Apparatus and method for high-throughput atomic layer deposition

Abstract

Atomic layer deposition apparatus for depositing a film in a continuous fashion. The apparatus includes a process tunnel, extending in a transport direction and bounded by at least a first and a second wall. The walls are mutually parallel and allow a flat substrate to be accommodated there between. The apparatus further includes a transport system for moving a train of substrates or a continuous substrate in tape form, through the tunnel. At least the first wall of the process tunnel is provided with a plurality of gas injection channels that, viewed in the transport direction, are connected successively to a first precursor gas source, a purge gas source, a second precursor gas source and a purge gas source respectively, so as to create a tunnel segment that—in use—comprises successive zones containing a first precursor gas, a purge gas, a second precursor gas and a purge gas, respectively.

What is claimed is: 
     
         1 . An atomic layer deposition apparatus, comprising:
 a first, lower wall;   a second, upper wall parallel to the first wall and spaced apart from the first wall;   two side walls connecting the first and the second wall at lateral sides thereof; and   a transport system configured to support and move a train of substrates or a continuous substrate in tape form, from an entrance of the process tunnel, along the transport direction, to an exit of the process tunnel;   wherein the first wall, the second wall and the two side walls bound a process tunnel configured to allow a substantially flat substrate, oriented parallel to said first and second walls, to be accommodated in the process tunnel leaving a first narrow gap between an upper side of the substrate and the second wall and a second narrow gap between a lower side of the substrate and the first wall, the process tunnel having a longitudinal direction which, in use, is a transport direction of the substrate in the process tunnel, and the process tunnel having a lateral direction that is substantially perpendicular to the longitudinal direction and parallel to the first and second walls, the first wall defining a lower, innermost boundary of the process tunnel and the second wall defining an upper, innermost boundary of the process tunnel,   wherein both the first wall and the second wall of the process tunnel are provided with a plurality of gas injection channels,   wherein outflow openings of said plurality of gas injection channels are distributed over respective inner-most surfaces of the first and second walls in a spaced apart manner both along the transport direction and in the lateral direction, said plurality of gas injection channels being configured to inject gas into the process tunnel over the whole length of the tunnel so as to form gas bearings for floatingly supporting the substrate,   wherein a plurality of gas exits are provided at both of the two side walls and configured to exhaust gas from tunnel space regions between both lateral edges of the substrate and the respective side walls,   wherein gas injection channels of the plurality of gas injection channels which are located in the first wall, viewed in the transport direction, are connected successively to a first precursor gas source, a first purge gas source, a second precursor gas source and a second purge gas source respectively, so as to create a tunnel segment that, in use, comprises, in succession along the transport direction, laterally extending zones containing a first precursor gas, a first purge gas, a second precursor gas and a second purge gas, respectively,   wherein two or more of such tunnel segments are disposed in succession in the transport direction;   wherein positions of the plurality of gas injection channels and positions of the plurality of gas exits are configured to provide that said gases in said laterally extending zones flow substantially in the lateral direction towards the plurality of gas exits; and   wherein the laterally extending zone containing the first purge gas and the laterally extending zone containing the second purge gas are configured to facilitate lateral gas flow velocities so as to create gas phase diffusion barriers that keep the first and the second precursor gases separated.   
     
     
         2 . The atomic layer deposition apparatus according to  claim 1 , wherein a cross-section through the process tunnel extending in the lateral direction comprises three or more of the outflow openings. 
     
     
         3 . The atomic layer deposition apparatus according to  claim 2 , wherein the cross-section through the process tunnel extending in the lateral direction comprises nine or more of the outflow openings. 
     
     
         4 . The atomic layer deposition apparatus according to  claim 1 , wherein the first and the second walls are spaced apart such that each of the first narrow gap and the second narrow gap measures 2 mm or less. 
     
     
         5 . The atomic layer deposition apparatus according to  claim 1 , wherein the first and the second walls are spaced apart such that each of the first narrow gap and the second narrow gap is in the range of 0.15-0.25 mm. 
     
     
         6 . The atomic layer deposition apparatus according to  claim 1 , wherein the first and second walls are oriented substantially horizontally, and wherein the second wall is located above the first wall. 
     
     
         7 . The atomic layer deposition apparatus according to  claim 1 , wherein the gas injection channels in the second wall are connected to a source of inert gas. 
     
     
         8 . The atomic layer deposition apparatus according to  claim 1 , wherein opposite gas injection channels in the first and second walls are connected to gas sources of substantially identical gas compositions. 
     
     
         9 . The atomic layer deposition apparatus according to  claim 1 , wherein at least one gas injection channel of the plurality of gas injection channels is configured to inject gas into the process tunnel in a direction having a positive component in the transport direction. 
     
