Holding apparatus and method for holding a substrate

A holding apparatus, in particular a chuck, for a substrate comprises a main body with a upper side, a carrier element arranged in a recess of the main body so as to be vertically movable such that it can be adjusted between a protruding loading position and a retracted clamping position, the carrier element comprising a support surface for placement of the substrate. The support surface has a smaller diameter than the main body. A lifting element lifts the carrier element to the loading position. The carrier element seals the recess such that a sealed cavity is provided between the main body and the carrier element, which cavity can have a negative pressure applied thereto which counteracts the effect of the lifting element.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY

This patent application claims priority from NL Patent Application No. 2021006 filed May 29, 2018, which is herein incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to the field of holding and fixing substrates, in particular in manufacturing equipments for microstructure devices.

BACKGROUND OF THE INVENTION

Substrates, such as semiconductor wafers, are processed in special manufacturing equipments for microstructure devices, e.g. in coating equipments (coaters). In particular, substrate holders, so-called chucks, are frequently used in order to hold the substrates in these equipments. Frequently, they are spinner chucks which rotate the substrates at a high rotational speed, e.g. in order to coat the substrates uniformly. The substrates are fixed on the chuck, e.g. by means of vacuum suction.

The substrates processed in this manner are mostly flat and planar. However, they can also deviate from an ideally planar shape and have a bow. Bowed wafers are defined e.g. as warped wafers. It is difficult to fix bent substrates on spinner chucks by means of vacuum suction because no vacuum or only an insufficient vacuum can be established between the chuck upper side and the substrate lower side on account of the bow.

In order to improve the fixing of bowed substrates, it is known to arrange soft sealing lips on the support surface of the chuck. The substrate is supported on the periphery of the sealing lip so that a vacuum can be established between the substrate and chuck.

However, in this case it is disadvantageous that the substrate is not guided horizontally during the suction process. When the air is being evacuated, the substrate can laterally slide or float within the holding surface and a resulting vertical movement until finally it is supported in a planar manner on the chuck. This adversely affects the centring of the substrate with respect to the chuck, which in the subsequent course of the process can result in undesired effects, such as vibrations or a non-homogeneous, i.e. fluctuating along the periphery, edge bead removal (EBR).

Further disadvantages arise as a result of soiling and ageing of the sealing lips. The sealing lips can generate particles and change their surface and friction properties over time. This can result in specifically increased maintenance outlay, e.g. arising from replacement of the sealing lips, correction of the storage position or cleaning of the sealing lips.

Therefore, it is the object of the present invention to hold and fix a substrate, in particular a bowed substrate, efficiently and securely.

BRIEF DESCRIPTION OF THE INVENTION

This object is achieved by the features of the independent claims. Advantageous developments are the subject matter of the dependent claims, the description and the drawings.

According to a first aspect, the invention relates to a holding apparatus, in particular a chuck, for a substrate, comprising a main body with a upper side, a carrier element, wherein the carrier element is arranged in a recess of the main body so as to be vertically movable such that it can be adjusted between a protruding loading position and a retracted clamping position, and wherein the carrier element comprises a support surface for placement of the substrate, wherein the support surface has a smaller diameter than the main body, and a lifting element which lifts the carrier element to the loading position, wherein the carrier element seals the recess such that a sealed cavity is provided between the main body and the carrier element, which cavity can have a negative pressure applied thereto which counteracts the effect of the lifting element. This provides the advantage that substrates, to which suction cannot readily be applied, in particular bowed wafers (warped wafers), can be held securely and guided in the vertical movement by reason of the initially small vacuum surface.

The small size of the support surface of the carrier element means that in the loading position sufficient sealing can be achieved in order to fix a bowed wafer initially on the carrier element. Subsequently, the substrate can be pulled in the clamping position against the upper side of the main body and finally can be firmly clamped.

The upper side of the main body can correspond to a clamping surface for the substrate, on which the substrate is firmly clamped in the clamping position.

In this case, a vertical movement refers to a movement coaxial to a transverse axis of the main body. In particular, this means a movement perpendicular to the support surface of the carrier element.

The diameter of the carrier element is e.g. less than half, a third or a quarter of the diameter of the substrate and/or the diameter of the main body. In particular, in the case of significantly bowed substrates, it is advantageous for the diameter of the carrier element to be as small as possible in order to generate sufficient vacuum suction in the loading position.

The carrier element can be arranged so as to be movable in the recess in the manner of piston.

