Semiconductor Device Fabrication
We briefly saw this in ECE222, but this is actually SO COOL.
- Photoresist material
Ahh, what is explained here is directly shown in Sam’s latest video
Sams’ Hackaday talk is a really solid introduction
- This is how PCBs are made, and at a smaller scale, how ICs are made
Manufacturing an Integrated Circuit
These notes are too high level.
With a special chemical process, we add materials to silicon that allow tiny areas to transform into one of three devices:
- Excellent Conductor of electricity (using either microscopic copper or aluminum wire)
- Excellent insulator from electricity (like plastic sheathing or glass)
- Areas that can conduct or insulate under specific conditions (as a switch) → this is where Transistor come into play
- We start with a silicon crystal ingot, which looks like a giant sausage. Today, ingots are 8–12 inches in diameter and about 12–24 inches long.
- An ingot is finely sliced into Wafers no more than 0.1 inches thick.
- These wafers then go through a series of processing steps, during which patterns of chemicals are placed on each wafer, creating the transistors, conductors, and insulator
It’s really hard to manufacture a perfect chip without defects, so there is a lot of verification when we manufacture the chips.
The wafer is cut into dies.
A die, in the context of integrated circuits, is a small block of semiconducting material on which a given functional circuit is fabricated.