Apparatus and method for atomic layer deposition

Abstract

Apparatus for atomic layer deposition on a surface of a sheeted substrate, comprising: an injector head comprising a deposition space provided with a precursor supply and a precursor drain; said supply and drain arranged for providing a precursor gas flow from the precursor supply via the deposition space to the precursor drain; the deposition space in use being bounded by the injector head and the substrate surface; a gas bearing comprising a bearing gas injector, arranged for injecting a bearing gas between the injector head and the substrate surface, the bearing gas thus forming a gas-bearing; a conveying system providing relative movement of the substrate and the injector head along a plane of the substrate to form a conveying plane along which the substrate is conveyed. A support part arranged opposite the injector head, the support part constructed to provide a gas bearing pressure arrangement that balances the injector head gas-bearing in the conveying plane, so that the substrate is held supportless by said gas bearing pressure arrangement in between the injector head and the support part.

1 . An apparatus for atomic layer deposition on a surface of a sheeted substrate, comprising:
 an injector head comprising
 a deposition space provided with a precursor supply and a precursor drain; said supply and drain arranged for providing a precursor gas flow from the precursor supply via the deposition space to the precursor drain; the deposition space in use being bounded by the injector head and the substrate surface; 
 a bearing gas injector arranged for injecting a bearing gas between the injector head and the substrate surface, the bearing gas thus forming an injector head gas-bearing; 
   a conveying system providing relative movement of the substrate and the injector head along a plane of the substrate to form a conveying plane along which the substrate is conveyed; and   a support part arranged opposite the injector head, the support part constructed to provide a gas bearing pressure arrangement from an opposite side of the substrate with respect to the injector head gas-bearing, the gas bearing pressure arrangement providing a gas bearing pressure that balances the injector head gas-bearing in the conveying plane, so that the substrate is held supportless by said gas bearing pressure arrangement, between the injector head and the support part;   
       wherein the bearing gas injector defines, relative to the substrate, a gap distance which in combination with the gas bearing pressure provides a gas bearing stiffness between 10 3  and 10 10  N/m 3 . 
     
     
         2 . The apparatus of  claim 1 , wherein the gas-bearing pressure arrangement balances the injector head by having an identical flow arrangement in the support part as is provided by the injector head. 
     
     
         3 . The apparatus of  claim 1 , wherein the gas bearing pressure is within a range of 1.2 to 20 bar. 
     
     
         4 . The apparatus of  claim 3 , wherein the gas bearing pressure is within 3 to 8 bar. 
     
     
         5 . The apparatus of  claim 1 , further comprising a prestressing arrangement for applying a prestressing force on the injector head directed towards the substrate surface. 
     
     
         6 . The apparatus of  claim 5 , wherein the prestressing arrangement comprises an element selected from the group consisting of a magnetic element for magnetically providing the prestressing force, a weight, an elastic element a spring, and combinations thereof. 
     
     
         7 . The apparatus of  claim 1 , wherein the precursor drain is provided adjacent the precursor supply, whereby the precursor gas flow is aligned with the relative movement of the substrate; and/or wherein, in use, the precursor drain and the precursor supply are both facing the substrate surface. 
     
     
         8 . The apparatus of  claim 1 , wherein the injector head comprises pressure control for switching any of the precursor supply, the precursor drain, and/or the bearing gas injector, dependent on the presence of a substrate. 
     
     
         9 . The apparatus of  claim 8 , wherein the support part comprises a further drain opposite the precursor drain, said further drain being switchable dependent on the presence of a substrate in the deposition space, so that, when a substrate edge passes the precursor drain, the precursor gas flow is directed away from the opposite side of the substrate. 
     
     
         10 . The apparatus of  claim 1 , wherein the injector head comprises a further deposition space provided with a reactant supply, the further deposition space in use being bounded by a flow barrier. 
     
     
         11 . The apparatus of  claim 10 , wherein the apparatus is configured for providing at least one of a reactant gas, a plasma, a laser-generated radiation, and ultraviolet radiation, in the further deposition space for reacting the precursor gas after deposition on at least part of the substrate. 
     
     
         12 . The apparatus of  claim 1 , wherein the conveying system comprises a lead in zone; and a working zone adjacent the lead in zone and aligned relative to the conveying plane; wherein the injector head is provided in the working zone, and wherein the sheeted substrate can be inserted in the lead in zone, the lead in zone constructed to reduce a working height above the conveying plane in a direction towards the working zone. 
     
     
         13 . The apparatus of  claim 12 , wherein the lead in zone has a top wall part that is movable to set a working height. 
     
     
         14 . The apparatus of  claim 12 , provided with a first centering air bearing and a second centering air bearing for centering the substrate so as to move the substrate along a central line between the lead in zone and lead out zone. 
     
     
         15 . The apparatus of  claim 1 , wherein the injector head is movable towards and away from the conveying plane. 
     
     
         16 . The apparatus of  claim 1 , wherein the conveying system comprises transport elements provided with alternatingly arranged pairs of gas inlets and outlets, the conveying system further comprising a gas flow control system arranged to provide movement of the substrate by controlling gas flow along the conveying plane. 
     
     
         17 . The apparatus of  claim 16 , wherein the pairs of gas outlets and inlets are provided in pockets facing the conveying plane for providing the gas flow, in the pockets, along the conveying plane from the outlets to the inlets; and wherein the gas outlets are provided with a flow restrictor to provide a directional air bearing. 
     
     
         18 . A method for atomic layer deposition on a surface of a substrate using an apparatus including an injector head, the injector head comprising a deposition space provided with a precursor supply and the injector head further comprising a bearing gas injector, the method comprising the steps of:
 supplying a precursor gas from the precursor supply into the deposition space for contacting the substrate surface;   injecting a bearing gas between the injector head and the substrate surface, the bearing gas thus forming a gas-bearing wherein the gas bearing defines, relative to the substrate, a gap distance;   establishing relative motion between the deposition space and the substrate in a conveying plane along which the substrate is conveyed; and   providing a gas bearing pressure arrangement that balances the injector head gas-bearing in the conveying plane, so that the substrate is held supportless by said gas bearing pressure arrangement, between the injector head and the support part;   wherein the gas bearing pressure arrangement in use provides a gas bearing pressure such that in combination with the gap distance provides a gas bearing stiffness between 10 3  and 10 10  N/m 3 .   
     
     
         19 . The method of  claim 18 , wherein the gas bearing pressure is within a range of 1.2 to 20 bar. 
     
     
         20 . The method of  claim 19 , wherein the gas bearing pressure is within 3 to 8 bar. 
     
     
         21 . The method of  claim 18 , further comprising applying a prestressing force on the injector head, said prestressing force being directed towards the substrate surface. 
     
     
         22 . The method of  claim 18 , wherein the apparatus comprises a reaction space, the method further comprising providing at least one of a reactant gas, a plasma, laser-generated radiation, and ultraviolet radiation, in the reaction space for reacting the precursor gas to obtain an atomic layer on the at least part of the substrate surface. 
     
     
         23 . The method of  claim 18 , further comprising:
 providing a gas flow along the conveying plane, to provide a reciprocating motion of the substrate relative to the injector head, by controlling a gas flow system.