Process of making an IC is fascinating and truly an engineering marvel. There is expertise of several fields of engineering, physics,
chemistry and material sciences that is required to make an IC do what it is supposed to do.
It all started when Bill Shockley and his team discovered the transistor in 1947. Transistors alone were not good enough as the size of
the logic demanded more, Jack Kilby (along with Bob Noyce) created the first integrated circuit in late 1950s just before the Apollo program
was kicking into action. Gordon Moore at Intel looked at the trend of transistors getting smaller, and created the famous Moore's Law --
which some people think is on the verge of an end.
What actually goes into IC:
It starts with sand. After oxygen, silicon is the most common element on earth’s surface (~28%). Sand has a high percentage of Silicon Dioxide (SiO2)
and is an important ingredient of semiconductor processing.
Next, mono-crystal silicon ingot is created: Silicon is purified in multiple steps till it reaches extremely high purity (~ 99.9999%). An ingot is created using the pure silicon.
Czochralski process is one of the methods used to create this ingot.
Next, wafers are created from this ingot. These wafers are then exposed to UV light via a mask which acts like stencil:
Following this metal layers are added, and each transistor is given connections to power supply, ground and signal lines. Finally, the wafer is cut into individual dies:
and packaged together:
If you want to read more refer to this blog post which goes more into the details (http://electronics.stevenvh.net/cpu/index.php)
The process of making an IC is truly incredible and has needed a combined knowledge of decades and thousands of people, and what goes on to make it is nothing short of extra-ordinary.