Ultra-high aspect-ratio FinFET technology

作者：Jovanovic Vladimir^*; Suligoj Tomislav; Poljak Mirko; Civale Yann; Nanver Lis K

来源：Solid-State Electronics, 2010, 54(9): 870-876.

DOI：10.1016/j.sse.2010.04.021

• CMOS
• FinFET
• TMAH
• (111) Channel
• Carrier confinement

FinFETs with ultra-large height-to-width ratio have been processed on (1 1 0) bulk silicon wafers by employing crystallographic etching of silicon with TMAH, which results in nearly vertical sidewalls with a (1 1 1)/(1 1 2) surface orientation. Tall fins, which corresponds to wide transistor channels per single fin offer more efficient use of the silicon area and improved performance for multi-fin devices in high-frequency analog applications. N-channel FinFETs with 1.9-nm-wide fins demonstrate the downscaling potential of the technology and devices with a height of the active part of the fin of 625 nm have the largest aspect-ratio of the fins reported thus far. Both devices with highly and moderately scaled fin-widths exhibit excellent subthreshold performance while electrons have higher mobility in 15-nm-wide FinFETs, which gives them larger on-state currents. The comparison between FinFETs and wide tri-gate devices shows that FinFETs have better current drivability in this simple process, even with larger source/drain series resistances. The differences in threshold voltage and low-field electron mobility between 1.9-nm-wide and 15-nm-wide FinFETs have been related to the increase in subband energies due to carrier confinement in the extremely narrow fins.

• 出版日期2010-9