# How a CPU Is Made from Silicon

- Original post: https://www.twitter.com/i/status/2118335698038132856
- Source account: [@thekitze](https://x.com/thekitze)
- Source language: English
- Duration: 1:37
- Published: 2026-11-07
- Canonical URL: https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon

## Transcript

[0:00](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon) First, get a rock. Then smash the rock. Now you've got 98% concentrated silicon dioxide.

[0:07](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=7) Now purify it to 99.9% pure silicon dioxide.

[0:11](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=11) Purify it to 99.9999999% polysilicon metal.

[0:17](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=17) Put the polysilicon ingots into a crucible.

[0:20](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=20) Heat the silicon ingots to 1,698 degrees Kelvin.

[0:24](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=24) Take a small seed monocrystal and dip it into the vat of molten silicon.

[0:28](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=28) Slowly pull the crystal out as it cools.

[0:31](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=31) Now you've got a monocrystal of pure silicon.

[0:34](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=34) Next, cut the monocrystalline silicon ingot into thin slices.

[0:38](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=38) Now you've got pristine, freshly cut silicon wafers.

[0:41](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=41) Dope it with some boron or phosphorus. Put photoresist on the wafer.

[0:45](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=45) Take your chromium-etched photolithographic quartz mask and shine a laser beam through it onto the wafer.

[0:51](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=51) The shadows produced by the photomask will control the location of highly localized chemical reactions on the surface of the silicon wafer.

[0:58](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=58) Now develop the photoresist. Acid etch the exposed parts of the wafer.

[1:02](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=62) Wash away the leftover photoresist. Now do some homoepitaxy, heteroepitaxy, pseudoepitaxy, diffusion doping, copper interconnects, chemical mechanical polishing.

[1:12](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=72) Now you've got a finished silicon wafer.

[1:15](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=75) Cut your silicon wafer into pieces. Now you've got unpackaged silicon dies.

[1:19](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=79) Locate the pads on the silicon chip and attach bond wires or use the flip chip method.

[1:24](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=84) The bond wires provide an electrical connection between the pins on the chip package and the pads on the silicon die.

[1:30](https://www.translate.mom/transcript/eTFIJPYvodux/en/how-a-cpu-is-made-from-silicon?t=90) Subscribe. You just watched a rock learn to think, and that's how you make a CPU.