DE102016121375A1 - Device and method for holding a mask in a flat position - Google Patents

Abstract

The invention relates to a device for coating at least one substrate by feeding a starting material into a process space (2), comprising a substrate holder (5) for receiving the at least one substrate (6) and a mask (7) which is supported by a mask transport system (8). can be brought to the surface of the substrate (6) before coating and can be removed from the surface of the substrate (6) after coating, wherein the mask (7) is at least partially magnetically or magnetically activatable. In order to prevent particles from detaching from the mask during the substrate or mask change, magnetically active mask stabilization means (19, 20, 21, 22, 23) are provided for removing the mask (7) after it has been removed from the surface of the substrate (6) in a predetermined surface extension position, in particular to stabilize a flat, wherein the magnets (19) on a shield element (17) are arranged, which between the mask (7) and a gas inlet member (9) can be brought.

Description

Field of engineering

The invention relates to a method and a device for coating at least one substrate by feeding a starting material into a process space, comprising a substrate holder for receiving the at least one substrate and a mask, which is moved from a mask transport system into a contacting contact with the surface of the substrate can be brought and removed after the coating of the surface of the substrate, wherein the mask is at least partially magnetically or magnetically activated.

State of the art

A device for coating in particular substrates made of glass with an organic starting material is described in US Pat DE 10 2010 000 447 A1 described. A shield element can be brought between a gas inlet element, from which organic starting materials brought into the gaseous form are brought into a process space by means of a carrier gas, and a cooled substrate holder on which the substrate rests. With the screen element, the substrate and / or a mask can be brought into the process space. The mask is placed on the substrate lying flat on the substrate holder. The mask has framed windows so that deposition of the starting material can take place only in the areas left free by the windows on the surface of the substrate. The deposition is essentially due to a condensation of the gaseous starting materials on the surface of the substrate to a solid. On the window framing bars also takes place a coating. Upon release of the mask from the substrate, the mask is merely caught at its edge by a mask transporting means, and displaced in a vertical direction. Due to the force of gravity acting on the mask, the surface portion of the mask lying between the edges bulges downward. This deformation of the mask has the consequence that the deposited on the webs of the mask coating peels off. Particles form which fall down by gravity or which are transported to places where they interfere due to gas flow within the process space.

From the US 2016/0248049 A1 It is known to use magnets to fix a mask.

In addition, in the literature regulated magnetic fields are described with which a magnetic or magnetically activatable object is held in suspension, for example in IEEE Transactions on Semiconductor Manufacturing, Vol. 3, NO. August 3, 1990 "Applications of Magnetic Levitation-Based Micro-Automation in Semiconductor Manufacturing" ,

Summary of the invention

The object of the invention is to advantageously improve a generic device or a generic method, in particular to provide measures which prevent particles from detaching from the mask after the mask has been detached from the substrate.

The object is achieved by the invention specified in the claims. The dependent claims represent not only advantageous developments, but also independent solutions to the problem.

