WO2012028775A1

WO2012028775A1 - Nozzle head

Info

Publication number: WO2012028775A1
Application number: PCT/FI2011/050742
Authority: WO
Inventors: Pekka Soininen; Olli Pekonen
Original assignee: Beneq Oy
Priority date: 2010-08-30
Filing date: 2011-08-25
Publication date: 2012-03-08
Also published as: CN103080375B; CN103080375A; FI20105904A0; TW201210701A

Abstract

The present invention relates to a nozzle head (2) for subjecting a surface (4) of a substrate (6) to successive surface reactions of at least a first precursor (A) and a second precursor (B). The nozzle head (2) comprising two or more first precursor nozzles (8) for the first precursor (A), the first precursor nozzle (8) having at least one first inlet port (18) and at least one first outlet port (20), two or more second precursor nozzles (10) for the second precursor (B), the second precursor nozzle (10) having at least one second inlet port (22) and at least one second outlet port (24). According to the invention the nozzle head (2) comprises at least one first connection element (30) for conducting first precursor (A) from the one first precursor nozzle (8) to the one or more other first precursor nozzles (8).

Description

Nozzle head

Background of the invention

The present invention 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 claim 1 .

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 pre- cursor 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 one or more first precursor nozzles for subjecting the surface of the substrate to the first precursor, one or more second precursor nozzles for subjecting the surface of the substrate to the second precursor, one or more purge gas channels and one or more discharge channels for discharging both precursors and purge gas 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. The nozzle is preferably moved in relation to the substrate for producing a number of growth layers.

Another type of prior art nozzle head for continuous ALD comprises alternatively in succession: a first precursor nozzle, a purge gas channel, a second precursor nozzle and purge gas channel, optionally repeated a plurality of times. In this prior art nozzle head each of the precursor nozzles and purge gas channels is provided with an inlet port and an outlet port such that the precursor and the purge gas is both supplied and discharged using the same nozzle. Therefore there are no separate discharge channels. The problem with this prior art nozzle head is that purge gas will leak to the precursor nozzle such that the precursor concentration will dilute. Thus the nozzle head is unable to provide a uniform gas supply over the whole length of the precursor nozzle or over the whole output face of the nozzle head. Furthermore the construction is complicated as there are inlet port and outlet port in each of the nozzles. Also this nozzle head may be moved relative to the substrate for producing a num- ber of growth layers.

Brief description of the invention

Thus the object of the present invention is to provide a nozzle head and an apparatus such that the above mentioned prior art problems are solved. The objects of the present invention are achieved with a nozzle head according to the characterizing part of claim 1 , characterized in that the nozzle head comprises at least one first connection element for conducting first precursor from the one first precursor nozzle to the one or more other first precursor nozzles.

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

The present invention is based on the idea that two or more first precursor nozzles are connected to each other such that the first precursor supplied to one first precursor nozzle may further conducted to another or two or more other first precursor nozzles. This is achieved by providing a fluid connection between at least one outlet port of one first precursor nozzle and at least one inlet of another first precursor nozzle. The fluid connection may be provided with a connection element arranged between at least one outlet port of one first precursor nozzle and at least one inlet of another first precursor nozzle. The connection element may comprise one or more pipes, channels or conduits for conducting the precursor. In the same way two or more second precursor nozzles may be connected to each other such that the second precursor supplied to one second precursor nozzle may further conducted to another or two or more other second precursor nozzles.

The advantage of the present invention is that the structure of a nozzle had may be provided simpler. This advantage may be achieved as there is no need to provide a precursor supply connection to every nozzle of the nozzle head as precursor may be supplied from one muzzle to another. Furthermore, the use of the precursor materials becomes more efficient such that less precursor material is discharged from the nozzle head as the excess precursor of one nozzle may be conducted to another nozzle.

