how they are made.

[ExKage]

Issues in the silicon wafer. Issues in the epitaxial layer. Microscopic defects that you can't detect in a SEM or cross-section and SEM. Issues that can't be detected by a 4 point probe or a CV plotter and needs an SRP done. Wafer Fabs are filled with techs/engineers who have to probe wafers. Put the wafers on the loaders. Put them in the Spin Rinse Dryer. They have to align the masks. They have to load the furnaces. The furnaces better be good or else they may be issues with a wafer in the lot. The techs may be part of The Great Resignation, moving elsewhere as a labor shortage. The equipment engineers leaving. The equipment engineers being trained being left with incomplete training. Multiple things. Your diffusion tube goes down. The materials like gases weren't delivered on time. The prices of metals that are deposited or sintered going up. So many things that isn't just a machine can make so many die on a wafer.

Edit: This doesn't even go into what goes into reliability testing for semiconductors or the assembly processes. Packaging? What about packaging issues. What if the one maker of the clips you use to seal your semiconductor into a ceramic or other DIP package is leaving the business or doesn't make the clip you use anymore? Now if you have to find a new source for that, quickly. You can't just leave parts in a drybox indefinitely. Most semiconductors have a seal by date. Now if you buy new clips you run the issue of improper seals. Incompletes or pinholes. Testing? 10 day+ burn-ins, temperature tests, temp cycling etc. You don't just test a semiconductor to a set of parameters and say walah done.

[EZGIL]

Issues in the silicon wafer. Issues in the epitaxial layer. Microscopic defects that you can't detect in a SEM or cross-section and SEM. Issues that can't be detected by a 4 point probe or a CV plotter and needs an SRP done. Wafer Fabs are filled with techs/engineers who have to probe wafers. Put the wafers on the loaders. Put them in the Spin Rinse Dryer. They have to align the masks. They have to load the furnaces. The furnaces better be good or else they may be issues with a wafer in the lot. The techs may be part of The Great Resignation, moving elsewhere as a labor shortage. The equipment engineers leaving. The equipment engineers being trained being left with incomplete training. Multiple things. Your diffusion tube goes down. The materials like gases weren't delivered on time. The prices of metals that are deposited or sintered going up. So many things that isn't just a machine can make so many die on a wafer.

Edit: This doesn't even go into what goes into reliability testing for semiconductors or the assembly processes. Packaging? What about packaging issues. What if the one maker of the clips you use to seal your semiconductor into a ceramic or other DIP package is leaving the business or doesn't make the clip you use anymore? Now if you have to find a new source for that, quickly. You can't just leave parts in a drybox indefinitely. Most semiconductors have a seal by date. Now if you buy new clips you run the issue of improper seals. Incompletes or pinholes. Testing? 10 day+ burn-ins, temperature tests, temp cycling etc. You don't just test a semiconductor to a set of parameters and say walah done.

This post just made me realize I have no idea whats going on.

[Akiudo]

This post just made me realize I have no idea whats going on.

and that is perfectly fine and reasonable. sadly a lot of people fail to have this realization which than gives us the current forums full of people that know better than full time developers working on this game.