標題: | Investigation of Cell Stability and Write Ability of FinFET Subthreshold SRAM Using Analytical SNM Model |
作者: | Fan, Ming-Long Wu, Yu-Sheng Hu, Vita Pi-Ho Su, Pin Chuang, Ching-Te 交大名義發表 National Chiao Tung University |
關鍵字: | FinFET;Poisson's equation;static noise margin (SNM);subthreshold SRAM |
公開日期: | 1-六月-2010 |
摘要: | In this paper, the static noise margin (SNM) of FinFET static random access memory (SRAM) cells operating in the subthreshold region was investigated using an analytical solution of 3-D Poisson's equation. An analytical SNM model for subthreshold FinFET SRAM was demonstrated and validated by 3-D technology computer-aided design (TCAD) mixed-mode simulations. When compared with bulk SRAM, the standard 6T FinFET cell showed larger nominal READ SNM (RSNM), better variability immunity, and lesser temperature sensitivity of cell stability. Furthermore, examination of the stabilities of several novel independently controlled gate FinFET SRAM cells by using the proposed SNM model showed significant nominal RSNM improvements in these novel cells. However, the write ability is found to be degraded, which thus becomes an important concern for certain configurations in the subthreshold region. The result obtained indicates that the READ/WRITE word line voltage control technique is more effective than transistor sizing in improving the stability and write ability of the FinFET subthreshold SRAM. Furthermore, the impacts of process-induced variations on cell stability were also assessed. When compared with RSNM, it was found that WRITE SNM is more susceptible to process variations. While 6T is not a viable candidate for subthreshold SRAM, and 8T/10T cells must be used in bulk CMOS, the present analysis established the potential of 6T FinFET cells for subthreshold SRAM applications. |
URI: | http://dx.doi.org/10.1109/TED.2010.2046988 http://hdl.handle.net/11536/5298 |
ISSN: | 0018-9383 |
DOI: | 10.1109/TED.2010.2046988 |
期刊: | IEEE TRANSACTIONS ON ELECTRON DEVICES |
Volume: | 57 |
Issue: | 6 |
起始頁: | 1375 |
結束頁: | 1381 |
顯示於類別: | 期刊論文 |