TW201347029A - Apparatus and method for processing flat substrate - Google Patents

Abstract

In an apparatus for processing a flat substrate in a continuous process, liquid treatment medium is filled into a trough container until reaching a preset liquid level. By means of transport device, the substrate can be guided through guide elements to pass the liquid treatment medium along the transport direction in the horizontal transport plane, such that at least one processing side of the substrate is immersed into the treatment medium. The treatment medium is able to circulate in the trough container by means of a circulating device. The circulating device includes a suction device and an output device. The treatment medium is extracted from the trough container through the suction device. The extracted treatment medium passes the output device to the trough container. An incident flow element is provided in the trough container below the height level of the transport plane. The output device of the circulating device includes plural outlet nozzles. The outlet nozzles are disposed below the height level of the incident flow element and designed such that each of the outlet nozzles aims explicitly toward the main part of the incident flow element for outputting the treatment medium. Also disclosed is a method for processing a flat substrate.

Description

Apparatus and method for processing a flat substrate

The invention relates to a device for processing a flat substrate in a continuous process comprising a) a tank container filled with a liquid treatment medium until a certain liquid level; b) a transport device by means of said The transport device, the substrate can be transported through the processing medium in a transport direction in the transport plane of the level by the guiding element, such that at least one processing side of the substrate is immersed in the processing medium; c) the loop device, the processing medium The loop device can be looped in the tank container, and the loop device includes a suction device and an output device through which the treatment medium is withdrawn from the tank container, and the extracted processing medium passes through the output device Output to the slot container.

Furthermore, the invention relates to a method for processing a flat substrate, in particular for the semiconductor industry and the solar industry, wherein a) the substrate is guided by the guiding element to be transported in the transport direction in the transport plane of the level. The liquid processing medium is such that at least one processing side of the substrate is immersed in the processing medium; b) the processing medium is looped by means of a loop device.

Such processing apparatus and methods are known from the market and are used, for example, in the processing of flat substrates, such as in the semiconductor and solar industries. Different types of wet processes are carried out in the form of slabs, that is to say in the form of so-called wafers, rafts and glass sheets. Of particular interest herein is the wet chemical etching of the substrate.

In this regard, the substrate to be processed whose surface should be changed is conveyed through the liquid etching treatment medium. During the etching process, the surface of the substrate is characterized as necessary for its subsequent use. Here, for example, a transport roller is used as a guiding element for the substrate during its passage through the processing medium, said substrate being placed flat on said transport roller. There is a device in which a substrate is guided through a processing medium under a liquid level, as well as a device in which the substrate is floated to a certain extent on the surface of the treatment medium such that the upper side of the substrate is not wetted Stand out from the processing medium.

In a chemical etching process, in general, the composition of the processing medium at the substrate location is a decisive parameter in terms of the quality of the etching results. During the etching process, by-products formed in the reaction after the actual etching process are formed on the substrate in addition to the direct reaction product. In particular, nitrogen oxide is formed on a substrate such as NO _x, the catalytic oxide in the vicinity of the substrate immediately adjacent to and in terms of uniform corrosion as a specific need in the concentration range at the substrate. The groove vessel, typically constructed of NO _x nitrogen oxide concentration gradient in the known apparatus of the type in which _the NO _x concentration increases as the groove depth decreases.

However, when the nitrogen oxide NO _x is not derived from the substrate, causing localized supersaturation in the vicinity of the substrate, which in turn lead to an uneven etched image on the substrate.

Because nitrogen oxides NO _x from the treatment liquid can escape into the atmosphere above the liquid level, so in addition, when the process medium consumption on the substrate is not replaced by a fresh treatment medium, in a possible production stop in etching speed Falling very quickly. When production-related causes an interrupt, it must be restored each time the process on a substrate and then create a concentration of NO _x nitrogen oxides, and must be re-set process parameters such as other etch bath temperature and transport velocity.

Thereby, significant fluctuations in the quality of the etching result can be caused; at the same time, this is manifested in the reduced yield of the processing equipment.

