NOZZLE AND NOZZLE HEAD

A nozzle and nozzle head arranged to subject a surface of a substrate to gaseous precursors. The nozzle includes an output face via which the precursor is supplied, a longitudinal precursor supply element for supplying precursor and a longitudinal discharge channel open to and along the output face for discharging at least a fraction of the precursor supplied from the precursor channel. The precursor supply element is arranged to extend inside the discharge channel such that the precursor supply element divides the discharge channel in the longitudinal direction to a first discharge sub-channel and a second discharge sub-channel on opposite sides of the precursor supply element for supplying precursor through the discharge channel.

FIELD OF THE INVENTION

The present invention relates to a nozzle for subjecting a surface of a substrate to a gaseous precursor and particularly to a nozzle head according to the preamble of claim1. The present invention further relates to a nozzle head for subjecting a surface of a substrate to successive surface reactions of at least a first precursor and a second precursor, and particularly to a nozzle head according to the preamble of claim16.

BACKGROUND OF THE INVENTION

In the prior art several types of apparatuses, nozzle heads and nozzles are used for subjecting a surface of a substrate to successive surface reactions of at least a first precursor and a second precursor according to the principles of atomic layer deposition method (ALD). In ALD applications, typically two gaseous precursors are introduced into the ALD reactor in separate stages. The gaseous precursors effectively react with the substrate surface, resulting in deposition of a growth layer. The precursor stages are typically followed or separated by an inert-gas purge stage that eliminates the excess precursor from the surface of the substrate prior to the separate introduction of the other precursor. Therefore an ALD process requires alternating in sequence the flux of precursors to the surface of the substrate. This repeated sequence of alternating surface reactions and purge stages between is a typical ALD deposition cycle.

The prior art apparatuses for continuously operating ALD usually comprise a nozzle head having precursor nozzles arranged successively adjacent to each other such that the surface of the substrate may be subjected successively to surface reaction of at least a first and second precursors. The nozzles provide one or more first precursor supply channels for supplying the first precursor and one or more second precursor supply channels for supplying the second precursor. A nozzle head is usually also provided with one or more purge gas channels and one or more discharge channels for discharging both precursors and purge gas. In one prior art nozzle head the channels are arranged in the following order: at least a first precursor nozzle, a first discharge channel, purge gas channel, a discharge channel, a second precursor nozzle, a discharge channel, a purge gas channel and a discharge channel, optionally repeated a plurality of times.

The problem with this prior art nozzle head is that it comprises several different nozzles and channels which makes the nozzle head complicated and rather large. When the surface of the substrate is processed the nozzles and the nozzle head are moved in relation to the substrate such that the nozzles and nozzle head scan over the surface of the substrate subjecting the substrate surface successively to the different precursors. In industrial applications it is advantageous to form as many ALD cycles as possible with one scan. The prior art nozzles and nozzle heads do not provide compact and effective constructions for industrial scale apparatuses.

BRIEF DESCRIPTION OF THE INVENTION

The object of the present invention is to provide a nozzle and a nozzle head such that the above mentioned prior art problems are solved or at least alleviated. The objects of the present invention are achieved with a nozzle according to the characterizing part of claim1, in which a precursor supply element is arranged to extend inside a discharge channel such that the precursor supply element divides the discharge channel in the longitudinal direction to a first discharge sub-channel and a second discharge sub-channel on opposite sides of the precursor supply element for supplying precursor through the discharge channel. The objects of the present invention are further achieved with a nozzle head according to the characterizing part of claim16, in which at least one of first and second precursor supply channels is arranged to supply precursor through a discharge channel for dividing the discharge channel in the longitudinal direction to a first discharge sub-channel and a second discharge sub-channel on opposite sides of the precursor supply channel.

The preferred embodiments of the present invention are described in dependent claims.

