Title of Invention

APPARATUS AND METHOD FOR WET-CHEMICAL PROCESSING OF FLAT, THIN SUBSTRATES IN A CONTINUOUS METHOD

Abstract The invention relates to a method and apparatus for wet-chemical processing (cleaning, etching, stripping, coating, dehydration) in a continuous method for flat, thin and fracture-sensitive substrates, the substrate transport and the wet process being effected by media-absorbing rollers.
Full Text Title: Apparatus and Method for Wet-Chemical Processing of Flat, Thin Substrates in a
Continuous Method
Description
The invention relates to a method and an apparatus for the wet-chemical processing of flat,
thin and fracture-sensitive substrates for microelectronic, micromechanical, and optical
applications, wherein wet-chemical processes such as cleaning, etching, stripping, coating,
and drying are used in a continuous method (inline) for the production of microelectronic
components, solar cells, etc.
The wet process technique for the production of microelectronic components is presently
carried out primarily in bath processes, wherein the substrates, which are accommodated in
magazines, are immersed in process baths. The process is carried out discontinuously in
batches of 1 to 50 substrates. The use of continuous (inline) wet process systems, for
example for the production of solar cells, is on the rise, wherein the substrates located on
rollers or belts are continuously conveyed into process baths or are sprayed in spray modules
with media, such as process chemicals or water, and then dried with warm air or nitrogen,
which may optionally be enriched with isopropanol. The presently available wet-chemical
processes are limited to immersion processes and spraying processes, which were
developed and optimized substantially for standard substrates in the semi-conductor industry.
In modern microelectronics and thin-film technology, in the future increasingly thinner
substrates will be used, for example with substrate thicknesses of less than 100 µm. These
practically film-like, very fracture-sensitive substrates cannot be processed in magazines and
immersion basins because on the one hand the requirements with respect to transportation

stability, and on the other also the productivity criteria, are not met. Some process
requirements, such as one-sided processing, are also not possible. While existing inline
process systems for the simultaneous processing of a large number of such substrates in a
continuous method meet the throughput criteria, they are associated with unacceptably high
breakage rates and cannot be employed for all necessary process types.
The method described hereinafter, and the apparatus that is described, meet all the
requirements for an inline process device for thin, fracture-sensitive substrates, both with
respect to the transport (handling) within the process path and also with respect to the
expanded processes for all required applications through the use of microporous,
compressible rollers. By using such rollers, forces perpendicular to the transport direction are
avoided, and at the same time the rollers allow uniform coverage of the substrates with the
process media, either on both sides or only on the front or back of the substrate. As a result,
during processing not only chemical, but also physical methods with direct cleaning contact
are effective through the controlled interaction with the process media. In addition, a rinsing
and drying step can be integrated in the same method.
In the present method, the substrates to be processed are guided in a continuous method via
rotating, media-compatible sponge rollers that are installed on one side or both sides.
Absolutely uniform movement is achieved by coupling the drives on at least one side. The
media (liquid or gaseous) required for the desired process are applied directly or indirectly
during the pass and are removed again in rinsing and drying steps. Depending on the
embodiment, processing can be performed on one side or both sides of the substrates, and a
plurality of process steps (using the same or different media) can be combined in one

process line by stringing process modules together. This line can have one or more lanes.
The method can end both with wet or dry substrates.
Description of different embodiments and illustrations:
The substrates 1 (FIG. 1) to be processed are fed horizontally to a process module 2A.
Feeding is carried out in that the substrate is transported on rollers 3 or on bands or belts, or
by an alternative handling system (such as robots), to the rollers 4 and 5 of the process
modules 2A.
As soon as the substrate is picked up by the porous, compressible rollers 4 and 5, the
substrate is conveyed further by identical, subsequent rollers of the process module 2A. The
rollers are characterized in that they absorb the process medium used in the process module
2A, wherein the medium is fed from an immersion bath 6 or spraying device 7, or directly
through the core of the rollers 8, and in that they transmit the process medium to the
substrate surface due to the contact of the rollers 9 and 10 (FIG. 2) with the surface of the
substrate 11. The rolling motion of the roller fed with the process medium on the substrate
surface at the same time effects a friction effect, which supports the process and intensifies
processing during cleaning, etching, stripping, and rinsing.
In an alternative method, which can also be combined with that described above, the
distance of the rollers 12 and 13 (FIG. 3) can be configured such that between the rollers 12
and 13 process media can additionally be guided by spray nozzles 14. Furthermore, the
spray nozzles can be configured as ultrasonic or megasonic nozzles.

