(19)
(11)EP 1 757 978 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
10.12.2014 Bulletin 2014/50

(21)Application number: 06254461.4

(22)Date of filing:  25.08.2006
(51)Int. Cl.: 
G03F 1/36  (2012.01)
H01L 27/32  (2006.01)
H01L 51/00  (2006.01)

(54)

Apparatus for laser induced thermal imaging (LITI) and LITI method using the same, as well as fabrication method of a corresponding LITI mask

Apparat für laserinduzierte thermische Bildgebung (LITI) und LITI-Verfahren unter seiner Verwendung, sowie Herstellungsmethode einer Maske für das LITI Verfahren

Appareil pour imagerie thermique par laser (LITI) et procédé LITI l'utilisant, et procédé de fabrication d'un masque utilisé par le procédé LITI


(84)Designated Contracting States:
DE FR GB

(30)Priority: 25.08.2005 KR 20050078466

(43)Date of publication of application:
28.02.2007 Bulletin 2007/09

(73)Proprietor: Samsung Display Co., Ltd.
Gyeonggi-Do (KR)

(72)Inventors:
  • Kang, Tae-Min c/o Legal & IP Team Corp. Planning Staff
    Yongin-si, Gyeonggi-do (KR)
  • Lee, Jae-Ho Samsung SDI Co., Ltd.
    Gyeonggi-do (KR)
  • Lee, Seong-Taek Samsung SDI Co., Ltd.
    Gyeonggi-do (KR)

(74)Representative: Mounteney, Simon James 
Marks & Clerk LLP 90 Long Acre
London WC2E 9RA
London WC2E 9RA (GB)


(56)References cited: : 
EP-A- 0 432 608
EP-B- 1 015 938
US-A1- 2004 133 872
EP-A- 1 441 572
US-A- 4 347 300
US-A1- 2005 024 706
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    BACKGROUND OF THE INVENTION


    1. Field of the Invention



    [0001] The present invention relates to an apparatus comprising a mask for laser induced thermal imaging (LITI) and a LITI method using the same, and more particularly, to an apparatus comprising a mask for LITI and a LITI method using the same, in which an output of an optical unit is uniform.

    2. Description of the Related Art



    [0002] Among flat panel displays, an organic light emitting display device has a relatively fast response time of 1 ms or less, and consumes relatively low power. Further, the organic light emitting display device emits light by itself, so that it can have a wide viewing angle regardless of its size. Thus, the organic light emitting display device has advantages as a display medium of moving images, such as videos. Further, the organic light emitting display device can be manufactured at low temperatures and by a simple process based on existing semiconductor process technology. Accordingly, the organic light emitting display device has attracted much attention as a next-generation flat panel display device.

    [0003] An organic light emitting device used in the organic light emitting display device may be classified into a polymer device using a wet process and a small molecular device using a deposition process depending on utilized materials and processes. One method for patterning a polymer or small molecular emission layer is an inkjet-printing method that has limitations in the type of usable materials to form organic layers other than the emission layer and requires a complicated structure on a substrate for the ink. Another method for patterning is a deposition method where the emission layer is patterned by the deposition process, which requires use of a metal mask, which makes it difficult to manufacture a large-sized device.

    [0004] Accordingly, laser induced thermal imaging (LITI) has recently been developed as an alternative to the above-described patterning methods.

    [0005] The LITI transforms a beam of light output from a light source, such as a laser, into heat energy, and transfers a pattern-forming material to a target substrate using the heat energy to form a pattern. The LITI requires a donor substrate having a transfer layer, a light source, and a target substrate. In the LITI, the donor substrate and the target substrate are fixed on a stage while the donor substrate entirely covers the target substrate (i.e., a receptor substrate). Then, the LITI is applied to the donor substrate, thereby completing the patterning.

    [0006] When the patterning is performed by a projection method using a mask, the mask has a predetermined pattern such as a rectangular pattern.

    [0007] FIG. 1A is a graph showing pattern characteristics according to positions of a substrate with respect to a mask, FIG. 1B is a graph showing a power density of a laser beam relative to positions on a substrate, and FIG. 2 is a plan view of a patterned substrate of FIGS. 1A and 1B.

    [0008] Referring to FIG. 1A, a position (x, y) of an image patterned on the substrate should be in a predetermined proportion to a position (v, y) of a mask (the dotted-line). That is, the patterns of the substrate should correspond to the pattern position (v, y) of the mask in a 1:1 ratio. Accordingly, the patterns on the substrate should be formed at regular intervals and have uniform shapes. However, the actual patterned image (the solid-line) may be distorted by a projection lens.

    [0009] Referring to FIG. 2, comparing a center axis 5 of the mask patterns(not shown) in a mask 3 with a pattern 7 on a substrate 1, the image of the pattern 7 on the substrate 1 becomes increasingly distorted in the pattern 7 located towards the edges of the mask 3. That is, the pattern 7 on the substrate 1 located near the edges has a center axis that is more distant from the center axis 5 of the mask patterns, and this effect becomes more pronounced as one moves from the center towards the edges of the mask 3. Thus, an emission region 9 near the edge of the substrate 1 may not be completely patterned even when one mask is utilized.

