TSMC’s 2nm process which is said to utilize the GAA technology is said to be going through development at a faster than expected rate. While Samsung is already planning to switch to GAA technology with its 3nm node in 2021 (mass production), TSMC has stated that its 3nm node will continue to use the FinFet process while the 2nm node based on the GAA technology will enter mass production in the second half of 2023.
At present though, TSMC is well ahead of its Korean rival, with the majority of chipmakers looking to adopt its 5nm process in 2021, following Apple. As per sources, yields for the 5nm node are even better than the existing 7nm process. The 3nm process, on the other hand, will be mass-produced in the second half of 2022. TSMC seems to believe that its 5nm and 3nm nodes will be more than enough to combat Samsung’s 3nm GAA process.
On advantage TSMC has is that it’ll continue to be Apple’s primary foundry partner right till the 2nm GAA node which is being jointly developed with ample support from the smartphone maker.
In case you are wondering what the big deal with GAA is, it’s more about current leakage as you shrink transistors. Usually, current only flows between the source and drain of a transistor when you turn it on. However, if you go below certain limits in terms of gate length, the current beings to flow between the source and drain even when the transistor is off.
As you can see in the above image, the Gate in the middle covers the source-drain from three sides. It’s a 3D structure as shown in the earlier image. This is a side-view. With GAA, the gate (in purple below) covers all the source-drain channel from all the four sides, further reducing leakage.