Coverage of the lower rollers 15 and 16 can optionally be achieved by the direct absorption of
the process medium from the tub 17, or according to the above-described embodiment of the
upper rollers via spray nozzles, and can additionally be supported by ultrasonic or megasonic
excitation (18) of the process medium. The media can also be fed to the roller 19 (FIG. 4)
through the roller core 20 in that the roller core is provided with bores 21 for discharging the
media. Due to the microporous structure of the roller, the process medium reaches the roller
body and/or roller surface and, in the apparatus that is described, the surfaces of the
substrate to be processed.
Depending on the substrate type and the desired process, both the vertical distance 23 of the
rollers in relation to the substrate (FIG. 6) and the horizontal distance 22 of the rollers to one
another as well as the roller quantity 24 can be configured in accordance with the process
requirements and substrate type. Likewise, the pressure of the rollers on the substrate can be
brought about in accordance with the desired process and substrate type by means of fine
adjustment, gravity (pressure of the upper rollers on the lower rollers), or by actuators
(pneumatic, electric, or hydraulic).
The rollers are rotated by electric drives in that the roller rotation and thus the substrate
transport is continuously variable.
Alternatively, a process wherein the rollers rotate in opposite directions, for example during
cleaning processes, is possible (FIG. 5) in that the roller contact pressure of the rollers 25,
26, 27 and 28 performing the substrate transport is accordingly higher in relation to the
substrate than the roller contact pressure of the rollers 29 and 30, and in that the rollers 29
and 30 rotate opposite to the direction of rotation of the rollers 25, 26, 27 and 28 and/or
opposite to the transport direction of the substrate, thus creating an additional cleaning effect.

Likewise, rollers having different roller diameters (FIG. 7) 31, 32, 33 and 34 can be used for
the transport and processing, if they are adapted in their combination to the process (see
FIG. 7). In addition, the rotational speed of each roller can be individually controlled and, in
combination with the roller pressure and roller direction of rotation, can be associated with
every roller in order to achieve appropriate process control during the individual processes.
For different, consecutive processes, such as etching, rinsing, drying, the process modules
can be set up successively in a line 2A, 2B, 2C (see FIG. 1) and be separated from one
another with respect to the different process media by separating walls, comprising a slot for
continuous substrate transport. Separation of the process modules from one another can also
be achieved solely by the rollers and appropriate process media supply in that the last rollers
within the process modules are supplied a reduced media volume.
Drying of the substrate surface, for example after spraying processes, is likewise performed
substantially by the microporous rollers. However, these rollers are not supplied a process
medium. Due to the rolling motion of the dry roller across the substrate surface, the roller
absorbs liquid from the surface (see FIG. 8). The absorbed liquid is continuously removed
through additional wiping and/or rolling 36 and 37 (FIG. 8) of the rollers 39 and 39 used for
the drying process, thus preparing the roller for further absorption of liquid in a process run.
Likewise, the liquid absorbed by the roller can be removed from the substrate surface in that
the absorbed liquid is suctioned out of the roller through the perforated roller core 20 (FIG. 4)
by a vacuum.
In a second embodiment, surface drying after absorption of the liquid following the rolling
motion of the rollers on the substrate surface can occur in that following the last roller the

substrate surface is inflated with gases, which can additionally be heated, such as heated
nitrogen or hot air, and by heating the substrate, for example by means of infrared radiation
or heating rods, or in a combination of the described methods.
In a further, alternative embodiment, residue-free surface drying of the substrates can be
carried out by introducing a gas-steam mixture into the liquid on the substrate surface,
wherein the steam can be mixed with the liquid and mixing results in reduced surface tension
of the liquid on the interface between the substrate and roller surfaces compared to the liquid
without admixed steam. This method, known as the Marangoni effect or surface tension
gradient drying, can be applied to the present invention, as is shown in FIG. 9. Due to the
rolling motion of the rollers 40 and/or 41, the liquid previously absorbed from the wet
substrate surface during rolling of the rollers, or the liquid additionally fed to the rollers
according to the possibilities described above, produces a meniscus between the roller and
substrate surface. From the nozzles 45 and/or 46, the gas-steam mixture is conducted in the
direction of the meniscus through flow-conducting outlets 47 and/or 48. If the steam
penetrates the liquid meniscus, mixing and therefore a reduction in surface tension in relation
to the liquid outside of the meniscus are brought about. This results in a force (Marangoni
force) in the direction of the liquid region having higher surface tension outside of the
meniscus, which causes the substrate to dry. This drying process is substantially free of
particles and residue.
The one-sided surface treatment of a flat substrate can occur in that the substrate 49 (FIG.
10) is fed on conveying rollers 50 to a process roller 51, which is supplied with a process

medium 52 and transfers the process medium 53 onto the substrate surface during the rolling
motion across the substrate. The appropriate arrangement of the conveying rollers 50
prevents them from coming in contact with the process roller 51.
A further possibility of one-sided surface treatment can occur in that the substrate 54 (FIG.
11) is transported with the surface to be processed by the rollers 55, which are immersed in a
process medium and during rotation of the rollers during the substrate transport transmit this
medium 56 to the substrate bottom. If this substrate 57 (FIG. 12) is additionally pressed
against the soft rollers 58 by pressure rollers 59 (FIG. 13), also the substrate edge is treated
with the process medium.