Brief description of the figures

In the following the invention will be described in greater detail, in connection with preferred embodiments, with reference to the attached drawings, in which

Figure 1A a schematic cross sectional view of an embodiment of a nozzle head;

Figure 1 B is a top view of the nozzle head of the apparatus of figure

1A;

Figure 2 is a schematic cross sectional view another embodiment of a nozzle head;

Figure 3 is a schematic top view of yet another embodiment of a nozzle head of figure 1A;

Figure 4 shows a cross sectional view of still another embodiment of a nozzle head; and

Figure 5 shows a cross sectional view of one embodiment of a nozzle of a nozzle head.

Detailed description of the invention

Figure 1 shows a cross sectional view of one embodiment of an ap- paratus for subjecting a surface 4 of a substrate 6 to successive surface reactions of at least a first precursor A and a second precursor B according to the principles of ALD. The first and second precursors A and B may be any gaseous precursors used in ALD, such as ozone, TMA (trimethylaluminium), water, TiCI₄, DEZ (diethylzinc), or precursor may also be plasma, such as NH₃, Ar, O₂, N₂, H₂ or CO₂ plasma. The apparatus comprises a process chamber 26 having inside a gas atmosphere 14. The gas atmosphere 14 may comprise inert gas, such as nitrogen, or dry air, or any other gas suitable to be used as purge gas in ALD method. Also plasma may be used for purging, for example nitrogen or argon plasma. In that this context purge gas comprises also plas- ma. The purge gas source is connected to process chamber 36 for supplying purge gas into the process chamber 26. A nozzle head 2 is arranged inside the process chamber 26. The nozzle head comprises an output face 5, one or more first precursor nozzles 8 for subjecting the surface 4 of the substrate 6 to the first precursor A and one or more second precursor nozzles 10 for subject- ing the surface 4 of the substrate 6 to the second precursor B. The apparatus further comprises means for supplying the first and second precursor A, B to the nozzle head 2 as well as means for discharging the first and second precursor A, B from the nozzle head 2. As shown in figure 1 A, the first and second nozzles are arranged alternatively is succession for subjecting the surface 4 of the substrate 6 to alternative surface reactions of the first precursor A and second precursor B as the substrate 6 and the nozzle head 2 move relative to each other. The apparatus may be provided such that the nozzle head 2 may be moved, for example back and forth, and the substrate 2 is stationary. Alternatively the nozzle head 2 is static and the substrate 6 is moved or also the both substrate 6 and the nozzle head 2 may be moved. The substrate 6 may be a separate substrate loaded into the process chamber and processed by batch processing or alternative substrates may be arranged to be transported through the process chamber 26. The apparatus may also be constructed for roll to roll -process such that a flexible substrate is transported from one roll through the process chamber 26 to another roll, or from any source through the process chamber 26 to any receptacle, and processed with the nozzle head 2 inside the process chamber 26.

The precursor nozzles 8, 10 are preferably elongated. The first precursor nozzle 8 is provided with a first channel 3 extending the longitudinal di- rection of the first precursor nozzle 8 and comprising a first open portion 9 extending along the first channel 3 and open to the output face 5 of the nozzle head 2. The second precursor nozzle 10 is provided with a second channel 7 extending the longitudinal direction of the second precursor nozzle 10 and comprising a second open portion 1 1 extending along the second channel 7 and open to the output face 5 of the nozzle head 2. As shown in figure 1 B the first precursor nozzle 8 comprises a first inlet port 18 for supplying first precursor A to the first channel 3 and two first outlet ports 20 for exhausting the second precursor from the first channel 3 after the surface reactions of the first precursor A. Similarly the second precursor nozzle 10 comprises a second in- let port 22 for supplying second precursor B to the second channel 7 and two second outlet ports 24 for exhausting the second precursor from the second channel 7 after the surface reactions of the second precursor B. In this embodiment the inlet ports 18, 22 are arranged in the middle of the length of the first and second channel 3, 7 and the outlet ports 20, 24 are arranged to the opposite ends of the first and second channel 3, 7, as shown in figure 1 B. However, it should be noted that there may also be two or more inlet ports 18, 22 and one or more outlet ports 20, 24 in the first and second channel 3, 7. The inlet ports 18, 22 and the outlet ports 20, 24 may also be situated in any other position in the first and second channel 3, 7.

