- Magnetron sputtering
- Atomic layer deposition (ALD, PEALD)
- Vacuum evaporation
Atomic layer deposition (ALD, PEALD)
Atomic layer deposition (ALD) is a thin film deposition technique that is based on the sequential use of a gas phase chemical process. The majority of ALD reactions use two chemicals, typically called precursors. These precursors react with the surface of a material one at a time in a sequential, self-limiting, manner. In contrast to chemical vapor deposition, the precursors are never present simultaneously in the reactor, but they are inserted as a series of sequential, non-overlapping pulses. In each of these pulses the precursor molecules react with the surface in a self-limiting way, so that the reaction terminates once all the reactive sites on the surface are consumed. Consequently, the maximum amount of material deposited on the surface after a single exposure to all of the precursors (a so-called ALD cycle) is determined by the nature of the precursor-surface interaction. By varying the number of cycles it is possible to grow materials uniformly and with high precision (practically by atomic layer) on arbitrarily complex and large substrates. (see https://en.wikipedia.org/wiki/Atomic_layer_deposition )
We have a Beneq TFS 200 ALD system which is equipped with liquid and gas precursor lines and plasma option (for plasma enhanced ALD). Currently available precursors: TMA, DEZ and TiCl4 for Al2O3, ZnO and TiO2 preparation, respectively, by both thermal and plasma enhanced processes.