A device for depositing a layer by means of a process gas introduced through one or more gas outlet openings of a gas inlet element into a process chamber arranged between the gas outlet openings and a substrate holder opposite the gas outlet openings, has a substrate for positioning a mask on a substrate resting against a contact surface of the substrate facing the gas outlet openings the substrate or for removing the mask from the substrate, wherein the mask rests on the directed to the gas outlet openings plan broad side of the substrate during the deposition of the layer. The mask has magnetic zones or magnetically activated zones. The mask may interact with an external magnetic field such that it may be attracted by a magnetic field generating magnet or, if the mask itself is magnetic, may be repelled. What is essential is a mask stabilizer which includes mask stabilization means for stabilizing the mask after removal from the surface of the substrate in a given areal extent. The predetermined areal extent corresponds to the areal extent that the mask occupies when it rests on the substrate. If the substrate is a flat, plane object, for example a glass plate, then the surface extension layer is a flat layer. It is provided that the mask removed from the substrate is held in the predetermined surface extension position by means of a magnetic force generated by a control device by means of a control device. The magnetic forces interact with the magnetic or magnetizable zones of the mask. The invention further relates to a method in which the mask removed from the substrate, by means of a controlled magnetic force cooperating with magnetic or magnetizable zones of the mask, removes the mask removed from the substrate a flatness is maintained. The magnetization device may comprise electromagnets or permanent magnets. To control magnetic field strength sensors and / or distance sensors may be provided. In particular, it is provided to use Hall sensors, distance sensors, capacitive or inductive proximity switches to control the magnetic force. The mask stabilizing means may be placed between the gas outlets of a gas inlet member and the substrate holder. It is provided, in particular, to associate the mask stabilizing means with a screen plate of a screen element which is moved from a storage chamber into the process space in order to prevent heat transfer between substrate holder and gas inlet element in a screen position. In particular, it is provided that the mask holding device engage only at the edge of the preferably rectangular mask. However, the mask stabilization means can also be arranged in the substrate holder. It is thus provided that mask stabilizing means in the form of magnets, in particular permanent magnets and / or electromagnets and sensors for determining the magnetic field strength or a vertical position of the mask are assigned to the substrate holder and / or can be brought from outside into the process space. With the sensor elements, the vertical position of the mask with respect to the position of the sensor or the position of the substrate holder and / or the shield plate is determined in particular at locations which are spaced from the edge of the mask. The magnetic fields preferably engage in a surface center portion of the mask, that is, in a surface area of the mask, which is spaced from the edge of the mask to keep this area center portion in a sense in limbo. This prevents the surface extension position of the mask from being changed by gravity-induced deformation when the mask, which is only gripped at the edge, is removed from the substrate in a vertical direction. By means of a control device, the magnetic fields generated by electromagnets are controlled such that the mask is held in suspension or that the distance measured by the sensors occupies a desired value. A plurality of sensors distributed over the entire areal extent of the mask are preferably provided, wherein the sensors are assigned to the substrate holder and / or the screen element. The electromagnets, which are controlled by the control device according to the specifications of the sensors, are associated with the substrate holder and / or the shielding element. The control device is capable of holding the mask in a predetermined vertical position at each of the plurality of measuring points on each of which a sensor is arranged. It is also envisaged to use only one sensor and to position it approximately in the middle of the mask surface or to arrange a plurality of sensors only in the surface center section of the mask. The invention relates both to coating devices in which the substrate holder is arranged in the vertical direction above the gas inlet member as well as those devices in which the substrate holder is arranged in the vertical direction below the gas inlet member. The gas inlet member preferably extends over the entire surface of the mask and has a plurality of arranged in a gas outlet surface gas outlet openings, which are arranged like a shower head and is brought by a vaporous starting material by means of a carrier gas in the process chamber. The mask is preferably made of INVAR, a material which in a variant of the invention has no permanent magnetic properties, but is attracted in a magnetic field generated by a magnet in the direction of the magnet. When using such a mask, both above and below the mask arranged magnets are used, each exerting an attractive force on the mask. By means of the control device, the magnetic fields generated by the opposing magnets are controlled in such a way that the mask is held in suspension, that is, the magnetically oppositely acting forces on the mask compensate for the force acting on the mask gravity. Preferably, there are pairs of magnets facing one another, one magnet being associated with the screen element and the other magnet with the substrate holder. The pair of magnets may be spatially associated with a magnetic field sensor or a distance sensor, respectively. But it is also envisaged that a sensor is arranged between a pair of magnets and a plurality of magnets are associated control technology a sensor.

The method according to the invention is exerted when a coating process in which, in particular, an OLED layer has been applied to a substrate is completed. In carrying out the coating process, solid or liquid particles are fed into a carrier gas. The aerosol thus formed is supplied to an evaporator by means of an aerosol transport line. The evaporator has surfaces heated to an evaporation temperature, which heat the carrier gas and the aerosol particles in such a way that the aerosol particles evaporate. The steam thus generated is fed through the gas inlet member into the process space. This is done by a heated gas inlet member. The organic vapor condenses on the substrate which rests on a cooled substrate holder. In this case, the substrate may abut against the downwardly facing substrate abutment surface of a substrate holder or on an upwardly facing abutment surface of a substrate holder. After completion of the coating process, the mask is raised or lowered by means of mask transport means or a mask holder. When loosening the Mask from the substrate attack the mask transport means or the mask holder only at the edge of the mask. The mask made of magnetizable material is pressed against the surface of the substrate during the coating process with magnetic force, wherein the magnets are arranged within the substrate holder and in particular can generate a regulated magnetic field. Before removing the mask from the substrate in the vertical direction, a slider is moved into the process space. This slide is preferably a screen element which is intended to interrupt heat radiation from the heated gas inlet element to the substrate holder. This slider may also have magnets that build a magnetic field together with the magnet of the substrate holder. The magnetic field is regulated in such a way that its surface extension position does not change during the vertical displacement of the mask. If, for example, the mask lies in a flat position on the substrate, the magnets hold the mask in a vertical position during its vertical displacement, without the mask bending. In a variant of the invention, either only the substrate holder or only the slider, which may be a screen element, have the magnet for the controlled position stabilization of the mask.