     
         10 . The atomic layer deposition apparatus according to  claim 9 , wherein said at least one gas injection channel is connected to a third purge gas source. 
     
     
         11 . The atomic layer deposition apparatus according to  claim 1 , wherein the transport system comprises one or more drive pins configured to engage an individual substrate at a circumferential edge, and to move said individual substrate along the transport direction through the process tunnel. 
     
     
         12 . The atomic layer deposition apparatus according to  claim 1 , wherein one of the entrance of the process tunnel and the exit of the process tunnel is provided with at least one end portion having an enlarged gap between the first and second walls. 
     
     
         13 . The atomic layer deposition apparatus according to  claim 1 , comprising one or more tunnel segments of a first configuration for injecting a first combination of precursor gases, and one or more tunnel segments of a second configuration for injecting a second combination of precursor gases. 
     
     
         14 . The atomic layer deposition apparatus according to  claim 1 , wherein the lateral gas flow velocities are in a range of 1-2 m/s. 
     
     
         15 . An atomic layer deposition apparatus, comprising:
 a first, lower wall;   a second, upper wall parallel to the first wall and spaced apart from the first wall by a process tunnel gap;   two side walls connecting the first and the second wall at lateral sides thereof; and   a plurality of gas injection channels located in both the first wall and the second wall of the process tunnel,   wherein the first wall, the second wall and the two side walls bound a process tunnel, the process tunnel having a longitudinal direction, and the process tunnel having a lateral direction that is substantially perpendicular to the longitudinal direction and parallel to the first and second walls, the first wall defining a lower, innermost boundary of the process tunnel and the second wall defining an upper, innermost boundary of the process tunnel,   wherein outflow openings of the plurality of gas injection channels are distributed over respective inner-most surfaces of the process tunnel in a spaced apart manner along both the longitudinal direction and the lateral direction, said plurality of gas injection channels being configured to inject gas into the process tunnel over the whole length of the tunnel so as to form gas bearings to floatingly support a substrate; and   a plurality of gas exits at lateral sides of the process tunnel and configured to exhaust gas from tunnel space regions,   wherein the plurality of gas injection channels are connected to sources of different gases so as to create, in succession along the transport direction, a plurality of different gas zones which extend laterally across the process tunnel,   wherein the outflow openings and the plurality of gas exits are configured to provide that gases in the plurality of zones flow substantially in the lateral direction towards the plurality of gas exits, and   wherein at least one zone in the plurality of zones creates a gas phase diffusion barrier that separates gases in neighboring zones of the plurality of zones.   
     
     
         16 . The atomic layer deposition apparatus according to  claim 15 , further comprising a drive system configured to move a substrate being floatingly supported by the gas bearings from an entrance of the process tunnel, along the longitudinal direction, to an exit of the process tunnel. 
     
     
         17 . The atomic layer deposition apparatus according to  claim 16 , wherein the substrate is a tape substrate and the drive system is a collection roll. 
     
     
         18 . The atomic layer deposition apparatus according to  claim 16 , wherein the drive system comprises at least one gas injection channel of the plurality of gas injection channels which is configured to inject gas into the process tunnel in a direction having a positive component in the longitudinal direction towards the exit of the process tunnel. 
     
     
         19 . The atomic layer deposition apparatus according to  claim 15 , further comprising a pre-heat tunnel segment comprising heated gas injection channels configured to inject a heated purge gas into the pre-heat tunnel segment. 
     
     
         20 . The atomic layer deposition apparatus according to  claim 19 , wherein the heated purge gas is helium. 
     
     
         21 . The atomic layer deposition apparatus according to  claim 15 , wherein the first and second walls are oriented substantially horizontally, and wherein the second wall is located above the first wall. 
     
     
         22 . The atomic layer deposition apparatus according to  claim 15 , wherein the second, upper wall is spaced apart from the first wall by a process tunnel gap,
 and the atomic layer deposition apparatus further comprises an entrance section having an entrance gap between a first, lower entrance wall and a second, upper entrance wall which is larger than the process tunnel gap.   
     
     
         23 . The atomic layer deposition apparatus according to  claim 15 , wherein the gas injection channels are connected to a first precursor gas, a first purge gas, a second precursor gas and a second purge gas so as to create a tunnel segment that, in use, comprises, in succession along the transport direction, laterally extending zones containing a first precursor gas, a first purge gas, a second precursor gas and a second purge gas, respectively, wherein two or more of such tunnel segments are disposed in succession in the transport direction. 
     
     
         24 . The atomic layer deposition apparatus according to  claim 23 , wherein two or more tunnel segments of a first configuration adapted to inject a first combination of precursor gases are succeeded by two or more tunnel segments of a second configuration adapted to inject a second combination of precursor gases to deposit a nanolaminate film on the substrate being floatingly supported by the gas bearings.