ALD is a state of the art deposition technique for inorganic films that is based on a cyclic, complementary, self-limiting surface reaction and results in excellent thickness and surface morphology control. For example, to form a metal oxide film a metal organic complex and a suitable oxidizer such as H2O are used as reagents. The process begins with a suitably functionalized surface that is exposed sequentially to each of the precursors separated by appropriate purge cycles. The process is complementary because each exposure prepares the surface for reaction with the next reagent and cyclic because in the end of a process cycle the surface returns to its initial state.
Advantages of ALD
Interest in ALD has increased exponentially in the past decade due to some unique features of this approach including:
Elimination of gas-phase reactions
Ability to deposit uniform films on high aspect ratio features
Monolayer growth control
A picture of our ALD reactor
