Laser processing method, reduction projection optical system, substrate manufacturing method and laser processing device

Abstract

To realize larger and finer receptor substrates in a lift device and shorter tact time while maintaining high lift position accuracy.SOLUTION: A mechanism is constructed such that each stage group that moves while holding a donor substrate carrying an object to be lifted and / or a beam shaping optical system and a reduction projection optical system, and the stage group that holds the receptor substrate to be lifted is constructed on a separate solid bases, thereby minimizing vibrations caused by the relative scanning of each substrate with respect to the laser light and abnormalities in the synchronous position accuracy of the stages responsible for the scanning.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present invention relates to an apparatus for precisely lifting an object located on a donor substrate onto a receptor substrate (LIFT: Laser Induced Forward Transfer) using laser irradiation. [Background technology]

[0002] There is a technology in which a laser is irradiated onto an organic EL layer on a donor substrate and the layer is lifted onto an opposing circuit substrate. Patent Document 1 discloses a technology in which one laser beam is converted into multiple rectangular laser beams with a uniform intensity distribution in a rectangular shape, which are arranged in series and at equal intervals, and the laser beams are irradiated onto a predetermined region of the donor substrate in a superimposed manner a predetermined number of times at intervals of at least a certain time, which are absorbed by a metal foil positioned between the donor substrate and the organic EL layer, generating elastic waves, which lift the peeled organic EL layer onto the opposing circuit substrate.

[0003] In this technology, a spacer, preferably 80 to 100 μm, is sandwiched between the donor substrate and the circuit substrate, and the integrated substrate is placed on a stage while maintaining a constant gap between them, and the substrate is scanned relative to the laser light. However, this requires a separate process for integrating the opposing donor substrate and circuit substrate, and a donor substrate of the same size as the circuit substrate is required, which increases manufacturing costs and the size of the equipment required to meet the demand for larger circuit substrates.

[0004] Similarly, Patent Document 2 discloses a technique for lifting an organic EL layer on a donor substrate to an opposing circuit substrate, in which a light absorbing layer is provided between the donor substrate and the organic EL layer, and laser light irradiated onto the light absorbing layer is absorbed, generating shock waves that lift the organic EL layer to the opposing circuit substrate spaced 10 to 100 μm apart. However, the patent document does not disclose a laser light scanning method, a stage configuration for achieving this, or a lifting device. Therefore, the patent document cannot be used as a reference for maintaining or improving the lift position accuracy to accommodate larger circuit substrates.

[0005] Furthermore, Patent Document 3 discloses a step-and-scan exposure method for exposure apparatuses used in semiconductor device manufacturing. The basic concept is to intermittently expose a line of shot areas along the scanning exposure direction of a wafer stage, skipping some shot areas along the way, without stopping the wafer stage midway. Specifically, the exposure apparatus includes a reticle stage that holds a reticle, a wafer stage that holds a wafer, and a projection optical system that projects the reticle pattern onto the wafer. The reticle stage and wafer stage are scanned together relative to the projection optical system to perform exposure, projecting the reticle pattern sequentially onto multiple shot areas on the wafer. The exposure apparatus intermittently exposes multiple shot areas on the wafer aligned along the scanning direction while moving the wafer stage without stopping it. This reduces the impact of vibrations and swings associated with stage scanning on exposure accuracy, compared to the step-and-repeat method, which repeatedly accelerates and decelerates the wafer stage, in response to demands for larger wafers and faster processing speeds.

[0006] However, the technology disclosed in Patent Document 3 is a semiconductor exposure apparatus technology based on reduced projection exposure, and its technical field is different from the lift technology of the present invention. In other words, the configuration and scanning technology of the reticle stage and wafer stage in the exposure apparatus are completely different from the stage configuration and scanning technology of the present invention for reducing and projecting a mask pattern onto an object on a donor substrate with high positional accuracy and then lifting the object onto a receptor substrate with the same high positional accuracy. Therefore, this document cannot be used as a reference for the specific stage configuration and scanning technology of the present invention. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-67671 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-40380 [Patent Document 3] Japanese Patent Application Laid-Open No. 2000-21702 Summary of the Invention [Problem to be solved by the invention]

[0008] The donor stage that holds the donor substrate and the optical stage that holds the optical system mounted on the donor stage are configured as independent mechanisms from the receptor stage that holds the receptor substrate, and further, the optical stage is not directly mounted on the donor stage but is independently installed on a highly rigid base, thereby minimizing the impact of vibrations and various errors that accompany the scanning of each stage on the synchronous position accuracy between the stages.As a result, the objective of this invention is to provide a lift device that contributes to larger and more detailed receptor substrates and shorter takt time while maintaining lift position accuracy. [Means for solving the problem]

[0009] A first invention is an apparatus for selectively peeling off an object located on a front surface of a moving donor substrate by irradiating the object with a pulsed laser beam from the back surface of the donor substrate, and lifting the object onto a receptor substrate that moves facing the donor substrate, the apparatus comprising: a pulsed laser device; a telescope that collimates the pulsed laser beam emitted from the laser device; a shaping optical system that uniformly shapes the spatial intensity distribution of the pulsed laser beam that has passed through the telescope; a mask that passes the pulsed laser beam shaped by the shaping optical system in a predetermined pattern; and a field lens located between the shaping optical system and the mask. a projection lens that reduces and projects the laser light that has passed through the pattern of the mask onto the surface of the donor substrate; a mask stage that holds the field lens and the mask; an optical stage that holds the shaping optical system, the mask stage, and the projection lens; a donor stage that holds the donor substrate so that its back surface faces the laser light incident side; a receptor stage that holds the receptor substrate; and a programmable multi-axis control device having a trigger output function for the pulsed laser light oscillation and a stage control function, wherein the receptor stage has a Y axis when the horizontal plane is an XY plane, a Z axis in the vertical direction, and an XY axis. a θ-axis in a plane, the donor stage having an X-axis, a Y-axis, and a θ-axis, the projection lens is held on the optical stage together with a Z-axis stage for the projection lens, the telescope, the shaping optical system, the field lens, the mask, and the projection lens form a reduction projection optical system that reduces and projects the pattern of the mask onto the surface of the donor substrate, the X-axis of the donor stage is set on a base plate 1, the Y-axis of the receptor stage is set on a base plate 2 different from the base plate 1, and the Y-axis of the donor stage is suspended from the X-axis of the donor stage.

[0010] Here, the "moving" substrate refers to a substrate that moves without stopping even when irradiated with pulsed laser light (denoted as "LS" in FIG. 1A. Note that while FIG. 1A shows the main components of the second invention, it is referred to because it includes components common to the first invention. The same applies below.) and a substrate that stops when irradiated with pulsed laser light and moves and stops repeatedly. These configurations are selected based on the lifting process using the lifting device of the present invention and the required takt time, etc. Also included are a configuration in which the donor substrate (D) moves and stops repeatedly while the receptor substrate (R) does not stop, and vice versa. When only one shot is used to peel the target object from the donor substrate and a short takt time is required, a configuration in which the donor substrate and receptor substrate move without stopping at the same or different speeds is preferably selected. On the other hand, when it is desired to stack the target object to a constant thickness, a configuration in which the donor substrate moves without stopping and the receptor substrate stops for a certain number of shots may be selected.

[0011] Furthermore, the term "object" is not particularly limited, and includes an object to be lifted that is provided on a donor substrate or on a donor substrate via a light-absorbing layer (not shown in FIG. 1A), and includes, but is not limited to, a thin film such as the organic EL layer described in the aforementioned patent document, or a large number of fine elements arranged regularly. The lifting mechanism includes, but is not limited to, a mechanism in which the light-absorbing layer is irradiated with laser light to generate a shock wave, which causes the object to be peeled off from the donor substrate and lifted toward the receptor substrate, and a mechanism in which the object does not have a light-absorbing layer and is peeled off by laser light irradiated directly onto the object.