As shown in figure 1A and 1 B, the first and second nozzles 8, 10 are separated from each other by purge gas channels 12 open to the gas atmosphere 14 surrounding the nozzle head 2 in the process chamber 26 and to the output face 5 of the nozzle head 2. The purge gas channels 12 are formed as gaps extending between the first and second precursor nozzles 8, 10. The gaps 12 thus provide a fluid connection to the gas atmosphere 14 comprising purge gas. The gaps form a purge gas channel 12 between the first and second precursor nozzles 8, 10 for separating the first and second nozzles 8, 10 and first and second precursors A, B from each other. In figures 1 A and 1 B the nozzle head 2 is provided as a grate-like structure in which the first and second precursor nozzles 8, 10 form the rods and the purge gas channels 12 form the gaps between the rods. The precursor nozzles 8, 10 are engaged to one another by connectors 33. However it should be noted that the purge gas channel 12 may also be provided by one or more channels, holes or conduits having a passive fluid connection to the gas atmosphere 14 or at least partly open to the gas atmosphere 14. These channels may be similar to first and second channels 3, 7.

In a preferred embodiment the first precursor nozzles 8 are arranged to operate at a first pressure at the output face 5, and the second precursor nozzles 10 are arranged to operate at a second pressure at the output face 5. The gas atmosphere 14 is provided to a third pressure higher than the first and second pressure. Thus the purge gas in the gas atmosphere 14 flows to the purge gas channel 12 and keeps the first and second precursor A, B separated. Some purge gas will also flow to the first and second channels 3, 7 from the purge gas channel between the output face 5 of the nozzle head 2 and the surface 4 of the substrate 6. The first, second and third pressure may be lower than the normal air pressure (NTP; 1 bar, 0 °C), or substantially the same as the normal air pressure or higher than the normal air pressure or even at vacuum. The pressure differences of the nozzles and the atmosphere is the key factor. The first and second pressure are measured at the output face 5 of the nozzle head 2 and the pressure in the first and second channel may be different from the first and second pressure, normally higher than the first and second pressure.

Figure 2 shows another embodiment of the nozzle head 2 in which nozzle head 2 is provided with a separate purge gas container 39 arranged around the nozzle head 2. The purge gas container 39 has a gas atmosphere 16 inside. In figure 2 the purge gas container 39 is arranged to the nozzle head 2 and the gas atmosphere inside the purge gas container comprises purge gas. In this embodiment the first and second precursor nozzles 8, 10 are similar to precursor nozzles of figures 1 A and 1 B, therefore they are not described in detail. In figure 2 there is provided a purge gas channel 12 between the first and second precursor nozzles 8, 10 for subjecting the surface 4 of the sub- strate 6 to a purge gas and separating the first and second precursor A, B from each other. The purge gas channel 12 is a channel extending in parallel with first and second precursor nozzles 8, 10. The purge gas channels 12 are arranged in passive fluid connection to the gas atmosphere 16 of the purge gas container 39 though conduits 35 extending from the purge gas container 39 to the purge gas channel 12. A purge gas source may be connected to the purge gas container 39 for supplying purge gas into the purge gas container 39. The purge gas channel 12 may also be formed by one or more gaps, holes or openings in passive fluid connection to the purge gas container 39 and at least partly open to the output face 5 of the nozzle head 2. The edge areas of the output face 5 are further provided with additional purge gas channels 12, as shown in figure 2. These additional purge gas channels 12 separate the nozzle head 2 and particularly the output face 5 of the nozzle head from the ambient atmosphere such that the nozzle head 2 may also optionally be used in atmospheric pressure as precursor gases are prevented from flowing to the am- bient atmosphere. The additional purge gas channels may be provided separately to every edge area of the output face or they can extend as rings on the edge area and around the whole output face 5.