In order to achieve a uniform mixing treatment medium tank container and thereby to achieve uniform distribution of nitrogen oxides NO _x in the processing medium, the processing apparatus used in the loop the loop tank treatment medium in the known apparatus and methods, whereby , the reaction product and nitrogen oxides NO _x derived from the processing position and in particular the nitrogen oxide NO _x uniformly distributed in the processing tank.

It is known for this purpose to output a processing medium of the loop from the bottom towards the substrate via the output device such that an intermediate space between two adjacent guide elements, for example between two adjacent transport rollers, is output back. The main part of the processing medium of the circle. However, experience has shown that localized inhomogeneities of the image are also caused here, and in the production-related pauses, the bath activity is rapidly lost. The effect can be partially offset by changing and resetting other process parameters such as transport speed or tank temperature. However, this is necessary after each interruption, which results in the need to re-evaluate the etching results each time. The process of setting up the process can be very time consuming and takes a few minutes each time. So overall, the whole process is not satisfactory.

It is an object of the invention to achieve an apparatus and method of the type mentioned at the outset in which the spent processing medium is replaced quickly and reliably with an unconsumed processing medium at the processing position and, in particular, a uniform mixing of the processing medium is ensured and this ensure uniform distribution of nitrogen oxides nO _x in the processing medium, without causing the above-described difficulties, or at least reduce the above difficulties.

The object is achieved in a device of the type mentioned at the outset, d) the upstream element is arranged in the tank container at a level below the transport level; e) the output device of the loop device comprises an output nozzle, said output nozzle It is disposed at a level below the level of the flow-through element and is designed such that each of the output nozzles specifically outputs a major portion of the processing medium toward each of the flow-through elements.

It should be understood that although a portion of the processing medium output by the determined output nozzle is capable of flowing through the flow-through element, the flow path is not significantly affected by the flow-through element. However, the main part of the processing medium output by the determined output nozzle is desirably flowed onto the associated flow-facing element such that the direct flow path of the processing medium that interrupts the loop is interrupted by the upstream element.

The present invention is based on the following knowledge, in this case can be achieved and a uniform flow pattern and effectively replace the process medium uniformly at the treatment position, whereby, in particular, nitrogen oxide NO _x can be achieved even in the process medium distributed.

In this case, it is particularly expedient if the output nozzle is arranged in a region which is situated from above in the clear contour of the flow-facing element, wherein the corresponding net contour is The flow-through element is defined by a corresponding output nozzle that outputs a treatment medium to the flow-through element.

It is advantageous in terms of construction that the output device comprises a plurality of nozzle strips with output openings, wherein each output opening forms an output nozzle.

Preferably, the nozzle strips are arranged parallel to one another and parallel to the transport direction of the substrate.

Alternatively, the nozzle strip can be arranged perpendicular to the transport direction.

Therefore, the same or similar flow effects are caused at all of the flow-facing elements loaded with the treatment medium, it is expedient if the nozzle strips are arranged in a common horizontal plane, that is to say that the associated nozzle strips are equidistant from the upstream elements. .

It can be advantageous if the output device comprises a plurality of individual nozzles which respectively form an output nozzle.

The individual nozzles can then be transported with a looped treatment medium either alone or in the form of a group consisting of two or more separate nozzles. Thereby, the flow distribution in the treatment tank can be adjusted over a wide range.

It is generally preferred to be able to adjust the volumetric flow of the treatment medium delivered to the loop of the output device.

The loop device can be designed such that a) always transports the looped processing medium to the entire output nozzle with the same volume flow; or b) can deliver a separate volumetric flow of the treatment medium to each output nozzle or by two a group consisting of one or more output nozzles, independent of the remaining output nozzles or with the remaining groups consisting of two or more output nozzles turn off.

In the latter case, a particularly fine adjustment of the flow properties can be achieved in the tank container.

It is particularly advantageous if the upstream element is formed by a guiding element of the transport device. In this case, no other components are required. This means that the output nozzle of the output device is intended to output the processing medium from the lower to the guiding element of the transport device.