[0012] The material of the donor substrate should be transparent to the wavelength of the laser light, and is preferably one that sags little when the substrate is large. If the sagging is so large that it cannot maintain a uniform gap between the donor substrate and the receptor substrate, the donor substrate can be mechanically corrected by, for example, providing a suction area near the center of the donor substrate on the donor stage (Yd, θd). Alternatively, a gap sensor in combination with a height sensor (described later) can be used to correct the sagging.

[0013] In the present invention, the movable range of the donor stage refers to the range of movement in the XY plane over which the donor substrate must move in order to lift an object located near the edge of the donor substrate onto the receptor substrate, and this range depends on the size of the receptor substrate. For example, if the size of the donor substrate in the XY plane is 200 × 200 mm and the receptor substrate is 400 × 400 mm, the predetermined range over which the donor stage (Xd, Yd) must move is approximately 800 × 800 mm. This is shown in Figure 4. If further movement is required to remove the donor substrate, this range is also included.

[0014] Furthermore, the term "surface plate" does not limit the material, but must be a material with extremely high rigidity. Surface plate 1 (G1) is preferably U-shaped or square-shaped when viewed from above to provide rigidity. While surface plate 2 is shown as a single piece in Figure 1A, it may be configured as two surface plates installed in the Y-axis direction, with a linear scale and linear motor placed between them. Surface plates 1 and 2 may be fixed on the same base surface plate (G). Furthermore, G1 may be configured as a combination of surface plate 11 (G11) and surface plate 12 (G12).

[0015] The surface plates must be made of a highly rigid material such as steel, stone, or ceramic. For example, the stone material can be, but is not limited to, granite. Furthermore, it is not necessary for all the surface plates to be made of the same material.

[0016] The movement of each stage will be explained in detail in the examples below, but generally, it operates as follows: First, the X-axis (Xd) of the donor stage is installed on G1 with the Y-axis (Yd) of the donor stage suspended, and moves in the X-axis direction. This movement changes the relative position along the X-axis between the donor substrate and receptor substrate. The movement is shown in Figure 1B. Note that in neither figure are the details of the stage's movable table, linear guides, etc.

[0017] The optical stage (Xo) can be mounted on any suitable surface, including Xd, the same surface as Xd, or a different surface. Xo moves in the X-axis direction parallel to Xd, moving the shaping optical system (H), field lens (F), mask (M), and projection lens (Pl) together without changing their relative positions. Moving Xo along the X-axis also changes the relative positional relationship between the donor substrate and the projection lens. This movement is shown in Figure 1C.

[0018] If there is no need to change the relative positions of the donor substrate and the projection lens in the X-axis direction, the donor substrate and the projection lens can be configured to always move along the X-axis of the donor stage, i.e., the optical stage can be omitted, and the homogenizer, field lens, mask, and projection lens can all be fixed on the X-axis of the donor stage or on a separate surface plate.

[0019] The mask is held on a mask stage, which has at least a W axis that moves in the X axis direction together with the field lens, and preferably also has a U axis in the Y axis direction, a V axis that moves in the Z axis direction, an R axis that is a rotation axis in the YZ plane, a TV axis that adjusts the tilt relative to the V axis, and a TU axis that adjusts the tilt relative to the U axis. In addition, to reduce the amount of heat input to the mask due to laser irradiation, an aperture mask with a pattern slightly larger than the mask pattern can be provided in front of the mask, and combined with the mask to form a double mask structure.

[0020] The Y-axis (Yd) of the donor stage and the Y-axis (Yr) of the receptor stage move at the same or different speeds while maintaining a constant gap between the donor substrate and the receptor substrate and extremely high parallelism during the lifting process. The movement method of each stage group and the above-mentioned structure of the bases supporting them limit the receptor substrate movement mechanism to the Y-axis and separate it from the donor substrate movement mechanism, thereby suppressing mutual influence due to interference and vibration between the movement areas of the respective substrates and enabling the receptor substrate to be made larger and more compact.

[0021] The second invention is a lift device characterized in that, in the first invention, the X axis of the donor stage is placed on the base plate 1, and the optical stage is placed on the X axis of the donor stage.

[0022] Fig. 1A shows the main components of the lift device according to the second invention (side view). Fig. 1B shows the state (side view) in which Xd has moved with Xo on it from the state shown in Fig. 1A. Fig. 1C shows the state (side view) in which Xo has moved on Xd from the state shown in Fig. 1B. Fig. 1D shows the top view of Fig. 1C.

[0023] The third invention is a lift device according to the first invention, characterized in that the optical stage is placed on the base 1 and the X axis of the donor stage is suspended from the base 1.

[0024] Figure 2A shows the main components of the lift device according to the third invention (side view). Figure 2B shows the state (side view) where Xd and Xo have moved the same distance on G1 (Xd is suspended from G1) from the state of Figure 2A. Figure 2C shows the state (side view) where only Xo has moved on G1 from the state of Figure 2B.

[0025] The fourth invention is a lift device characterized in that, in the first invention, the X-axis of the donor stage is installed on the base plate 1, and the optical stage is placed on a base plate 3 that is different from both the base plate 1 and the base plate 2.

[0026] Here, "installed on the surface plate 1" includes, but is not limited to, a state in which it is placed on the surface plate 1 and a state in which it is suspended from the surface plate 1.

[0027] The fifth invention is a lift device according to the first invention, characterized in that it has a rotation adjustment mechanism between the X axis of the donor stage and the base plate 1, and between the X axis of the donor stage and the Y axis of the donor stage, for fine-tuning the installation angle in the XY plane between the two.

[0028] An example of a rotation adjustment mechanism (RP) installed between the X-axis (Xd) of the donor stage and surface plate 1 (G1) is shown in Figure 3A. In Figure 3A, the left side shows a top view, and the right side shows a side view from the X-axis direction. The outer row of holes in the top view is used for fixing to G1 and has "play" (room / slack) to provide rotation adjustment functionality. The inner two rows of holes in the top view are used to pass screws for fixing the RP and the Xd linear guide. It is possible to use the side with "play" as the hole for the Xd linear guide, but fixing two linear guides independently and parallel may increase the difficulty of the installation process.

[0029] On the other hand, an example of an RP installed between the Xd and the Y axis (Yd) of the donor stage suspended from it is shown in Figure 3B. The two rows of holes located on the outside in the top view are used to fix the RP to the Xd and have "play" to provide rotation adjustment functionality. Furthermore, two rows of holes aligned along the Y axis are used to fix the RP to the Yd.

[0030] In addition, a different RP can be used as the RP placed between G1 and Xd. For example, (not shown) a fulcrum (rotation axis in the Z-axis direction) for rotating and adjusting the RP on which Xd is placed relative to G1 within the XY plane is placed on the contact surface between the RP and G1, and a force point for the fulcrum is placed on the side (vertical plane) of the RP, sufficiently distant from the fulcrum. A large screw is placed on G1 near the force point, pushing it horizontally toward the force point. Similarly, a large screw is placed on the side of the RP on the opposite side. This allows the RP on which Xd is placed to rotate within the XY plane relative to G1 on the order of μrad, centered on the fulcrum.

[0031] The sixth invention is a lift device according to the second invention, characterized in that it has a rotation adjustment mechanism for fine-tuning the installation angle in the XY plane between the X axis of the donor stage and the base plate 1, between the X axis of the donor stage and the optical stage, and between the X axis of the donor stage and the Y axis of the donor stage.