The invention is based on the idea of supplying the gaseous precursor material through a discharge channel such that a discharge sub-channel is formed on opposite sides of the precursor supply. The present invention provides a nozzle comprising an output face via which the precursor is supplied, a precursor supply element for supplying precursor and a longitudinal discharge channel open to and along the output face for discharging at least a fraction of the precursor supplied from the precursor channel. According to the present invention the precursor supply element is arranged to extend inside the discharge channel such that the precursor supply element divides the discharge channel in the longitudinal direction to a first discharge sub-channel and a second discharge sub-channel on opposite sides of the precursor supply element for supplying precursor through the discharge channel. Therefore the present invention provides a nozzle in which the precursor supply channel is arranged inside a discharge channel and the precursor is supplied through the discharge channel. This nozzle arrangement may further be used in a nozzle head having an output face and comprising one or more first longitudinal precursor supply channels for subjecting the surface of the substrate to the first precursor via the output face, one or more second longitudinal precursor supply channels for subjecting the surface of the substrate to the second precursor via the output face, and one or more longitudinal discharge channels open to the output face for discharging at least a fraction of the first and second precursor supplied from the first and second precursor supply channels. In the nozzle head at least one of the first and second precursor supply channels is arranged to supply precursor through a discharge channel for dividing the discharge channel in the longitudinal direction to a first discharge sub-channel and a second discharge sub-channel on opposite sides of the precursor supply channel. Therefore at least one of the first and second precursor supply channels may be arranged inside a discharge channel for dividing the discharge channel in the longitudinal direction to a first discharge sub-channel and a second discharge sub-channel on opposite sides of the precursor supply channel.

An advantage of the nozzle and nozzle head of the present invention is a compact structure in which the discharge channel and the precursor supply channel are nested. This eliminates the need for separate discharge channels and precursor supply channels. Furthermore, a single discharge channel is arranged to form a discharge sub-channel on both sides of the precursor supply channel instead of two separate discharge channels. Therefore, the nozzle and nozzle head is simpler in structure and more compact. This means that a larger number of precursor supply channels may be formed on a certain surface area of the output face of the nozzle head and further growth layers may be produces on the substrate surface with one scan.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1shows schematically one embodiment of a nozzle head1according to the present. The nozzle head1comprises nozzle head body2and a nozzle head output face4via which the gaseous precursors are supplied. In the embodiment ofFIG. 1the nozzle head output face4is planar, but in an alternative embodiment it may also be non-planar, curved, cylindrical or have any other suitable form. The nozzle head1is provided with nozzles8arranged adjacently to each other and extending longitudinally along the output face4. The nozzles8are shown with dashed lines inFIGS. 1 and 2. The nozzles8are separated with a distance or gap12from each other. The nozzles8comprise a discharge channel6and a precursor supply channel10arranged inside the discharge channel6. In this embodiment the discharge channel6and the precursor supply channel10are formed as longitudinal channels. As shown inFIG. 1the precursor supply channel10divides the discharge channel6into two discharge sub-channels in the longitudinal direction, one on each side of the precursor supply channel10for discharging at least a fraction of the supplied precursor. In a preferred embodiment the discharge channel6and the precursor supply channel10flush with the nozzle head output face4. Alternatively the discharge channel6and/or the precursor supply channel may protrude from the nozzle head output face4or may be partly below the nozzle head output face4. It should be noted that the nozzles8may be integral parts of the nozzle head1and the nozzle head body2or alternatively they may be detachable parts which may be removed or replaced. The gap12between the nozzles8is in this embodiment provided with a purge gas channel44for supplying purge gas, such as nitrogen. The purge gas channels are preferably longer than the nozzles8or the precursor supply channels. The purge gas channel44is provided for separating the adjacent nozzles8and the precursors from each other and for purging the surface of the substrate. The nozzle head output face4is further provided with discharge perimeter5, which surrounds the nozzles8and the purge gas channels44. The discharge perimeter5is connected to vacuum pump or the like such that it may discharge precursors and purge gas from the nozzle head output face4. In this embodiment the discharge perimeter5is continuous, but alternative it may be formed from two or more separate discharge channels parts arranged to surround the nozzles8and the purge gas channels44. It should be noted that a purge gas perimeter (not shown) may also be arranged to the nozzle in the same way as the discharge perimeter5. The purge gas perimeter is preferably provided on inner side of the discharge perimeter5on the nozzle head output face4.