Also in this embodiment the first precursor nozzles 8 are arranged to operate at a first pressure at the output face 5, and the second precursor nozzles 10 are arranged to operate at a second pressure at the output face 5. The purge gas container 39 is arranged to a third pressure higher than the first and second pressure in the same way as in embodiment of figures 1A and 1 B. The first and second nozzles 8, 10 may also be operated in similar pressures as described in connection to figures 1A and 1 B. As the third pressure is higher than the first and second pressure the purge gas container provides a static supply of purge gas to the purge gas channels 12. Furthermore it should be noted that the nozzle head 2 of figure 2 may also be constructed such that the purge gas channels 12 are in fluid connection with the gas atmosphere 14 surround the nozzle head 2. Then the conduits 35 may be connected to the gas atmosphere 14 instead of purge gas container 39. The precursors and purge gas may be supplied to the nozzle head 2 via fluid connections. Alternatively the nozzle head 2 is provided with one or more precursor and/or purge gas containers, bottles or the like such that the precursors and/or the move together with the nozzle if the nozzle head is moved. This arrangement decreases the number of difficult fluid connections to a moving nozzle head 2.

The invention of figures 1 A, 1 B and 2 may also be constructed using any kind of precursor nozzles and purge gas channels. The purge gas channels may be formed by two or more separate holes, openings or any kind of features providing a fluid connection to the gas atmosphere 14 or a separate purge gas container 39. The embodiment of figures 1A, 1 B and 2 enables purge gas to be used to separate precursor nozzles from each other without actively supplying purge gas and using a same kind of nozzle structure as the precursor nozzles 8, 10.

A prior art way of constructing a nozzle head of figure 2 is to provide a first precursor nozzle having at least one first inlet port and at least one first outlet port, a second precursor nozzle having at least one second inlet port and at least one second outlet port, and a purge gas channel between the first and second precursor nozzles, the purge gas channel having only one or more third inlet ports and no outlet ports. These three nozzle are repeated one or more times to form a nozzle head. The purge gas supplied to the purge gas channel from third inlet ports is discharge through first and second outlet ports of the first and second precursor nozzles.

Figure 3 shows another embodiment in which the nozzle head 2 has the same kind of structure as the nozzle head of figures 1A and 1 B. It should be noted that the nozzle head may also be constructed in some other way than in figure 3. The nozzle head 2 comprises two or more first precursor nozzles 8 for subjecting the surface of the substrate to the first precursor A and two or more second precursor nozzles 10 for subjecting the surface 4 of the substrate 6 to the second precursor B. The first precursor nozzle 8 comprises at least one first inlet port 18 for supplying the first precursor A and at least one first outlet port 20 for exhausting the first precursor A. In figure 3 the first precursor nozzle head 8 comprises one first inlet port 18 provided at one of the elongated first precursor nozzle 8 and one first discharge port 20 provided at the other end of the first precursor nozzle 8. Similarly the second precursor nozzle 10 comprises one second inlet port 22 provided at one of the elongated second precursor nozzle 10 for supplying the second precursor B and one second discharge port 24 provided at the other end of the second precursor nozzle 10 for exhausting the second precursor B. The inlet ports 18, 22 and the outlet ports 20, 24 may also be located in on other way, for example as in figure 1 B, the there may be also two or more inlet ports and outlet ports in each nozzle 8, 10. Furthermore, as will be described later, the nozzle head may also be con- structed such that the precursor nozzles 8, 10 do not comprise any outlet ports 20, 24, but the nozzle head is provided with one or more separate discharge channels.

