, Veeraraghavan Dhandapani, Srikanth B. Samavedam, Senior Member, IEEE, William J. Taylor, John M. Grant, LuRae G. Dip, Dina H. Triyoso, Rama I. Hegde, David C. Gilmer, Ricardo Garcia, Darrell Roan, M. Luke Lovejoy, Raghaw S. Rai, Elizabeth A. Hebert, Hsing-Huang Tseng, Senior Member, IEEE, Steven G. H. Anderson, Bruce E. White, and Philip J. Tobin, Member, IEEE Abstract—We report here that Fermi pinning at the polysil-icon/metal oxide interface causes high threshold voltages in MOSFET devices. Results indicate that pinning occurs due to the interfacial Si–Hf and Si–O–Al bonds for HfO2 and Al2O3, respectively. Oxygen vacancies at polysilicon/HfO2 interfaces also lead to Fermi pinning. We show that this fundamental characteristic affects the observed polysilicon depletion. In Part I, the theoretical background is reviewed, and the impact of the different gate stack regions are separated out by investigating the relative threshold voltage shifts of devices with Hf-based dielectrics. The effects of the interfacial bonding are examined in Part II. (PDF) Fermi-Level Pinning at the Polysilicon/Metal Oxide Interface—Part I. Available from: https://www.researchgate.net/publication/3065559_Fermi-Level_Pinning_at_the_PolysiliconMetal_Oxide_Interface-Part_I [accessed Jul 25 2022].
- Badges
- Science topic
- Similar topics
- Engineering
- Materials Engineering
- Powders