As already explained above, the upstream element can preferably be constructed as a transport roller onto which the substrate lies.

In terms of the method of the type mentioned at the outset, the above object is achieved by c) that the main part of the processing medium of the loop is explicitly directed towards the upstream element from a height level lower than the upstream element, said upstream element itself Set in the tank container at a level below the transport plane.

This advantage corresponds to the advantages stated above for the processing device.

As already discussed above for the processing device, it is advantageous in the method for the treatment medium to be output from the region which is situated above the net contour of the upstream element as viewed from above, towards the respective upstream element, wherein each The profile is defined by an upstream element that outputs a processing medium onto the upstream element.

In this case, it is also expedient for the guiding element to be used as an inflow element.

It is also preferred that the transport roller is used as a flow-through element and the substrate is laid flat onto the transport roller.

In Figures 1 and 2, the apparatus for processing a flat substrate is generally labeled 2, wherein a plurality of rafts 4, for example for manufacturing solar cells, are exemplarily shown.

The treatment device 2 comprises a tank container 6 which is filled with a liquid treatment medium 10 up to a certain liquid level 8. The tank container has a level inlet port 12 in its first end wall and a level outlet port 14 in its opposite second end wall. By means of the transport device 16, the jaws 4 are transported through the treatment medium 10 in the transport position 18 indicated by the arrows in the level position, thereby defining the level of transport plane 20 indicated in Figures 1, 3, 6 and 7. At the feed opening 12 and the discharge opening 14, respectively, there is a sealing device 21 which is not of further concern here, so that the treatment medium 10 is not able to penetrate there. Such sealing devices are known per se.

The liquid level 8 is only a small amount, for example 0.1 to 10 mm above the upper side 22 of the seesaw 4. Therefore, the seesaw 4 is completely immersed in the treatment medium 10 when passing through the tank container 6 in this embodiment.

In this regard, the transport device 16 as a guiding element comprises a lower transport roller 24 on which the raft 4 is transported through the treatment medium 10 with its underside 26 lying flat on the transport roller. The lower side 26 is the treated side of the seesaw 4 that should be subjected to an etching process.

It is also possible to have other structures as guiding elements instead of the transport roller 24, for example, a simple sliding element can also be considered, on which the jaws 4 lie flat and via the slip when passing through the processing medium 10 The component moves the seesaw 4.

In a variant, the jaw 4 is only immersed into the treatment medium 10 with its treatment side 26, while its upper side 22 protrudes unimpregnated into the atmosphere above the treatment medium 10. The level 8 of the treatment medium 10 is correspondingly lower in this case.

Furthermore, the transport device 16 in the present embodiment comprises an upper transport roller 28 which rolls on the upper side 22 of the jaw 4, respectively. Here, an upper transport roller 28 is arranged opposite each other for the lower transport roller 24, so that the substrate plate 4 is accommodated between the roller pairs 24, 28. In the figures, only some of the transport rollers 24 and 28 are accordingly provided with reference numerals. Transport rollers 28 and 24 are shown in perspective in FIG.

The lower and upper transport rollers 24 and 28 extend in a horizontal line transverse to the transport direction 18 and are themselves placed in the support block 30 outside of the trough container 6. The upper transport roller 28 can be driven by means of one or more motors not specifically shown here.

The transport rollers 28 are simultaneously used such that the jaws 4 are always placed flat on the lower transport roller 24 and are not raised upwards from the jaws 4. The upper conveying roller 20 is placed such that the conveying roller can move vertically within a certain range. If necessary, for example, the upper transport roller 28 can be flexible or can be placed vertically. It is ensured by the measures that the upper transport roller 28 is able to adapt its vertical position to the difference in thickness of the jaws 4.

In order to achieve a uniform mixing treatment medium and whereby nitrogen oxide NO _x at the beginning of the cell container 6 mentioned, the processing device 10 includes a loop means 32 2. By means of the loop device 32, the treatment medium 10 is aspirated from the region of the transport rollers 24, 28 and is again output from below into the treatment medium 10 still in the tank container 6.

