GAA technology has been under development since the early 2000s by Samsung and other firms. GAA transistors are field-effect transistors (FET) that feature a gate on all four sides of the channel to overcome the physical scaling and performance limitations of FinFETs, including supply voltage.The South Korean giant also confirmed it plans to start 7nm LPP EUV production in the second half of this year. Other nodes on the roadmap include 5nm FinFET production in 2019 and 4nm FinFET in 2020.
Samsung's proprietary GAA technology, known as multi-bridge-channel FET (MBCFET), has been in development since 2002, according to Ryan Sanghyun Lee, vice president of market for Samsung Foundry. MCBFET uses a nano-sheet device to enhance gate control, significantly improving the performance of the transistor, according to the company.
More details can be read at EE Times. The site says analysts were impressed by Samsung's annual foundry technology forum as they didn't expect GAA transistors until some time in 2022.