list of figures

• 1 Im Querschnitt ein erstes Ausführungsbeispiel einer Beschichtungsvorrichtung, bei der ein Gaseinlassorgan oberhalb eines Substrathalters angeordnet ist und der Substrathalter und ein Schirmelement 17 insbesondere paarweise sich gegenüberliegende Magnete aufweisen, zwischen welchen Magneten eine Maske in der Schwebe gehalten wird,
• 2 eine Darstellung gemäß 1, jedoch mit einer Magnetanordnung lediglich im Schirmelement,
• 3 eine Darstellung ähnlich gemäß 1 eines dritten Ausführungsbeispiels, bei dem das Gaseinlassorgan unterhalb eines Substrathalters angeordnet sind, wobei insbesondere paarweise angeordnete Magnete dem Substrathalter und dem Schirmelement zugeordnet sind und die Maske durch die von Magneten erzeugte Magnetkraft in einer Schwebe gehalten wird,
• 4 eine Darstellung gemäß 3 eines vierten Ausführungsbeispiels, bei dem die die Maske in einer Schwebe haltenden Magnete nur im Substrathalter angeordnet sind,
• 5 vergrößert und schematisch eine zwischen einem Substrathalter und einem Schirmelement angeordnet Maske, die mit von einer Regeleinrichtung geregelten Magneten erzeugten Magnetfeldern in einer Schwebe gehalten wird, in der sich Abstände zwischen Maske und Substrathalter bzw. Maske und Schirmelement zeitlich konstant gehalten werden,
• 6 schematisch den zeitlichen Verlauf der in 5 mit magnetischen Feldstärken, um eine Maske ohne Veränderung ihrer Flächenerstreckungslage von einer Anlagestellung am Substrat 6 in einer Entferntlage zum Substrat vertikal zu verlagen.

Embodiments of the invention are explained below with reference to accompanying drawings. Show it:

• 1 In cross-section, a first embodiment of a coating apparatus in which a gas inlet member is disposed above a substrate holder and the substrate holder and a screen member 17 in particular in pairs opposite magnets, between which magnet a mask is held in suspension,
• 2 a representation according to 1 but with a magnet arrangement only in the screen element,
• 3 a representation similar to 1 a third embodiment, wherein the gas inlet member are arranged below a substrate holder, wherein in particular paired magnets are associated with the substrate holder and the screen member and the mask is held by the magnetic force generated by magnets in a hover,
• 4 a representation according to 3 a fourth embodiment, in which the magnets holding the mask in a levitation are arranged only in the substrate holder,
• 5 enlarges and schematically holds a mask arranged between a substrate holder and a screen element, which is held in levitation with magnetic fields generated by a controller controlled by magnets, in which distances between mask and substrate holder or mask and screen element are kept constant over time,
• 6 schematically the time course of in 5 with magnetic field strengths to vertically displace a mask without changing its areal extent from an abutment position on the substrate 6 in a removed position to the substrate.

Description of the embodiments

The in the 1 . 2 . 3 . 4 and 5 devices shown have a reactor housing 1 which is a process room 2 gas-tight capsules to the outside. At an opening 4 , which is lockable, adjoins a storage room 3 to the cavity of the reactor housing 1 in which the process room 2 located.

Inside the reactor housing 1 there is a substrate holder 5 which is coolable to a condensation temperature. The substrate holder 5 has a substrate abutment surface on which a substrate 6 in contact with surface area. The substrate 6 may be due to electrostatic forces on the substrate contact surface of the substrate holder 5 being held.

A mask holder 8th which is part of a mask transport means is capable of forming a mask 7 from an investment position in which the mask touching on the process room 2 pointing side of the substrate 6 abuts in the vertical direction to move in a distance position. The mask holder engages 8th only on the edge 7 ' the mask 7 at.

The storage room 3 stores a magnetic carrier, which in the embodiments of a screen element 17 is trained. The screen element 17 has a shield plate, which has a heat-insulating effect and by means of a guide 18 or by means of displacement of the storage chamber 3 in the process room 2 mobile is where the screen element 17 in a screen position the substrate holder 5 thermally from a gas inlet member 9 separates which at one to the process space 2 pointing gas outlet surface gas outlet openings 10 through which a process gas enters the process space 2 can flow in. The process gas contains a vaporous organic starting material, which is heated by heating the gas inlet member 9 is held in the vapor form and which in a coating step in the areas of windows between webs of the mask 7 on the substrate 6 condensed.

