Patent attributes
A method of growing a thin film onto a substrate placed in a reaction chamber according to the ALD method by subjecting the substrate to alternate and successive surface reactions. The method includes providing a first reactant source and providing an inactive gas source. A first reactant is fed from the first reactant source in the form of repeated alternating pulses to a reaction chamber via a first conduit. The first reactant is allowed to react with the surface of the substrate in the reaction chamber. Inactive gas is fed from the inactive gas source into the first conduit via a second conduit that is connected to the first conduit at a first connection point so as to create a gas phase barrier between the repeated alternating pulses of the first reactant entering the reaction chamber. The inactive gas is withdrawn from said first conduit via a third conduit connected to the first conduit at a second connection point.