process used in microfabrication

Photolithography is the combination of photography and lithography. Its uses include the mass printing of photographs. Microphototolithography is the use of photolithography to transfer geometric shapes on a photomask to the surface of a semiconductor wafer for making integrated circuits.

Manufacturing Edit

Photolithography makes integrated circuits such as memory and central processing units.

A special light-and-shadow pattern is shone through a photomask, onto a sheet or wafer of silicon that had been covered with a material called a photoresist. The light hardens the photoresist. When the board is dipped into a special acid, the parts that had no light on them are dissolved away.

Memory chips have thousands or millions of identical cells. Because is much easier to make than a CPU, (a large die with a non-repetitive structure), RAM chips are far less expensive than processors.