Carrier transport in HfO/sub 2//metal gate MOSFETs: physical insight into critical parameters
- 27 March 2006
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Electron Devices
- Vol. 53 (4), 759-768
- https://doi.org/10.1109/ted.2006.870888
Abstract
Electron and hole mobility in HfO/sub 2//metal gate MOSFETs is deeply studied through low-temperature measurements down to 4.2 K. Original technological splits allow the decorrelation of the different scattering mechanisms. It is found that even when charge trapping is negligible, strong remote coulomb scattering (RCS) due to fixed charges or dipoles causes most of the mobility degradation. The effective charges are found to be located in the HfO/sub 2/ near the SiO/sub 2/ interface within 2 nm. Experimental results are well reproduced by RCS calculation using 7/spl times/10/sup 13/ cm/sup -2/ fixed charges at the HfO/sub 2//SiO/sub 2/ interface. We also discuss the role of remote phonon scattering in such gate stacks. Interactions with surface soft-optical phonon of HfO/sub 2/ are clearly evidenced for a metal gate but remain of second order. All these remote interactions are significant for an interfacial oxide thickness up to 2 nm, over which, these are negligible. Finally, the metal gate (TiN) itself induces a modified surface-roughness term that impacts the low to high effective field mobility even for the SiO/sub 2/ gate dielectric references.Keywords
This publication has 38 references indexed in Scilit:
- The impact of interface roughness scattering and degeneracy in relaxed and strained Si n-channel MOSFETsSolid-State Electronics, 2004
- Characterization and modeling of nanometric SiO2 dielectricsMicroelectronic Engineering, 2004
- Effects of remote-surface-roughness scattering on carrier mobility in field-effect-transistors with ultrathin gate dielectricsApplied Physics Letters, 2004
- Remote Coulomb scattering in metal–oxide–semiconductor field effect transistors: Screening by electrons in the gateApplied Physics Letters, 2003
- Remote charge scattering in MOSFETs with ultra-thin gate dielectricsPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2002
- Improved theory for remote-charge-scattering-limited mobility in metal–oxide–semiconductor transistorsApplied Physics Letters, 2002
- Fundamentals of Carrier TransportPublished by Cambridge University Press (CUP) ,2000
- A physically-based model of the effective mobility in heavily-doped n-MOSFETsIEEE Transactions on Electron Devices, 1998
- MOSFET electron inversion layer mobilities - a physically based semi-empirical model for a wide temperature rangeIEEE Transactions on Electron Devices, 1989
- Electronic properties of two-dimensional systemsReviews of Modern Physics, 1982