In this regard, the loop device 32 comprises a suction device 34 and an output device 36, through which the treatment medium 10 is withdrawn from the tank container 6, the extracted process medium being again output to the tank container 6 via the output device .

The loop unit belongs to a suction device 34, which in the present embodiment is in the form of a so-called flow box 38. The loop unit draws the process medium 10 from a region of the treatment tank via a plurality of intake nozzles 40 - in the present embodiment three such intake nozzles 40 - the lower transport roller 24 is disposed in the region in. Thus, the hopper 38 draws the treatment medium 10 from the area of the treatment tank near the lower side 26 of the raft 4.

The flow box 38 carries the withdrawn processing medium 10 to an output device 36, the output device 36 comprising a plurality of nozzle strips 42 with a plurality of output nozzles 44, wherein each of the output nozzles passes through the nozzle strip 42 The output opening 46 is formed. Only some of the nozzle strips 42, output nozzles 44 and output openings 46 are provided with reference numerals in the figures.

The nozzle strips 42 and thus the output nozzles 44 are disposed at a lower level than the transport rollers 24 and are designed such that each of the output nozzles 44 purposely directs the main portion 48 of the processing medium 10 of the loop that is indicated by the arrow toward the lower portion. Each of the transport rollers 24 outputs.

As already mentioned at the outset, it should be understood here that although a part of the treatment medium 10 output by the determined output nozzle 44 can flow into the area above the lower transport roller 24 and thus flow to the seesaw 4 without It flows onto the lower transport roller 24 associated with the output nozzle 44. However, the main portion 40 of the processing medium 10 output by the determined output nozzle 44 is desirably flown onto the associated lower transport roller 24 such that the processing medium 10 of the loop is interrupted by the lower transport roller 24 to the seesaw 4 The direct flow path.

Here, the output nozzle 44 is arranged in the present embodiment such that the output nozzle 44 is viewed from above in the region of the lower contour of the transport roller 24, which is defined by the lower transport roller 24 as follows, The determined output nozzle 44 outputs the processing medium 10 to the lower transport roller. The net profile of the lower transport roller 24 is indicated by dashed lines in FIG. 1 and is provided with the reference numeral 50. Thus, when the output nozzles 44 are disposed at a corresponding distance below the transport roller 24, the angle at which the process medium exits the output nozzle 44 from the determined lower portion of the transport roller 24 can always remain relatively large.

However, in a variant of the treatment device 2 not specifically shown, it is also possible to have some or all of the output nozzles 44 as long as the main portion 48 of the looped process medium 10 encounters the corresponding lower transport roller 24 in the manner described above. It is disposed outside of the corresponding net contour 50 of the transport roller 24.

It is also not necessary to provide one or more output nozzles 44 below each transport roller 24; likewise there can be transport rollers 24 to which the process medium 10 that is not looped flows. Thus, the output nozzle 44 can, for example, be associated with only one or every other two lower transport rollers 24.

Thus, in general, a flow-facing element is formed by the transport roller 24, which is arranged below the transport plane 20 in the tank container 6 and the output nozzle 44 outputs the main portion 48 of the treatment medium 10 to said upstream On the component. In a variant, the upstream element can also be present as a separate component in the tank container 6. This is only indicated in FIG. 1 by the flow-through element 51 shown by the dashed line, which is situated below the transport roller 24 there. The geometry of such a separate flow element 51 can be different. Again, in general, it is currently important that the current-carrying element is placed at a level below the transport plane 20 of the substrate, and that the output nozzle 44 is situated at a lower level than the upstream element, wherein the upstream element may A separate upstream element 51 or a guiding element such as a transport roller 24 is provided. Again generally speaking, the net profile 50 is correspondingly the net profile of the respective inflow element 51.

In the following, reference is made to the transport roller 24 as the upstream element, which for this purpose also applies correspondingly to the individual flow-through element.