    [0010] Referring to FIG. 1B, the power density of the laser beam should be constant the dotted-line) with regard to the position (x, y) of the pattern. However, the power density of the laser beam may not be uniform (the solid-line) because of the laser beam's uneven distribution and non-uniformity due to a deformation of the laser's projection lens. That is, patterns near the edge of the mask are scanned with less laser energy than patterns near the center. Therefore, the area of the substrate 1 corresponding to the edge patterns of the mask 3 may not be completely transferred, and those patterns 7 are likely to be broken and unclear, thereby distorting an image.

    [0011] As described above, the distortion of the image causes a problem in forming a uniform pattern, thereby deteriorating the quality of products, decreasing yield and increasing production cost.

    [0012] EP 10515938 discloses a process for placement of spaces onto a receptor which provide uniform spacing and structural support in flat panel displays.

    [0013] EP 1441572 discloses a precision deposition mask that is aligned with a glass substrate in evaporating an emitting layer of an organic EL display.

    [0014] US 2005/0024706 discloses a light valuve for use in an imaging head for imaging a regular pattern in a pre-determined oritentation.

    SUMMARY OF THE INVENTION



    [0015] In view of the above, the present invention sets out to provide a mask capable of preventing distortion of a patterned image;

    a LITI method using such a mask; and

    a method of fabricating an organic light emitting display device using such a LITI method.



    [0016] According to a first aspect of the present invention, an apparatus is provided according to claim 1.

    [0017] Further, optional features of this aspect of the invention are set out in Claims 2 to 7.

    [0018] A further aspect of the invention provides an LITI method according to claim 8. Further, optional features of this aspect of the invention are set out in Claims 9 to 14.

    [0019] Another aspect of the invention provides a a method of forming a mask according to claim 15. Further optional features of this aspect of the invention are set out in Claims 16 and 17.

    [0020] In one embodiment, each pattern has a width b, a laser beam power density h(x, y), a beam scanning direction y, a direction perpendicular to the beam scanning direction x; and a center of the second pattern in a center region (0, 0) and its length d, then the first pattern having centered at x=a in the mask has a length p satisfying the following equation.



    [0021] The length d may be shorter than length p.

    [0022] The mask may comprise a plurality of patterns each having a center axis, wherein spacing between adjacent center axes of adjacent patterns becomes narrower in the adjacent patterns located towards the edges of the mask.

    [0023] Gaps between adjacent edges of the patterns may become narrower in the adjacent patterns that are located towards the edges of the mask.

    [0024] When the mask is used with substrate patterns having center axes corresponding to the center axes of the patterns, misalignment between center axes of substrate patterns and the corresponding center axes of the patterns of the mask may be reduced in the substrate patterns and the patterns of the mask that are located towards the edges of a substrate or the mask.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0025] Embodiments of the invention will be described by way of example and with reference to the accompanying drawings, in which:-

    FIG. 1A is a graph showing pattern characteristics according to positions of a substrate with respect to a mask;

    FIG. 1B is a graph showing a power density of a laser beam relative to positions on a substrate;

    FIG. 2 is a plan view of a patterned substrate of FIGS. 1A and 1B;

    FIG. 3 is a perspective view of a LITI apparatus according to an embodiment of the present invention;

    FIG. 4 is a side view showing a mask and an optical unit of the LITI apparatus according to an embodiment of the present invention;

    FIGS. 5A and 5B are a diagram and coordinates illustrating a method of fabricating the mask of the LITI apparatus according to an embodiment of the present invention, respectively;

    FIGS. 6A and 6B are perspective views illustrating a LITI method according to an embodiment of the present invention;

    FIG. 6C is a plan view of a patterned substrate according to an embodiment of the present invention; and

    FIG. 7 is a cross-sectional view of an organic light emitting display device fabricated according to an embodiment of the present invention.


    DETAILED DESCRIPTION OF THE EMBODIMENTS



    [0026] FIG. 3 is a perspective view of a Laser Induced Thermal Imaging (LITI) apparatus according to an embodiment of the present invention.
    Referring to FIG. 3, the LITI apparatus includes an optical unit 10 and a stage 30. The stage 30 is placed under the optical unit 10. The stage 30 also includes a base 33 and a transport plate 35. A chuck 37 is provided on the transport plate 35. The chuck 37 is movable in the Y-axis direction so that a substrate 20 is more efficiently and accurately positioned during LITI.

    [0027] As shown in FIG. 3, the substrate 20 is placed on the chuck 37 and a donor substrate 25 is placed on the substrate 20. The donor substrate 25 is provided with a transfer layer (not shown) which can be used as an emission layer of an organic light emitting display device.

    [0028] The optical unit 10 is supported by a supporter 15, and the optical unit 10 is movable along the supporter 15 in the X-axis direction. The optical unit 10 includes a laser and a projection lens (shown in FIG. 4 as numerals 5 and 8, respectively).

    [0029] Further, a mask 40 is disposed between the projection lens 8 and the laser 5. The mask 40 may have predetermined patterns 43 arranged in one or more rows.

