Doping while deposition (growing the crystal)
- Not yet sure how CVD is done, but there’s gases involved.
- So we just make one of the gases our dopant.
Doping after growing
Diffusion
- Exactly what it sounds like.
- Exposing silicon to high temp gases containing our dopants, transfers some of the dopants into our substrate through diffusion.
Ion implantation
- You literally blast the substrate with ions of your dopant.
The two above can be controlled by lithography+masking.
Spin Coater
- Literally spin coating the substrate with a mixture of stuff with the dopant and then stripping + baking the substrate at a high temp.