Patent DE-102011104132-B3 (DE)
Title: Plasma assisted atomic layer deposition useful for forming thin layer on substrate, in reaction zone, comprises carrying out coating cycles, rinsing reaction area and converting adsorbed fraction of layer-forming process gas into thin layer
Inventor: FEDDERSEN-CLAUSEN OLIVER
IPC: C23C16/455
Filed: 2011-06-14
Granted: 2012-11-29
Abstract: Plasma assisted atomic layer deposition (ALD) for forming thin layer on substrate in reaction zone at process pressure reduced by vacuum system, comprises coating cycles, within which layer-forming process gas is supplied in cycle steps, rinsing reaction area and subsequently converting adsorbed fraction of layer-forming process gas by the supply or generation of reactive process gas, into thin layer. The process gas with rinsing properties is supplied over first process area with limited flow cross-section to second process area with respect to first process area larger flow cross-section. Plasma assisted atomic layer deposition (ALD) for forming a thin layer on a substrate in a reaction zone at a process pressure reduced by a vacuum system, comprises coating cycles, within which a layer-forming process gas is supplied in cycle steps, rinsing the reaction area and subsequently converting the adsorbed fraction of the layer-forming process gas by the supply or generation of a reactive process gas, into a thin layer. The process gas with rinsing properties is supplied over a first process area with a limited flow cross-section to a second process area with respect to the first process area larger flow cross-section and is pumped out, where the ratio and size of the flow cross sections, the pumping capacity of the vacuum system and the supply time and the mass flow of the process gas is adjusted at least during a cycle step such that a transition flow is formed between molecular and viscous flow with local process pressure different in both the process areas and different ratios between flow and diffusion, such that the first process area is rinsed due to predominant flow, the supplied process gas remains in the second process area due to the predominant diffusion, such that two different process steps are performed at least partially at the same time during a cycle step. An independent claim is also included for a device comprising (i) a processing chamber having device for the supply of process gases, device for generating plasma coupled in a capacitive manner, and a vacuum system for evacuating the process gases, preferably for plasma assisted ALD, and (ii) at least one electrode arranged in the reaction chamber and is configured in such a hollow manner that it forms the first flow region and a substrate can be introduced into the electrode, the process gases can be fed through the electrode, and openings in the electrode are provided between the substrate and a counter electrode and are in fluid contact with the second process area, which corresponds to the process chamber, and the vacuum system, such that the plasma is generated in the process chamber, which ensures an uniform film formation reaction in response to a substrate contained in the electrode, by diffusion of the process gas radicals in the first flow region and by a suitable arrangement and design of the electrode openings.