    [0030] FIG. 4 is a side view showing a mask and an optical unit of the LITI apparatus of FIG. 3. Referring to FIGS. 3 and 4, the optical unit 10 includes a laser 5 and a projection lens 8. A beam 5a of a laser 5 is emitted from the laser 5 towards the mask 40, and the beam 5a of the laser 5 that passes through the mask 40 arrives on the substrate 20 placed on the stage 30 via the projection lens 8. Specifically, the laser 5 emits the laser beam 5a. That is, the laser 5 is placed above the mask 40 and emits the laser beam 5a in a direction perpendicular to the mask 40. The laser beam 5a penetrates the projection lens 8 and the mask 40, so that the laser beam 5a is patterned.

    [0031] The mask 40 is formed with patterns 43 arranged in a direction perpendicular to a beam scanning direction (for example, the X-axis direction in FIG. 3), and the sizes and shapes of the patterns 43 vary depending on their position on the mask 40. For example, the patterns 43 positioned away from the center and towards the edges of the mask 40 have gradually increasing lengths. That is, a length t1 of the pattern 43 located near the center of the mask 40 is different from a length t2 of the pattern 43 near the edge of the mask 40, and the length t2 is longer than the length t1. Therefore, the patterns 43 are configured such that when the mask 40 is installed in a LITI apparatus they are arranged along a row that extends substantially in a direction perpendicular to the beam scanning direction. In addition, the patterns 43 are arranged so that the length of the patterns (as measured in the scanning direction) increases with distance from the centre of the row.

    [0032] Accordingly, even though a beam profile is deformed during a scanning process and the energy of the laser beam 5a becomes reduced in the patterns 43 that are located towards the edges of the mask 40, the reduced energy can be compensated by the enlarged mask patterns on those patterns 43 located near the edge of the mask 40. Thus, the LITI can be applied completely and uniformly to all the areas of the substrate 20 corresponding even to the edge patterns 43 of the mask 40.

    [0033] Further, spacing between adjacent center axes of the adjacent patterns 43, i.e., between axes that pass through the center of each of the pattern 43 and which are parallel to a lengthwise direction in each of the pattern 43 (shown as vertical dotted lines in FIG. 4) become narrower in the adjacent patterns 43 located towards the edges. Accordingly, the gaps between adjacent edges of the patterns 43 also become narrower in those that are located towards the edges of the mask 40. In other words, a gap a2 between edges of the patterns 43 near the edge is smaller than a gap a1 between the patterns 43 near the center of the mask 40.

    [0034] Accordingly, a misalignment between the center axes of the patterns 23 on the substrate 20 and the corresponding center axes of the mask patterns 43 is reduced in those patterns 23 and 43 located towards the edges of the substrate 20 or the mask 40 due to the projection lens, so that the entire area of the substrate 20 are scanned and have patterns at proper regular intervals.

    [0035] Thus, energy is applied uniformly to the substrate 20, and the patterns 23 are formed on the substrate 20 at regular intervals. Accordingly, the LITI apparatus with the mask 40 can improve pattern characteristics without an additional apparatus.

    [0036] FIG. 5A is a diagram illustrating a method of fabricating a mask of a LITI apparatus according to an aspect of the present invention in terms of a flowchart for forming the patterns 43, and FIG. 5B shows coordinates of patterns on a mask of the LITI apparatus according to an embodiment of the present invention.

    [0037] Referring to FIGS. 5A and 5B, image deformation caused by the projection lens 8 is measured in operation (i). On the assumption that the mask 40 has coordinates (x, y) and an image to be formed on the substrate has coordinates (u, v), image deformation caused by the projection lens 8 can be expressed as functions of the mask coordinates as follows.
    u=f(x, y), v=g(x, y)

    [0038] Here, since the center (x=0, y=0) of the patterns in a center region of the mask should be coincident with the center (u=0, v=0) of the patterns in a center region of an image, the following conditions are obtained. 0=f(0,0), 0=g(0,0).

    [0039] Then, the power distribution of the laser beam 5a is measured in operation (ii). Here, the power distribution of the laser beam 5a can be represented as a ratio of the distribution of the laser beam 5a to a median value of the power density distribution due to deformation of the optical unit. Accordingly, the power distribution can be represented as a power density function e=h(x, y). In this case, assuming that the power density at the center (x=0, y=0) of the patterns located in the middle of the mask is 1, the following condition is obtained: 1=h(0, 0).

    [0040] Then, the center size and the center position of the pattern of the mask are determined respectively in operations (iii) and (iv), and the width of the pattern of the mask is calculated based on the determined size of the pattern in operation (v). For example, assuming that the pattern has a width of "b" and a length of "d" and is located at a position x=0, y=0 on the mask, then the pattern edges will be located at x=b/2 and x=-b/2. If the pattern has a center at x=a, and has a width of "b," then the pattern will be located from x=a-b/2 to x=a+b/2. Then, the length of the pattern is calculated in operation (vi).

    [0041] Based on the above, the pattern whose center is at y=0 should satisfy the following equation,


    because the total energy of the laser beam passing through patterns centered at x=0,


    and the total energy of the laser beam passing through the patterns centered at x=a is



    [0042] On the basis of the foregoing equation, the length of the pattern centered at x=a, i.e., a length "p", can be calculated in a scanning direction (the length or the Y-axis direction) of the laser beam.

    [0043] By the foregoing method, the sizes of the patterns located anywhere between the center and the edge of the mask 40 can be calculated in operation (vii), so that the positions and the sizes of the patterns in the mask are defined and determined.