In figure 3 the nozzle head 2 is provided with first connection elements 30 for conducting first precursor A from the one first precursor nozzle 8 to the one or more other first precursor nozzles 8. The nozzle head 2 is further provided with second connection elements 32 for conducting second precursor B from the one second precursor nozzle 10 to the one or more other second precursor nozzles 10. The connection elements 30, 32 preferably comprise a pipe, a piping, a closed channel or a conduit and any other necessary compo- nents for providing a fluid connection between the two or more first precursor nozzles 8 or two or more second precursor nozzles 10. As shown in figure 3 the first outlet port 20 of one first precursor nozzle 8 is connected the first inlet port 18 of another first precursor nozzle 8 with the first connection element 30 for conducting first precursor A from the one first precursor nozzle 8 to the oth- er first precursor nozzle 8. Similarly the second outlet port 24 of one second precursor nozzle 10 is connected to the second inlet ports 22 of another second precursor nozzles 10 with the at least one second precursor nozzle 10 for conducting second precursor B from the one second precursor nozzle 10 to the another second precursor nozzle 10. According to the above mentioned the idea of this is to connect two or more precursor nozzles 8, 10 in series such that precursor may flow in succession through two or more precursor nozzles 8, 10.

It should be noted that the connection elements 30, 32 may also be arranged some other way than as shown in figure 3 in which each connection element 30, 32 is provided between two or more precursor nozzles 8 or 10. The first connection element 30 may be arranged between one first precursor nozzle 8 and two or more other first precursor nozzles 8 for conducting first precursor A from the one first precursor nozzle 8 to two or more other first precursor nozzles 8. Also the second connection element 32 may be arranged between one second precursor nozzle 10 and two or more other second precursor nozzles 10 for conducting second precursor B from the one second precursor nozzle 10 to two or more other second precursor nozzles 10.

The embodiment of figure 3 and as described above provides way for enhancing the material efficiency of the precursors A, B. When precursor A, B is supplied to a precursor nozzle 8, 10 some of the precursor A, B reacts of the surface 4 of the substrate 6, but usually an overdose of precursor A, B is supplied. Thus at least part of the precursor A, B supplied to the precursor channel 8, 10 does not react on the substrate 6 surface. In the prior art this excess precursor A, B is discharged as waste. The embodiment of figure 3 en- ables the excess precursor A, B to be used in some other precursor nozzle 8, 10. It should also be noted that the fluid connection with the connection element 30, 32 may be formed in different ways depending on the structure of the nozzle head 2. Furthermore, it should be noted that the there is a pressure drop when precursor is conducted from one precursor nozzle 8, 10 to another.

The first connection element 30 may be arranged between one or more first precursor nozzles 8 and at least another first precursor nozzle 8. Thus one first precursor nozzle 8 may be connected to several other first precursor nozzles 8, or several first precursor nozzles 8 may be connected to one other first precursor nozzles 8, or several first precursor nozzles 8 may be connected to several other first precursor nozzles 8 using the first connection elements 30. In one embodiment the nozzle head 2 comprises two or more first connection elements 30 between two first precursor nozzles 8. Thus precursor is conducted from one first precursor nozzle 8 to another first precursor nozzle 8 and the discharged. The nozzle head 2 may thus comprise two or more these together connected units of two first precursor nozzles 8. The sec- ond precursor nozzles 10 may be connected in the same way using the second connection elements 32.

Figure 4 shows a schematic view of one embodiment in which the nozzle head comprises first precursor nozzles 8, second precursor nozzles 10 and purge gas channels 12 provided between the elongated precursor nozzles 8, 10. The precursor nozzles 8, 10 comprise a supply channel 40, 44 extending in the longitudinal direction of the elongated precursor nozzle 8, 10. The precursor nozzles 8, 10 further comprises a discharge channel 42, 46 extending in the longitudinal direction of the elongated precursor nozzle 8, 10 sub- stantially parallel and adjacent to the supply channel 40, 44 for discharging precursor A, B by using vacuum or suction. The first precursor nozzle 8 comprises a first supply channel 40 and a first discharge channel 42, while the second precursor nozzle 10 comprises a second supply channel 44 and a second discharge channel 46. Therefore, figure 4 shows an embodiment in which the supply channel 40, 44 and the discharge channel 42, 46 are provided to the same precursor nozzle 8, 10 and separated from each other by a partition wall 52. However, it should be noted that the discharge channels 42, 46 may also be formed as a separate structural part arranged between a precursor nozzle 8, 10 or supply channel 40, 44 and the purge gas channel 12.