[0032] As these RPs, for example, the RP used between G1 and Xd shown in FIG. 3A, the RP used between Xd and Xo shown in FIG. 3C, and the RP used between Xd and Yd shown in FIG. 3B can be used.

[0033] The seventh invention is a lift device according to the third invention, characterized in that it has a rotation adjustment mechanism for fine-tuning the installation angle in the XY plane between the X axis of the donor stage and the base plate 1, between the optical stage and the base plate 1, and between the X axis of the donor stage and the Y axis of the donor stage.

[0034] Here, for example, the RP shown in Fig. 3A is used as the rotation adjustment mechanism between Xo and G1 and between Xd and G1, while the RP shown in Fig. 3B is used as the rotation adjustment mechanism between Xd and Yd. The former RP has holes through which the Xo and Xd linear guide fixing screws pass, and the "play" provided in these holes is used to adjust the installation angle in the XY plane between the RP to which the linear guides for each stage are fixed and G1.

[0035] The eighth invention is a lift device according to the fourth invention, characterized in that it has a rotation adjustment mechanism for fine-tuning the installation angle in the XY plane between the X axis of the donor stage and the base plate 1, between the optical stage and the base plate 3, and between the X axis of the donor stage and the Y axis of the donor stage.

[0036] A ninth invention is a lift device according to any one of the first to eighth inventions, characterized in that the pulse laser device is an excimer laser.

[0037] Here, the oscillation wavelength of the excimer laser is mainly 193, 248, 308 or 351 [nm], but a wavelength is suitably selected from these depending on the material of the light absorption layer and the light absorption characteristics of the object.

[0038] A tenth aspect of the present invention is the lift device according to the ninth aspect of the present invention, characterized in that it includes a pulse shutter that blocks any pulse train of laser pulses emitted from the pulse laser device.

[0039] Pulse-oscillating laser devices receive a trigger signal from the programmable multi-axis control device and begin oscillation. However, the energy of a certain number of pulses or pulses within a certain time period immediately after oscillation is known to be unstable enough to be unusable depending on the application. Therefore, a mechanical shutter operation is required to eliminate these unstable pulses. Specifically, for an excimer laser oscillating at 1 kHz, the time window between adjacent laser pulses is approximately 1 ms, requiring a high-speed shutter function that can move (cross) a certain distance within this time. This certain distance depends on the spatial size of the laser light at the location where the shutter is operated. If the distance is 5 mm, the required shutter operation speed is 5 m / s, requiring an ultra-high-speed shutter that moves an optical element in and out of the optical path using a voice coil or the like. Even if the spatial size can be reduced by using a shaping optical system or the like to shorten the distance traversed by the shutter element, the shutter can easily be damaged depending on the energy density of the laser light.

[0040] The 11th invention is a lift device according to any one of the first to tenth inventions, characterized in that the programmable multi-axis control device has the function of simultaneously controlling at least the Y-axis of the receptor stage and the Y-axis of the donor stage, and is equipped with means for correcting the movement position error using two-dimensional distribution correction value data created in advance to correct the movement position error of each stage.

[0041] For example, the positions of the receptor substrate and the donor substrate during laser light irradiation are corrected using two-dimensional distribution correction value data information in a pseudo XY plane, which is a combination of Xd or Xo and Yr or Yd. The causes of position errors to be corrected include, but are not limited to, pitching, yawing, and rolling associated with the movement of each stage. Furthermore, the parameters that determine the correction values ​​include the movement speeds of Yr and Yd and their ratio, in addition to the position information of each stage.

[0042] The twelfth invention is a lift device according to any one of the first to eleventh inventions, characterized in that a high-magnification camera for monitoring the position of the donor substrate is installed on the Z axis of the receptor stage, or a high-magnification camera for monitoring the position of the receptor substrate is installed on the X axis of the donor stage or a part that moves with it, or on the optical stage or a part that moves with it.

[0043] Here, the "portion that moves with the X-axis of the donor stage" also includes Yd, which is suspended from Xd. In the present invention, the parallelism of the Y-axes of each stage, the parallelism of the X-axes of each stage, and the squareness of the Y-axis and X-axis of each stage are important parameters that determine the lift position accuracy. When verifying the parallelism and squareness of each stage during assembly, a high-magnification, high-resolution camera is used to monitor the amount of misalignment in the direction perpendicular to the movement distance of each stage holding the alignment substrate, and the rotation adjustment mechanism is used to adjust the squareness. Furthermore, when adjusting the parallelism between Yr and Yd, both stages are moved synchronously (parallel) the same distance, and a high-magnification camera attached to one stage is used to observe whether the position of the pattern-matched alignment mark image (e.g., a cross mark) on the opposing stage remains stationary without movement. In this case, movement in the Y-axis direction indicates an abnormality in synchronization between Yd and Yr, and movement in the X-axis direction indicates an incorrect adjustment of the parallelism between Yd and Yr.

[0044] Generally, a CCD camera is used as the high-magnification camera. Although the magnification depends on the lift position accuracy, for example, to detect the aforementioned deviation amount on the order of μrad, that is, to detect a deviation amount of 1 μm for a stage movement distance of 1 m, it is recommended to use a camera with a resolution of 1 μm and a magnification of about 20 to 50 times.

[0045] The 13th invention is a lift device according to any one of the first to 12th inventions, characterized in that the donor stage and the receptor stage are equipped with a gap sensor that measures the gap between the surface (lower surface) of the donor substrate and the surface of the receptor substrate.

[0046] Here, the gap sensor is a combination of height sensors installed on both the donor and receptor stages. The height sensor installed on the donor stage measures the distance to the receptor substrate, and the height sensor installed on the receptor stage measures the distance to the donor substrate. The gap between the donor substrate and the receptor substrate is calculated from these measurements and the height information from the height sensors.

[0047] The 14th invention is a lift device according to any one of the 11th to 13th inventions, characterized in that it is equipped with position measurement means using laser interferometers for the Y axis of the receptor stage and the Y axis of the donor stage.

[0048] The laser interferometer for the Y-axis (Yr) of the receptor stage can be configured with a mirror (Ic) held in a part that moves with Yr, an interferometer laser (IL) fixed to a surface plate that is less susceptible to vibrations caused by the movement, such as surface plate 2 (G2), and a quarter-wave plate (not shown). Preferably, a three-axis corner cube (retroreflector) is used as the mirror, and it is desirable to position it as close as possible to the position (height) of the receptor substrate. An outline is shown in Figure 5A. (The Z-axis and θ-axis of the donor stage group and receptor stage are not shown.)

[0049] Although Yr is controlled by a programmable multi-axis control device based on position information from the linear encoder, this laser interferometer is used to calibrate the linear encoder and also to calibrate the gear ratio when finely adjusting the gear mode operation of Yr and Yd, which will be described later.

[0050] The laser interferometer for the Y-axis (Yd) of the donor stage can be configured with an Ic held on a surface that moves with the Yd suspended from the Xd, an IL fixed to the Xd, and a quarter-wave plate (not shown). Again, a three-axis corner cube (retroreflector) is preferably used as the mirror, and it is desirable to position it as close as possible to the position (height) of the donor substrate. A schematic diagram is shown in Figure 5B. (The receptor stages are not shown.) The detection method for either interferometer laser can be optimally selected depending on the required lift position accuracy.

[0051] The 15th invention is a lift device characterized in that, in any one of the first to fourteenth inventions, it is equipped with a confocal beam profiler having an imaging plane at a position conjugate to the position where the mask pattern is reduced and projected by the projection lens to form an image.

