Patent ID: 8657959

Claim:
Apparatus for atomic layer deposition of a material on a moving substrate, the apparatus comprising: a conveying arrangement for moving a substrate along a predetermined path of travel through the apparatus; and a coating bar having at least one precursor delivery channel and first and second inert gas delivery channels defined therein, the precursor delivery channel having an upstream and a downstream side relative to the path of travel of the substrate, an outlet end, and a precursor flow restrictor disposed therewithin, the precursor delivery channel being adapted to conduct a precursor fluid containing a material to be deposited on the substrate with the precursor flow restrictor presenting a predetermined impedance Z fc to the flow through the precursor delivery channel, the flow through the impedance Z fc having a friction factor f, and the first and second inert gas delivery channels being respectively disposed on the upstream and downstream sides of the precursor delivery channel, each having an outlet end and an inert gas flow restrictor therewithin, and each of the inert gas delivery channels being adapted to conduct an inert fluid toward the substrate with the inert gas flow restrictor presenting a predetermined impedance Z′ fc to the flow through the respective inert gas delivery channel, the flow through the impedance Z′ fc having a friction factor f′; so that, when the apparatus is in use, a substrate movable along the path of travel defines a gap between the substrate and the outlet ends of the precursor delivery channel and each inert gas delivery channel, and the gap defines an impedance Z g to a flow of fluid from the precursor delivery channel and an impedance Z′ g to a flow of fluid from each inert gas delivery channel, wherein the precursor restrictor and the inert gas restrictors are sized such that the impedance Z fc is at least five (5) times the impedance Z g , the friction factor f is less than 100, the impedance Z′ fc is at least five (5) times the impedance Z′ g , and f′ is less than 100, with the gap ranging from 0.1 mm to 0.2 mm, so that during continuous flow operation of the apparatus for atomic layer deposition the flow of the precursor fluid and the flow of the inert fluid are tolerant of dimensional variations in the gap and a steady-state coating profile is attained.