Investigation of Fixed Oxide Charge and Fin Profile Effects on Bulk FinFET Device Characteristics

• Published in: IEEE electron device letters Vol. 34; no. 12; pp. 1485 - 1487
• Main Authors: Bomsoo Kim, Dong-Il Bae, Zeitzoff, Peter, Xin Sun, Standaert, Theodorus E., Tripathi, Neeraj, Scholze, Andreas, Oldiges, Philip J., Dechao Guo, Huiling Shang, Kang-Ill Seo
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.12.2013; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Bulk FinFET; Degradation; Doping; Electronics; Exact sciences and technology; FinFETs; fixed oxide charge; low-doped channel doping; mobility improvement; punch-through; random dopant fluctuation; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; shoulder-shaped Fin cross section; Silicon; subthreshold degradation; tapered Fin; Transistors; variability reduction; Bulk FinFET; MOSFET; low-doped channel doping; Circuit design; variability reduction; Doping; PMOS technology; Doped materials; Dual gate transistor; Self aligned technology; Degradation; punch-through; Long channel; subthreshold degradation; mobility improvement; fixed oxide charge; shoulder-shaped Fin cross section; tapered Fin; NMOS technology; random dopant fluctuation; Computer aided design; Electrical characteristic; Damaging
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2013.2285914

The effect of positive fixed oxide charge (Q f ) on the electrical characteristics of bulk FinFET devices is investigated and newly addressed as a Fin scaling detractor. The aggressively scaled Fin width leads to abnormal subthreshold slope (SS) degradation in nMOS devices even with a long channel length, while pMOS is free of such degradation. This observation is reproduced and analyzed by a well-calibrated TCAD simulation deck with Q f introduced. A new Fin profile suppressing the Q f effect is proposed, and the benefits of the new profile are predicted in terms of variability reduction and mobility improvement, as well as Q f immunity.