[0052] This confocal beam profiler allows the position and spatial intensity distribution of the laser light projected onto the donor substrate surface in a reduced size, as well as its imaging state, to be monitored in real time with an accuracy equivalent to the imaging resolution of the reduced imaging optical system.

[0053] The 16th invention is a method of using a lift device according to any one of the 13th to 15th inventions, characterized in that, in any one of the 13th to 15th inventions, the amount of deflection of the donor substrate is measured in advance using the gap sensor along with XY position information of the donor substrate, and based on the two-dimensional distribution data of the amount of deflection obtained by the measurement, the gap between the donor substrate and the receptor substrate is corrected by adjusting the Z axis (Zr) of the receptor stage or the Z axis stage of the projection lens to lift the donor substrate.

[0054] A seventeenth aspect of the present invention is a method for adjusting the parallelism of the Y axis of the receptor stage and the Y axis of the donor stage in the assembly process of the lift device according to any one of the eleventh to sixteenth aspects of the present invention, comprising the steps of: using the Y axis, whose straightness has been adjusted together with the Z axis and θ axis of the receptor stage, as a reference, adjusting the perpendicularity of the Y axis of the receptor stage and the X axis of the donor stage by a rotation adjustment mechanism located between the base 1 and the X axis of the donor stage; and rotating the Y axis of the donor stage suspended from the X axis of the donor stage whose perpendicularity has been adjusted. a step of synchronously moving the Y axis of the receptor stage and the Y axis of the donor stage in parallel, and observing the alignment mark on the Y axis of the opposing donor stage with a high-magnification camera attached to a position that moves together with the Y axis of the receptor stage; and a step of adjusting the parallelism of the Y axis of the receptor stage and the Y axis of the donor stage based on the results of the observation using a rotation adjustment mechanism between the X axis of the donor stage and the Y axis of the donor stage.

[0055] In addition, in order to accurately check and adjust the parallelism of Yd and Yr, it is desirable to attach the high-magnification camera to the highest and most rigid part of each stage, plate, etc. placed on Yr. [Effects of the Invention]

[0056] The present invention, based on the high synchronous positional accuracy of the donor substrate and receptor substrate, realizes an increase in the size of the receptor substrate in the lift device and a reduction in the takt time while maintaining high lift positional accuracy. [Brief explanation of the drawings]

[0057] [Figure 1A] 1 shows the main components (side view) of a lift device according to the present invention (second invention). [Figure 1B] This shows the state (side view) in which the X axis of the donor stage has moved with the optical stage mounted thereon from the state in FIG. 1A. [Figure 1C]This shows the state (side view) in which the optical stage has moved on the X-axis of the donor stage from the state in FIG. 1B. [Figure 1D] Top view of Figure 1C. [Figure 2A] 1 shows the main components (side view) of a lift device according to the present invention (third invention). [Figure 2B] This shows a state (side view) in which the X axis of the donor stage and the optical stage have moved the same distance on the surface plate 1 from the state in FIG. 2A. [Figure 2C] This shows a state (side view) in which only the X axis of the donor stage has moved on the surface plate 1 from the state in FIG. 2B. [Figure 3A] An example of a rotation adjustment mechanism used between G1 and Xd is shown below. [Figure 3B] An example of a rotation adjustment mechanism used between Xd and Yd is shown below. [Figure 3C] An example of a rotation adjustment mechanism used between Xd and Xo is shown below. [Figure 4] The range of movement of the donor stage is shown depending on the size of the receptor substrate. [Figure 5A] This shows the installation of a laser interferometer for the Y axis of the receptor stage. [Figure 5B] This shows the installation of a laser interferometer for the Y axis of the donor stage. [Figure 6] An example of a pattern applied to a mask is shown. [Figure 7] 1 shows the lift process using multiple rows of mask patterns. [Figure 8] The confocal beam profiler monitor is shown. [Figure 9A] Shows the first shot of the lifting process. [Figure 9B] Shows the second shot of the lifting process. [Figure 9C] Shows the third shot of the lifting process. [Figure 10] The appearance of the receptor substrate after one scan with a gear ratio of 1:2 is shown. [Figure 11] The figure shows the step scanning of the X axis of the donor stage. [Figure 12] The synchronous position error when translating the Y axis of the receptor stage and the Y axis of the donor stage is shown. [Figure 13A] The first shot of the lift process using a matrix of donor substrates is shown. [Figure 13B] The second shot of the lift process using a matrix of donor substrates is shown. [Figure 13C] The third shot of the lift process using a matrix of donor substrates is shown. DETAILED DESCRIPTION OF THE INVENTION

[0058] Hereinafter, a specific configuration of a lift device according to the present invention will be described in detail with reference to the drawings. [Example]

[0059] In this Example 1, a layered (solid) object formed in one piece on a 200 x 200 mm donor substrate via a light-absorbing layer is lifted onto a 400 x 400 mm receptor substrate as element-shaped lift objects, each with a shape of 10 x 10 μm, in a matrix of 12,000 vertical x 12,000 horizontal, totaling 144 million. The lift positions of these 144 million objects have a positional accuracy of ±1 μm, and each has a vertical and horizontal pitch of 30 μm.

[0060] First, the main components of a lifting device according to an embodiment of the present invention are shown in Figure 1A. Note that the laser device, control device, and other monitors are omitted from Figure 1A, and the X-, Y-, and Z-axis directions are shown in the figure. Surface plate 1 (G1), surface plate 11 (G11), surface plate 12 (G12), and surface plate 2 (G2) are all stone surface plates made of granite. Furthermore, highly synthetic iron is used for the base surface plate (G). This embodiment is based on the configuration of the sixth invention described above.

[0061] The configuration of the lifting device according to Example 1 of the present invention will be described in order along the propagation of the laser light from when the pulsed laser light is emitted from the laser device until it is irradiated onto an object on a donor substrate. First, the laser device used in Example 1 is an excimer laser with an oscillation wavelength of 248 [nm]. The spatial distribution of the emitted laser light is approximately 8 x 24 [mm], and the beam divergence angle is 1 x 3 [mrad]. All figures are expressed as (length x width), and the numerical values ​​are FWHM.

[0062] Note that there are various specifications for excimer lasers, including differences in output, repetition frequency, beam size, beam divergence angle, and even lasers that emit vertically long laser light (where the vertical and horizontal directions are reversed), but there are many excimer lasers that can be used in this Example 1 by adding, omitting, or modifying the design of the optical system. Furthermore, although it depends on the size of the laser device, it is generally installed on a base (laser surface plate) that is different from the base on which the stages of the lift device are installed.

[0063] The light emitted from the excimer laser enters the telescope optical system and propagates to the shaping optical system. Here, as shown in FIG. 1A, the shaping optical system is held on an optical stage (Xo) with its optical axis aligned along the X-axis, and the optical stage is installed on the X-axis (Xd) of the donor stage that moves the donor substrate. The laser light just before entering the shaping optical system is adjusted by the telescope optical system so that it becomes approximately parallel at any position within the X-axis movement range of the donor stage. Therefore, regardless of the movement of Xd and / or Xo in the X-axis direction, the laser light always enters the shaping optical system with approximately the same size and at the same angle (vertical). In this Example 1, the size is approximately 25 × 25 mm (length × width).

[0064] The shaping optical system (H) in this Example 1 is a combination of two pairs of uniaxial cylindrical lens arrays arranged at right angles in a plane perpendicular to the optical axis direction. The first lens array in each group is arranged to form an image on the mask (M) through the second lens array and a condenser lens (not shown) located behind it.

[0065] The laser light that passes through the shaping optical system is incident on the mask via a field lens (F), which, in combination with the projection lens (Pl), constitutes an image-side telecentric reduction projection optical system. The size of the laser light on the mask is 1 x 50 mm (FWHM), and the size of the area where the spatial intensity distribution uniformity is within ±5% is maintained at 0.5 x 45 mm or larger.