    [0044] Thus, the mask having the patterns formed by the foregoing process is provided in the LITI apparatus so that image distortion is reduced, thereby improving the quality of products, increasing yield, and decreasing production cost.

    [0045] FIGS. 6A and 6B are perspective views illustrating a LITI method according to an embodiment of the present invention. Referring to FIG. 6A, first, the LITI apparatus includes an optical unit 10 having a laser and a projection lens. As shown, a stage 30 is placed under the optical unit 10. A mask 40 is disposed between the laser 5 and the projection lens 8to compensate and/or to ensure the uniform output of the optical unit 10. The mask 40 includes patterns arranged in a direction perpendicular to the beam scanning direction. As shown in FIGS. 4A through 4C, the patterns 43 located towards the edge of the mask 40 are incrementally longer in length than the patterns 43 located in or near the center.

    [0046] A chuck 37 is placed under the optical unit 10 and is moved on the stage 30. As shown, a substrate 20 is placed on the chuck 37, and a donor substrate 25 having a transfer layer (not shown) is placed on the substrate 20.

    [0047] After aligning the optical unit 10 with the substrate 20, the optical unit 10 is fixed and a laser beam 5a is radiated through the mask pattern 43 while the chuck 37 moves in the Y-axis direction. Therefore, the transfer layer is patterned on the substrate 20 according to the mask patterns 43. Here, the transfer layer patterns 23 may be an emission layer of an organic light emitting display device.

    [0048] The laser beam 5a emitted from the laser 5 scans the substrate 20 in a beam scanning direction Y of the mask pattern 43, thereby patterning the transfer layer. The beam scanning direction Y of the laser beam 5a may be a column direction of the pattern 43. That is, while the chuck 37 moves in the beam scanning direction Y at a constant speed, the laser beam 5a is imparted with a pattern corresponding to the pattern 43 of the mask 40. Therefore, the transfer layer patterns 23 is patterned as laser beam 5a imparted with the pattern scans the substrate 20.

    [0049] Referring to FIG. 6b, after the scanning operation is completed in the beam scanning direction Y, the optical unit 10 moves in a direction X perpendicular to the beam scanning direction Y. Then, the optical unit 10 and the substrate 20 are aligned with each other, and the scanning is performed again by the method shown in FIG. 5A. Accordingly, the surface area of the transfer layer 24 and/or the donor substrate 25 is patterned.

    [0050] FIG. 6C is a plan view partially illustrating a patterned substrate according to an aspect of the present invention. Referring to FIG. 6C, the transfer layer patterns 23 patterned by the method shown in FIGS. 6A and 6B is formed having a stripe shape in an emission region 9 of each unit pixel. The patterns 23 entirely cover the emission region 9, and are patterned without variation or misalignment of the center positions. Further, the laser energy is uniformly applied to all patterns 23 at an initial point (s) and an ending point (e) of the patterning, so that the transfer layer patterns 23 can be patterned with uniformity in every unit pixel.

    [0051] FIG. 7 is a cross-sectional view of an organic light emitting display device fabricated according to an embodiment of the present invention, taken along line I-I' of FIG. 6C.

    [0052] Referring to FIG. 7, a pixel electrode 145 is formed on a substrate 20. Before the pixel electrode 145 is formed, the substrate 20 is provided with a thin film transistor Tr per unit pixel. The thin film transistor Tr includes a semiconductor layer 100, a gate electrode 120, a source electrode 130a, and a drain electrode 130b, formed on the substrate 20.

    [0053] Then, an insulating layer 141 is formed on the substrate 20 that includes the thin film transistor Tr. The insulating layer 141 can be formed of an inorganic layer, an organic layer or a stacked layer thereof. For example, the insulating layer 141 can be formed of an inorganic passivation layer 135, an organic passivation layer 140, and a stacked layer thereof.

    [0054] A via hole 142 is formed in the insulating layer 141 to expose the source electrode 130a or the drain electrode 130b. Then, a conductive layer is formed on the insulating layer 141 and then patterned to form the pixel electrode 145. Further, an insulating layer can be formed on the substrate 20 having the pixel electrode 145 and then patterned, thereby forming a pixel defining layer 150 to partially expose the pixel electrode 145.

    [0055] Referring back to FIG. 3, the substrate 20 having the pixel electrode 145 is positioned opposite to and laminated with the donor substrate 25 having the transfer layer.Then, the laminated substrate 20 is placed on the chuck 37. Then, the transfer layer patterns 23 are patterned on the substrate 20 by the method shown in FIGS. 6A and 6B.

    [0056] Referring back to FIG. 7, the transfer layer patterns 23 may be an emission layer 23a. Further, charge injection layers or charge transport layers may be formed on or under the emission layer 23a. For example, a hole injection or transport layer 155a can be formed under the emission layer 23a, and an electron injection or transport layer 155b can be formed on the emission layer 23a. That is, an organic layer 155 including the emission layer 23a can be formed on the pixel electrode 145. After forming a counter electrode 160 on the substrate 20 having the patterned emission layer 23a, the substrate 20 is encapsulated, thereby completing the organic light emitting display device.