The recess can be a depression in the main body, in particular along a central axis of the main body. The recess can have a circular diameter. The diameter of the recess can correspond to, or can be minimally larger than, the diameter of the carrier element.

The cavity can be the space which remains between the bottom of the recess and the carrier element. The size of cavity can be defined by the position of the carrier element and can vary with the movement of the carrier element.

The substrate can be a wafer. The substrate can be disk-shaped. The substrate can have a largely round periphery with a diameter of 2, 3, 4, 5, 6, 8, 12 or 18 inches. Furthermore, the substrate can be largely flat and can have a thickness between 50 and 4000 μm. The substrate can have a straight edge (flat) and/or can have at least one notch. Furthermore, the substrate can be angular, in particular square or rectangular.

The substrate can be formed from a semiconductor material, e.g. silicon (Si) or gallium arsenide (GaAs), a glass, e.g. quartz glass, a synthetic material or a ceramic. The substrate can be formed from a monocrystalline, a polycrystalline or an amorphous material. Furthermore, the substrate can comprise a multiplicity of associated materials.

The substrate can comprise electric circuits, e.g. transistors, light-emitting diodes or photodetectors, electric conductive tracks which connect these circuits, or optical devices as well as MEMS or MOEMS structures. Furthermore, the substrate can have coatings, e.g. structured chromium layers, pre-cross-linked or hardened bond adhesives or separation layers.

According to one embodiment, spacers are provided which define the clamping position of the carrier element in which the support surface of the carrier element is arranged substantially flush with the upper side of the main body. This provides the advantage that the position of the carrier element can be fixed in the clamping position such that the support surface and the upper side of the main body form a common support for the substrate, on which the substrate can be clamped in the clamping position.

Preferably, a height deviation between the support surface of the carrier element and the upper side of the main body after lowering is less than a height fluctuation of the substrate by reason of a deformation or bow. Particularly preferably, the height deviation is less than a substrate thickness.

According to one embodiment, the main body comprises a sealing means, in particular a sealing lip, which surrounds the carrier element with a spaced interval and can seal between the upper side of the main body and the substrate. This provides the advantage that in the clamping position the substrate can be subjected to suction and clamped in a particularly efficient manner. With the aid of the sealing means, a vacuum can be produced underneath the substrate which exerts a uniform force upon the substrate and clamps it.

According to one embodiment, the carrier element is provided with a seal which seals against the lateral wall of the recess in the main body. This provides the advantage that the sealing-tightness of the cavity and the frictionless movement of the carrier element in the recess can be ensured.

According to one embodiment, the carrier element comprises fixing means for fixing the substrate supported on the support surface, in particular suction openings. This provides the advantage that the substrate can be securely fixed on the support surface.

According to one embodiment, the main body has further fixing means for fixing the lowered substrate on the upper side. The further fixing means can comprise further suction openings.

According to one embodiment, the cavity and the fixing means are fluidically connected. This provides the advantage of permitting a particularly simple construction and control of the holding apparatus. For example, an individual pressure supply is sufficient in order to control the fixing of the substrate and the lowering of the carrier element.

According to one embodiment, the holding apparatus has a pressure connection, by means of which the pressure in the cavity can be controlled. This provides the advantage of permitting control of the functions of the carrier element by means of the application of pressure, e.g. via an external pressure supply.

According to one embodiment, the lifting element comprises a clamping element, in particular a compression spring, which is designed to exert a force upon the carrier element in order to raise it.

The lifting element generates a force upon the carrier element, which counteracts the pulling force generated by the negative pressure in the cavity. The lifting element, in particular the clamping element, can be arranged between the main body and the carrier element, in particular in the recess of the main body.

Furthermore, the holding apparatus can comprise a stop, wherein the lifting element is designed to urge the carrier element against the stop. The stop defines e.g. the loading position of the carrier element and prevents the carrier element from sliding out of the recess.

According to one embodiment, the holding apparatus comprises a rotating apparatus for rotating the holding apparatus, in particular the main body and the carrier element. This provides the advantage that a substrate which is held particularly securely by the holding apparatus can be rotated for further processing steps, such as the application of coatings.

According to a second aspect, the invention relates to a manufacturing equipment for microstructure devices, which comprises a holding apparatus as claimed in any one of the preceding claims. This provides the advantage that substrates, to which suction cannot readily be applied, in particular bowed wafers (warped wafers), can be efficiently and securely held and processed in the manufacturing equipment.