[0066] The mask is fixed to the mask stage, which has a six-axis adjustment mechanism: the W axis, which moves in the X-axis direction together with the field lens as mentioned above; the U axis, which moves in the Y-axis direction; the V axis, which moves in the Z-axis direction; the R axis, which is the axis of rotation within the YZ plane; the TV axis, which adjusts the tilt relative to the V axis; and the TU axis, which adjusts the tilt relative to the U axis.

[0067] The mask used in this Example 1 is a synthetic quartz plate with a pattern drawn (applied) by chrome plating. A schematic diagram is shown in Figure 6. In this mask, the white window areas (a) without chrome plating transmit the laser light, while the colored chrome-plated areas (b) block the laser light. Each window (a) measures 50 × 50 μm, and a total of 300 of these are arranged in the X-axis direction (single row) at 150 μm intervals over a distance of 43.85 mm. The chrome-plated surface is the laser light exit side, while the laser light entrance side is coated with an anti-reflection film for 248 nm. Instead of chrome plating, aluminum deposition or a dielectric multilayer film can also be used.

[0068] In the case of a lift process in which multiple patterns are used on a single mask by switching between them, masks with different patterns drawn on them can be used as long as they are within the range of the size of the laser light irradiated onto the mask from the shaping optical system and within the movable range of the mask stage.

[0069] 7, when a lifting process is used in which the donor substrate (D) is scanned multiple times or back and forth at the same speed while the receptor substrate (R) is scanned once (including stops along the way), it is possible to use a mask pattern with multiple rows (however, the laser irradiation is performed intermittently and selectively within the mask pattern; in FIG. 7, this is shown as a 3 × 2 matrix) instead of the single row shown in FIG. 6. This makes it possible to use a donor substrate that is smaller than the receptor substrate.

[0070] The laser light that passes through the mask pattern is redirected vertically downward (-Z direction) by an epi-mirror and enters the projection lens. This projection lens is coated with an anti-reflection coating for 248 nm and has a reduction ratio of 1 / 5. Details are shown in Table 1 below.

[0071] [Table 1]

[0072] The laser light emitted from the projection lens is incident on the back surface of the donor substrate and is accurately projected onto a predetermined position on the light absorption layer formed on the front surface (bottom surface) of the donor substrate at a reduced size of 1 / 5 of the mask pattern. Here, the predetermined position in the XY plane is determined after adjustment by the X axis (Xd), Y axis (Yd), and θ axis (θd) of the donor stage based on an alignment mark or the like previously attached to the donor substrate.

[0073] To adjust the image plane of the mask pattern projected by the projection lens so that it is focused on the interface between the surface of the donor substrate and the light-absorbing layer, the Z-axis stage (Zl) of the projection lens and the W-axis position of the mask stage carrying the field lens (F) are adjusted. Note that it is possible to add a function for adjusting the Z-axis direction of the donor substrate (Z-axis stage), but it is necessary to consider the decrease in lift position accuracy due to the increased load on the X-axis (Xd) of the donor stage.

[0074] When adjusting the imaging position at the interface between the donor substrate surface and the light absorption layer, a real-time monitor using a confocal beam profiler (BP) whose imaging plane is a plane conjugate to the imaging plane is effective. The adjustment screen is shown in Figure 8. In this Example 1, the spatial intensity distribution of the laser light imaged in a reduced form at the interface between the donor substrate surface and the light absorption layer is monitored in real time with high resolution.

[0075] The above is the function performed by the device configuration in the present embodiment 1 regarding the propagation of the pulsed laser light emitted from the laser device.

[0076] Next, a brief description will be given of how the parallelism of the Y axis (Yr) of the receptor stage and the Y axis (Yd) of the donor stage in the device according to the present invention is mechanically achieved using the configuration of this first embodiment.

[0077] As shown in Figure 1A, the donor stage's X-axis (Xd) is placed on granite surface plate 1 (G1), and the optical stage (Xo) is placed on top of that. The receptor stage group (Yr, θr, Zr) is placed on granite surface plate 2 (G2). The entire system is constructed on a base plate (G). Rotation adjustment mechanisms (RP) are installed between G1 and Xd, between Xo and Xd, and between Xd and Yd (not shown).

[0078] To adjust the perpendicularity and parallelism of the axes of each stage, an adjustment substrate AD is used instead of the donor substrate, which is held on the donor stage, and an adjustment substrate AR is used instead of the receptor substrate, which is placed on the receptor stage. Lines indicating the X-axis (alignment line X) and Y-axis (alignment line Y), which are precisely perpendicular to each other, are drawn on both adjustment substrates as alignment lines, and marks are also attached at predetermined positions (intervals).

[0079] 1) Parallelism between Yr and AR(Y) (squareness between Yr and AR(X)) To adjust the parallelism between the Y-axis (Yr) of the receptor stage and the alignment line Y on the adjustment substrate AR, the adjustment substrate AR placed on the Z-axis (Zr) of the receptor stage is observed using a high-magnification CCD camera fixed to the optical stage (Xo) or the Z-axis stage for the projection lens installed thereon. The Yr-axis is moved 400 mm, and adjustment is made using the θ-axis (θr) of the receptor stage so that the deviation of the alignment line Y in the X-axis direction is within 1 μm. Note that the stage movement distance at this time is within the range of the stage's effective stroke, and the allowable deviation varies depending on the required lift accuracy. (The same applies below.)

[0080] 2) Parallelism between AR(X) and Xd (perpendicularity between Yr and Xd) Next, using the alignment line X of the adjusted substrate AR adjusted as described above, the perpendicularity between the X-axis (Xd) of the donor stage and the Y-axis (Yr) of the receptor stage is adjusted while observing with a high-magnification CCD camera fixed to the optical stage (Xo) or the Z-axis stage for the projection lens attached thereto. The Xd axis is moved 400 mm, and the mounting angle between G1 and Xd is adjusted using the rotation adjustment mechanism between them, and the mounting angle between G1 and Xd, i.e., Xd relative to Yr, is also adjusted so that the deviation of the alignment line X in the Y-axis direction is within 1 μm.

[0081] 3) Parallelism between AR(X) and Xo (squareness between Yr and Xo, parallelism between Xd and Xo) Using the alignment line X of the adjusted substrate AR adjusted as described above, the parallelism between the optical stage (Xo) and the X-axis (Xd) of the donor stage is adjusted while observing with a high-magnification CCD camera fixed to the optical stage (Xo) or the Z-axis stage for the projection lens installed on it. The Xo axis is moved 200 mm, and the parallelism of the optical stage (Xo) with respect to the X-axis (Xd) of the donor stage is adjusted by the rotation adjustment mechanism between them so that the deviation of the alignment line X in the Y-axis direction is within 0.5 μm.

[0082] 4) Parallelism of Yd and AD(Y) To adjust the parallelism between the Y-axis (Yd) of the donor stage and the alignment line Y on the adjustment substrate AD, the adjustment substrate AD held on the θ-axis (θd) of the donor stage is observed using a high-magnification CCD camera fixed to the optical stage (Xo) or the Z-axis stage for the projection lens installed on it. The Yd-axis is moved 200 mm, and the θ-axis (θd) of the donor stage is used to adjust the deviation of the alignment line Y in the X-axis direction so that it is within 0.5 μm.

