What is Atomic Layer Deposition

Atomic Layer Deposition: Making a Chip One Atom at a Time
Some of the critical film layers in a 22nm transistor are only a few atoms thick. To make these infinitesimal structures, a technique called atomic layer deposition (ALD) is becoming increasingly common. The ALD process builds up material through chemical reactions on the surface of the chip, one monolayer at a time, to produce the thinnest, most uniform films possible.