Asymmetric Underlap in Scaled Floating Body Cell Memories
WU Qing-Qing1,2, CHEN Jing1**, LUO Jie-Xin1, LU Kai1,2, CHAI Zhan1, YU Tao1, WANG Xi1
1The State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 2University of the Chinese Academy of Sciences, Beijing 100049
Abstract：The asymmetric underlap device for a floating body cell is proposed without any extra process or photomask during fabrication. The electric field in the gate-drain underlap region is quietly relaxed. It is found that memory operation would fail in bipolar-based floating body cells because band-to-band tunneling significantly alters the body potential. Measurements show the proposed structure could indeed suppress the undesirable band-to-band tunneling greatly so that the bistable state via the parasitic bipolar junction transistor is ensured in scaled floating body cells. The parasitic capacitances in both word line and bit line are also reduced.
[1] Okhonin S, Nagoga M, Sallese J M and Fazan P IEEE SOI Conference (Durango, USA 1–4 October 2001) p 153 [2] Lu Z, Collaert N, Aoulaiche M, Wachter B D, Keersgieter A D, Schwarzenbach W, Bonnin O, Bourdelle K K, Nguyen B Y, Mazure C, Altimime L and Jruczak M IEEE International Electron Devices Meeting (San Francisco, USA 6–8 December 2010) p 12.3.1 [3] Shim K S, Chung I Y and Park Y J 2012 IEEE Electron Device Lett.33 14 [4] Choi S J, Han J W, Moon D I and Choi Y K 2010 IEEE Electron Device Lett.31 393 [5] Aoulaiche M, Simoen E, Caillat Ch, Collaert N, Groeseneken G and Jurczak M 2012 Microelectronics Solid-State Electron.1 33 [6] Aoulaiche M, Collaert N, Simoen E, Mercha A, Wachter De B, Bourdelle K K, Nguyen B Y, Boedt F, Delprat D, Jurczak M and Altimime L IEEE SOI Conference (San Diego, USA 11–14 October 2010) p 1 [7] Lim T and Kim Y 2008 Electron. Lett.44 157 [8] Nicoletti T, Aoulaiche M, Almeida L M, Santos S D, Martino J A, Veloso A, Jurczak M, Simoen E and Claeys C 2012 IEEE Electron Device Lett.33 940 [9] Andreas S 2010 Solid-Stade Electron.54 115 [10] Sentaurus-2012 User's Manual (Mountain View, CA, Synopsis Inc.) [11] Chen H F, Hao Y, Ma X H, Zhang J C, Li K, Cao Y R, Zhang J F and Zhou P J 2006 Chin. Phys. B 15 645 [12] Hu S G, Hao Y, Ma X H, Cao Y R, Chen C and Wu X F 2009 Chin. Phys. Lett.26 017304
2013, Vol. 30 