[0083] 5) Parallelism between AD(X) and Xo (Parallelism between AD(X) and Xd, Squareness between Xd and Yd) To adjust the perpendicularity of the X-axis (Xd) of the donor stage and the Y-axis (Yd) of the donor stage, the alignment line X on the adjustment substrate AD is observed using a high-magnification CCD camera fixed to the optical stage (Xo), whose parallelism with the X-axis (Xd) of the donor stage has already been adjusted, or the Z-axis stage for the projection lens attached to the optical stage. The optical stage (Xo) is moved 200 mm, and the perpendicularity of the alignment line X with the Y-axis (Yd) of the donor stage suspended from the X-axis (Xd) of the donor stage is adjusted using the rotation adjustment mechanism between them so that the deviation of the Y-axis of the alignment line X is within 0.5 μm.

[0084] 6) Parallelism between AD(Y) and Yr (Parallelism between Yd and Yr) Finally, to check the parallelism between the Y axis (Yd) of the donor stage and the Y axis (Yr) of the receptor stage, a high-magnification CCD camera is attached to the Y axis (Yd) of the donor stage, and the alignment line Y of the adjustment substrate AR placed on the opposing receptor stage is observed. At this time, the adjustment board AD is removed. The X-axis (Xd) of the donor stage is moved so that the high-magnification CCD camera can observe any end of the receptor stage. Next, the Y-axis (Yd) of the donor stage is moved 400 mm to confirm that the deviation of the alignment line Y in the X-axis direction is within 1 μm. To perform the same check at the other end of the receptor stage, Xd is moved to the other end, and then Yd is moved 400 mm again to confirm that the deviation of the alignment line Y in the X-axis direction is within 1 μm. It is also possible to move Yd and Yr in parallel to observe the fluctuations in the alignment mark position.

[0085] Furthermore, if a high-magnification CCD camera is attached to the Y-axis (Yd) of the donor stage, it may come into contact with these depending on the position of the X-axis of the donor stage and the shape (opening) of the stone surface plate 1. In that case, it is also possible to attach the high-magnification CCD camera to the Z-axis (Zr) of the receptor stage instead of Yd, and move the Y-axis (Yr) of the receptor stage by 200 mm to observe the alignment line Y of the adjustment substrate AD and check the amount of deviation in the X-axis direction.

[0086] Because granite surface plate 1 (G1) and granite surface plate 2 independently support each stage, and Yd is suspended from Xd installed on G1, the parallelism of Yr and Yd cannot be directly adjusted. However, as described above, the parallelism of Yr and Yd is adjusted in steps on the order of μrad. Note that as the adjustment steps from 1) to 6) are carried out, errors in parallelism (squareness) accumulate, so it is desirable to adjust the allowable deviation in the initial stage as small as possible. Furthermore, although the adjustment steps from 1) to 6) above describe the adjustment of the parallelism and squareness of each stage in the XY plane, adjustments around other axes (X and Y axes) are also necessary.

[0087] Next, the scanning of the donor substrate and receptor substrate during lifting in this Example 1 will be described with reference to Figures 9A to 9C. Here, the top views of Figures 9A to 9C show an image in which an operator is placed on the left side of these figures, and the donor substrate (D) and receptor substrate (R) are scanned back and forth relative to the operator.

[0088] First, the deflection of the donor substrate, which is attached to the θ-axis (θd) of the donor stage, is measured across the entire surface of the donor substrate, and this is mapped as two-dimensional data along with the position information. This information is used as a correction amount for the Z-axis (Zr) of the receptor stage, which corresponds to the X-axis (Xd) and Y-axis (Yd) of the donor stage that moves during the lifting process.

[0089] For the sake of convenience in the following explanation, a predetermined position on the front left of the receptor substrate (R) and donor substrate (D) as seen from the operator is defined as the origin of each substrate. The positions of the optical stage (Xo) and receptor stage (Yr, θr) when the laser light is irradiated onto the origin of the receptor substrate are also defined as the origin. Similarly, for the donor substrate, the position of the donor stage (Xd, Yd, θd) when the laser light (LS) is irradiated is also defined as the origin. However, the origin of each stage is not necessarily one end of its stroke range, but is a position that leaves a stroke for subsequent lifting steps and substrate removal.

[0090] FIG. 9A shows the donor substrate (D) and receptor substrate (R) at their origin positions irradiated with the first pulse of laser light (LS). Both side and top views are shown. The dashed-dotted line indicates the laser light being irradiated onto the target (S) via a reduced projection optical system. The irradiated 10 × 10 μm area of ​​the light-absorbing layer (not shown) absorbs the laser light, causing ablation and generating a shock wave, which lifts the target of the same area onto the opposing receptor substrate. While three targets are shown, in this Example 1, a total of 300 targets are lifted toward the receptor substrate at one time.

[0091] In this Example 1, the laser device oscillates at 200 Hz, and the lift is performed in one shot, so the receptor stage (Yr) scans the receptor substrate in the -Y direction at a speed of 6 mm / s without stopping until it reaches the next irradiation position.

[0092] Meanwhile, the Y axis (Yd) of the donor stage is synchronized with the Y axis (Yr) of the receptor stage, and the donor substrate is scanned in the -Y direction at a speed of 3 mm / s without stopping. In other words, the ratio of the movement speeds (gear ratio) of Yd and Yr is 1:2. Figure 9B shows the state of the second shot after each substrate has moved.

[0093] The positions of Yr and Yd are synchronized by setting Yr as the reference (master) and Yd as the slave (slave), using the gear command of the stage system to operate both stages in gear mode synchronization.A programmable multi-axis control device is used for the control system.

[0094] In addition, the actual stage position measured by a laser interferometer is used to determine the gear ratio in the gear command. A corner cube (Ic) constituting a laser interferometer is attached near the receptor substrate and moves with the moving table Yr, and a He-Ne laser (IL) with a wavelength of 632.8 [nm] and a light receiving unit (not shown in Figure 5A) are installed on the stone surface plate 2 (or an equivalent fixed position). Similarly, a corner cube is attached to the side of the moving table Yd, and the interferometer laser and light receiving unit (not shown in Figure 5B) are installed on Xd. This allows for accurate position synchronization of each stage.

[0095] As mentioned above, each stage begins accelerating from a position just before the origin so that it is already moving at a stable, uniform velocity at the origin. During this acceleration time and the time it takes for the stage to reach the origin, the laser pulse must be blocked to prevent laser light from being irradiated onto the donor substrate. Therefore, the programmable multi-axis control device sends an external oscillation trigger or a high-speed shutter operation start trigger to the laser device, as well as a stage drive signal, with high precision.

[0096] The third shot is shown in Figure 9C. As can be seen from the figure, the distance traveled by the receptor substrate (R) is twice that of the donor substrate (D). The movement of the receptor substrate and donor substrate continues in the same manner.

[0097] When the donor substrate has scanned 180 mm in the -Y direction, and when the receptor substrate has scanned 360 mm in the -Y direction, the laser oscillation is temporarily stopped or the laser light irradiation is blocked by a high-speed shutter. By scanning this distance, 300 objects lined up in the X-axis direction are lifted 12,000 times in the Y-axis direction of the receptor substrate, for a total of 3.6 million objects. Figure 10 shows this process.

[0098] During this pause, the Y-axis (Yr) of the receptor stage and the Y-axis (Yd) of the donor stage both return to their origins. (However, the acceleration distance for the next scan must be taken into consideration. The same applies below.) Meanwhile, the X-axis (Xd) of the donor stage returns to a position -9 mm from the previous origin. Then, the lift process begins again from a new area. This process is repeated.