Claims
1. A method for wet-chemical treatment, particularly for cleaning, etching, stripping, coating,
or dehydration, in a continuous method for flat, thin and fracture-sensitive substrates,
characterized in that the substrate transport and processing are carried out by rollers
absorbing the process media.
2. The method according to claim 1, characterized in that the absorbed process medium in
the roller is transmitted to the substrate surface during substrate transport.
3. The method according to claim 1 or 2, characterized in that process media is fed to the
rollers during the rolling motion of the rollers on the substrate surface.
4. A method according to any one of the preceding claims, characterized in that the wet-
chemical treatment occurs only on one side of the substrate or on both sides.
5. A method according to any one of the preceding claims, characterized in that the wet-
chemical treatment comprises a drying step.
6. A method according to any one of the preceding claims, characterized in that the wet-
chemical treatment occurs in a plurality of process steps that can be arbitrarily combined.
7. An apparatus for wet-chemical treatment, particularly for cleaning, etching, stripping,
coating, or dehydration, in a continuous method for flat, thin and fracture-sensitive substrates,
characterized in that process media-absorbing rollers are provided, by means of which the
substrate transport and process are carried out.

8. The apparatus according to claim 7, characterized in that the roller is configured such that
the process medium absorbed in the roller can be transmitted to the substrate surface during
the substrate transport.
9. The apparatus according to claim 7 or 8, characterized in that the feeding of process
medium occurs during the rolling motion of the rollers on the substrate surface.

10. An apparatus according to any one of the claims 7 to 9, characterized in that the wet-
chemical treatment occurs only on one side of the substrate or on both sides.
11. An apparatus according to any one of the claims 7 to 10, characterized in that the roller
has a microporous design such that the media is fed by introducing the process medium in
the microporous roller.
12. An apparatus according to any one of the claims 7 to 11, characterized in that a media
bath is provided such that the media is absorbed by the roller by immersing the roller in the
media bath.
13. An apparatus according to any one of the claims 7 to 12, characterized in that a spraying
device is provided such that the media is fed to the roller by spraying onto the roller and/or by
metering the process medium between the rollers.
14. An apparatus according to any one of the claims 7 to 13, characterized in that an arbitrary
number of rollers is provided to create a process line.

15. An apparatus according to any one of the claims 7 to 15, characterized in that the
distance and/or length of the rollers can be freely selected in accordance with the substrate
size.
16. An apparatus according to any one of the claims 7 to 15, characterized in that the
positions of the rollers disposed on top of one another are arbitrary.
17. An apparatus according to any one of the claims 7 to 16, characterized in that the
distance of the upper rollers to the lower rollers is adjustable.
18. An apparatus according to any one of the claims 7 to 17, characterized in that the
pressure of the rollers on the substrate varies and/or is adjustable.
19. An apparatus according to any one of the claims 7 to 18, characterized in that the roller
profiles have different surfaces and particularly are smooth or have nubs, or longitudinal
and/or transverse grooves.
20. An apparatus according to any one of the claims 7 to 19, characterized in that the
rotational speed of each roller can be individually adjusted.
21. An apparatus according to any one of the claims 7 to 20, characterized in that the sense
of rotation (direction of rotation) of each roller can be selected to be different.
22. An apparatus according to any one of the claims 7 to 21, characterized in that in addition
to the rollers further process-supporting systems, particularly ultrasonic or megasonic
systems, can be integrated in the process modules.
23. An apparatus according to any one of the claims 7 to 22, characterized in that drying

