The main source is WikiChip. It appears that the wiki is edited by the people who work in the industry and has a lot of information that seems to be fairly reliable. Unfortunately, it rarely has in-line citation to its primary sources, but still a good source.
Read,
* 14 nm lithography process
https://en.wikichip.org/wiki/14_nm_lithography_process
* 10 nm lithography process
https://en.wikichip.org/wiki/10_nm_lithography_process
Other sources include:
* Life at 10nm. (Or is it 7nm?) And 3nm Views on Advanced Silicon Platforms
https://www.eejournal.com/article/life-at-10nm-or-is-it-7nm-...
* A Brief History of Process Node Evolution
https://www.design-reuse.com/articles/43316/a-brief-history-...
* 14nm, 7nm, 5nm: How low can CMOS go? It depends if you ask the engineers or the economists…
https://www.extremetech.com/computing/184946-14nm-7nm-5nm-ho...
* Is Intel Really Starting To Lose Its Process Lead? 7nm Node Slated For Release in 2022
https://wccftech.com/intel-losing-process-lead-analysis-7nm-...
You get dig deeper using these links.
And don't ask me why I'm just copy & paste Wikipedia citations. I added those citations...