The supply channel 40, 44 is provided with at least one inlet port for supplying precursor A, B through the output face 5 of the nozzle head 2. The inlet ports are preferable arranged such that precursor A, B may be supplied along the whole length of the supply channel 40, 44. Then the discharge channel 42, 46 is provided with at least one outlet port for discharging precursor A, B. The outlet ports are preferably arranged such that the precursor A, B may be discharged along the whole length of the discharge channel 42, 46. Therefore the inlet port and the outlet port may be a longitudinal opening extending along the supply channel 40, 44 and discharge channel 42, 46 respectively. Alternatively the supply channel 40, 44 and discharge channel 42, 46 may com- prise series of inlet ports and outlet along the length of the supply channel 40, 44 and discharge channel 42, 46, respectively. As seen in figure 4 the supply channel 40, 44 and the discharge channel 42, 46 are at least partly open to the output face 5. The supply channel 40, 44 is provided with a supply opening 47, 48 extending the longitudinal direction of the supply channel 40, 44 and being open to the output face 5. Also the discharge channel 42, 46 is provided with a discharge opening 43, 45 extending the longitudinal direction of the discharge channel 42, 46 open the output face 5. The precursor nozzle 8, 10 or the supply channel 40, 44 is arranged to supply precursor A, B substantially perpendicularly to the output face 5, and precursor nozzle 8, 10 or the discharge channel 42, 46 is arranged to discharge precursor A, B substantially perpen- dicularly to the output face 5. This has the advantage that the perpendicular gas flow helps to break the gas layer on the substrate surface enhancing surface reactions of the precursors.

It should be noted that the embodiment of figure 4 may also be constructed such that the supply channel 40, 44 is part of the precursor nozzle 8, 10, but the discharge channel 42, 46 is a separate part. The basic idea is that the nozzle head 2 comprises on the output face 5 precursors nozzles 8, 10, purge gas channels 12 and the discharge channels 42, 46 in succession in the following order: at least a first precursor nozzle 8, a first discharge channel 42, purge gas channel 12, a second precursor nozzle 10, a second discharge channel 46 and a purge gas channel 12, optionally repeated a plurality of times. It is irrelevant if the supply channel 40, 44 and the discharge channel 42, 46 are provided to same structural part or not. The purge gas channel 12 may be provided in the same as in the embodiment of figures 1A, 1 B, 2 and 3 or the purge gas channels 12 may be provided with same kind of nozzles as the precursor nozzles 8, 10 or supply channels 40, 44. Thus the purge gas channel 12 may be arranged in passive fluid connection with a purge gas atmosphere 14, 16 for subjecting the surface 4 of the substrate 6 to a purge gas, as shown in figure 1 A, 1 B and 2. The purge gas atmosphere is the gas atmosphere 14 surrounding the nozzle head 2 or a separate purge gas container 39. The one or more first precursor nozzles 8 is arranged to operate at a first pressure at the output face 5, and that the one or more second precursor nozzles 10 are arranged to operate at a second pressure at the output face 5, and that the purge gas atmosphere is arranged to a third pressure higher than the first and second pressure. The first and second pressures may also be measured at the output face 5 between the supply channel and the discharge channel in embodiment of figure 4.