A non-proportional section of the treatment device 2 is shown in FIG. 3, in which a section of the nozzle strip 42 with a transport roller 24 arranged above the nozzle strip can be identified, on which the raft 4 is transported . In the nozzle strip 42, below each of the transport rollers 24, a plurality of output nozzles 46 are distributed along the longitudinal direction of the transfer roller 24 on the circumference of the nozzle strip 42, such that the process medium is fanned toward the The transport roller 24 is output with the flow sector unfolding in the longitudinal direction of the transport roller 24. This is indicated in Figure 3 by corresponding arrows, wherein not all of the output openings 46 have the reference numerals.

The number of output openings 46 can vary over a wide range. Only a single output opening 46 can always be present, respectively, as shown in the nozzle strip 42 of FIG. The maximum possible number of output openings 46 is particularly the diameter of the nozzle strip 42 as viewed and the diameter of each output opening 46. Related to the spacing between each other.

In particular, it has been found in practice that the plurality of output openings 46 are arranged and distributed over an angular range of more than 160°, that is to say in the two directions starting from the vertical line V, respectively, and distributed over 80°. However, the angular range can also be reduced and is for example only 120°. The arrangement of the output openings 46, which are particularly effective for a particular device, can be determined experimentally by means of common mechanisms.

When the looped process medium 10 now comes out of the corresponding output nozzle 44 and encounters the lower transport roller 24, the flow is generally homogenized, with interruptions and reductions present in the process medium 10 flowing upward from the output nozzle 44. Eddy current.

Thereby, the looped process medium 10 flows uniformly to the position where the etching process is performed at the lower side 26 of the seesaw 4, and as a whole, in the region of the seesaw 4 and at the liquid level 8 of the process medium 10. Form a uniform flow pattern. This is illustrated by Figures 4 and 5.

The flow pattern at the liquid level 8 occurring in the processing device 2 can be identified in FIG. 4; FIG. 5 shows the flow pattern at the liquid level S of the processing medium M, which can be present in the processing device A The treatment device is known from the market and in the treatment device, the looped treatment medium M flows between the transport rollers T here.

In the latter case, when the seesaw 4 has no blocked path, the looped processing medium M flows on a direct path with respect to the liquid level S. Thus, at the liquid level S, a "flowing mushroom top" P is formed by a strong and direct upward flow, locally undesirable etching and reaction products can be concentrated in said In the mushroom top, the etching and reaction products also affect the composition of the processing medium at the etched location, i.e., at the underside of the raft, such that the resulting etch does not have the desired quality.

Conversely, Figure 4 shows how a uniform flow pattern is produced by the output device 36 with the nozzle strips 42, wherein the turbulence at the liquid level 8 of the treatment medium 10 is modest, such that the treatment medium is at the upper portion Only a slight flow projection 52 is created between the transport rollers 28. Here, the media processing loop 10 more uniformly in the groove 6 and the container nitrogen oxides NO _x in the treatment medium 10 uniformly distributed, so that the uniformity of etching to ensure high quality, as is set forth above in the beginning.

The flow box 38 provides a loop of treatment medium 10 for each nozzle strip 42 that passes through a respective nozzle strip 42 and exits again via an output opening 46 located in the nozzle strip 42. The volumetric flow of the processing medium 10 delivered by the chute 38 to the loop of the output device 38 can be adjustable. Here, the flow box 38 can be designed such that the processing medium 10 of the loop is always delivered to all of the nozzle strips 42 in the same volume flow. Alternatively, the flow box 38 can also be designed such that a separate volume flow of the process medium 10 can be delivered to each nozzle strip 42 regardless of the remaining nozzle strips 42.

The seesaw 4 is generally divided into so-called tracks on which the subsequent effective surface is placed. In practice, it has proven to be particularly advantageous for the output nozzles 44 to be arranged one after the other in parallel with the rails, so that the nozzle strips 42 are arranged parallel to the transport direction 18 and parallel to one another in a common horizontal plane. However, in a variant that is not specifically shown, the spray The mouth strip 42 extends, for example, also parallel to the lower transport roller 24, or generally perpendicular to the transport direction 18, such that there is a nozzle strip 42 under the determined transport roller 24, the output nozzle 44 of which will loop the processing medium 10 The main portion 48 is all output to the determined transport roller 24.

