Making an Integrated Circuit

Depicts the step-by-step process by which the transistors of an integrated circuit are made.

This is an Intel 4004 IC, the original microprocessor or "computer on a chip." The chip is packaged inside a 16 Pin DIP (dual inline package). This package protects the chip and provides electrical connections. On the chip, the individual transistors are so small that they can be seen only with a very powerful microscope.

Now letŒs walk through the (many) steps it takes to fabricate this transistor:

First a layer of SiO₂ is grown on the silicon substrate by heating in O₂ gas. (Si is shown here in blue but it is actually metallic-charcoal in color). Then a layer of Si₃N₄ is grown by heating in combination of NH₃ and SiH₄.