occurs by running through dry rollers, wherein the liquid absorbed by the roller is wiped off.
24. An apparatus according to any one of the claims 7 to 23, characterized in that the
absorbed liquid of the roller can be removed by suctioning it out of the roller.
25. An apparatus according to any one of the claims 7 to 24, characterized in that process-
supporting devices and/or methods, such as blowing the substrate off with heated gas, a
localized reduction in the surface tension, or substrate heating, for example by means of
infrared radiation, are provided for drying the substrate.
26. An apparatus according to any one of the claims 7 to 25, characterized in that gaseous
media can be conducted through the roller core (20) into the rollers.
27. An apparatus according to any one of the claims 7 to 26, characterized in that, along the
contact surface of the roller with the substrate, a gas flow particularly comprising nitrogen can
be introduced, wherein the flow comprises steam, particularly with isopropanol IPA, which
mixes with the liquid on the substrate surface, and in that the mixture has lower surface
tension than the liquid prior to mixing.
28. An apparatus according to any one of the claims 7 to 27, characterized in that all process
media employed can be heated.
29. An apparatus according to any one of the claims 7 to 28, characterized in that the media
fed to the individual rollers can be removed by a rolling motion of the roller on the substrate.

30. An apparatus according to any one of the claims 7 to 29, characterized in that the
coverage or coatings on the substrate front and substrate bottom are different.
31. An apparatus according to any one of the claims 7 to 30, characterized in that a plurality
of substrates can be processed adjacent to one another at the same time.
32. An apparatus according to any one of the claims 7 to 31, characterized in that a plurality
of process chambers are disposed in series to form a process line in order to be able to
consecutively carry out etching processes, rinsing processes, drying processes, and the like.
33. An apparatus according to any one of the claims 7 to 32, characterized in that a plurality
of process lines are configured on top of one another.
34. An apparatus according to any one of the claims 7 to 33, characterized in that the
process medium or media can be fed only to the substrate top via rollers above the substrate.
35. An apparatus according to any one of the claims 1 to 34, characterized in that the
process medium or media can be fed only to the one substrate side via rollers beneath the
substrate.
36. An apparatus according to any one of the claims 1 to 35, characterized in that the
process medium or media can be fed only to one substrate side and the substrate edge.

The invention relates to a method and apparatus for
wet-chemical processing (cleaning, etching, stripping,
coating, dehydration) in a continuous method for flat,
thin and fracture-sensitive substrates, the substrate
transport and the wet process being effected by media-absorbing
rollers.

Documents:

01912-kolnp-2008-abstract.pdf

01912-kolnp-2008-claims.pdf

01912-kolnp-2008-correspondence others.pdf

01912-kolnp-2008-description complete.pdf

01912-kolnp-2008-drawings.pdf

01912-kolnp-2008-form 1.pdf

01912-kolnp-2008-form 2.pdf

01912-kolnp-2008-form 3.pdf

01912-kolnp-2008-form 5.pdf

01912-kolnp-2008-international publication.pdf

01912-kolnp-2008-international search report.pdf

01912-kolnp-2008-pct request form.pdf

1912-KOLNP-2008-(08-04-2014)-ABSTRACT.pdf

1912-KOLNP-2008-(08-04-2014)-ANNEXURE TO FORM 3.pdf

1912-KOLNP-2008-(08-04-2014)-CLAIMS.pdf

1912-KOLNP-2008-(08-04-2014)-CORRESPONDENCE.pdf

1912-KOLNP-2008-(08-04-2014)-DESCRIPTION (COMPLETE).pdf

1912-KOLNP-2008-(08-04-2014)-FORM-2.pdf

1912-KOLNP-2008-(26-11-2012)-CORRESPONDENCE.pdf

1912-KOLNP-2008-CORRESPONDENCE 1.2.pdf

1912-KOLNP-2008-CORRESPONDENCE OTHERS-1.1.pdf

1912-KOLNP-2008-FORM 18.pdf

1912-KOLNP-2008-FORM 26.pdf

1912-KOLNP-2008-OTHERS.pdf

1912-KOLNP-2008-PCT REQUEST FORM-1.1.pdf

1912-KOLNP-2008-PRIORITY DOCUMENT.pdf

abstract-1912-kolnp-2008.jpg


Patent Number 263433
Indian Patent Application Number 1912/KOLNP/2008
PG Journal Number 44/2014
Publication Date 31-Oct-2014
Grant Date 29-Oct-2014
Date of Filing 13-May-2008
Name of Patentee ACP-ADVANCED CLEAN PRODUCTION GMBH
Applicant Address RONTGENSTRASSE 30, 73730 ESSLINGEN
Inventors:
# Inventor's Name Inventor's Address
1 HORST KUNZE-CONCEWITZ WALDENSERSTRASSE 41, 75446 WIERNSHEIM
PCT International Classification Number H01L 21/00,B08B 1/04
PCT International Application Number PCT/EP2006/011166
PCT International Filing date 2006-11-22
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10 2005 057109.3 2005-11-26 Germany