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.
I found these great videos 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 lithographic process, using a series of masks