FIG. 2shows an alternative embodiment in which the precursor supply channel comprises several supply holes14extending and opening towards the nozzle head output face4. The precursor supply channel10is furthermore arranged in the middle of the discharge channel6such that the discharge channel6surrounds the precursor supply channel10from all directions on the nozzle head output face4. In other words the ends of the discharge channels6on the opposite sides of the precursor supply channel6are connected to form a discharge channel surrounding the precursor supply channel10. Also in this embodiment the precursor supply channel divides the discharge channel6into two discharge sub-channels in the longitudinal direction, one on each side of the precursor supply channel. In addition, the ends of the discharge sub-channels connect to each other forming a circumferential discharge channel around the precursor supply channel on the nozzle head output face4. InFIGS. 1 and 2the gap12between the nozzles8may be provided with a purge gas channel for supplying purge gas, such as nitrogen for purging the substrate surface. In the embodiment ofFIG. 2, the purge channels44are connected to each other such that the purge gas channels44surround separately each nozzle8and also all the nozzles8on the nozzle head output face4. It should be noted that the purge gas channels44also be arranged to surround only each nozzle8separately or only all the nozzles8. When the purge gas channels44are arranged to surround the nozzles8the surrounding discharge perimeter5, shown inFIG. 1, may be omitted. However, the discharge perimeter5may also be provided on the nozzle head output face4surrounding the connected purge gas channels44.

It should be noted that the same structural parts are denoted with same reference numerals inFIGS. 1 to 8.

FIG. 3shows one embodiment the nozzle8according to the present invention. The nozzle8comprises a nozzle body20and a precursor supply element30for supplying precursor on the surface of a substrate100. InFIG. 3the nozzle8is shown disassembled such that the precursor supply element30is out of the nozzle body20. Thus in this embodiment the precursor supply element30and the nozzle body20are separate parts, but in alternative embodiment they may also be integral parts. Therefore, the precursor supply element30may be integral part of the body20or a separate part. The nozzle body20comprises a nozzle output face24via which the precursor is supplied. The nozzle body20further comprises a longitudinal discharge channel6open to and along the nozzle output face24. The discharge channel6has side walls27extending the longitudinal direction of the discharge channel6. The nozzle body20further comprises a discharge conduit22extending substantially parallel and in fluid connection with the discharge channel6for exhausting discharged material from the discharge channel6. Accordingly the nozzle body20is arranged to form the discharge channel6and discharge conduit22having longitudinal walls29. The width of the discharge conduit22is greater than the width of the discharge channel22for enhancing the discharge pressure. The discharge conduit22and the discharge channel6are connected to a suction device (not shown) for providing suction. In a preferred embodiment the suction may be arranged to one or both longitudinal ends or the discharge conduit22and/or discharge channel6.

The precursor supply element30is arranged to be installed at least partly inside the nozzle body20. The precursor supply element30comprises one or more longitudinal precursor supply channels10open to the nozzle output face24for supplying precursor via the output face24. The precursor supply element30further comprises a precursor conduit32in fluid connection with the precursor supply channel10for conducting precursor to the precursor supply channel10. In the embodiment ofFIG. 3the precursor supply channel10is formed as a longitudinal channel open to and along the output face24and extending a as channel from the precursor conduit32to the end face34of the precursor supply channel10. The longitudinal precursor supply channel10comprises an expansion38in the vicinity of the output face24and the end face34for increasing the width of the longitudinal precursor channel10at the output face24. The expansion spreads and uniforms the precursor supply to the substrate surface. The expansion38equalizes the precursor supply in the width direction of the precursor supply channel10and decelerates the supply rate of the precursors. The expansion38provides a pressure balancing structure when the nozzle8or the nozzle head1is arranged close to a substrate surface.

In an alternative embodiment the precursor supply element may comprise one or more one or more precursor supply holes14extending from the precursor conduit32and opening to the output face24for forming the precursor supply channel. These kinds of supply holes14may extend in a transversal direction in relation to the longitudinal direction of the discharge channel6. The precursor supply holes14may form the supply channel or channels. Alternatively the precursor supply holes14extend between the precursor conduit32and the longitudinal precursor supply channel10open to and along the output face24. In one embodiment the longitudinal expansion38may form the precursor supply channel10and the supply holes extend between the expansion38and the precursor conduit32.