To generate the organic vapor, a carrier gas, which is hydrogen, Nitrogen or a noble gas can act in a carrier gas line 5 fed. The carrier gas line 5 flows into an aerosol generator 13 where by means of a dosing solid or liquid particles in a reservoir 14 be stored, are fed into the carrier gas stream, so that an aerosol is formed, which by means of an aerosol line 16 an evaporator 12 having heated walls that heat the carrier gas and the aerosol particles such that the aerosol particles evaporate to be vaporized by a gas supply line 11 in the gas inlet process 9 to be brought.

In the in the 1 illustrated embodiment are in the substrate holder 5 one or more magnets 20 , which are electromagnets provided. At several points in particular evenly distributed over the substrate contact surface distance sensors 22 arranged, with which the distance of the mask 7 to the substrate holder 5 is determinable.

The screen element 17 also has one or more magnets 19 , which are electromagnets and distance sensors 21 to the distance between screen element 17 and mask 7 to determine.

It is especially envisaged that the one or more magnets 19 of the screen element 17 and the one or more magnets 20 of the substrate holder 5 in pairs opposite each other and to each magnet pair 19 . 20 at least one magnetic sensor 21 heard, so that each two magnets 19 . 20 together with the distance sensor 21 . 22 form a control loop. One of the two magnets 19 . 20 can also be a permanent magnet.

With one in the 5 illustrated control device 23 be the magnetic fields B1, those of the magnets 20 be generated and the magnetic fields B2, by the magnets 19 be generated in such a way that the distances a between substrate holder 5 and mask 7 by means of the distance sensors 22 and / or the distances b the mask 7 from the screen element 17 that with the distance sensors 21 be determined to have a predetermined value.

To the mask from the substrate holder 5 to remove, the setpoint of the distance a increased over time until the mask 7 has reached a predetermined end distance. Alternatively, the setpoint of the distance b be reduced in time until the mask 7 has reached the predetermined final distance.

The mask 7 can consist of INVAR or another material that is not itself magnetic but can be polarized in a magnetic field, that is magnetically attracted or repelled by a magnet. The one from the magnets 19 . 20 generated magnetic fields B ₁ . B ₂ thus each have an attractive, if necessary, a repulsive effect on the mask 7 , An upward of the magnetic field B ₁ generated force and a downward, from the magnetic field B ₂ The force generated is balanced so that it covers the mask 7 compensate for applied gravity, thus the mask 7 to hold in the balance.

In the embodiments, the magnets 19 . 20 preferably uniformly over the substantially rectangular contact surface of the substrate holder 5 or the rectangular extension surface of the screen element 17 arranged distributed. Between individual magnets 19 . 20 can the distance sensors 21 . 22 be provided. The number of distance sensors 21 . 22 is preferably less than the number of magnets 19 . 20 so that one becomes a distance sensor 21 . 22 having a variety of magnets 19 . 20 each of the substrate holder 5 or the screen element 17 belong.

In the embodiments, the magnetic carrier 17 formed by a screen element. But it is also possible to form the magnetic carrier otherwise.

In the in the 2 and 4 illustrated embodiment has either only the substrate holder 5 one or more magnets 20 and one or more distance sensors 22 or only the screen element 17 one or more magnets 19 and one or more distance sensors 21 , These are electromagnets 19 . 20 , whose magnetic force can be controlled so that their on the mask 7 exerted attraction on the mask 7 acting gravity compensated.

The controller is arranged to be capable of forming the mask extending in a flat position 7 without changing their flatness by changing the magnetic fields B ₁ . B ₂ shift vertically. The mask 7 is only at the edge 7 ' from the mask holder 8th under attack. In order to avoid that the mask sags downward in its area center section, the controlled magnetic fields B ₁ . B ₂ preferably only in that of the edge 7 ' the mask 7 surrounded area center portion of the mask 7 a power on the mask 7 exercise. The magnetic fields are controlled in such a way that the surface extension position, in particular the flatness of the mask, does not change during its vertical displacement.

The 6 shows the temporal course of the magnetic field strengths B ₁ . B ₂ that from the magnets 19 . 20 be generated to the vertical position x the mask 7 to change.

The above explanations serve to explain the inventions as a whole, which further develop the state of the art independently, at least by the following feature combinations, namely:

A device characterized by magnetically acting mask stabilizing means 19 . 20 . 21 . 22 . 23 to the mask 7 after their removal from the surface of the substrate 6 to stabilize in a given areal extent, in particular a flatness;

A device characterized in that the mask stabilizing means comprises one or more magnets 19 . 20 , in particular permanent and / or electromagnets, which are the substrate holder 5 are assigned or from outside into the process space 2 can be brought;

A device characterized in that the magnets 19 on a screen element 17 are arranged, which between the mask 7 and a gas inlet member 9 can be brought;

