Si 1-x Ge x Positive Feedback Field-effect Transistor with Steep Subthreshold Swing for Low-voltage Operation

• Published in: Journal of semiconductor technology and science Vol. 17; no. 2; pp. 216 - 222
• Main Authors: Hwang, Sungmin, Kim, Hyungjin, Kwon, Dae Woong, Lee, Jong-Ho, Park, Byung-Gook
• Format: Journal Article
• Language: Korean
• Published: 2017
• Subjects: positive feedback; Low power devices; field-effect transistor; steep subthreshold slope
• ISSN: 1598-1657

The most prominent challenge for MOSFET scaling is to reduce power consumption; however, the supply voltage ($V_{DD}$) cannot be scaled down because of the carrier injection mechanism. To overcome this limit, a new type of field-effect transistor using positive feedback as a carrier injection mechanism (FBFET) has been proposed. In this study we have investigated the electrical characteristics of a $Si_{1-x}Ge_x$ FBFET with one gate and one-sided $Si_3N_4$ spacer using TCAD simulations. To reduce the drain bias dependency, $Si_{1-x}Ge_x$ was introduced as a low-bandgap material, and the minimum subthreshold swing was obtained as 2.87 mV/dec. This result suggests that a $Si_{1-x}Ge_x$ FBFET is a promising candidate for future low-power devices.