    [0057] As described above, embodiments of the present invention can include a mask for LITI and a LITI method using the same, in which the mask for uniformly applying power density of a laser to each pattern is used, so that a transfer layer can be patterned with uniform characteristics. Thus, a LITI apparatus can improve pattern characteristics without an additional apparatus.

    [0058] Further, embodiments of the present invention can include a mask for LITI and a LITI method using the same, in which the mask for compensating the uniformity of a projection lens is used, so that leaning of image patterns formed on a substrate towards the edge is reduced.

    [0059] Although a few aspects of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made without departing from the scope of the invention, which is defined in the appended claims.


    Claims

    1. A laser induced thermal imaging (LITI) apparatus comprising:

    a stage (30); and

    an optical unit (10) disposed on the stage (30), the optical unit (10) comprising a laser and (5) a projection lens, (8) and a mask (40), the mask (40) disposed between the laser (5) and the projection lens.; wherein the mask (40) comprises:

    a first pattern not located in a centre of the mask (40); and

    a second pattern located in or near the centre of the mask (40); wherein

    the first and second patterns are arranged such that when light passes through the mask the densities of light outputted from the first and second patterns are equal; and

    wherein the first and second pattern form at least part of a plurality of patterns (43) which are configured such that (i) they are arranged along a row that extends substantially in a direction perpendicular to a beam scanning direction of the apparatus; and (ii) they are arranged so that the length of the patterns (43), as measured in the scanning direction, increases with distance from the centre of the row.


     
    2. Apparatus according to claim 1, wherein when each pattern (43) has a width b, a laser beam power density h(x, y), a beam scanning direction y, a direction perpendicular to the beam scanning direction x, and a centre of the pattern in a centre region (0, 0) and its length d, then the pattern centred at x=a has a length p satisfying the following equation.


     
    3. Apparatus according to claim 1 or 2, wherein the patterns (43) are adapted to be used to pattern an emission layer of an organic light emitting display device.
     
    4. Apparatus according to any one of claims 1 to 3, wherein the spacing between the centre axes of adjacent patterns (43) on the mask (40) located towards the edge of the mask (40) are incrementally narrower than the spacing between centre axes of adjacent patterns (43) near the centre of the row.
     
    5. Apparatus according to claim 2, wherein the length d is shorter than length P.
     
    6. Apparatus according to any one of claims 1 to 5, wherein gaps between adjacent edges of the patterns (43) become narrower in the adjacent patterns that are located towards the edges of the mask (40).
     
    7. Apparatus according to any one of claims 1 to 6, wherein the mask (40) is arranged such that when the mask (40) is used with substrate patterns having centre axes corresponding to the centre axes of the patterns, misalignment between centre axes of substrate patterns and the corresponding centre axes of the patterns of the mask (40) is reduced in the substrate patterns and the patterns of the mask that are located towards the edges of a substrate or the mask (40).
     
    8. A laser induced thermal imaging (LITI) method using a LITI apparatus comprising an optical unit (10) having a laser (5) and a projection lens (8), and a stage (30) placed under the optical unit (10), the method comprising:

    disposing a mask (40) for the LITI apparatus between the laser (5) and the projection lens (8); and

    placing a substrate on the stage placed under the optical unit (10); wherein the mask comprises:

    a first pattern not located in a centre of the mask (40); and

    a second pattern located in or near the centre of the mask (40); wherein

    the first and second patterns are arranged such that when light passes through the mask the densities light outputted from the first and second patterns are equal; and

    wherein the first and second pattern form at least part of a plurality of patterns (43) which are configured such that (i) they are arranged along a row that extends substantially in a direction perpendicular to a beam scanning direction of the apparatus; and (ii) they are arranged so that the length of the patterns (43), as measured in the scanning direction, increases with distance from the centre of the row.


     
    9. A LITI method according to claim 8, further comprising a laser beam scanning the substrate in the beam scanning direction after placing the substrate on - the stage (30).
     
    10. A LITI method according to claim 9, further comprising moving the optical unit (10) in the direction of the row after the scanning operation, and the laser beam performing another scanning.
     
    11. A LITI method according to claim 8, 9 or 10, wherein when each pattern (43) has a width b, a laser beam power density h(x, y), a beam scanning direction y, a direction perpendicular to the beam scanning direction x, and a centre of the pattern in a centre region (0, 0)and its length d, then the pattern centred at x=a in the mask (40) has a length p satisfying the following equation.


     
    12. A LITI method according to one of claims 8 to 11, wherein spacing between adjacent centre axes of the adjacent patterns (43) on the mask (40) located towards the edge of the mask are incrementally narrower than the spacing between adjacent centre axes of adjacent patterns in or near the centre of the mask (40).
     
    13. A LITI method according to one of claims 8 to 12, further comprising placing a donor substrate having a transfer layer on the substrate.
     
    14. A LITI method according to claim 13, wherein the transfer layer is used as an emission layer of an organic light emitting display device.
     
    15. A method of forming a mask for use in a laser induced thermal imaging (LITI) apparatus, comprising:

    determining a size of a first pattern (43) not located in or near a centre of the mask (40);

    determining a size of a second pattern (43) located in or near the centre of the mask (40) such that when laser light of the LTTI apparatus passes through a projection lens and the mask the densities of light outputted from the first and second patterns are equal; and

    forming the first and second patterns of the mask (40) according to the determined sizes of the first and second patterns.