In Figs. 6 and 7, the modified processing device 2' is now shown as the second embodiment. In the processing device, the components and components corresponding to the components and components in the processing device 2 according to FIGS. 1 to 4 have the same reference numerals, and the contents of the above processing device 2 are correspondingly applied in the sense.

The processing device 2' differs from the processing device 2 in the modified output device 36. In the treatment device 2', the output nozzles 44 are formed by separate nozzles 54, wherein each individual nozzle is connected to the flow box 38 via a separate delivery channel 56, of which only a few individual nozzles are provided with reference numerals. In the manner described, the looped process medium 10 can be separately delivered from the flow bin 38 to each individual nozzle 54.

In a variant which is not specifically shown, the group of individual nozzles 54 with two or more individual nozzles 54 can also transport the treatment medium 10 to which the loops are fed via respective common conveying lines.

Furthermore, the individual nozzles 54 can also be used in combination with one or more nozzle strips 42 as they are provided in the processing device 2.

M‧‧‧Processing media

S‧‧‧ liquid level

V‧‧‧ vertical line

A‧‧‧Processing equipment

T‧‧‧Transport roller

2‧‧‧Processing equipment

2’‧‧‧Processing equipment

4‧‧‧矽板

6‧‧‧Slot container

8‧‧‧ liquid level

10‧‧‧Processing media

12‧‧‧ Feed inlet

14‧‧‧Outlet

16‧‧‧Transportation device

18‧‧‧Transportation direction

20‧‧‧Transportation plane

21‧‧‧ Sealing device

22‧‧‧Upper side

24‧‧‧Transport roller

26‧‧‧lower side, treatment side

28‧‧‧Transport roller

32‧‧‧Circle device

34‧‧‧Suction device

36‧‧‧Output device

38‧‧‧Stream box

40‧‧‧Intake intake

42‧‧‧Nozzle strips

44‧‧‧ output nozzle

46‧‧‧Output opening

48‧‧‧ main part

50‧‧‧ mark, net outline

51‧‧‧Inrush element

52‧‧‧Flow projections

54‧‧‧Single nozzle

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Which shows: 1 shows a vertical sectional view according to a section line II in FIG. 2 of an apparatus for processing a flat substrate according to a first embodiment, in which a loop device is present; FIG. 2 shows an edge of the apparatus of FIG. 1 is a cross-sectional view taken along line II-II of FIG. 1; FIG. 3 shows a disproportionate cross-sectional view of a nozzle strip with a plurality of output openings; FIGS. 4 and 5 show in the apparatus according to the present invention. A schematic diagram comparing the flow on the surface of the groove in a device according to the prior art; FIG. 6 shows a line according to section line IV-IV in FIG. 5 according to the apparatus for processing a flat substrate according to the second embodiment. Vertical cross-sectional view; Fig. 7 is a cross-sectional view of the apparatus of Fig. 4 taken along line VII-VII of Fig. 4.

2‧‧‧Processing equipment

2’‧‧‧Processing equipment

4‧‧‧矽板

6‧‧‧Slot container

8‧‧‧ liquid level

10‧‧‧Processing media

12‧‧‧ Feed inlet

14‧‧‧Outlet

16‧‧‧Transportation device

18‧‧‧Transportation direction

20‧‧‧Transportation plane

21‧‧‧ Sealing device

22‧‧‧Upper side

24‧‧‧Transport roller

26‧‧‧lower side, treatment side

28‧‧‧Transport roller

32‧‧‧Circle device

34‧‧‧Suction device

36‧‧‧Output device

38‧‧‧Stream box

40‧‧‧Intake intake

42‧‧‧Nozzle strips

44‧‧‧ output nozzle

46‧‧‧Output opening

48‧‧‧ main part

50‧‧‧ mark, net outline

51‧‧‧Inrush element

Claims (16)