The manufacturing equipment can be a coater, a lacquerer, a developer, a spin dryer, a mask aligner, a projection scanner, a laser stepper, a wafer bonder, a photomask system, a cleaning system or an imprint system.

According to a third aspect, the invention relates to a method for holding a substrate in a holding apparatus comprising a main body and a carrier element, wherein the method comprises the following method steps: raising the carrier element to a loading position, wherein the carrier element has a smaller diameter than the substrate, placing the substrate onto a support surface of the carrier element, fixing the substrate on the support surface and lowering the carrier element to a clamping position in which the support surface of the carrier element is arranged substantially flush with an upper side of the main body. This provides the advantage that substrates, to which suction cannot readily be applied, in particular bowed wafers (warped wafers), can be held securely and guided in the vertical movement by reason of the initially small vacuum surface.

The diameter of the carrier element is e.g. less than half, a third or a quarter of the diameter of the substrate and/or the diameter of the main body. In particular, in the case of significantly bowed substrates, it is advantageous for the diameter of the carrier element to be as small as possible in order to generate sufficient vacuum suction in the loading position.

The small diameter in comparison with the wafer size results in a vacuum surface, which is initially smaller and easier to seal, to apply suction to the wafer in the loading position. In particular, in the case of a bowed wafer, the suction is simplified by the smaller vacuum surface. Subsequently, the substrate is pulled against the upper side of the main body where finally it can be firmly clamped over its entire surface in the clamping position.

According to one embodiment, in order to fix the substrate on the support surface a first negative pressure is applied to a cavity of the holding apparatus, and in order to lower the carrier element to the clamping position a second negative pressure is applied to the cavity, wherein the second negative pressure is a lower pressure than the first negative pressure. This provides the advantage that the control of the holding apparatus, in particular the fixing of the substrate and the movement of the carrier element, can be effected by means of a single pressure connection. By virtue of the change in the negative pressure, the substrate can initially be preliminarily fixed, then the carrier element can be adjusted and then the substrate can be finally fixed.

According to one embodiment, the placing of the substrate onto the support surface of the carrier element produces a pressure reduction in the cavity, in particular by means of the sealing of suction openings on the support surface, wherein the lowering of the carrier element to the clamping position is triggered and/or assisted by the pressure reduction. This provides the advantage of permitting particularly simple control of the holding apparatus because in particular a manual change in pressure is no longer required in order to lower the carrier element.

For example, in order to fix the substrate on the support surface the first negative pressure is initially applied to the cavity of the holding apparatus, and then the second negative pressure is applied in the cavity after the substrate is placed onto the carrier element, e.g. by the covering of suction openings on the support surface by the substrate.

According to one embodiment, the carrier element urges the substrate in the clamping position against the upper side of the main body, wherein a force exerted upon the substrate is of such a magnitude that possible bowing of the substrate is reduced. This provides the advantage that the bowed substrates can be smoothed out by the holding apparatus. As a result, further processing of the substrate, e.g. the application of a coating, can be simplified or even permitted. Furthermore, a smoothed-out substrate can be held in a more stable manner, in particular during rotation of the chuck.

The bowed substrate can be a so-called warped wafer. The bow can occur by reason of a smaller thickness of the substrate and/or by reason of internal stresses in the substrate.

According to one embodiment, the substrate is pulled against the upper side of the main body by means of a negative pressure acting between the substrate and the upper side. This provides the advantage that the substrate in the clamping position can be securely and firmly fixed on the upper side.

According to one embodiment, the method further comprises rotating the substrate, in particular after lowering the carrier element. This provides the advantage that the substrate which is held particularly securely in this manner can be rotated for further processing steps.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1shows a schematic view of a holding apparatus100for a substrate101according to one embodiment.

The holding apparatus100comprises a main body103having an upper side105, a carrier element107which is arranged in a recess109of the main body103so as to be vertically movable such that it can be adjusted between a protruding loading position and a retracted clamping position, wherein the carrier element107comprises a support surface111for placement of the substrate101, wherein the support surface111has a smaller diameter than the main body103. Furthermore, the holding apparatus100comprises a lifting element which raises the carrier element107to the loading position.

The carrier element107seals the recess109such that a sealed cavity113is provided between the main body103and the carrier element107, which cavity can have a negative pressure applied thereto which counteracts the effect of the lifting element.

The upper side105of the main body103can correspond to a clamping surface for the substrate101, on which the substrate101is firmly clamped in the clamping position.

The carrier element107can be received in the recess109in such a manner as to be adjustable in the manner of a piston. By applying a negative pressure to the sealed cavity, the carrier element107can be moved from the loading position to the clamping position.