     
    16. A method according to claim 15, wherein when each pattern has a width b, a laser beam power density h(x, y), a beam scanning direction y, a direction perpendicular to the beam scanning direction x; and a centre of the second pattern in a centre region (0, 0) and its length d, then the first pattern centred at x=a in the mask has a length p satisfying the following equation.


     
    17. A method according to claim 16, wherein the length d is shorter than length
     


    Ansprüche

    1. Vorrichtung zur laserinduzierten thermischen Abscheidung (LITI), umfassend:

    ein Gestell (30); und

    eine optische Einheit (10), die auf dem Gestell (30) angeordnet ist, wobei die optische Einheit (10) einen Laser (5) und ein Projektionsobjektiv (8) und eine Maske (40) umfasst, wobei die Maske (40) zwischen dem Laser (5) und dem Projektionsobjektiv angeordnet ist; wobei die Maske (40) umfasst:

    eine erste Struktur, die sich nicht in einer Mitte der Maske (40) befindet; und

    eine zweite Struktur, die sich in oder nahe der Mitte der Maske (40) befindet; wobei

    die erste und zweite Struktur so angeordnet sind, dass, wenn Licht durch die Maske fällt, die Dichte des Lichts, das aus der ersten und zweiten Struktur austritt, gleich ist; und

    wobei die erste und zweite Struktur zumindest einen Teil einer Mehrzahl von Strukturen (43) bilden, die so ausgelegt sind, dass (i) sie entlang einer Reihe angeordnet sind, die sich im Wesentlichen in einer Richtung senkrecht zu einer Strahlabtastrichtung der Vorrichtung erstreckt; und (ii) sie so angeordnet sind, dass die Länge der Strukturen (43), gemessen in der Abtastrichtung, mit dem Abstand zur Reihenmitte größer wird.


     
    2. Vorrichtung nach Anspruch 1, wobei, wenn jede Struktur (43) eine Breite b, eine Laserstrahl-Leistungsdichte h(x, y), eine Strahlabtastrichtung y, eine zur Strahlabtastrichung senkrechte Richtung x und eine Mitte der Struktur in einem Mittenbereich (0, 0) und ihre Länge d aufweist, die auf x=a zentrierte Struktur eine Länge p aufweist, die die folgende Gleichung erfüllt:


     
    3. Vorrichtung nach Anspruch 1 oder 2, wobei die Strukturen (43) so ausgelegt sind, dass sie zur Strukturierung einer Emissionsschicht einer organischen lichtemittierenden Anzeigevorrichtung verwendet werden.
     
    4. Vorrichtung nach einem der Ansprüche 1 bis 3, wobei der Abstand zwischen den Mittelachsen benachbarter Strukturen (43) auf der Maske (40), die sich zum Rand der Maske (40) hin befinden, zunehmend schmaler ist als der Abstand zwischen Mittelachsen benachbarter Strukturen (43) nahe der Reihenmitte.
     
    5. Vorrichtung nach Anspruch 2, wobei die Länge d kürzer ist als die Länge P.
     
    6. Vorrichtung nach einem der Ansprüche 1 bis 5, wobei Zwischenräume zwischen benachbarten Rändern der Strukturen (43) in den benachbarten Strukturen, die sich zu den Rändern der Maske (40) hin befinden, schmaler werden.
     
    7. Vorrichtung nach einem der Ansprüche 1 bis 6, wobei die Maske (40) so angeordnet ist, dass, wenn die Maske (40) mit Substratstrukturen verwendet wird, deren Mittelachsen den Mittelachsen der Strukturen entsprechen, ein Versatz zwischen Mittelachsen von Substratstrukturen und den entsprechenden Mittelachsen der Strukturen der Maske (40) in den Substratstrukturen und den Strukturen der Maske, die sich zu den Rändern eines Substrats oder der Maske (40) hin befinden, geringer ist.
     
    8. Verfahren zur laserinduzierten thermischen Abscheidung (LITI) unter Verwendung einer LITI-Vorrichtung, die eine optische Einheit (10) mit einem Laser (5) und einem Projektionsobjektiv (8) sowie ein unter der optischen Einheit (10) platziertes Gestell (30) umfasst, wobei das Verfahren umfasst:

    Anordnen einer Maske (40) für die LITI-Vorrichtung zwischen dem Laser (5) und dem Projektionsobjektiv (8); und

    Platzieren eines Substrats auf dem unter der optischen Einheit (10) platzierten Gestell; wobei die Maske umfasst:

    eine erste Struktur, die sich nicht in einer Mitte der Maske (40) befindet; und

    eine zweite Struktur, die sich in oder nahe der Mitte der Maske (40) befindet; wobei

    die erste und zweite Struktur so angeordnet sind, dass, wenn Licht durch die Maske fällt, die Dichte des Lichts, das aus der ersten und zweiten Struktur austritt, gleich ist; und

    wobei die erste und zweite Struktur zumindest einen Teil einer Mehrzahl von Strukturen (43) bilden, die so ausgelegt sind, dass (i) sie entlang einer Reihe angeordnet sind, die sich im Wesentlichen in einer Richtung senkrecht zu einer Strahlabtastrichtung der Vorrichtung erstreckt; und (ii) sie so angeordnet sind, dass die Länge der Strukturen (43), gemessen in der Abtastrichtung, mit dem Abstand zur Reihenmitte größer wird.


