Influence of the Ge concentration on the threshold voltage and subthreshold slope of nanoscale vertical Si/SiGe pMOSFETs
An analytical model has been set up to investigate the influence of SiGe in the source on the threshold voltage and subthreshold behaviour of heterojunction pMOSFETs. The use of SiGe in the source region of the pMOSFET introduces an extra degree of freedom for fine-tuning of the subthreshold and on-state behaviour of the devices. It will be shown that the short channel behaviour of these devices is greatly improved in comparison with vertical homojunction Si structures. Careful design and optimisation of these devices show that the use of Ge is only advantageous for sub 0.1 µm devices. Structures with channel lengths down to 30 nm exhibit promising characteristics.
KeywordsThreshold Voltage Channel Length Short Channel SiGe Layer Subthreshold Slope
Unable to display preview. Download preview PDF.
- M. Yoshimi, M. Terauchi, A. Murakoshi, M. Takahashi, K. Matsuzawa, N. Shigyo and Y. Ushiku, “Technology Trends of Silicon-On-Insulator—Its Advantages and Problems to be Solved,” IEDM, pp. 429–432, 1994.Google Scholar
- U.S. Provisional Patent Application Number: 60/001,022; July 7th, 1995, C.J.R.P. Augusto, IMEC.Google Scholar
- N. Collaert and K. De Meyer, “Current calculation of a submicron Si/SiGe heterojunction MOSFET,” Proceedings of the International Semiconductor Device Research Symposium, pp. 517–520, 1997.Google Scholar
- SIA roadmap, Semiconductor Industry Association, 1997.Google Scholar