An apparatus for processing a flat substrate in a continuous process, with a) a tank container (6) filled with a liquid treatment medium (10) up to a certain liquid level (8); b) a transport device (16) by means of the transport device, the substrate (4) can be transported through the processing medium (10) in a transport direction (18) in a transport plane (20) through the guiding element (24), such that At least one processing side (26) of the substrate (4) is immersed in the processing medium (10); c) a looping device (32) by means of which the looping device can be 6) a middle loop, and the loop device comprises a suction device (34) and an output device (36) through which the treatment medium (10) is withdrawn from the tank container (6), the treatment being withdrawn The medium (10) is again output into the tank container (6) via the output device, characterized in that d) the flow-in element (24; 51) is arranged below the transport plane in the tank container (6) (20) a height level; e) the output device (36) of the loop device (32) includes an output nozzle (44) disposed at a level below the level of the flow element (24; 51) and design Thus, each of the output nozzles (44) purposely outputs a major portion (48) of the processing medium (10) toward each of the flow-through elements (24; 51). According to the device described in claim 1 of the patent application, wherein The outlet nozzle is arranged in a region from above which is situated within the clear contour (50) of the flow-facing element (24; 51), wherein the corresponding net contour (50) is defined by the upstream element (24; 51), A corresponding output nozzle (44) outputs the processing medium (10) to the flow-through element. The apparatus of claim 1, wherein the output device (36) has a plurality of nozzle strips (42) with output openings (46), wherein each output opening (46) forms an output nozzle (44) ). The device according to claim 3, wherein the nozzle strips (42) are arranged parallel to each other and parallel to the transport direction (18) of the substrate (4). The device of claim 3, wherein the nozzle strip (42) is disposed perpendicular to the transport direction (18). The apparatus of claim 4, wherein the nozzle strips (42) are disposed in a common horizontal plane. The apparatus of claim 1, wherein the output device (36) includes a plurality of individual nozzles (54) that respectively form an output nozzle (44). The apparatus of claim 7, wherein the individual nozzles (54) are capable of being transported with a loop of processing medium either alone or in the form of a group consisting of two or more separate nozzles (54) ( 10). The apparatus of claim 1, wherein the volumetric flow of the treatment medium (10) delivered to the loop of the output device (36) is adjustable. The device according to claim 1, wherein the The loop device (32) is designed such that a) the looped processing medium (10) is always delivered to the entire output nozzle (44) in the same volume flow; or b) the individual volume of the processing medium (10) can be The flow is supplied to each of the output nozzles (44) or a group of two or more output nozzles (44), independent of the remaining output nozzles (44) or consisting of two or more output nozzles (44) The rest of the group has nothing to do with it. The device according to any one of the preceding claims, wherein the flow-through element (24) is formed by the guiding element (24) of the transport device (16). The device according to claim 11, wherein the oscillating member (24) is configured as a transport roller (24) which is placed flat on the transport roller (24). A method for processing a flat substrate, wherein a) the substrate (4) is transported in a continuous process in the transport direction (18) in the transport plane (20) through the guiding element (24) in the level transport plane (20) At least one processing side (26) of the substrate (4) is immersed in the processing medium (10) by a liquid processing medium (10); b) the processing medium (10) is by means of a loop device (32) The loop is characterized in that c) the main portion (48) of the looped processing medium (10) is clearly directed from the height level below the current-carrying element (24; 51) towards the upstream element (24; 51) Output, the current-facing element (24; 51) itself is in the slot The container (6) is placed at a level below the transport plane (20). The method according to claim 13 wherein the processing medium (10) is output towards the respective upstream element (24) from a region within the net profile (50) of the upstream element (24) as viewed from above. The corresponding net profile (50) is defined by the upstream element (24) to which the processing medium (10) is output. The method of claim 13 or 14, wherein the guiding element (24) is used as an inflow element (24). The method according to claim 15 wherein the transport roller (24) is used as a flow-through element (24) which is placed flat on the transport roller (24).