In factories, electrical impurities are baked in from special gases. However, these gases are toxic and
flammable, so we use a different method:
Silicon wafers are placed next to wafers of BN. The BN is oxidized to create B2O3.
This evaporates and carries the B to the Si wafers where it can bake in. This creates areas which conduct
electricity via positive holes (missing bonding electrons). The valves and flowmeters allow us to switch
from oxidizing the B to baking it into the Si.