Silicon is purified to around 99.9999999%! Then it is sliced into very thin round sheets called wafers.

The type used in the Skywater 130nm process is doped to become p-type.

Here’s a great video about how silicon wafers are made.

And these great videos are about the birth of the Japanese semiconductor industry. Jump to about 12 minutes in to see how they pull the silicon ingot out of the molten material.

After the wafers are ready, they can be patterned using the photolithographic process, using a series of masks.

Course feedback

If you've got any interest in how the sausage is made you should get on the course and you should dig in and find out more. I mean this was the work of secret witches and wizards in mysterious cloaks casting strange incantations over a cauldron! This was all secret stuff and I love that this project is trying to do to silicon design what the open source community has been trying to do with software for the last 30 years. This feels like the next logical step and I think we'll look back and say well of course you can make your own chips that's just a thing and it will just be obvious and commonplace and I look forward to that.

Jonathan Pallant (digital course)