Spatial Atomic Layer Deposition (s-ALD)
Atomic layer deposition (ALD) technology uses cyclic exposure of a substrate to different precursors where in each cycle a single monolayer of atoms is formed. This ensures absolute thickness control, extreme layer homogeneity without porosity or pinholes and superb conformity, even of high aspect ratio surfaces. Because the ALD process takes place at atmospheric pressure, this technology avoids the cost of vacuum tooling such as pumps and load locks.
Spatial ALD is the enhanced form of traditional ALD improving the deposition rate by several orders of magnitude. Instead of filling and flushing a process chamber repeatedly, spatial ALD uses a multitude of precursor slits under which the substrates passes by at high speed. Gas bearing and exhaust slits in between the precursor zones, keep the precursors from mixing avoiding parasitic deposition.
This same principle we apply in our rotary spatial ALD equipment, improving the deposition rate further by putting the precursor slits on a rotating drum. When the flexible substrate moves over the rotating drum in the opposite direction, it is exposed to the precursor materials a great number of times building many atomic layers each rotation. The same principle can be applied in the form of a rotating disc. The gas barrier also provides the benefit of a gas layer between drum and substrate ensuring transportation without contact to the coated layer
ALD can be used to deposit a wide variety of materials for many different applications.