Ah, Solid State Physics. Semiconductors are heavily based on this branch, because it explains the physical (mechanical, electrical, thermal, etc.) properties of solids based on how their atoms are organized. These properties lead into how transistors function, and why.

Put it back, Allyn.

Anandtech has published a seven-page article that digs into physics and builds upon itself. It starts with a brief explanation of conductivity and what makes up the difference between a conductor, an insulator, and a semiconductor. It uses that to build a simple transistor. From there it explains logic gates, wafers, and lithography. It works up to FinFETs and then keeps going into the future. It is definitely not an article for beginners, but it can be progressed from start to finish given enough effort on the part of the reader.

While this was not mentioned in the article, at least not that I found, you can derive the number of atoms per "feature" by dividing its size by the lattice-distance of the material. For silicon, that is about half of a nanometer at room temperature. For instance, 14nm means that we are manufacturing features that are defined by less than 30 atoms (up to rounding error). The article speculates a bit about what will happen after the era of silicon. This is quite interesting to me, particularly since I did my undergraduate thesis (just an undergrad thesis) on photonic crystals, which route optical light across manufactured defects in an otherwise opaque solid to make an optical integrated circuit. It has the benefit of, with a mixture of red, orange, and maybe green lasers, being able to "go plaid".

If you are interested, be sure to read the article. It is a bit daunting, but much more manageable than most sources. Congratulations to Joshua Ho and anyone else who might have been involved.