FIG. 4shows two nozzles8,8′ ofFIG. 3are installed adjacently and assembled such that precursor supply element30is inside the nozzle body20. The first nozzle8is arranged to supply a first precursor via the first precursor supply channel10and the second precursor8′ is arranged to supply second precursor via the second precursor supply channel10′. Between the nozzles8,8′ there is provided a purge gas element for supplying purge gas.

The purge gas element comprises a purge gas conduit40and a purge gas supply channel44open to the nozzle output face24. A nozzle head ofFIGS. 1 and 2may be formed by arranging two or more nozzles10,10′ adjacently.

A shown inFIG. 4, the precursor supply element30is arranged to extend through the discharge channel6to the output face24. Thus the precursor supply element30is arranged to extend longitudinally inside the discharge channel6such that the precursor supply element30divides the discharge channel6in the longitudinal direction to a first discharge sub-channel7and a second discharge sub-channel9on opposite sides of the precursor supply element30for supplying precursor through the discharge channel6. This means that the precursor is supplied from the nozzle8,8′ through the discharge channel6. In the embodiment ofFIG. 4the precursor supply element30is also arranged to extend through the discharge conduit22and the discharge channel6to the output face24such that the precursor channel10divides the discharge conduit22to two discharge sub-conduits on opposite sides of the precursor supply element30. The precursor supply element30may be arranged to provide a fluid connection between the discharge subconduits of the discharge conduit22. Alternatively there is no fluid connection between the discharge sub-conduits. The precursor supply element30is preferably arranged to extend inside the discharge channel6such that the end face34of the supply element30is substantially flush with the output face24. The discharge sub-channels7,9are thus formed between the outer wall35of the precursor supply channel10and the inner walls27of the discharge channel6.

The nozzle8,8′ ofFIG. 4enables one discharge channel6to be used for providing two discharge channels7,9on opposite sides of the precursor supply channel10,10′. This also enables to use one suction device or suction connection for these both discharge sub-channels7,9. The precursors may be supplied to the precursor conduits32from the longitudinal ends of the precursor conduits32. Furthermore, the present invention enables different precursors to be supplied from different ends to the longitudinal precursor conduits32.

FIG. 5shows an alternative embodiment in which the purge gas channels45is formed to the nozzle body20. The nozzle body20therefore comprises a purge gas conduit41and a purge gas supply channel open to the nozzle output face24and extending longitudinally substantially in the direction of the discharge channel6. This purge gas arrangement provides an integral purge gas supply to the nozzle8.FIG. 6shows an alternative embodiment in which a nozzle head is formed by arranging nozzles adjacent to each other. In this embodiment the nozzle body20comprises a purge gas channel47extending open to the nozzle output face24and extending longitudinally substantially in the direction of the discharge channel6. In this embodiment one purge gas channel47is provided between two discharge channels6and between the discharge sub-channels7and9. In this embodiment there is no expansion in the vicinity of the end face34of the precursor supply element30. The nozzle head has a compact structure the nozzle body20or the nozzle head body2has only two different channels on the output face4,24, the purge gas channel45,47and the discharge channel6as the precursor supply channel10is formed inside the discharge channel6.

FIG. 7shows a nozzle head in which the nozzle head body2comprises discharge conduits22in fluid connection to the discharge channels6. There is also a precursor supply channels10extending through the discharge conduit22and the discharge channel6to the nozzle head output face4. In this embodiment the longitudinal discharge channels6, discharge conduits22and the precursor supply channels10are formed as integral parts or machined shapes to the nozzle head body2. The discharge channels and the discharge conduits22are separated from each other with partitioning walls21. It should be noted as there is no precursor conduit in the embodiment ofFIG. 7, also the discharge conduit22may be omitted or the discharge channel6may have uniform width also in the height direction.

