It is a mix: digital logic is almost entirely laid out by machine, but analog circuits and the underlying logic cells (as well as certain specialised digital bl

It is a mix: digital logic is almost entirely laid out by machine, but analog circuits and the underlying logic cells (as well as certain specialised digital blocks like memories) are a lot less automated. The most expensive part isn't doing that: it's doing the validation and simulation of the design so that it'll have the best chance of working after you've spend 5-6 figures and many months on actually building it (and then there's the cost of testing it in reality and figuring out what isn't actually working and how to fix it: the first batch of chips still extremely rarely works).