ARM could be introducing Fin-Shaped Field Effect Transistors (FinFET) in 20 nm and smaller chip designs.
According to a blog post by Jean Luc Pelloie, the company's Fellow Director of SOI Technology, 20 nm may represent an inflection point in which it will be necessary to transition from a metal-oxide semiconductor field-effect transistor (MOSFET) to Fin-Shaped Field Effect Transistors (FinFET) or 3D transistors, which Intel refers to as tri-gate designs that are set to debut with the company's 22 nm Ivy Bridge product generation.
Pelloie explains that it is "increasingly difficult to control the vertical electric field between the gate and the substrate while maintaining the channel depletion below threshold and then minimize the leakage current" when shrinking transistors. FinFETs are considered a solution to solve this problem. The engineer wrote that FiNFETs could be used on either bulk or SOI wafers. However, ARM still has work to do and especially investigate the scalability of this technology. "However, 3D devices are clearly on the road for sub-20nm nodes … and FinFET’s time may finally be here," Pelloie wrote.
FinFET history goes back to a December 2000 paper published in IEEE Transactions on Electron Devices entitled "FinFET - A Self-Aligned Double Gate MOSFET Scalable to 20 nm". Intel was first to move to tri-gates and take this technology into mass-production, but was accused of having switched to 3D transistors only because it was not able to scale its SRAMs, which the company traditionally uses to unveil a manufacturing process, from 32 nm to 22 nm. Intel's tri-gate technology was announced back in May of this year. Intel hopes that tri-gate technology will keep up with Moore's Law and especially drive low-voltage and low-power features.