FIG. 8shows an alternative embodiment of the nozzle in which the precursor supply element50extends inside the discharge conduit22or discharge channel but not through the discharge conduit22in the height or width direction. Thus the precursor supply element50may provide a fluid connection between the first and second discharge sub-channels7,9. The precursor supply element50extends substantially in a nested fashion inside the discharge conduit22or the discharge channel6, at least in the lateral direction of the discharge channel6. In one embodiment the precursor supply element50may also extend substantially coaxially inside the discharge conduit22or the discharge channel6, at least in the lateral direction of the discharge channel6. The precursor supply element50comprises a precursor conduit52and a precursor supply channel10opening on and along the nozzle output face24such that it divides the discharge channel6into two discharge sub-channels7,9. The precursor supply element50is arranged to extend inside the discharge channel6such that the end face34the supply element50is substantially flush with the nozzle output face24.

FIG. 9shows an alternative embodiment in which both the precursor supply channel10and the discharge channels7,9are arranged to extend longitudinally inside the purge gas element55such that they divide the purge gas channel in the longitudinal direction to a first purge sub-channel53and a second purge gas sub-channel54on opposite sides of the precursor supply element50and the discharge channels7,9. The purge gas element also comprises a purge gas conduit56for supplying purge gas to the purge gas sub-channels53,54. In this embodiment the precursor supply element50and the nozzle body20forming the discharge channels7,9are nested inside the purge gas element55and purge gas conduit56. Thus there is fluid connection between the purge gas sub-channels53,54via the purge gas conduit56. The discharge conduit22may extends substantially in a nested fashion inside purge gas element55. In one embodiment the discharge conduit22may also extend substantially coaxially inside the purge gas conduit56, at least in the lateral direction of the discharge channels7,9. It should be noted the principle shown inFIG. 9may also be applied to the nozzles and nozzle heads offigure 1 to 8. In other words the precursor supply channel and the discharge channel may be arranged inside the purge gas channel such that the precursor supply channel and the discharge channel divide the purge gas channel into first and second purge gas sub-channels53,54on opposite side of the discharge channel and precursor supply channel. Therefore his principle may also be used in the nozzle structures shown inFIGS. 3 to 8.

The present invention therefore provides a nozzle head in which nozzle8,8′ described above may be used for subjecting a surface of a substrate to successive surface reactions of at least of first and second gaseous precursor for forming thin film on the surface of the substrate according to the principles of atomic layer deposition.25. The nozzle described above may be used for subjecting a surface of a substrate to surface reaction a gaseous precursor.

The nozzle head of the present invention for subjecting a surface of a substrate100to successive surface reactions of at least a first gaseous precursor and a second gaseous precursor may comprise one or more first longitudinal precursor supply channels10for subjecting the surface of the substrate100to the first precursor via the nozzle head output face4, one or more second longitudinal precursor supply channels10′ for subjecting the surface of the substrate100to the second precursor via the output face4, and one or more longitudinal discharge channels6open to the output face4for discharging at least a fraction of the first and second precursor supplied from the first and second precursor supply channels10,10′. According to the present invention at least one of the first and second precursor supply channels10,10′ is arranged to supply precursor through a discharge channel6for dividing the discharge channel6in the longitudinal direction to a first discharge sub-channel7and a second discharge sub-channel9on opposite sides of the precursor supply channel10,10′. In a preferred embodiment all the precursors are supplied through the discharge channels6. Thus the first and second supply channels10,10′ may be each arranged to supply precursor through a discharge channel6, or that the first and second supply channels10,10′ may be each arranged inside a discharge channel6. Alternatively it is also possible that only one precursor channels is arranged according to the present invention.

Accordingly at least one of the first and second precursor supply channels10,10′ of the nozzle head is arranged inside a discharge channel6for dividing the discharge channel6in the longitudinal direction to a first discharge sub-channel7and a second discharge sub-channel9on opposite sides of the precursor supply channel10,10′. This means that the first and second precursor supply channels10,10′ may be arranged to extend through the discharge channel6to the nozzle head output face4in a direction transversal to the longitudinal direction of the discharge channel6. The first and second precursor supply channels10,10′ are arranged to extend inside and along the discharge channel6. They may also be arranged to extend substantially coaxially inside and along the discharge channel6, at least in the width direction of the discharge channel6.