A fin field-effect transistor (FinFET) is a multigate device, a MOSFET (metal–oxide–semiconductor field-effect transistor) built on a substrate where the gate is placed on two, three, or four sides of the channel or wrapped around the channel, forming a double or even multi gate structure. These devices have been given the generic name "FinFETs" because the source/drain region forms fins on the silicon surface. The FinFET devices have significantly faster switching times and higher current density than planar CMOS (complementary metal–oxide–semiconductor) technology.
FinFET is a type of non-planar transistor, or "3D" transistor. It is the basis for modern nanoelectronic semiconductor device fabrication. Microchips utilizing FinFET gates first became commercialized in the first half of the 2010s, and became the dominant gate design at 14 nm, 10 nm and 7 nm process nodes.
It is common for a single FinFET transistor to contain several fins, arranged side by side and all covered by the same gate, that act electrically as one, to increase drive strength and performance.
History
After the MOSFET was first demonstrated by Mohamed Atalla and Dawon Kahng of Bell Labs in 1960, the concept of a double-gate thin-film transistor (TFT) was proposed by H. R. Farrah (Bendix Corporation) and R. F. Steinberg in 1967. A double-gate MOSFET was later proposed by Toshihiro Sekigawa of the Electrotechnical Laboratory (ETL) in a 1980 patent describing the planar XMOS transistor. Sekigawa fabricated the XMOS transistor with Yutaka Hayashi at the ETL in 1984. They demonstrated that short-channel effects can be significantly reduced by sandwiching a fully depleted silicon-on-insulator (SOI) device between two gate electrodes connected together.
The first FinFET transistor type was called a "Depleted Lean-channel Transistor" or "DELTA" transistor, which was first fabricated in Japan by Hitachi Central Research Laboratory's Digh Hisamoto, Toru Kaga, Yoshifumi Kawamoto and Eiji Takeda in 1989. The gate of the transistor can cover and electrically contact the semiconductor channel fin on both the top and the sides or only on the sides. The former is called a tri-gate transistor and the latter a double-gate transistor. A double-gate transistor optionally can have each side connected to two different terminal or contacts. This variant is called split transistor. This enables more refined control of the operation of the transistor.
Indonesian engineer Effendi Leobandung, while working at the University of Minnesota, published a paper with Stephen Y. Chou at the 54th Device Research Conference in 1996 outlining the benefit of cutting a wide CMOS transistor into many channels with narrow width to improve device scaling and increase device current by increasing the effective device width. This structure is what a modern FinFET looks like. Although some device width is sacrificed by cutting it into narrow widths, the conduction of the side wall of narrow fins more than make up for the loss, for tall fins. The device had a 35 nm channel width and 70 nm channel length.
The potential of Digh Hisamoto's research on DELTA transistors drew the attention of the Defense Advanced Research Projects Agency (DARPA), which in 1997 awarded a contract to a research group at the University of California, Berkeley to develop a deep sub-micron transistor based on DELTA technology. The group was led by Hisamoto along with TSMC's Chenming Hu. The team made the following breakthroughs between 1998 and 2004.
1998 N-channel FinFET (17 nm) Digh Hisamoto, Chenming Hu, Tsu-Jae King Liu, Jeffrey Bokor, Wen-Chin Lee, Jakub Kedzierski, Erik Anderson, Hideki Takeuchi, Kazuya Asano 1999 P-channel FinFET (sub-50 nm) Digh Hisamoto, Chenming Hu, Xuejue Huang, Wen-Chin Lee, Charles Kuo, Leland Chang, Jakub Kedzierski, Erik Anderson, Hideki Takeuchi 2001 15 nm FinFET Chenming Hu, Yang-Kyu Choi, Nick Lindert, P. Xuan, S. Tang, D. Ha, Erik Anderson, Tsu-Jae King Liu, Jeffrey Bokor 2002 10 nm FinFET Shibly Ahmed, Scott Bell, Cyrus Tabery, Jeffrey Bokor, David Kyser, Chenming Hu, Tsu-Jae King Liu, Bin Yu, Leland Chang 2004 High-κ/metal gate FinFET D. Ha, Hideki Takeuchi, Yang-Kyu Choi, Tsu-Jae King Liu, W. Bai, D.-L. Kwong, A. Agarwal, M. Ameen
They coined the term "FinFET" (fin field-effect transistor) in a December 2000 paper, used to describe a non-planar, double-gate transistor built on an SOI substrate.