[0099] Figure 11 shows the state immediately before the stage returns to a position 15 μm in the −X direction (shown by the solid line) from the previous origin (shown by the dotted line) after completing 20 steps of Xd. This point becomes the new origin, and the stage then begins a similar operation. After this, the Y-axis scans of both stages (180 mm (Yd) and 360 mm (Yr)) and the −9 mm × 20 steps of Xd are repeated. This allows the laser beam to irradiate areas not irradiated by the laser beam during the initial 180 mm Xd scan (20 steps of −9 mm). This allows the laser beam to be irradiated to areas scheduled for the next laser beam (LS) irradiation during the initial 180 mm Xd scan (shown by the dashed-dotted line). This effectively lifts the target object on the donor substrate to the receptor substrate.

[0100] The approximate processing time is 360 mm / 6 mm / s x 40 times = 2400 seconds. Note that this time does not include the time it takes for the receptor stage's Y-axis (Yr) to travel the distance required for acceleration and deceleration, or the time it takes for the receptor stage to return to the origin after each Y-axis scan. In addition, by increasing the repetition frequency of the excimer laser to 1 kHz, this processing time can be reduced to 1 / 5.

[0101] 12 shows the synchronous position error of the two stages when the Y axis (Yr) of the receptor stage (master) is moved synchronously over a distance of 400 mm at a moving speed of 150 mm / s, and the Y axis (Yd) of the donor stage (slave) is moved synchronously over a distance of 200 mm at a moving speed of 75 mm / s, using the apparatus configuration of Example 1. Specifically, the difference (ΔYdr = δYd - δYr) between the position information obtained from the linear encoder and the position information measured by the laser interferometer for the Yr (master) stage and the error (δYd) between the position information obtained from the linear encoder and the position information measured by the laser interferometer for the Yd (slave) stage, which moves synchronously at half the speed of the Yr (slave), is plotted against the elapsed time corresponding to the moving speed of the receptor stage. As can be seen from these results, a position synchronization accuracy of within ±1 μm was achieved over a travel distance of 400 mm.

[0102] As described above, the lift pattern of the object onto the receptor substrate in this Example 1 is a matrix of 10 x 10 μm lifted at intervals of 30 μm. However, if the interval is set to 60 μm, for example, one donor substrate can lift the equivalent of four receptor substrates. [Example]

[0103] In Example 2, unlike Example 1 in which the objects on the surface of the donor substrate were in a single layer state, a total of 144 million objects, each 10 x 10 μm in size and spaced 15 μm apart, were formed in a matrix on a donor substrate also measuring 200 x 200 mm, and were then lifted onto a receptor substrate measuring 400 x 400 mm in size at half the density of the donor substrate, i.e., at intervals of 30 μm, in the same matrix state.

[0104] The arrangement of the objects finally lifted onto the receptor substrate is the same as in Example 1, but in Example 2, the objects are similarly arranged on the donor substrate in advance at twice the density, and are then lifted onto the receptor substrate with a positional accuracy of ±1 μm. In this case, the positional synchronization accuracy of the Y axis (Yd) of the donor stage and the Y axis (Yr) of the receptor stage is required to be even stricter than in Example 1.

[0105] 13A to 13C show the state from the first pulse of laser light (LS) to the third shot irradiated onto the donor substrate (D) and receptor substrate (R) at the origin position, as in Example 1. [Example]

[0106] In Example 3, the method for lifting an object on the surface of the donor substrate to the receptor substrate is the same as in Example 1 or 2. However, the method for adjusting the parallelism between the Y axes of each stage, the parallelism between the X axes of each stage, and the perpendicularity between each Y axis and X axis differs from the previous examples. That is, while the adjustment method described in Example 1 performs the adjustment steps 1) to 6) to adjust the parallelism between the Y axis (Yr) of the receptor stage and the Y axis (Yd) of the donor stage, in Example 3, the parallelism between Yr and Yd is adjusted at an early stage of the adjustment steps.

[0107] 1) Straightness of Yr, θr, and Zr This adjustment step is a premise common to Examples 1 and 2. The straightness of the Y-axis (Yr) of the receptor stage placed on the stone surface plate 2 (G2), the θ-axis (θr) placed thereon, the Z-axis (Zr), and the receptor substrate holder (straightness with respect to the Z-axis, which is the vertical direction when the horizontal plane is the XY plane) are adjusted using a laser interferometer or the like. Note that, after this adjustment, basically, no adjustments that may affect the squareness of the receptor stage group are made, and all adjustments of other stages are made based on the receptor stage group, for example, its top surface.

[0108] 2) Parallelism between Yr and AR(Y) (squareness between Yr and AR(X)) As in adjustment step 1) of Example 1, the parallelism between the Y axis (Yr) of the receptor stage and the alignment line Y on the adjustment substrate AR is adjusted. This also adjusts the perpendicularity between Yr and the alignment line X. Note that if an alignment line or alignment mark drawn directly on Yr is used without using the adjustment substrate AR, this adjustment step 1) can be omitted.

[0109] 3) Parallelism of AR(X) and Xd (perpendicularity of Yr and Xd) Next, the alignment line X of the adjustment substrate AR is observed using a high-magnification CCD camera installed on an optical stage (Xo) mounted on the X-axis (Xd) of the donor stage. The Z-axis position of this high-magnification CCD camera depends on the design of the projection optical system, but in this Example 3, it is fixed using a Z-axis stage (Zl) that holds the projection lens near the position of the projection lens (Pl). Xd is moved 400 mm, and the mounting angle of Xd relative to the stone surface plate 1, i.e., the perpendicularity of Xd relative to Yr, is adjusted using a rotation adjustment mechanism so that the deviation of the alignment line X in the Y-axis direction is within 0.3 μm.

[0110] 4) Parallelism of Yr and Yd in the YZ plane In the description of Example 1, adjustment steps around other axes (X-axis and Y-axis) were omitted. Here, we will briefly explain the steps for adjusting parallelism around the X-axis, i.e., in the YZ plane. The underside of the Y-axis (Yd) of the donor stage is observed using a height sensor installed on the Z-axis (Zr) or other location of the receptor stage. Yr and Yd are simultaneously moved (paralleled) the same distance by 200 mm or more in sync, and the fluctuation in the measurement value (distance between Zr and Yd) measured by the gap sensor is observed. A shim plate is inserted between the rotation adjustment mechanism installed between Xd and Yd and Yd or between Xd and Yd, and the parallelism in the YZ plane between Yr and Yd is adjusted so that the fluctuation is within 5 μm, or within a range sufficiently smaller than the focal depth of the projection lens.

[0111] 5) Parallelism of Yr and Yd The alignment mark for pattern matching on the underside of Yd is observed using a high-magnification CCD camera installed on Zr or elsewhere. Yr and Yd are moved the same distance in sync (parallel), and if the position of the pattern-matched alignment mark image (such as a cross mark) moves in the X-axis direction, a rotation adjustment mechanism installed between Xd and Yd is used to correct this. Note that instead of an alignment mark, it is also possible to use the alignment line Y on the adjustment substrate AD attached to the Y-axis of the donor stage.

[0112] 6) Perpendicularity of Yr and Xo The alignment line X of the adjusted substrate AR, whose perpendicularity with the Y axis (Yr) of the receptor stage has been adjusted in the adjustment step 1), is observed with a high-magnification CCD camera installed on the optical stage (Xo). Xo is moved 400 mm, and the mounting angle of Xo relative to Xd is adjusted using a rotation adjustment mechanism installed between them so that the deviation of the alignment line X in the Y axis direction is within 0.3 μm. [Example]

[0113] Figure 2A shows the main components of the lifting device of Example 4. This example is based on the seventh aspect of the present invention. The laser device, control device, and other monitors (all of which are the same as in Example 1) are omitted from Figures 2A to 2C, and the X-, Y-, and Z-axis directions are shown in the figures. The donor substrate, receptor substrate, and the arrangement of the lifting object on the donor substrate and on the receptor substrate after lifting are the same as in Example 2.