Figure 5 shows one embodiment in which the nozzle head 2 comprises a reaction space 50 provided between the supply channel 40, 44 and the discharge channel 42, 46. The reaction space 50 is open to the output face 5 for subjecting the surface 4 of the substrate 6 to precursor A, B. In figure 4 is shown a precursor nozzle similar to figure 4 in which the discharge channel 42, 46 is formed to the precursor nozzle 8. However, it should be noted that the reaction space 50 may also be provided between a precursor nozzle 8, 10 having only supply channel 40, 44 and a separate discharge channel 42, 46. The reaction space 50 is arranged between the supply channel 40, 44 and the dis- charge channel 42, 46. The reaction space 50 is arranged to extend substantially along the whole length of the supply channel 40, 44 and between the output face 5 and the supply and discharge channels 40, 44, 42, 46. The reaction space 50 is arranged such that precursor A, B is arranged to flow from the supply channel 40, 44 through the reaction space 50 to the discharge channel 42, 46 and the surface reactions of the precursors A, B take place at the reaction space 50.

The nozzle head 2 of figure 4 comprising on the output face 5 precursors nozzles 8, 10, purge gas channels 12 and the discharge channels 42, 46 in succession in the following order: at least a first precursor nozzle 8, a first discharge channel 42, purge gas channel 12, a second precursor nozzle 10, a second discharge channel 46 and a purge gas channel 12, optionally repeated one or more times, may be also constructed to comprise one or more connection elements 30, 32 shown in embodiment of figure 3. Thus the one or more first discharge channel 42 following one first precursor nozzle 8 or first supply channel 40 is connected to one or more other first precursor nozzle 8 or first supply channel 40 for conducting first precursor A to the one or more other first precursor nozzles 8 or first supply channels 40. Similarly the one or more second discharge channel 46 following one second precursor nozzle 10 or second supply channel 44 is connected to one or more other second precursor nozzle 10 or second supply channel 44 for conducting second precursor B to the one or more other second precursor nozzle 8 or second supply channel 44.

From the above description it should be evident that all the embodiment disclosed and shown in figures 1 A, 1 B, 2, 3, 4 and may be combined

It should be obvious to a person skilled in the art that as the tech- nology advantages, the inventive concept can be implemented in variety of ways. The invention and its embodiments are not restricted to the above examples, but may vary within the scope of the claims.

Claims

1 . A nozzle head (2) for subjecting a surface (4) of a substrate (6) to successive surface reactions of at least a first precursor (A) and a second pre- cursor (B), the nozzle head (2) having an outlet face (5) comprising:

- two or more first precursor nozzles (8) for subjecting the surface (4) of the substrate (6) to the first precursor (A), the first precursor nozzle (8) having at least one first inlet port (18) for supplying the first precursor (A),

characterized in that the nozzle head (2) comprises at least one first connection element (30) for conducting first precursor (A) from a first precursor nozzle (8) to one or more other first precursor nozzles (8).

2. A nozzle head (2) according to claim 1 , characterized in that the first precursor nozzle (8) comprises at least one first inlet port (18) for supplying the first precursor (A) and at least one first outlet port (20) for exhausting first precursor (A), and that the second precursor nozzle (10) comprises at least one second inlet port (22) for supplying the second precursor (B) and at least one second outlet port (24) for exhausting second precursor (B).

3. A nozzle head (2) according to claim 2, characterized in that at least one first outlet port (20) of one or more first precursor nozzles (8) is con- nected to at least one first inlet port (18) of one or more other first precursor nozzles (8) with the at least one first connection element (30).

4. A nozzle head (2) according to any one of claims 1 to 3, characterized in that the at least one first connection element (30) is arranged between one or more first precursor nozzles (8) and one or more other first pre- cursor nozzles (8).

5. A nozzle head (2) according any one of claims 1 to 4, characterized in that the first connection element (30) is arranged between one first precursor nozzle (8) and two or more other first precursor nozzles (8), or the first connection element (30) is arranged between two or more first precursor noz- zles (8) and one other first precursor nozzle (8).

6. A nozzle head (2) according to any one of claims 1 to 5, characterized in that the nozzle head (2) comprises two or more first connection elements (30) for connecting three or more first precursor nozzles (8) sequentially in fluid connection with one another.

