Planar technology: working the silicon wafer surface by repeating a series of basic operations.
Heat treatment: diffusion, oxidation, tempering.
Deposition: CVD, epitaxy, evaporation.
lithography: definition of geometry.
chemical attacks: dry and wet for the selective removal of material.
doping: ion implantation and diffusion.
etc. etc.
These are the common procedures for the preparation of an integrated circuit.