TSMC has their order book filling up nicely as more than 20 customers are lined up for 7mn wafers to be made and taped up for pick and place machines.
Apple has their A12 CPU for the next gen phone and they are first in line. AMD, Qualcomm and NVIDIA are likely to get their orders late in 2018 or early in 2019.
Recall NVIDIA has a bunch of unsold semiconductors to get rid of so they are likely to have be willing to wait until 2019 for their order until their backlog of chips is sold.
AMD has a lot of cards sold to digital coin miners but its not clear if there are any problems with excess inventories.
7nm at TSMC is roughly the same as Intel’s 10nm lines. Both are getting the kinks worked out so that yields are high enough to keep costs down.
As feature sizes get smaller, it does get increasingly difficult. This is why 14nm devices were made for several years before smaller sized devices could be make more cost effectively.