Abstract
Ultra-thin body (UTB) SOI MOSFET is promising for sub-50 nm CMOS technologies [1]. However, recent experimental finding [2] suggests the need for serious reconsiderations of its long-term scaling capability into the sub-10 nm body thickness (T BODY) regime. Two new phenomena attributed to surface roughness (SR) are identified [2]; they are enhanced threshold voltage (V TH) shifts and drastic degradation of mobility with a T BODY dependence [2,3]. In this work, we detail a study of these two phenomena in UTB MOSFETs with sub 10 nm T BODY Si and Ge channels. Firstly, the phenomena of enhanced V TH shifts is modeled by accounting for the fluctuation of quantized energy levels due to SR up to second order approximation. Good corroboration with experimental results [2] is obtained. Our model is then applied to examine the impact of enhanced V TH shifts on metal gate workfunction requirements. Secondly, we modeled the SR-limited electron and hole mobility and discuss their impact on the choice of surface orientations. Mobility anisotropy are also examined for the various surface orientations.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 151-154 |
| Number of pages | 4 |
| Journal | Technical Digest - International Electron Devices Meeting, IEDM |
| State | Published - 2004 |
| Event | IEEE International Electron Devices Meeting, 2004 IEDM - San Francisco, CA, United States Duration: Dec 13 2004 → Dec 15 2004 |
Bibliographical note
Funding Information:We greatly appreciate the insightful and useful discussions with M. V. Fischetti (T. J. Watson Research, IBM) and C. Y. Mou (National Tsing Hua University) on modeling of SR-limited mobility. This work is supported by Singapore A?STAR R263-000-267-305 grant and IME/NUS JML R263-000-221-112 grant.
Funding Information:
Acknowledgements: We greatly appreciate the insightful and useful discussions with M. V. Fischetti (T. I. Watson Research, IBM) and C. Y. Mou (National Tsing Hua University) on modeling of SR-limited mobility. This work is supported by Singapore A*STAR R263-000- 267-305 grant and IME/NUSJU R263-000-221-112 grant.