7. A nozzle head (2) according to any one of claims 1 to 6, characterized in that the nozzle head (2) comprises two or more second nozzles (10) and at least one second connection element (32) for conducting second precursor (B) from one or more second precursor nozzles (10) to one or more other second precursor nozzles (10).

8. A nozzle head (2) according to any one of claims 2 to 7, charac- terized in that at least one second outlet port (24) of one or more second precursor nozzles (10) is connected to at least one second inlet port (22) of one or more other second precursor nozzles (10) with the at least one second precursor nozzle (10).

9. A nozzle head (2) according to claim 7 or 8, characterized in that the second connection element (32) is arranged between one or more second precursor nozzles (10) and one or more other second precursor nozzles (10).

10. A nozzle head (2) according to any one of claims 7 to 9 , characterized in that the nozzle head (2) comprises two or more second connection elements (32) for connecting three or more second precursor nozzles (10) sequentially in fluid connection with one another.

1 1 . A nozzle head (2) according to claim 1 , characterized in that the nozzle head (2) comprises on the output face (5) precursors nozzles (8, 10), purge gas channels (12) and the discharge channels (42, 46) in succession in the following order: at least a first precursor nozzle (8), a first discharge channel (42), purge gas channel (12), a second precursor nozzle (10), a second discharge channel (46) and a purge gas channel (12), optionally repeated one or more times.

12. A nozzle head (2) according to claim 1 1 , characterized in that the precursor nozzle (8, 10) comprises a supply channel (40, 44) extending in the longitudinal direction of the elongated precursor nozzle (8, 10).

13. A nozzle head (2) according to claim 12, characterized in that the discharge channel (42, 46) is provided to the precursor nozzle (8, 10) and extending in the longitudinal direction of the elongated precursor nozzle (8, 10) substantially parallel to the supply channel (40, 44).

14. A nozzle head (2) according to any one of claims 12 to 13, characterized in that the at least one first connection element (30) is arranged between one or more first discharge channels (42) and one or more first supply channels (40).

15. A nozzle head (2) according to any one of claims 12 to 14, cha- racterized in that the nozzle head (2) further comprises at least one second connection element (32) arranged between one or more second discharge channels (46) and one or more second supply channels (46).

16. A nozzle head (2) according to any one of claims 1 to 15, characterized in that the first and second precursor nozzles (8, 10) are arranged alternatively to each other.

17. A nozzle head (2) according to any one of claims 1 to 16, characterized in that the nozzle head (2) comprises one or more purge gas channel (12) for subjecting the surface (4) of the substrate (6) to a purge gas, the purge gas channel (12) being arranged between the first and second precursor nozzles (8, 10), and that the nozzle head (2) further comprises at least one third connection element arranged between two or more separate purge gas channels (12) for circulating at least part of the purge gas.

18. A nozzle head (2) according to any one of claims 1 to 17, characterized in that the first and second connection element (30, 32) comprises a pipe, a piping, a channel or a conduit.

19. A nozzle head (2) according to any one of claims 1 to 16, characterized in that the nozzle head (2) comprises at least one purge gas channel (12) arranged between the first and second precursor nozzles (8, 10) and arranged in passive fluid connection to a purge gas source (14, 16) for subjecting the surface (4) of the substrate (6) to a purge gas.

20. A nozzle head (2) according to claim 19, characterized in that the purge gas source is the gas atmosphere (14) surrounding the nozzle head (2) or a separate purge gas container (16).

21 . A nozzle head (2) according to claim 19 or 20, characterized in that the one or more first precursor nozzles (8) are arranged to operate at a first pressure at the output face (5), and that the one or more second precursor nozzles (10) are arranged to operate at a second pressure at the output face (5), and that the purge gas source (14, 16) is arranged to a third pressure higher than the first and second pressure.

22. A nozzle head (2) according to any one of claims 1 to 21 , characterized in that at least first precursor nozzles (8) are connected in series such that precursor (A) may be conducted from one first precursor nozzle (8) to one or more other precursor nozzles (8).