Title. I’ve read recently a bit about chips and wondered how it’s even possible for cutting edge chips, such as those produced my Intel and TSMC to just apply metal vapor to a wafer and know that they will behave like a transistor should.
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You’ve grossly oversimplified the process. A given wafer will go through hundreds or even thousands of steps to produce a working integrated circuit.
The one big thing you’re missing is that all the deposition and etching steps are patterned using an in situ mask (“photoresist”) on the surface of the wafer – protecting some areas from adding/subtracting material, while allowing it to happen in areas where the mask has an opening.
The photoresist is coated on the wafer, then exposed to UV or electron beams in the pattern needed for a given step, then washed to selectively remove resist material either where the exposure occurred (“positive tone”) or where it didn’t (“negative tone”). The wafer is then subjected to an etch or deposition step, then the resist is stripped off in preparation for the next coat/expose/process/strip cycle.
Transistors are made via implanting dopant atoms into the silicon. The metal layers are just wires interconnecting the transistors.
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