[0114] The state of the optical system from when the pulsed laser light is emitted from the excimer laser device to when it is irradiated onto the lift target on the donor substrate is the same as in Example 1, except for the differences in the construction of each stage group shown in Figures 1A and 2A, as described below. That is, in the case of the lift device according to the sixth invention shown in Figures 1A to 1C, the X-axis (Xd) of the donor stage is mounted on the stone surface plate 1 (G1), and the optical stage (Xo) is mounted on top of that, in that order, whereas in the case of the lift device according to the seventh invention shown in Figures 2A to 2C, the Xo is mounted on top of G1 and Xd is suspended below G1, which is the difference in the construction of these stage groups.

[0115] The light emitted from the excimer laser enters the telescope optical system and propagates to the shaping optical system. As shown in Figure 2A, this shaping optical system is installed on an optical stage (Xo) that moves in the X-axis direction so that its optical axis is parallel. Xo is placed on a granite stone surface plate 1 (G1), and a rotation adjustment mechanism (RP) is located between the two. Here, Xo is perpendicular to the Y-axis (Yr) of the receptor stage, which is placed on a different stone surface plate 2 (G2) from G1, and is parallel to the X-axis (Xd) of the donor stage. The laser light just before entering the shaping optical system is adjusted by the telescope optical system so that it has approximately the same shape (approximately 25 × 25 mm (length × width, FWHM)) regardless of the movement of Xo.

[0116] The X-axis (Xd) of the donor stage is suspended below G1, and the Y-axis (Yd) of the donor stage is suspended below G1. A rotation adjustment mechanism is provided between the two. Figure 2B shows a side view of Xo and Xd moved the same distance relative to G1. This allows the X-axis position relative to Yd to be changed without changing the relative positions of Xo and Xd on the X-axis. Figure 2C also shows a side view of Xo alone moved relative to G1. This allows the relative positions of Xd and Xo on the X-axis to be changed.

[0117] The details of the other reduced projection optical systems, namely the field lens (F), mask (M), and projection lens (P1), are the same as in Example 1. The laser light emitted from the projection lens is incident on the back surface of the donor substrate and accurately projects a reduced size of 1 / 5 of the pattern drawn on the mask onto the lift target formed on the front surface (bottom surface) of the donor substrate. Also, the imaging state on the surface of the donor substrate is measured using a confocal beam profiler, as in Example 1.

[0118] When a lift object placed on the surface of a donor substrate is lifted onto an opposing receptor substrate based on the mask pattern reduced and projected as described above, how the donor substrate and receptor substrate are scanned and how the lift object is lifted onto the receptor substrate are shown in Figures 6, 10, 11, and 13A to 13C.Furthermore, the positional synchronization accuracy in the movement of the Y axis (Yr) of the receptor stage and the Y axis (Yd) of the donor stage is the same as that shown in Figure 12 in Example 1.

[0119] Furthermore, the methods for adjusting the parallelism between the Y axes of each stage, the parallelism between the X axes of each stage, and the squareness between each Y axis and the X axis are the same as in Example 3. That is, the Y axis (Yr) of the receptor stage whose straightness has been adjusted is used as the adjustment reference, and the squareness between Yr and the X axis (Xd) of the donor stage suspended from the granite surface plate 1 (G1) is observed with a high-magnification CCD camera fixed to the Z axis (Zr) of the receptor stage and adjusted with a rotation adjustment mechanism (RP) between G1 and Xd. Then, the parallelism between the Y axis (Yd) of the donor stage suspended from the adjusted Xd and Yr is observed with the same high-magnification CCD camera and adjusted with the RP between Xd and Yd. Finally, the squareness between the optical stage (Xo) and Yr is observed with a high-magnification CCD that moves with Xo and adjusted with the RP between G1 and Xo. [Industrial Applicability]

[0120] The device can be used as a display manufacturing device. [Explanation of symbols]

[0121] AD Donor Stage Adjustment Board AR receptor stage adjustment board BP Confocal Beam Profiler CCD high magnification camera D donor substrate F field lens G base plate G1 Surface Plate 1 G11 Surface Plate 11 G12 Surface Plate 12 G2 Surface Plate 2 G3 Surface Plate 3 H Shaping optical system Ic Corner cube for laser interferometer IL Laser for laser interferometer LS laser light M Mask Pl Projection Lens R receptor substrate RP rotation adjustment mechanism S Object TE Telescope Xd X axis of the donor stage Xo Optical stage (X axis) Yd Y axis of the donor stage Yl Projection lens and camera switching stage Yr Y axis of receptor stage Zl Z-axis stage of the projection lens Zr Z axis of receptor stage θd θ axis of the donor stage θr θ axis of receptor stage

Claims

1. A laser processing method for removing a portion of a substrate using laser light, comprising: The laser light emitted from the laser device is converted into parallel light by a telescope, shaping the collimated laser light into a laser light having a region with a substantially uniform spatial intensity distribution by a shaping optical system; irradiating the shaped laser light onto a mask; a mask pattern is reduced and projected onto the portion of the substrate to be removed by a projection lens; the shaping optical system moves in the optical axis direction during a processing operation, In the laser processing method, the laser beam incident on the shaping optical system is adjusted by the telescope so as to become substantially parallel beam within the range of movement.

2. A laser processing method as described in claim 1, wherein the substrate moves relative to the pattern of the mask in an in-plane direction of the substrate during the processing operation.

3. A laser processing method as described in claim 1 or 2, wherein the movement of the shaping optical system is performed without changing the relative positions on the optical axis between the shaping optical system and the mask and the projection lens.

4. 4. The laser processing method according to claim 1, wherein the spatial intensity distribution of the laser light projected onto the substrate in a reduced scale has a region where it is substantially uniform.

5. 5. The laser processing method according to claim 1, wherein the uniformity of the spatial intensity distribution of the laser light on the mask has an area within ±5%.

6. 6. The laser processing method according to claim 1, wherein the laser light is an excimer laser.

7. A reduction projection optical system used in a laser processing apparatus that removes a portion of a substrate by laser light, a laser device that emits laser light; a telescope that converts the emitted laser beam into parallel beams; a shaping optical system that shapes the collimated laser light into a laser light having a region with a substantially uniform spatial intensity distribution; a mask that passes the shaped laser light in a predetermined pattern; a projection lens that reduces and projects a predetermined pattern of the laser light onto the portion of the substrate to be removed; and the shaping optical system moves in the optical axis direction during a processing operation, In the reduction projection optical system, the laser beam incident on the shaping optical system is adjusted by the telescope so as to become substantially parallel light within the range of movement.

8. A reduction projection optical system as described in claim 7, wherein the substrate moves relative to the predetermined pattern of the laser light in an in-plane direction of the substrate during the processing operation.

9. A reduction projection optical system as described in claim 7 or 8, wherein the movement of the shaping optical system is performed without changing the relative positions on the optical axis between the shaping optical system and the mask and the projection lens.

10. 10. The reduction projection optical system according to claim 7, wherein the laser light projected onto the substrate has a region in which the spatial intensity distribution is substantially uniform.

11. 11. The reduction projection optical system according to claim 7, wherein the uniformity of the spatial intensity distribution of the laser light on the mask has an area within ±5%.

12. 12. The reduction projection optical system according to claim 7, wherein the laser light is an excimer laser.

13. A method for manufacturing a substrate having a portion removed by the laser processing method according to any one of claims 1 to 6.

14. A laser processing device comprising the reduction projection optical system according to any one of claims 7 to 12, for removing a part of a substrate with a laser beam.

Images