     
    9. LITI-Verfahren nach Anspruch 8, das ferner einen Laserstrahl umfasst, der das Substrat nach dem Platzieren des Substrats auf dem Gestell (30) in der Strahlabtastrichtung abtastet.
     
    10. LITI-Verfahren nach Anspruch 9, das ferner das Bewegen der optischen Einheit (10) in der Richtung der Reihe nach dem Abtastvorgang und das Durchführen einer weiteren Abtastung durch den Laserstrahl umfasst.
     
    11. LITI-Verfahren nach Anspruch 8, 9 oder 10, wobei, wenn jede Struktur (43) eine Breite b, eine Laserstrahl-Leistungsdichte h(x, y), eine Strahlabtastrichtung y, eine zur Strahlabtastrichtung senkrechte Richtung x und eine Mitte der Struktur in einem Mittenbereich (0, 0) und ihre Länge d aufweist, die auf x=a zentrierte Struktur in der Maske (40) eine Länge p aufweist, die die folgende Gleichung erfüllt:


     
    12. LITI-Verfahren nach einem der Ansprüche 8 bis 11, wobei der Abstand zwischen benachbarten Mittelachsen der benachbarten Strukturen (43) auf der Maske (40), die sich zum Rand der Maske hin befinden, zunehmend schmaler ist als der Abstand zwischen benachbarten Mittelachsen benachbarter Strukturen in oder nahe der Mitte der Maske (40).
     
    13. LITI-Verfahren nach einem der Ansprüche 8 bis 12, das ferner das Platzieren eines Donorsubstrats mit einer Transferschicht auf dem Substrat umfasst.
     
    14. LITI-Verfahren nach Anspruch 13, wobei die Transferschicht als Emissionsschicht einer organischen lichtemittierenden Anzeigevorrichtung verwendet wird.
     
    15. Verfahren zum Ausbilden einer Maske zur Verwendung in einer Vorrichtung zur laserinduzierten thermischen Abscheidung (LITI), umfassend:

    Bestimmen einer Größe einer ersten Struktur (43), die sich nicht in oder nahe einer Mitte der Maske (40) befindet;

    Bestimmen einer Größe einer zweiten Struktur (43), die sich in oder nahe der Mitte der Maske (40) befindet, sodass, wenn Laserlicht der LITI-Vorrichtung durch ein Projektionsobjektiv und die Maske fällt, die Dichte des Lichts, das aus der ersten und zweiten Struktur austritt, gleich ist; und

    Ausbilden der ersten und zweiten Struktur der Maske (40) gemäß der bestimmten Größe der ersten und zweiten Struktur.


     
    16. Verfahren nach Anspruch 15, wobei, wenn jede Struktur eine Breite b, eine Laserstrahl-Leistungsdichte h(x, y), eine Strahlabtastrichtung y, eine zur Strahlabtastrichtung senkrechte Richtung x und eine Mitte der zweiten Struktur in einem Mittenbereich (0, 0) und ihre Länge d aufweist, die erste auf x=a zentrierte Struktur in der Maske eine Länge p aufweist, die die folgende Gleichung erfüllt:


     
    17. Verfahren nach Anspruch 16, wobei die Länge d kürzer ist als die Länge p.
     


    Revendications

    1. Appareil de formation d'image thermique induite par laser (LITI) comprenant :

    un étage (30) ; et

    une unité optique (10) disposée sur l'étage (30), l'unité optique (10) comprenant un laser (5) et une lentille de projection (8), et un masque (40), le masque (40) étant disposé entre le laser (5) et la lentille de projection ; dans lequel le masque (40) comprend :

    un premier motif qui n'est pas situé au centre du masque (40) ; et

    un deuxième motif qui est situé au centre ou à proximité du centre du masque (40) ; dans lequel

    les premier et deuxième motifs sont agencés de sorte que, lorsque la lumière passe à travers le masque, les densités de lumière délivrées par les premier et deuxième motifs sont égales ; et

    dans lequel les premier et deuxième motifs forment au moins une partie d'une pluralité de motifs (43) qui sont configurés de sorte (i) qu'ils sont agencés le long d'une rangée qui s'étend sensiblement dans une direction perpendiculaire à une direction de balayage de faisceau de l'appareil ; et (ii) qu'ils sont agencés de sorte que la longueur des motifs (43), telle que mesurée dans la direction de balayage, augmente avec la distance par rapport au centre de la rangée.


     
    2. Appareil selon la revendication 1, dans lequel, lorsque chaque motif (43) a une largeur b, une densité de puissance de faisceau laser h(x, y), une direction de balayage de faisceau y, une direction perpendiculaire à la direction de balayage de faisceau x et un centre du motif dans une région centrale (0, 0) et sa longueur d, alors le motif centré en x=a a une longueur p satisfaisant à l'équation suivante :


     
    3. Appareil selon la revendication 1 ou 2, dans lequel les motifs (43) sont conçus pour être utilisés pour structurer une couche d'émission d'un dispositif d'affichage électroluminescent organique.
     