A device characterized by a control device 23 , with that of electromagnets 19 . 20 the mask stabilizer generated magnetic fields B ₁ . B ₂ are controllable such that at least one surface center portion of the below or above with respect to a predetermined by gravity direction of the magnets 19 . 20 lying mask 7 is held in suspense;

A device, characterized in that the mask stabilization means comprise at least one distance sensor 21 . 22 have for determining a distance a . b between the distance sensor 21 . 22 and the mask 7 and / or between the substrate holder 5 and the mask 7 ;

A device characterized in that the mask 7 in a direction given by gravity either above or below the substrate holder 5 is arranged;

A device characterized in that the screen element 17 along a guide 18 and / or by displacement means from the storage chamber 3 out and into the process room 2 can be shifted in and out again;

A device characterized in that the mask 7 consists of INVAR;

A device characterized in that the mask 2 only at its edge by a mask holder associated with the mask transport system 8th is held and the mask stabilizer only at edge-removed portions of the mask 7 is mature;

A method characterized in that when removing the mask 7 from the substrate 6 the mask 7 is stabilized by means of magnetic force in a predetermined surface extension position.

All disclosed features are essential to the invention (individually, but also in combination with one another). The disclosure of the associated / attached priority documents (copy of the prior application) is hereby also incorporated in full in the disclosure of the application, also for the purpose of including features of these documents in claims of the present application. The subclaims characterize with their features independent inventive developments of the prior art, in particular to make on the basis of these claims divisional applications.

LIST OF REFERENCE NUMBERS

1

reactor housing

2

process space

3

Verwahrkammer

4

opening

5

substrate holder

6

substratum

7

mask

7 '

edge

8th

mask holder

9

Gas inlet element

10

Gas outlet

11

gas supply

12

Evaporator

13

aerosol generator

14

reservoir

15

Carrier gas supply line

16

aerosol line

17

screen element

18

guide

19

magnet

20

magnet

21

distance sensor

22

distance sensor

23

control device

B ₁

magnetic field

B ₂

magnetic field

a

distance

b

distance

x

vertical location

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102010000447 A1 [0002]
• US 2016/0248049 A1 [0003]

Cited non-patent literature

• Transactions on Semiconductor Manufacturing, Vol. 3, NO. August 3, 1990 "Applications of Magnetic Levitation-Based Micro-Automation in Semiconductor Manufacturing" [0004]

Claims (11)

Apparatus for coating at least one substrate by feeding a starting material into a process space (2), comprising a substrate holder (5) for receiving the at least one substrate (6) and a mask (7) from a mask transport system (8) prior to coating the surface of the substrate (6) can be brought and removed after the coating from the surface of the substrate (6), wherein the mask (7) is at least partially magnetically or magnetically activated, characterized by magnetically acting mask stabilizing means (19, 20, 21 , 22, 23) in order to stabilize the mask (7) after its removal from the surface of the substrate (6) in a predetermined areal extent, in particular a flatness. Device after Claim 1 , characterized in that the mask stabilization means one or more magnets (19, 20), in particular permanent and / or electromagnets which are associated with the substrate holder (5) or from outside in the process space (2) can be brought. Device according to one of the preceding claims, characterized in that the magnets (19) are arranged on a screen element (17) which can be brought between the mask (7) and a gas inlet member (9). Device according to one of the preceding claims, characterized by a control device (23) with which the magnetic fields (B ₁ , B ₂ ) generated by electromagnets (19, 20) of the mask stabilizing means are controllable such that at least one surface center section of the below or above relative to a predetermined by the gravity direction of the magnets (19,20) lying mask (7) is held in suspension. Device according to one of the preceding claims, characterized in that the mask stabilization means comprise at least one distance sensor (21, 22) for determining a distance (a, b) between the distance sensor (21, 22) and the mask (7) and / or between the substrate holder (5) and the mask (7). Device according to one of the preceding claims, characterized in that the mask (7) is arranged in a direction predetermined by gravity either above or below the substrate holder (5). Device according to one of the preceding claims, characterized in that the screen element (17) along a guide (18) and / or displacement means by means of displacement from the storage chamber (3) and into the process space (2) and back again. Device according to one of the preceding claims, characterized in that the mask (7) consists of INVAR. Device according to one of the preceding claims, characterized in that the mask (2) is held only at its edge by a mask holder (8) associated with the mask transport system, and the mask stabilizer only ripens at portions of the mask (7) remote from the edge. Method for coating a substrate using a device according to one or more of the preceding claims, characterized in that, when the mask (7) is removed from the substrate (6), the mask (7) is stabilized by means of magnetic force in a predetermined surface extension position. Apparatus or method characterized by one or more of the characterizing features of any one of the preceding claims.

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