The cavity is the space which remains between the bottom of the recess109and the carrier element101. Therefore, the size of the cavity can be changed with the position of the carrier element101and is dependent thereupon.

In an alternative embodiment, the cavity113can also be formed by further bores or fluid lines in the main body103.

In the embodiment shown, the lifting element is formed by two clamping elements115a,115bin the form of compression springs which are arranged in the recess109of the main body103, and exert a pushing force upon the carrier element.

In the embodiment shown inFIG. 1, a sealing means119is arranged on the surface of the main body. The sealing means119can improve vacuum suction of the substrate101on the support surface111and/or the upper-side surface105of the main body103in the clamping position. In particular, the sealing means119enables a vacuum to be established over a large surface between the substrate101and the holding apparatus100.

The substrate101can be a wafer. The substrate101can be disk-shaped. The substrate101can have a largely round periphery with a diameter of 2, 3, 4, 5, 6, 8, 12 or 18 inches. Furthermore, the substrate101can be largely flat and can have a thickness between 50 and 4000 μm. The substrate101can have a straight edge (flat) and/or can have at least one notch. Furthermore, the substrate101can be angular, in particular square or rectangular.

The substrate101can be formed from a semiconductor material, e.g. silicon (Si) or gallium arsenide (GaAs), a glass, e.g. quartz glass, a synthetic material or a ceramic. The substrate can be formed from a monocrystalline, a polycrystalline or an amorphous material. Furthermore, the substrate101can comprise a multiplicity of associated materials.

The substrate101can comprise electric circuits, e.g. transistors, light-emitting diodes or photodetectors, electric conductive tracks which connect these circuits, or optical devices as well as MEMS or MOEMS structures. Furthermore, the substrate101can have coatings, e.g. structured chromium layers, pre-cross-linked or hardened bond adhesives or separation layers.

Furthermore, the holding apparatus100comprises a seal125which seals against the lateral wall of the recess109in the main body103. The seal125can be an O-ring or a sealing lip.

Furthermore, the carrier element107has spacers117a,117b, e.g. in the form of pins, on its lower side.

The spacers117a,117bcan be used to define a lowering depth of the carrier element107into the recess109and to ensure that the support surface111of the carrier element107in the clamping position is arranged substantially flush with the upper side105of the main body103. Furthermore, the spacers117a,117bcan prevent the carrier element107from being lowered completely into the recess and thus ensure a minimum size of the cavity113.

In the embodiment shown inFIG. 1, the carrier element107also has fixing means123a,123bfor fixing the substrate supported on the support surface. The fixing means123a,123bcan be suction openings. Furthermore, the fixing means123a,123bcan comprise a vacuum bore or vacuum grooves.

The main body103comprises a fluid channel121for applying pressure to the cavity113.

The fluid channel121can be a bore, in particular a central bore, in the main body113which issues in the recess109or the cavity113formed by the recess109.

According to one embodiment, the holding apparatus100has a pressure connection, not shown inFIG. 1, by means of which the pressure in the cavity113can be controlled. The fluid channel121can connect the cavity113fluidically to the pressure connection. When the negative pressure is applied to the cavity113, the cavity consequently also lies against the fixing means123a,123b, whereby said fixing means can apply suction to the substrate101.

Furthermore, the holding apparatus100can comprises a stop, against which the carrier element107is urged in the loading position. Therefore, the stop can be used to define the position of the carrier element107in the loading position. The stop can be used, as it were, to prevent the carrier element107from sliding out of the recess109.

FIG. 2a-FIG. 2dshows schematic views of the holding apparatus100during placement of a substrate101according to a further embodiment.

The carrier element107of the holding apparatus100inFIG. 2a-FIG. 2dcomprises four suction openings201a,201b,201c,201d. The suction openings201a,201b,201c,201dform the fixing means for fixing the substrate101on the support surface111.

The suction openings201a,201b,201c,201dare connected fluidically to the cavity113via a fluid channel203.

The holding apparatus100inFIG. 2a-FIG. 2dcan comprise a rotating apparatus, not shown. In particular, the holding apparatus100is a spinner chuck, in which a vacuum is maintained in a hollow shaft of the motor with respect to the chuck100or with respect to the cavity103in order, on the one hand, to apply suction to the substrate101and, on the other hand, to adjust the position of the carrier element107.

FIG. 2ashows the holding apparatus100in the loading position prior to placement of the substrate101.

The vertically movable carrier element107is raised by the compression springs115a-band is urged against a stop, not shown.

A first negative pressure P1is applied to the cavity113, thus producing a low vacuum in the cavity113. The resulting force is too small in order to compress the compression springs115a-bso that the carrier element107continues to lie against the stop and protrude beyond the upper side105of the main body103.

Moreover, by reason of the fluidic connection of the suction openings201a,201b,201c,201dto the cavity113air can be drawn into the cavity113which, in addition, can prevent an excessively strong vacuum from being produced in the cavity113.

FIG. 2bshows the substrate101being placed onto the support surface111of carrier element107.

Suction is applied to the substrate101through the suction openings201a,201b,201c,201don the support surface111and the substrate is fixed thereon. At the same time, the substrate101covers the suction openings201a,201b,201c,201d.

Covering the suction openings201a,201b,201c,201dprevents e.g. air from the surrounding area entering into the cavity113. This can effect an additional pressure reduction in the cavity113in which a second negative pressure P2is thus present, wherein P2<P1.

In an alternative embodiment, the second negative pressure P2can also be adjusted manually after the substrate101has been placed, e.g. by means of a pressure connection on the chuck100.

FIG. 2cshows the carrier element107being lowered to the clamping position after placement of the substrate101.

The carrier element107is lowered by reason of the pressure reduction in the cavity113. The pulling force exerted upon the carrier element107by the negative pressure P2in the cavity113outweighs the pushing force exerted by the clamping elements115a,115bupon the carrier element107. As a consequence, the clamping elements115a,115bare compressed.

The carrier element107is lowered into the recess109to such an extent that the support surface111is arranged approximately flush with the upper side105of the main body103, and the substrate101lies not only on the support surface111but also on the upper side105. The maximum lowering depth of the carrier element107is determined by the spacers117a,117b.

The support surface111and the upper side105form, in the clamping position, a common clamping surface for the substrate101. In the embodiment shown inFIG. 2a-FIG. 2d, the diameter of the main body103corresponds to the diameter of the substrate so that the substrate is supported with its complete rear side on the upper side105and the support surface111.

Alternatively, the main body103can also have a larger diameter than the substrate or, as shown inFIG. 1, can have a smaller diameter than the substrate101. Therefore, the holding apparatus100can also be used for particularly small or particularly large substrates101.

FIG. 2shows the substrate101being treated after the carrier element107has been lowered.

During the treatment, the substrate101is rotated, e.g. by a rotating apparatus, not shown, which causes the main body103and the carrier element107to rotate.

To this end, the main body103can be mounted in a rotatable manner in a rigid holding element of the holding apparatus100. In particular, the holding apparatus100is designed as a spin chuck.

In addition to the suction openings201a,201b,201c,201dshown inFIG. 2a-FIG. 2d, the main body103can have further fixing means for fixing or clamping the lowered substrate101on the upper side105. The further fixing means can comprise further suction openings.

Furthermore,FIG. 2dshows an application apparatus205, by means of which a fluid can be applied to the rotating substrate. The fluid is e.g. a lacquer, in particular a photoresist, a coating liquid, a cleaning liquid or a solvent.

In an alternative embodiment, the sealing means119shown inFIG. 2a-FIG. 2d, e.g. a sealing lip, can be omitted. In the clamping position, the substrate101then comes directly into contact with the upper side105of the main body103. This provides the advantage that maintenance outlay is reduced because the sealing lips no longer have to be regularly replaced and the sealing lips no longer have to be cleaned. Furthermore, possible floating of the substrate101as it is being deposited on the sealing lips is avoided.

Furthermore, the movable carrier element100can replace lifting pins for transferring the substrate101to an end effector, as used in known chucks. In order to deposit the substrate on the holding apparatus100or in order to then pick it up from the holding apparatus100, the carrier element107can raise the substrate which means that no additional lifting pins are required.

In an alternative embodiment, the main body103comprises further application openings and/or nozzles for fluids which are arranged e.g. on the upper side105of the main body.

By means of these further application openings on the upper side105, a fluid can be applied to a rear side of the substrate101if, as shown inFIG. 2b, the holding apparatus100is located in the loading position and the substrate101is supported on the carrier element107.

The fluid can be applied to a surface on the rear side of the substrate101which is not covered by the carrier element107. This provides the advantage that coating or cleaning or solvent treatment of the substrate rear side is permitted without the substrate101having to be lifted from the holding apparatus100and turned.

FIG. 3shows a manufacturing equipment300for microstructure devices comprising a holding apparatus100according to one embodiment.

The manufacturing equipment300can be a coater, a lacquerer, a developer, a spin dryer, a mask aligner, a projection scanner, a laser stepper, a wafer bonder, a photomask system, a cleaning system or an imprint system.

The holding apparatus100can correspond to the holding apparatus100shown inFIG. 1and/orFIG. 2a-FIG. 2d. The holding apparatus100can be connected to a pressure supply of the manufacturing equipment300.

Furthermore,FIG. 3shows a robot arm301comprising an end effector303, on which a substrate101is supported. By means of this robot arm301, the substrate101can be placed onto the holding apparatus100, wherein the carrier element is raised during placement of the substrate101.

FIG. 4shows a flow diagram of a method400for holding the substrate101in the holding apparatus100according to one embodiment.

The substrate101can be a glass or semiconductor substrate. Furthermore, the substrate101can be a wafer or a mask. The substrate101can correspond to the substrate101shown inFIG. 1,FIG. 2a-FIG. 2dand/orFIG. 3.

The method400can be performed with the holding apparatus100ofFIG. 1and/orFIG. 2a-FIG. 2d, and comprises raising401the carrier element107to the loading position, wherein the carrier element107has a smaller diameter than the substrate100, placing403the substrate101onto the support surface111of the carrier element107, fixing405the substrate101on the support surface111, and lowering407the carrier element107to the clamping position.

In the clamping position, the support surface111of the carrier element107is arranged substantially flush with the upper side105of the main body103.

The substrate101can have a bow or deformation or can be very flexible. The bowed substrate101can be a so-called warped wafer.

The smaller diameter of the carrier element107in comparison with the substrate101ensures that suction can be applied more easily in particular to bowed substrates101than with a large-surface chuck because the size of the vacuum surface underneath the substrate101is smaller.

According to one embodiment, in order to fix405the substrate101on the support surface111a first negative pressure is applied to the cavity113of the holding apparatus100, and in order to lower the carrier element107to the clamping position a second negative pressure is applied to the cavity113, wherein the second negative pressure is a lower pressure than the first negative pressure.

The application of the negative pressure to the cavity113causes a pulling force to be produced which counteracts a pushing force of the lifting element. The lifting element is adjusted in such a manner that the pulling force exerted upon the carrier element107exceeds the pushing force of the lifting element during application of the second negative pressure. As a consequence, the carrier element107is lowered.

The negative pressure can be applied via an external pressure supply to a pressure connection of the holding apparatus.

In an alternative embodiment, in order to fix405the substrate on the support surface111the first negative pressure is applied to the cavity113of the holding apparatus100, and the second negative pressure is applied in the cavity113after the substrate101is placed onto the carrier element107, e.g. by the covering of suction openings201a-don the support surface111by the substrate101.

In the clamping position, the substrate101can be additionally pulled and/or fixed against the upper side105of the main body103by a negative pressure acting between the substrate101and the upper side105.

According to one embodiment, the carrier element107can urge a bowed or deformed substrate101in the clamping position against an upper side105of the main body103such that a force exerted upon the substrate101is so great that the bowing or deformation of the substrate101is reduced.

The substrate can be smoothed out and/or clamped by means of the force exerted in this manner.

Furthermore, the method400can comprise rotating the substrate101, in particular after lowering407the carrier element107to the clamping position.

After lowering the substrate101, the substrate101can be processed or treated, e.g. a coating can be applied to the rotating substrate.

The lowering407of the substrate101can be performed a predetermined time after placing403the substrate101or immediately after placing the substrate101, e.g. depending upon pre-set process parameters.

In a manufacturing equipment300, the mode of operation of the holding apparatus100is controlled e.g. by means of a process module.

When transferring a warped wafer from a substrate handler (robot, axle with end effector, etc.) to the holding apparatus100, the process module signals e.g. to a substrate handler the reception of the substrate on the “Z-chuck” (carrier element107) which has been lifted out, whereupon the holding vacuum is deactivated on the substrate handler. Therefore, a transfer error from the substrate handler to the holding apparatus100can be minimised.

As the carrier element107with the bowed substrate101is being lowered, the substrate is centred and guided. Lateral slippage or floating is no longer possible. A sealing lip119in the outer region of the holding apparatus100, e.g. on the upper side105of the main body105, can come into contact with the substrate101during the lowering procedure so that a large-surface vacuum is established underneath the substrate and the substrate101is pulled two-dimensionally in a planar manner.