    4. Appareil selon l'une quelconque des revendications 1 à 3, dans lequel les espacements entre les axes centraux des motifs (43) adjacents sur le masque (40) situés vers le bord du masque (40) deviennent plus étroits de manière incrémentale que l'espacement entre les axes centraux des motifs (43) adjacents à proximité du centre de la rangée.
     
    5. Appareil selon la revendication 2, dans lequel la longueur d est plus petite que la longueur P.
     
    6. Appareil selon l'une quelconque des revendications 1 à 5, dans lequel les espaces entre les bords adjacents des motifs (43) deviennent plus étroits dans les motifs adjacents qui sont situés vers les bords du masque (40).
     
    7. Appareil selon l'une quelconque des revendications 1 à 6, dans lequel le masque (40) est agencé de sorte que, lorsque le masque (40) est utilisé avec des motifs de substrat ayant des axes centraux correspondant aux axes centraux des motifs, un défaut d'alignement entre les axes centraux des motifs de substrat et les axes centraux correspondants des motifs du masque (40) est réduit dans les motifs de substrat et dans les motifs du masque qui sont situés vers les bords d'un substrat ou du masque (40).
     
    8. Procédé de formation d'image thermique induite par laser (LITI) en utilisant un appareil LITI comprenant une unité optique (10) comportant un laser (5) et une lentille de projection (8), et un étage (30) placé sous l'unité optique (10), le procédé comprenant :

    le placement d'un masque (40) pour l'appareil LITI entre le laser (5) et la lentille de projection (8) ; et

    le placement d'un substrat sur l'étage placé sous l'unité optique (10) ; dans lequel le masque comprend :

    un premier motif qui n'est pas situé au centre du masque (40) ; et

    un deuxième motif situé au centre ou à proximité du centre du masque (40) ; dans lequel

    les premier et deuxième motifs sont agencés de sorte que, lorsque la lumière passe à travers le masque, les densités de lumière délivrées par les premier et deuxième motifs sont égales ; et

    dans lequel les premier et deuxième motifs forment au moins une partie d'une pluralité de motifs (43) qui sont configurés de sorte (i) qu'ils sont agencés le long d'une rangée qui s'étend sensiblement dans une direction perpendiculaire à une direction de balayage de faisceau de l'appareil ; et (ii) qu'ils sont agencés de sorte que la longueur des motifs (43), telle que mesurée dans la direction de balayage, augmente avec la distance par rapport au centre de la rangée.


     
    9. Procédé LITI selon la revendication 8, comprenant en outre un faisceau laser balayant le substrat dans la direction de balayage de faisceau après le placement du substrat sur l'étage (30).
     
    10. Procédé LITI selon la revendication 9, comprenant en outre le déplacement de l'unité optique (10) dans la direction de la rangée après l'opération de balayage, et l'exécution par le faisceau laser d'un autre balayage.
     
    11. Procédé LITI selon la revendication 8, 9 ou 10, dans lequel, lorsque chaque motif (43) a une largeur b, une densité de puissance de faisceau laser h(x, y), une direction de balayage de faisceau y, une direction perpendiculaire à la direction de balayage de faisceau x, et un centre du motif dans une région centrale (0, 0) et sa longueur d, alors le motif centré en x=a dans le masque (40) a une longueur p satisfaisant à l'équation suivante :


     
    12. Procédé LITI selon l'une des revendications 8 à 11, dans lequel les espacements entre les axes centraux adjacents des motifs (43) adjacents sur le masque (40) situés vers le bord du masque deviennent plus étroits de manière incrémentale que l'espacement entre les axes centraux adjacents des motifs adjacents au centre ou à proximité du centre du masque (40).
     
    13. Procédé LITI selon l'une des revendications 8 à 12, comprenant en outre le placement d'un substrat de donneur comportant une couche de transfert sur le substrat.
     
    14. Procédé LITI selon la revendication 13, dans lequel la couche de transfert est utilisée en tant que couche d'émission d'un dispositif d'affichage électroluminescent organique.
     
    15. Procédé de formation d'un masque pour une utilisation dans un appareil de formation d'image thermique induite par laser (LITI), comprenant :

    la détermination d'une taille d'un premier motif (43) qui n'est pas situé au centre ou à proximité du centre du masque (40) ;

    la détermination d'une taille d'un deuxième motif (43) qui est situé au centre ou à proximité du centre du masque (40) de sorte que, lorsque la lumière laser de l'appareil LITI passe à travers une lentille de projection et le masque, les densités de lumière délivrées par les premier et deuxième motifs sont égales ; et

    la formation des premier et deuxième motifs du masque (40) conformément aux tailles déterminées des premier et deuxième motifs.


     
    16. Procédé selon la revendication 15, dans lequel, lorsque chaque motif a une largeur b, une densité de puissance de faisceau laser h(x, y), une direction de balayage de faisceau y, une direction perpendiculaire à la direction de balayage de faisceau x ; et un centre du deuxième motif dans une région centrale (0, 0) et sa longueur d, alors le premier motif centré en x=a dans le masque a une longueur p satisfaisant à l'équation suivante :


     
    17. Procédé selon la revendication 16, dans lequel la longueur d est plus petite que la longueur p.
     




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    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description