How are microchips made?

Over the years manufacturing techniques improved -- making for components (like transistors) to be fabricated in smaller and smaller dimensions. This gave rise to Moore’s Law, which stipulated that the number of transistors within an integrated circuit will double almost every two years.

And so, for the past 50 years, the size of transistors decreased from 10s-of-microns to about 10 nanometers (for comparison, this is going down to the size of molecules and atoms.)

Monocrystalline silicon is currently being used as the main substrate for building microchips.

Fabrication is done in a fashion, called the Planar Process, which includes Imaging, Depositing, and Etching: