Laser processing methods and methods utilizing them, reduction projection optical systems, substrate manufacturing methods, and laser processing apparatus.

Abstract

This invention provides a laser processing method and a method utilizing the same, a reduction projection optical system, a substrate manufacturing method, and a laser processing apparatus. While maintaining high transfer position accuracy, it achieves the scaling up, refinement, and reduction of cycle time for the recipient substrate of the transfer apparatus. In a mechanism constructed on separate platforms, each stage group moving in a state holding the donor substrate on which the transfer target is placed and / or the beam shaping optical system and the reduction projection optical system, and the stage group holding the recipient substrate as the transfer target, vibrations arising from the relative scanning of each substrate with respect to the laser and abnormalities in the synchronous position accuracy of the stage undertaking the scan are minimized.

Description

Technical Field

[0001] This invention relates to a transfer method and a photomask that uses laser irradiation to transfer an object located on a donor substrate to a recipient substrate with high precision (LIFT: Laser Induced Forward Transfer). Prior Technology

[0002] A previous technique involved irradiating an organic EL (electroluminescent) layer on a donor substrate with a laser and transferring it to an opposing circuit substrate. Patent Document 1 discloses a method where a single laser is converted into multiple rectangular lasers with uniform intensity distribution and a rectangular shape. These lasers are then arranged in series at equal intervals and irradiated onto a designated area of ​​the donor substrate at intervals of more than a certain time and overlapping a predetermined number of times. The laser beams are absorbed by a metal foil located between the donor substrate and the organic EL layer, generating an elastic wave that transfers the peeled-off organic EL layer to the opposing circuit substrate.

[0003] This technology uses a structure where a spacer with an appropriate value of 80-100 μm is sandwiched between a donor substrate and a circuit board. A component that maintains the spacing between the donor substrate and the circuit board in a fixed and integrated state is placed on a stage and scanned relative to a laser. However, in this case, in addition to the additional step of integrating the opposing donor substrate and circuit board, a donor substrate of the same size as the circuit board is required. Furthermore, with the need for larger circuit boards, manufacturing costs and device size increase.

[0004] Similarly, as a technique for transferring an organic EL layer on a donor substrate to an opposing circuit board, Patent Document 2 discloses a technique in which a light-absorbing layer is disposed between the donor substrate and the organic EL layer, and the light-absorbing layer absorbs irradiated laser light to generate a shock wave, thereby transferring the organic EL layer on the donor substrate to an opposing circuit board with a spacing of 10 to 100 μm. However, Patent Document 2 does not disclose a laser scanning method or a stage structure for implementing it, nor does it disclose a transfer device. Therefore, Patent Document 2 cannot be used as a reference for a technique to maintain and improve the transfer position accuracy that can correspond to the scaling up of circuit boards.

[0005] Furthermore, Patent Document 3 discloses a technique related to step-scanning in an exposure apparatus for semiconductor device manufacturing. Its basic consideration is as follows: an exposure is performed intermittently on a series of irradiation areas along the scanning exposure direction of the wafer stage while skipping several intermediate irradiation areas, without stopping the wafer stage midway. Specifically, Patent Document 3 discloses an exposure apparatus comprising: an intermediate photomask stage for holding an intermediate photomask; a wafer stage for holding a wafer; and a projection optical system for projecting a pattern of the intermediate photomask onto the wafer. Exposure is performed while the intermediate photomask stage and the wafer stage scan relative to the projection optical system, sequentially projecting the pattern of the intermediate photomask onto multiple irradiation areas of the wafer. The wafer stage is moved continuously while scanning, and multiple irradiation areas on the wafer arranged along the scanning direction are intermittently exposed. Therefore, under the requirements of larger wafers and higher processing speeds, compared to the step-and-repeat method of repeatedly accelerating and decelerating the wafer stage, the impact of vibration and wobbling caused by the scanning of the stage on exposure accuracy can be reduced.

[0006] However, the technology disclosed in Patent Document 3 is a semiconductor exposure apparatus technology based on reduced projection exposure, and its technical field differs from the transfer technology of the present invention. Specifically, the structure and scanning technology of the intermediate photomask stage and wafer stage of the exposure apparatus are completely different from the stage structure and scanning technology of the present invention. The stage structure and scanning technology of the present invention are used to reduce the photomask pattern of the present invention onto the object on the donor substrate with high positional accuracy, and then transfer the object onto the recipient substrate with the same high positional accuracy. Therefore, the specific stage structure and scanning technology of the present invention cannot refer to the technology disclosed in Patent Document 3.

[0007] Existing technical documents

[0008] Patent Document 1: Japanese Patent Publication No. 2014-67671

[0009] Patent Document 2: Japanese Patent Publication No. 2010-40380

[0010] Patent Document 3: Japanese Patent Publication No. 2000-21702 Summary of the Invention

[0011] By configuring the donor stage holding the donor substrate and the optical stage of the holding optical system placed on the donor stage as two independent mechanisms, and by configuring the receiver stage holding the receiver substrate as an independently mounted platform rather than placing the optical stage directly on the donor stage, the impact of vibrations and various errors generated during scanning of each stage on the synchronization position accuracy between stages is minimized. As a result, the object of the present invention is to provide a transfer device that, while maintaining transfer position accuracy, facilitates the scaling up and refinement of the receiver substrate and reduces cycle time.

[0012] The first invention is a transfer device that selectively peels off an object and transfers it to a recipient substrate that moves relative to the donor substrate by irradiating it with pulsed laser light from the back of a donor substrate onto the surface of the moving donor substrate. The transfer device includes: a pulsed laser device; a telescope that parallelizes the pulsed laser light emitted from the laser device; a shaping optical system that shapes the spatial intensity distribution of the pulsed laser light passing through the telescope into a uniform distribution; a mask that allows the pulsed laser light shaped by the shaping optical system to pass through in a predetermined pattern; a field lens located between the shaping optical system and the mask; a projection lens that reduces and projects the laser light patterned by 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; and a donor stage that allows the recipient substrate to be placed on the donor substrate. The donor substrate is held with its back side facing the laser injection side; a receiver stage holds the receiver substrate; and a programmable multi-axis control device has a trigger output function for pulsed laser oscillation and a stage control function. The receiver stage has a Y-axis when the horizontal plane is taken as the XY plane, a Z-axis in the vertical direction, and an θ-axis in the XY plane. The donor stage has an X-axis, a Y-axis, and an θ-axis. The projection lens is held on the optical stage together with the Z-axis stage for the projection lens. The telescope, the shaping optical system, the field lens, the photomask, and the projection lens constitute a reduction projection optical system. The reduction projection optical system projects the pattern of the photomask onto the surface of the donor substrate in a reduced manner. The X-axis of the donor stage is set on platform 1 (first platform), and the Y-axis of the receiver stage is set on platform 2 (second platform), which is different from platform 1. The Y-axis of the donor stage is suspended from the X-axis of the donor stage.

[0013] Here, the "moving" substrate includes a case where it moves continuously even when irradiated by a pulsed laser (referred to as "LS" in FIG1A; however, although FIG1A shows the main structural part of the second invention, it is referred to as such because it includes structural parts common to the structure of the first invention. The same applies below). The case where the moving substrate is selected based on the transfer process performed by the transfer apparatus according to the present invention and the required cycle time, etc., is also included. Furthermore, structures where the donor substrate (D) moves and stops repeatedly while the recipient substrate (R) does not stop, and structures where the opposite is true, are also included. When only one irradiation is used in the peeling of the object from the donor substrate and a high cycle time is required, a structure in which the donor substrate and the recipient substrate move continuously at the same or different speeds is suitable. On the other hand, when it is desired to laminate the object to a certain thickness, a structure in which the donor substrate moves continuously while the recipient substrate stops during a certain number of irradiations is sometimes selected.

[0014] Furthermore, the term "object" is not particularly limited and refers to any object disposed on the donor substrate or disposed on the donor substrate as a single sheet, separated by a light-absorbing layer (not shown in Figure 1A). This includes thin films, such as the organic EL layer described in the patent document, and objects arranged in a regular pattern of tiny units, but is not limited to these types of objects. Additionally, the transfer mechanism includes the following: the light-absorbing layer, irradiated with laser light, generates a shock wave, thereby peeling the object from the donor substrate and transferring it toward the recipient substrate; or the object is peeled off by direct laser irradiation without a light-absorbing layer; however, it is not limited to these cases.

[0015] The material of the donor substrate only needs to have transmittance characteristics to the wavelength of the laser; ideally, it should be a material with minimal bending caused by the large size of the substrate. However, if the bending is so large that it does not satisfy the uniformity of the gap between the donor and recipient substrates, the method for holding the donor substrate in the donor stage (Yd, θd) can be, for example, mechanical correction by setting an adsorption region near the center of the donor substrate; or correction using a gap sensor formed by a combination of height sensors described later.

[0016] In this invention, in order to transfer an object located near the edge of the donor substrate to the recipient substrate, the movable range of the donor stage includes the XY plane region where the donor substrate should move, and refers to the range dependent on the size of the recipient substrate. As an example, when the size of the donor substrate in the XY plane is 200×200 [mm] and the same recipient substrate is 400×400 [mm], the predetermined range that the donor stage (Xd, Yd) should move is approximately 800×800 [mm]. Figure 4 illustrates this case. Furthermore, this region is also included when further movement is required to remove the donor substrate.

[0017] Furthermore, the material of the "platform" is not particularly limited, but it must be a material with extremely high rigidity. To ensure the rigidity of platform 1 (G1), it is desirable to have a "コ" or "□" shape when viewed from above. In Figure 1A, platform 2 is shown as a single platform, but more specifically, it can also be configured as two platforms arranged along the Y-axis, with a linear scale and linear motor placed between them. Additionally, platform 1 and platform 2 can be structures fixed to the same base platform (G). Furthermore, G1 can be composed of a combination of platform 11 (G11) and platform 12 (G12).

[0018] Furthermore, any platform must be constructed using high-rigidity materials such as steel, stone, or ceramic. For example, granite can be used, but it is not a limitation. Additionally, all platforms do not need to be made of the same material.

[0019] In the embodiments described later, the movement of each stage will be explained in detail, but the general operation is as follows. First, the X-axis (Xd) of the donor stage is set on G1 with the Y-axis (Yd) of the donor stage suspended thereon, and moves along the X-axis. Furthermore, this movement changes the relative position of the donor substrate and the recipient substrate along the X-axis. Figure 1B shows the movement. Also, the detailed structure of the movable worktable and linear guide rails, etc., of the stage is not shown in any of the figures.

[0020] The method of setting the optical stage (Xo) to the platform is not limited; various mechanisms can be selected, such as placing it on Xd, placing it on the same platform as the platform on which Xd is set, or placing it on a different platform from Xd. Xo and Xd move simultaneously and along the X-axis, while the relative positions of the shaping optical system (H), field lens (F), photomask (M), and projection lens (Pl) remain unchanged, allowing them to move as a whole. On the other hand, the movement of Xo along the X-axis changes the relative positional relationship between the donor substrate and the projection lens. Figure 1C illustrates this movement.

[0021] Alternatively, if it is not necessary to change the relative position of the donor substrate and the projection lens along the X-axis, it can be a structure that always moves together with the X-axis of the donor stage. That is, the optical stage is omitted, and the homogenizer, field lens, photomask and projection lens are all set on the X-axis of the donor stage or fixed on another platform.

[0022] The photomask is held on a photomask stage, which has at least a W-axis that moves along the X-axis direction together with the field lens. Preferably, it may also have: a U-axis in the Y-axis direction, a V-axis that moves along the Z-axis direction, an R-axis that serves as a rotation axis in the YZ plane, a TV-axis for adjusting the tilt relative to the V-axis, and a TU-axis for adjusting the tilt relative to the U-axis. Furthermore, to suppress the injection of heat generated by laser irradiation onto the photomask, an aperture photomask with a pattern slightly larger than the photomask pattern can be provided on the front side of the photomask, forming a double-photomask structure in conjunction with the photomask.

[0023] The donor stage's Y-axis (Yd) and the recipient stage's Y-axis (Yr) move at the same or different speeds while maintaining a fixed gap and extremely high parallelism between the donor and recipient substrates during the transfer process. Furthermore, according to the aforementioned structure of the movement method of each stage group and the platforms supporting them, by limiting the recipient substrate's movement mechanism to the Y-axis and separating it from the donor substrate's movement mechanism, mutual interference caused by disturbances and vibrations in the movement areas of their respective substrates can be suppressed, enabling the handling of increasingly larger and finer recipient substrates.

[0024] The second invention is based on the first invention, wherein the X-axis of the donor stage is placed on the platform 1, and the optical stage is placed on the X-axis of the donor stage.

[0025] Figure 1A shows the main structural parts of the transfer device of the second invention (side view). Figure 1B shows the case where Xd is placed on Xo and has moved from the state of Figure 1A (side view). Figure 1C shows the case where Xo has moved on Xd from the state of Figure 1B (side view). Figure 1D shows the top view of Figure 1C.

[0026] The third invention is based on the first invention, wherein the optical stage is placed on the platform 1, and the X-axis of the donor stage is suspended on the platform 1.

[0027] Figure 2A shows the main structural parts of the transfer device of the third invention (side view). Figure 2B shows the case where Xd and Xo have moved the same distance on G1 (Xd is suspended on G1) from the state of Figure 2A (side view). Figure 2C shows the case where only Xo has moved on G1 from the state of Figure 2B (side view).

[0028] The fourth invention is based on the first invention, wherein the X-axis of the donor stage is mounted on the platform 1, and the optical stage is placed on a platform 3 (third platform) that is different from both the platform 1 and the platform 2.

[0029] Here, "set on platform 1" includes the state of being placed on platform 1 and the state of being suspended from platform 1, but is not limited to these states.

[0030] The fifth invention is based on the first invention, and has a rotation adjustment mechanism between the X-axis of the donor stage and the platform 1 for fine adjustment of the setting angle in the XY plane between the two.

[0031] Here, Figure 3A shows an example of a rotation adjustment mechanism (RP) disposed between the X-axis (Xd) of the donor stage and platform 1 (G1). In Figure 3A, the left view is a top view, and the right view is a side view viewed from the X-axis direction. Furthermore, in the top view, the outer row of holes is used for fixing with G1, and has "clearance" (allowance, leeway) to provide rotation adjustment functionality. Additionally, in the top view, the two inner rows of holes are holes through which screws pass, used to fix the linear guides of the RP and Xd. Alternatively, the side with "clearance" could also be used as the hole for the linear guide of Xd, but fixing the two linear guides independently and parallel may increase the difficulty of the setup process.

[0032] On the other hand, Figure 3B shows an example of an RP disposed between Xd and the Y-axis (Yd) of a donor stage suspended on Xd. In the top view, the two rows of holes on the outer side are used for fixing with Xd and have "clearance" for rotational adjustment. Furthermore, the two rows of holes arranged along the Y-axis are used for fixing with Yd.

[0033] Furthermore, a different RP than the aforementioned RP can be used as the RP positioned between G1 and Xd. For example, a fulcrum (the rotation axis in the Z-axis direction) can be set on the contact surface between the RP and G1. This fulcrum is used to rotate and adjust the RP with Xd placed on it relative to G1 in the XY plane (illustration omitted). A force point relative to the fulcrum is set on the side (vertical plane) of the RP sufficiently far away from the fulcrum. A large screw is set on G1 near this force point, pushing horizontally towards the force point. Similarly, a large screw is set on the side of the RP on the opposite side. Thus, the RP with Xd placed on it can rotate relative to G1 about the fulcrum in the XY plane at a rate on the order of microradians [μrad].

[0034] The sixth invention is based on the second invention, and includes a rotation adjustment mechanism between the X-axis of the donor stage and the platform 1 for fine-tuning the setting angle in the XY plane between them; a rotation adjustment mechanism between the X-axis of the donor stage and the optical stage for fine-tuning the setting angle in the XY plane between them; and a rotation adjustment mechanism between the X-axis of the donor stage and the Y-axis of the donor stage for fine-tuning the setting angle in the XY plane between them.

[0035] For example, the RP used in the above-mentioned figure 3A between G1 and Xd, the RP used in the above-mentioned figure 3C between Xd and Xo, and the RP used in the above-mentioned figure 3B between Xd and Yd can be used.

[0036] The seventh invention is based on the third invention, and includes a rotation adjustment mechanism between the X-axis of the donor stage and the platform 1 for fine-tuning the setting angle in the XY plane between them, a rotation adjustment mechanism between the optical stage and the platform 1 for fine-tuning the setting angle in the XY plane between them, and a rotation adjustment mechanism between the X-axis of the donor stage and the Y-axis of the donor stage for fine-tuning the setting angle in the XY plane between them.

[0037] Here, for example, the RP shown in FIG3A is used as the rotation adjustment mechanism between Xo and G1 and between Xd and G1, respectively. On the other hand, the RP shown in FIG3B is used as the rotation adjustment mechanism between Xd and Yd. The former RP has holes through which screws for fixing the linear guides of Xo and Xd pass. Using the "clearance" of the holes, the setting angle in the XY plane of the RP and G1, which are fixed with the linear guides for each machine, is adjusted.

[0038] The eighth invention is based on the fourth invention, and includes a rotation adjustment mechanism between the X-axis of the donor stage and the platform 1 for fine-tuning the setting angle in the XY plane between them, a rotation adjustment mechanism between the optical stage and the platform 3 for fine-tuning the setting angle in the XY plane between them, and a rotation adjustment mechanism between the X-axis of the donor stage and the Y-axis of the donor stage for fine-tuning the setting angle in the XY plane between them.

[0039] The ninth invention is based on any one of the first to eighth inventions, wherein the laser device is an excimer laser.

[0040] Here, the oscillation wavelength of the excimer laser is mainly 193 [nm], 248 [nm], 308 [nm] or 351 [nm], and is appropriately selected from them according to the material of the light absorption layer and the light absorption characteristics of the object.

[0041] The tenth invention is based on the ninth invention, wherein the transfer device includes a pulse shutter that cuts off any pulse train of laser pulses emitted from the excimer laser.

[0042] As is known to the public, pulse-oscillating laser devices receive trigger signals from programmable multi-axis control devices and begin oscillation. However, the energy of the pulses after a certain number of oscillations or within a certain time is unstable to the point that they cannot be used due to different applications. Therefore, in order to eliminate this unstable pulse group, it is necessary to eliminate the pulse group by mechanical shutter operation. Specifically, for example, in the case of an excimer laser oscillating at 1 kHz, the time window between adjacent laser pulses is about 1 ms, and a high-speed shutter function that can move (traverse) a certain distance within this time is required. This certain distance depends on the size of the laser space where the shutter operates. If the distance is 5 mm, the required shutter operation speed is 5 m / s, requiring an ultra-high-speed shutter such as a voice coil to allow optical elements to enter and exit the optical path. In addition, even if the size of this space is reduced by using a shaping optical system or the like, which can shorten the traversal distance of the shutter component, it is still easily damaged by the energy density of the laser.

[0043] The eleventh invention is based on the tenth invention, wherein the programmable multi-axis control device has the function of controlling at least simultaneously the Y-axis of the recipient stage and the Y-axis of the donor stage, and includes means for correcting the movement position error using pre-made two-dimensional distribution correction value data for correcting the movement position error of the stage.

[0044] For example, using analogous two-dimensional distribution correction value information in the XY plane, representing any combination of Xd or Xo and Yr or Yd, the positions of the recipient and donor substrates during laser irradiation are corrected. The main causes of the corrected positional errors include, but are not limited to, pitching, yawing, and rolling, which occur with the movement of each stage. Furthermore, in addition to the position information of each stage, the parameters used to determine the correction values ​​also include the movement speeds of Yr and Yd and their ratio.

[0045] The twelfth invention is based on the eleventh invention, wherein a high-magnification camera for monitoring the position of the donor substrate is disposed on the Z-axis of the recipient stage, or on the X-axis of the donor stage or a portion thereof that moves together with the X-axis of the donor stage, or on the optical stage or a portion thereof that moves together with the optical stage.

[0046] Here, the "part that moves together with the X-axis of the donor stage" also includes Yd, which is suspended on Xd. In this invention, the parallelism between the Y-axis and the X-axis of each stage, as well as the perpendicularity between the Y-axis and the X-axis of each stage, are important parameters for the accuracy of left and right transfer positions. Furthermore, in checking the parallelism and perpendicularity when assembling each stage, a high-magnification, high-resolution camera is used to monitor the deviation in the direction perpendicular to the alignment substrate relative to the movement distance of each stage, and the perpendicularity is adjusted using the aforementioned rotation adjustment mechanism. In addition, in adjusting the parallelism between Yr and Yd, the two stages are moved synchronously (in parallel) by the same distance, and a high-magnification camera mounted on one stage is used to observe whether the position of the pattern-matched alignment mark image (cross mark, etc.) attached to the opposing stage remains stationary without moving. In this case, movement in the Y-axis direction indicates an abnormal synchronization of Yd and Yr, and movement in the X-axis direction indicates an error in the adjustment of the parallelism of Yd and Yr.

[0047] In addition, CCD cameras are typically used as high-magnification cameras. Magnification depends on the accuracy of the transfer position, but as an example, when detecting a deviation on the order of [μrad], that is, when detecting a deviation of 1 [μm] relative to a stage movement distance of 1 [m], a camera with a resolution of 1 [μm] and a magnification of 20x to 50x can be used.

[0048] The thirteenth invention is based on the twelfth invention, wherein the donor stage and the recipient stage include a gap sensor that measures the gap between the surface (lower surface) of the donor substrate and the surface of the recipient substrate.

[0049] Here, the gap sensor refers to a sensor that combines height sensors respectively installed on the donor and receiver stages. The height sensor installed on the donor stage measures the distance to the receiver substrate, and the height sensor installed on the receiver stage measures the distance to the donor substrate. Based on the two measurements and the height information from the height sensors, the gap between the donor substrate and the receiver substrate is calculated.

[0050] The fourteenth invention is based on the thirteenth invention, and includes a position measuring device using a laser interferometer for the Y-axis of the recipient stage and the Y-axis of the donor stage, respectively.

[0051] The structure of the laser interferometer for the Y-axis (Yr) of the recipient stage can include the following components: a mirror (Ic) held on a portion that moves with Yr; an interferometer laser (IL) fixed on a platform such as platform 2 (G2) that is not easily affected by vibrations caused by the movement; and a quarter-wave plate, etc. (illustration omitted). Furthermore, a triaxial corner cube prism (retro-reflector) is suitable as the mirror, and preferably positioned as close as possible to the recipient substrate (height). An overview is shown in Figure 5A (illustrations of the Z-axis and θ-axis of the donor stage assembly and recipient stage are omitted).

[0052] Based on position information from the linear encoder, Yr is controlled by a programmable multi-axis control device, and the laser interferometer is used as a calibration of the linear encoder, as well as as a calibration for finely adjusting the gear ratio in the gear mode operation of Yr and Yd described later.

[0053] The structure of the Y-axis (Yd) laser interferometer for the donor stage can include the following components: Ic, which is held on a plane that moves together with Yd, which is suspended on Xd; IL, which is fixed to Xd in the same manner; and a quarter-wave plate, etc. (illustrations omitted). Here, a triaxial pyramidal prism (retroreflector) is suitable as the reflector, preferably as close as possible to the donor substrate (height). An overview is shown in Figure 5B. (The receiver stage assembly is not shown.) Furthermore, the selection of the detection method for any interferometer laser can be based on the most suitable method according to the required transfer position accuracy.

[0054] The fifteenth invention is based on the fourteenth invention, wherein the transfer device includes a confocal beam profiler having a focal plane at a position conjugate to the position where the pattern of the photomask is projected and imaged by the projection lens.

[0055] This confocal beam profilometer enables real-time monitoring of the position and spatial intensity distribution of a laser projected onto the donor substrate surface with the same precision as the imaging resolution of a reduced imaging optical system, as well as its imaging state.

[0056] The sixteenth invention is a method of using a transfer device, which is the transfer device of the thirteenth invention. Using the gap sensor, the amount of bending of the donor substrate is pre-measured together with the XY position information of the donor substrate. Based on the two-dimensional distribution data of the bending amount obtained by the measurement, the gap between the donor substrate and the recipient substrate is corrected by using the adjustment made by the Z-axis (Zr) stage of the recipient stage or the Z-axis stage of the projection lens.

[0057] The seventeenth invention is a method for adjusting a transfer device, wherein the transfer device is any one of the transfer devices described in the fifth to eighth inventions. The method for adjusting the transfer device is a method for adjusting the parallelism of the Y-axis of the recipient stage and the Y-axis of the donor stage during the assembly process of the transfer device. The method for adjusting the transfer device uses the Y-axis of the recipient stage, which has been adjusted for straightness along with the Z-axis and θ-axis of the recipient stage, as a reference, and sequentially includes the following steps: adjusting the rotation mechanism located between the X-axis of the platform 1 and the donor stage... The perpendicularity of the Y-axis of the recipient stage to the X-axis of the donor stage is adjusted; the Y-axis of the donor stage, which is suspended on the X-axis of the donor stage with its perpendicularity adjusted, and the Y-axis of the recipient stage are moved synchronously and parallel to each other; the alignment mark on the Y-axis of the opposing donor stage is observed by a high-magnification camera mounted on a part that moves together with the Y-axis of the recipient stage; and based on the observation results, the parallelism of the Y-axis of the recipient stage to the Y-axis of the donor stage is adjusted by a rotation adjustment mechanism between the X-axis and the Y-axis of the donor stage.

[0058] In addition, in order to accurately confirm and adjust the parallelism of Yd and Yr, it is preferable that the high-magnification camera is located at the highest position among the various platforms and plates placed on Yr, and is mounted on a part with high rigidity.

[0059] This invention enables the large-scale transfer device and shortened cycle time while maintaining high transfer position accuracy, based on the high synchronous position accuracy of the donor substrate and the recipient substrate. Simple Explanation of the Diagram

[0060] Figure 1A shows the main structural parts (side view) of the transfer device of the present invention. (Second Invention) Figure 1B shows the X-axis of the donor stage after it has been placed on the optical stage and moved from the state shown in Figure 1A (side view). Figure 1C shows the situation where the optical stage has moved along the X-axis of the donor stage from the state shown in Figure 1B (side view). Figure 1D is a top view of Figure 1C. Figure 2A shows the main structural parts (side view) of the transfer device of the present invention. (Third Invention) Figure 2B shows the case where the X-axis of the donor stage and the optical stage have moved the same distance on platform 1 from the state shown in Figure 2A (side view). Figure 2C shows the case where only the X-axis of the optical stage has moved on platform 1 from the state shown in Figure 2B (side view). Figure 3A shows an example of a rotation adjustment mechanism used between G1 and Xd. Figure 3B shows an example of a rotation adjustment mechanism used between Xd and Yd. Figure 3C shows an example of a rotation adjustment mechanism used between Xd and Xo. Figure 4 shows the range that the donor stage should move according to the size of the recipient substrate. Figure 5A shows the case of a Y-axis laser interferometer with a receiver stage. Figure 5B shows the case of a Y-axis laser interferometer with a donor stage. Figure 6 shows an example of a pattern formed on a photomask. Figure 7 illustrates the transfer process using multiple rows of photomask patterns. Figure 8 shows the monitoring status of the confocal beam profiler. Figure 9A shows the first irradiation during the transfer process. Figure 9B shows the second irradiation during the transfer process. Figure 9C shows the third irradiation during the transfer process. Figure 10 shows the condition of the receptor substrate after one scan with a gear ratio of 1:2. Figure 11 shows the step scan of the donor stage along the X-axis. Figure 12 shows a synchronization error when the Y-axis of the recipient stage and the Y-axis of the donor stage are aligned. Figure 13A shows the first irradiation in the transfer process using a matrix-shaped donor substrate. Figure 13B shows the second irradiation in the transfer process using a matrix-shaped donor substrate. Figure 13C shows the third irradiation in the transfer process using a matrix-shaped donor substrate. Implementation

[0061] The specific structure of the transfer device of the present invention will now be described in detail with reference to the accompanying drawings.

[0062] [Example 1]

[0063] In this embodiment 1, the following embodiment is illustrated: On a donor substrate with dimensions of 200×200 [mm], a layered (solid film) object formed as a single sheet with a light absorption layer in between is transferred as a unit-shaped transfer object with a shape of 10×10 [μm], in a matrix of 144 million objects arranged in a vertical × horizontal matrix of 12000 × 12000. The position of the aforementioned 144 million objects is with a positional accuracy of ±1 [μm], and the interval between each vertical and horizontal element is 30 [μm].

[0064] First, Figure 1A shows the main structural parts of the transfer device related to the implementation of the present invention. Additionally, the laser device, control device, and other monitors are omitted in Figure 1A; the X, Y, and Z axis directions are shown in the figure. Platforms 1 (G1), 11 (G11), 12 (G12), and 2 (G2) are all granite stone platforms. Furthermore, the base platform (G) uses high-rigidity iron. This embodiment is based on the configuration of the sixth invention described above.

[0065] The configuration of the transfer device in Embodiment 1 of the present invention will be described sequentially according to the laser transmission sequence from the emission of pulsed laser from the laser device to the object on the donor substrate. First, the laser device used in Embodiment 1 is an excimer laser with an oscillation wavelength of 248 nm. The spatial distribution of the emitted laser is approximately 8 × 24 mm, and the beam divergence angle is 1 × 3 milliradians (mrad). All of the above are described in (vertical × horizontal) and the values ​​are in FWHM.

[0066] Furthermore, excimer lasers come in various specifications. Depending on the output, repetition frequency, beam size, and beam divergence angle, there are excimer lasers with a long longitudinal beam (reversing the longitudinal and transverse directions). However, by adding, omitting, or modifying the optical system, there are various excimer lasers that can be used in this embodiment 1. In addition, although the size of the laser device depends on its dimensions, it is generally mounted on a different base (laser platform) than the base of the stage assembly equipped with the transfer device.

[0067] The light emitted from the excimer laser enters the telescope optical system and is transmitted to the shaping optical system in front of it. Here, as shown in Figure 1A, the shaping optical system is held on the optical stage (Xo) so that the optical axis is along the X-axis. This optical stage is positioned on the X-axis (Xd) of the donor stage, which moves the donor substrate. Furthermore, the laser before entering the shaping optical system is adjusted by the telescope optical system to be substantially parallel to the light at any position within the range of movement of the donor stage along the X-axis. Therefore, regardless of the movement of Xd and / or Xo along the X-axis, the laser always enters the shaping optical system with substantially the same size and the same angle (vertical). In this embodiment 1, its size is approximately 25 × 25 mm (length × width).

[0068] The shaping optical system (H) of this embodiment combines two sets of single-axis cylindrical lens arrays into two right-angled sets in a plane perpendicular to the optical axis. The configuration is as follows: the lens array of the preceding stage in each set images onto the photomask (M) through the lens array of the following stage and a condenser lens (not shown).

[0069] The laser beam, passing through the shaping optical system, is projected onto the photomask via a field lens (F) that, in combination with a projection lens (Pl), forms an image-side telecentric reduction projection optical system. The laser beam on the photomask is 1 × 50 mm (FWHM), and the area with a spatial intensity distribution uniformity within ±5% is maintained at a size of 0.5 × 45 mm or larger.

[0070] The photomask is fixed on the photomask stage. As described above, the photomask stage has a total of six-axis adjustment mechanisms. The six axes are: the W axis, which moves along the X-axis direction together with the field lens; the U axis, which moves along the Y-axis direction; the V axis, which moves along the Z-axis direction; the R axis, which is a rotation axis in 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.

[0071] In this embodiment 1, a patterned photomask is drawn (formed) on a synthetic quartz plate by chrome plating. Figure 6 shows its schematic. In this photomask, the unplated, white window portion (a) transmits the laser, while the chrome-plated colored portion (b) blocks the laser. The shape (a) of a window is 50 × 50 [μm], and 300 of them are arranged continuously at 150 [μm] intervals along the X-axis (in a column) for a total of 43.85 [mm]. Furthermore, the chrome-plated surface is the laser emission side, while the laser injection side is provided with a 248 [nm] anti-reflection film. Alternatively, aluminum vapor deposition or a dielectric multilayer film can be used instead of chrome plating.

[0072] Furthermore, when switching between multiple pattern transfer processes on a single photomask, photomasks with different patterns can be used if the size of the laser irradiated from the shaping optical system onto the photomask is within the range of motion of the photomask stage.

[0073] Furthermore, in Figure 7, when a transfer process is used to scan the donor substrate (D) multiple times or back and forth at the same speed during one scan of the recipient substrate (R) (including interruptions), the photomask pattern shown in Figure 6 may not be a single column, but rather a multi-column pattern (however, laser irradiation is intermittent and selective in this photomask pattern; it is shown as a 3×2 column matrix in Figure 7). This allows the use of a donor substrate that is smaller than the recipient substrate.

[0074] The laser beam passing through the photomask pattern is redirected by a projection mirror to face vertically downwards (in the -Z direction) and then enters the projection lens. This projection lens has an anti-reflection coating for 248nm and a 1 / 5 magnification reduction. Details are shown in Table 1 below.

[0075] [Table 1] Detailed specifications of the projection lens Applicable wavelength [nm] 248 Projected surface size [mm] 1.0 × 15.0 Lens reduction magnification 1 / 5 Resolution (line and space) [μm] 2 NA 0.13 Distance from the photomask to the projection surface [mm] 1050

[0076] The laser emitted from the projection lens enters from the back of the donor substrate and projects precisely onto a predetermined position of the light-absorbing layer formed on its surface (lower surface) at a scaled-down size of 1 / 5 of the photomask pattern. Here, the predetermined position in the XY plane is determined by adjusting the X-axis (Xd), Y-axis (Yd), and θ-axis (θd) of the donor stage, using alignment marks or similar pre-attached to the donor substrate as a reference.

[0077] To ensure that the image plane of the photomask pattern generated by the projection lens is focused on the surface of the donor substrate and the edge interface of the light-absorbing layer, the positions of the Z-axis stage (Zl) of the projection lens and the W-axis of the photomask stage where the field lens (F) is placed are adjusted. Additionally, while an adjustment function (Z-axis stage) for the Z-axis direction of the donor substrate can be added, the decrease in transfer position accuracy due to the increased load on the X-axis (Xd) of the donor stage must be considered.

[0078] When adjusting the imaging position of the donor substrate surface and the edge interface of the light-absorbing layer, real-time monitoring using a confocal beam profilometer (BP) with a plane conjugate to the image plane on the focal plane is effective. Figure 8 shows the adjustment screen. In this embodiment 1, the spatial intensity distribution of the laser imaged on the donor substrate surface and the edge interface of the light-absorbing layer is monitored in real-time and with high resolution.

[0079] The above describes the functions achieved by the device structure of this embodiment 1 in relation to the transmission of pulsed laser emitted from the laser device.

[0080] Next, it will be briefly explained how the structure of Embodiment 1 is used in the device of the present invention to mechanically achieve the parallelism between the Y-axis (Yr) of the recipient stage and the Y-axis (Yd) of the donor stage.

[0081] As shown in Figure 1A, the donor stage's X-axis (Xd) is placed on stone platform 1 (G1), and the optical stage (Xo) is placed on it. The recipient stage assembly (Yr, θr, Zr) is placed on stone platform 2 (G2). Furthermore, the entire assembly is built on the base platform (G). Additionally, rotation adjustment mechanisms (RP) are provided between G1 and Xd, between Xo and Xd, and between Xd and Yd (illustrations omitted).

[0082] In addition, to adjust the perpendicularity and parallelism of the axes of each stage, an adjustment plate AD held on the donor stage is used instead of the donor plate, and an adjustment plate AR placed on the recipient stage is used instead of the recipient plate. On any one of the adjustment plates, lines indicating the accurate formation of right angles between the X-axis (alignment line X) and Y-axis (alignment line Y) are drawn as alignment lines, and markings are also added at specified positions (intervals).

[0083] 1) Parallelism between Yr and AR(Y) (Perpendicularity between Yr and AR(X))

[0084] To adjust the parallelism between the Y-axis (Yr) of the receiving stage and the alignment line Y on the adjustment substrate AR, the adjustment substrate AR, placed on the Z-axis (Zr) of the receiving stage, is observed using a high-magnification CCD camera fixed on the optical stage (Xo) or mounted on the Z-axis stage of the projection lens of the optical stage (Xo). The Yr axis is moved by 400 mm to adjust the θ-axis (θr) of the receiving stage so that the deviation of the alignment line Y in the X-axis direction is within 1 μm. Furthermore, the stage movement distance is within the effective travel range of the stage, and the allowable deviation varies depending on the required transfer accuracy. (The same applies below.)

[0085] 2) Parallelism between AR(X) and Xd (perpendicularity between Yr and Xd)

[0086] Next, using the alignment line X of the adjustment substrate AR adjusted in the above manner, the perpendicularity of the X-axis (Xd) of the donor stage and the Y-axis (Yr) of the recipient stage is adjusted while observing with a high-magnification CCD camera. The high-magnification CCD camera is also fixed on the optical stage (Xo) or mounted on the Z-axis stage of the projection lens on the optical stage (Xo). The Xd axis is moved by 400 mm, and the installation angle between G1 and Xd is adjusted using the rotation adjustment mechanism to ensure that the deviation of the alignment line X in the Y-axis direction is within 1 μm. The installation angle between G1 and Xd, i.e., Xd relative to Yr, is also adjusted.

[0087] 3) Parallelism between AR(X) and Xo (perpendicularity between Yr and Xo, parallelism between Xd and Xo)

[0088] Using the alignment line X of the adjustment substrate AR adjusted in the above manner, 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. The high-magnification CCD camera is fixed on the optical stage (Xo) or set on the Z-axis platform of the projection lens of the optical stage (Xo). The Xo axis is moved by 200 mm, and the parallelism between the optical stage (Xo) and the X-axis (Xd) of the donor stage is adjusted by a rotation adjustment mechanism between the two to ensure that the deviation of the alignment line X in the Y-axis direction is within 0.5 μm.

[0089] 4) Parallelism between Yd and AD(Y)

[0090] 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 on the optical stage (Xo) or mounted on the Z-axis platform of the projection lens of the optical stage (Xo). The Yd axis is moved by 200 mm to adjust the θ-axis (θd) of the donor stage so that the deviation of the alignment line Y in the X-axis direction is within 0.5 μm.

[0091] 5) Parallelism between AD(X) and Xo (parallelism between AD(X) and Xd, perpendicularity between Xd and Yd)

[0092] To adjust the perpendicularity of the X-axis (Xd) and Y-axis (Yd) of the donor stage, an alignment line X on the adjustment substrate AD is observed using a high-magnification CCD camera. The high-magnification CCD camera is fixed on an optical stage (Xo) whose parallelism with the X-axis (Xd) of the donor stage has been adjusted, or mounted on a Z-axis platform for the projection lens of the optical stage (Xo). The optical stage (Xo) is moved 200 mm, and the perpendicularity of the alignment line X to the Y-axis (Yd) of the donor stage, suspended on the X-axis (Xd), is adjusted via a rotation adjustment mechanism between the two, ensuring the deviation in the Y-axis direction is within 0.5 μm.

[0093] 6) Parallelism between AD(Y) and Yr (parallelism between Yd and Yr)

[0094] Finally, to confirm the parallelism between the Y-axis (Yd) of the donor stage and the Y-axis (Yr) of the recipient stage, a high-magnification CCD camera is mounted on the Y-axis (Yd) of the donor stage, and the alignment line Y of the adjustment substrate AR placed on the opposing recipient stage is observed. At this time, the adjustment substrate AD is removed beforehand. The X-axis (Xd) of the donor stage is moved so that the high-magnification CCD camera can observe either end of the recipient stage. Next, the Y-axis (Yd) of the donor stage is moved 400 mm, and it is confirmed that the deviation of the alignment line Y in the X-axis direction is within 1 μm. Furthermore, to perform the same confirmation on the other end of the recipient stage, after moving Xd to that other end, Yd is moved 400 mm, and the deviation of the alignment line Y in the X-axis direction is confirmed to be within 1 μm. Alternatively, Yd and Yr can be moved side-by-side, and the positional change of the alignment mark can be observed.

[0095] Furthermore, when the high-magnification CCD camera is mounted on the Y-axis (Yd) of the donor stage, there is a possibility that the high-magnification CCD camera may come into contact with the X-axis of the donor stage and the shape (opening) of the stone platform 1, depending on the position of the X-axis of the donor stage. In this case, instead of mounting the high-magnification CCD camera on the Yd, it is mounted on the Z-axis (Zr) of the receiver stage. By moving the Y-axis (Yr) of the receiver stage by 200 mm, it is also possible to observe the alignment line Y of the adjustment substrate AD and confirm the amount of deviation in its X-axis direction.

[0096] Since stone platform 1 (G1) and stone platform 2 independently support each stage, and Yd is suspended from Xd set on G1, although the parallelism of Yr and Yd cannot be directly adjusted, the parallelism of Yr and Yd can be adjusted step by step in the order of [μrad] as described above. Furthermore, since the parallelism (perpendicularity) error accumulates when the adjustment steps are followed in the order of 1) to 6), it is ideal to adjust in a way that minimizes the allowable deviation in the initial stage. In addition, although the adjustment steps 1) to 6) describe the adjustment of the parallelism and perpendicularity of each stage in the XY plane, adjustments on other axes (X-axis and Y-axis) are also required.

[0097] Next, referring to Figures 9A to 9C, the scanning of the donor substrate and recipient substrate during the transfer in Embodiment 1 will be described. Here, the top view of Figures 9A to 9C shows the operator positioned to the left of these figures, with the donor substrate (D) and recipient substrate (R) scanned back-to-back relative to the operator.

[0098] First, the bending amount of the donor substrate, adsorbed and positioned on the θ-axis (θd) of the donor stage, is measured across the entire surface of the donor substrate and plotted as two-dimensional data along with position information. This information is used as a correction amount for the Z-axis (Zr) of the acceptor stage, corresponding to the X-axis (Xd) and Y-axis (Yd) of the donor stage as it moves during the transfer process.

[0099] Furthermore, in the following description, for ease of explanation, the designated position on the left side of the receiver substrate (R) and donor substrate (D) as viewed from the operator's perspective is defined as the origin of each substrate. Additionally, the positions of the optical stage (Xo) and receiver stage (Yr, θr) when irradiating the origin of the receiver substrate are defined as their respective origins. Furthermore, in the donor substrate, the positions of the donor stages (Xd, Yd, θd) when irradiated by the laser (LS) are also defined as their respective origins. However, the origin of each stage is not limited to one end of its travel range, but rather is a position that allows for the travel portion of the journey during subsequent transfer processes and substrate removal.

[0100] Figure 9A illustrates the initial pulse of laser (LS) irradiating the donor substrate (D) and acceptor substrate (R) located at the origin. Both side and top views are shown. The dashed line indicates that the laser irradiates the object (S) through a reduced projection optics system. The light-absorbing layer (not shown) of the 10 × 10 [μm] region receiving this irradiation absorbs the laser, ablates, and generates a shock wave, thereby transferring the object from the same region to the opposing acceptor substrate. Although only three objects are shown, in this Example 1, a total of 300 objects are transferred to the acceptor substrate at once.

[0101] In this embodiment 1, the laser device oscillates at 200 Hz. Furthermore, since the transfer is performed with a single irradiation, the receiver stage (Yr) scans in the -Y direction at a speed of 6 mm / s until the next irradiation position without stopping the receiver substrate.

[0102] On the other hand, while synchronizing the position of the donor stage's Y-axis (Yd) with that of the recipient stage's Y-axis (Yr), the donor substrate is scanned in the same -Y direction at a speed of 3 [mm / s] without stopping. That is, the ratio of the movement speeds of Yd to Yr (gear ratio) is 1:2. Figure 9B shows the second irradiation after each substrate has moved.

[0103] Using Yr as the reference (master) and Yd as the slave (slave), the positions of Yr and Yd are synchronized by using gear commands in the stage system to synchronize the two stages in a gear-mode operation. A programmable multi-axis control device is used in the control system.

[0104] Furthermore, to determine the gear ratio of the gear command, the actual measured value of the stage position is used, measured by a laser interferometer. A pyramidal prism (Ic) is installed, and a 632.8 nm wavelength He-Ne laser (IL) and a light receiver (not shown in Figure 5A) are placed on platform 2 (or an equivalent stationary position). The pyramidal prism (Ic) moves together with the moving stage of Yr and forms a laser interferometer near the receiver substrate. Similarly, a pyramidal prism is installed on the side of the moving stage of Yd, and the interferometer laser and light receiver (not shown in Figure 5B) are placed on Xd. This achieves accurate position synchronization of each stage.

[0105] As described above, each stage accelerates from its position at the origin, moving at a stable, constant velocity, starting from a position directly in front of the origin. During this acceleration time and the time it takes for the stage to reach the origin, the laser pulse needs to be cut off to prevent the laser from irradiating the donor substrate. Therefore, a programmable multi-axis control device sends an external oscillation trigger signal or a high-speed shutter activation trigger signal, as well as a stage drive signal, to the laser device with high precision.

[0106] Furthermore, Figure 9C illustrates the third irradiation. It can be seen from the figure that the recipient substrate (R) moves twice as far as the donor substrate (D). Thereafter, both the recipient and donor substrates continue to move.

[0107] When the donor substrate scans 180 mm in the -Y direction and ends, similarly when the recipient substrate scans 360 mm in the -Y direction and ends, the oscillation of the laser device temporarily stops, or the laser irradiation is cut off by a high-speed optical shutter. Through this scanning distance, 300 objects arranged along the X-axis are transferred 12,000 rows, totaling 3.6 million objects, along the Y-axis of the recipient substrate. Figure 10 illustrates this process.

[0108] During the stop time, both the Y-axis (Yr) of the recipient stage and the Y-axis (Yd) of the donor stage return to their origins. (However, the acceleration distance for the next scan is taken into account. The same applies below.) On the other hand, the X-axis (Xd) of the donor stage returns to a position of -9 [mm] compared to the previous origin. Furthermore, the transfer process restarts from the new area. The above actions are repeated below.

[0109] Figure 11 shows the situation before the same operation begins, after the -9 mm × 20 step movement of Xd, when the laser returns from the previous origin (dashed line) to a position of 15 μm (solid line) in the -X direction, using this point as the new origin. Subsequently, the Y-axis scans (180 mm (Yd) and 360 mm (Yr)) of both stages are repeated with the -9 mm × 20 step operation of Xd. Thus, by irradiating the un-laser-irradiated area (the predetermined area for the next laser (LS) irradiation is indicated by a single-dotted line in the figure) during the initial 180 mm scan of Xd (20 step movements of -9 mm), laser light can be transferred to the donor substrate more efficiently and effectively without waste.

[0110] Furthermore, the approximate processing time is 360 [mm] / 6 [mm / s] × 40 [times] = 2400 [s]. This time does not include the time required for the Y-axis (Yr) movement of the receiving stage to accelerate and decelerate, or the time required for each Y-axis scan to return to the origin. Moreover, by increasing the repetition frequency of the excimer laser to 1 [kHz], the aforementioned processing time can be reduced by 1 / 5.

[0111] Figure 12 illustrates the synchronization position error of the two stages using the device structure of Embodiment 1, where the receiver stage's Y-axis (Yr) is used as the reference (master) and moves 400 mm at a speed of 150 mm / s, while the donor stage's Y-axis (Yd) is used as the slave and moves 200 mm at a speed of 75 mm / s. Specifically, the difference between the error (δYr) and the error (δYd) is plotted using the horizontal axis as the elapsed time corresponding to the receiver stage's movement speed (ΔYdr = δYd - δYr). The error (δYr) is the difference between the position information obtained from the linear encoder of the reference (master) Yr and the position information measured by a laser interferometer. The error (δYd) is the difference between the position information obtained from the linear encoder of the slave (slave) Yd, which moves synchronously at half the speed mentioned above, and the position information measured by a laser interferometer. The results show that a position synchronization accuracy within ±1 [μm] was achieved within a 400 mm movement distance.

[0112] As described above, in this embodiment 1, the transfer pattern of the object to the recipient substrate is a matrix transfer of 10×10μm at intervals of 30μm. However, if the interval is set to 60μm, for example, it is possible to transfer four recipient substrates using one donor substrate.

[0113] [Example 2]

[0114] In this embodiment 2, unlike the layer state in embodiment 1 where the object on the donor substrate surface is a single sheet, the embodiment is as follows: 144 million object objects, each with a shape of 10×10μm and a spacing of 15μm, are formed in a matrix on a donor substrate of the same size (200×200 mm). These object objects are then transferred to a recipient substrate of size (400×400 mm) at half the density of the donor substrate, with a spacing of 30μm and in the same matrix shape.

[0115] Finally, the arrangement of the objects transferred to the recipient substrate is the same as in Example 1. However, the difference is that in this Example 2, the objects are also arranged on the donor substrate at twice the density beforehand, and transferred to the recipient substrate with a positional accuracy of ±1 [μm]. Furthermore, in this case, compared to Example 1, the positional synchronization accuracy of the Y-axis (Yd) of the donor stage and the Y-axis (Yr) of the recipient stage is further strictly required.

[0116] Figures 13A to 13C show the process from the initial pulse of the laser (LS) to the third pulse, on the donor substrate (D) and acceptor substrate (R) located at the origin, similar to Example 1.

[0117] [Example 3]

[0118] In this embodiment 3, the method for transferring the object on the donor substrate surface to the recipient substrate is the same as in embodiment 1 or embodiment 2. However, the method for adjusting the parallelism between the Y-axis and X-axis of each stage, as well as the perpendicularity between the Y-axis and X-axis, differs from the embodiments described above. Specifically, the adjustment method described in embodiment 1 involves performing adjustment steps 1) to 6) to adjust the parallelism between the Y-axis (Yr) of the recipient stage and the Y-axis (Yd) of the donor stage. In contrast, in this embodiment 3, the parallelism between Yr and Yd is adjusted in the early stages of the adjustment steps.

[0119] 1) Straightness of Yr, θr, and Zr

[0120] This adjustment step is a common prerequisite for adjustments made in Embodiments 1 and 2. The straightness (relative to the Z-axis, which is the vertical direction when the horizontal plane is taken as the XY plane) of the receiver stage set on the stone platform 2 (G2) is adjusted using a laser interferometer or similar device. Furthermore, essentially after this adjustment, no adjustments that could potentially affect the verticality of the receiver stage assembly are made; all adjustments to other stages are performed with reference to, for example, the uppermost surface of the aforementioned receiver stage assembly.

[0121] 2) Parallelism between Yr and AR(Y) (Perpendicularity between Yr and AR(X))

[0122] Similar to adjustment step 1) in Example 1, the parallelism between the Y-axis (Yr) of the receiving 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. Furthermore, if an alignment line or alignment mark obtained by direct drawing on Yr is used instead of the adjustment substrate AR, this adjustment step 1) can be omitted.

[0123] 3) Parallelism between AR(X) and Xd (perpendicularity between Yr and Xd)

[0124] Next, the alignment line X of the adjustment substrate AR is observed using a high-magnification CCD camera mounted on an optical stage (Xo) placed on the X-axis (Xd) of the donor stage. The position of the high-magnification CCD camera in the Z-axis direction is determined by the design of the projection optical system; however, in this embodiment 3, a Z-axis stage (Zl) holding the projection lens is fixed near the position of the projection lens (Pl). Xd is moved 400 mm, and the mounting angle of Xd relative to the platform 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.

[0125] 4) Parallelism of Yr and Yd in the YZ plane

[0126] In the description of Example 1, the adjustment steps for other axis systems (X-axis and Y-axis) are omitted. Here, the adjustment steps for the parallelism in the YZ plane of the X-axis system are briefly described. The lower surface of the donor stage's Y-axis (Yd) is observed using a height sensor located on the Z-axis (Zr) or other part of the recipient stage. Yr and Yd are simultaneously moved (parallel moved) by the same distance of 200 mm or more, and the change in the measurement value (distance between Zr and Yd) of the gap sensor is observed. To ensure that this change is within 5 μm or sufficiently small compared to the focal depth of the projection lens, a shim is inserted between the rotation adjustment mechanism located between Xd and Yd, and between Yd or Xd, to adjust the parallelism in the YZ plane between Yr and Yd.

[0127] 5) Parallelism between Yr and Yd

[0128] Using a high-magnification CCD camera positioned on Zr or other locations, observe the alignment marks for pattern matching set on the lower surface of Yd. If Yr and Yd are moved synchronously (parallel) by the same distance, and the position of the alignment mark image (crosshair, etc.) for pattern matching is moved along the X-axis, adjust it using a rotation adjustment mechanism set between Xd and Yd to correct it. Alternatively, instead of alignment marks, the alignment line Y of the adjustment base plate AD mounted on the Y-axis of the donor stage can be used.

[0129] 6) Perpendicularity of Yr and Xo

[0130] Using a high-magnification CCD camera mounted on the optical stage (Xo), the alignment line X of the adjustment substrate AR, whose perpendicularity to the Y-axis (Yr) of the receiver stage was adjusted in adjustment step 1), was observed. Xo was moved 400 mm to ensure that the deviation of the alignment line X in the Y-axis direction was within 0.3 μm, and the mounting angle of Xo relative to Xd was adjusted using a rotation adjustment mechanism positioned between the two.

[0131] [Example 4]

[0132] Figure 2A shows the main structural parts of the transfer device in Embodiment 4. It is an embodiment based on the seventh invention of this invention. Furthermore, in Figures 2A to 2C, illustrations of the laser device, control device, and other monitors are omitted (these are all the same as in Embodiment 1), and the X, Y, and Z axes are shown. Moreover, the arrangement of the donor substrate, recipient substrate, and the donor substrate of the object to be transferred, as well as the arrangement after transfer to the recipient substrate, used in Embodiment 4, are the same as in Embodiment 2.

[0133] The optical system from which the pulsed laser is emitted from the excimer laser device and irradiates the transfer target on the donor substrate is as described below, except for the differences in the construction of the stages shown in Figures 1A and 2A, which are the same as in Embodiment 1. That is, in the case of the transfer device of the sixth invention shown in Figures 1A to 1C, the X-axis (Xd) of the donor stage is arranged sequentially on the stone platform 1 (G1) and the optical stage (Xo) is arranged thereon. In contrast, in the case of the transfer device of the seventh invention shown in Figures 2A to 2C, the difference in the construction of these stages is that Xo is placed on G1 and Xd is suspended below G1.

[0134] The light emitted from the excimer laser enters the telescope's optical system and propagates towards the shaping optical system in front of it. As shown in Figure 2A, the shaping optical system is positioned parallel to the optical axis of an optical stage (Xo) that moves along the X-axis. Furthermore, Xo is placed on a granite platform 1 (G1), with a rotation adjustment mechanism (RP) between them. Here, Xo is perpendicular to the Y-axis (Yr) of the recipient stage, which is placed on a different platform 2 (G2), and parallel to the X-axis (Xd) of the donor stage. Additionally, the laser beam before entering the shaping optical system is adjusted by the telescope's optical system to a substantially identical shape (approximately 25 × 25 mm) regardless of the movement of Xo.

[0135] The donor stage's X-axis (Xd) is suspended below G1, and the donor stage's Y-axis (Yd) is also suspended there. Furthermore, a rotation adjustment mechanism is provided between them. Figure 2B shows a side view of the case where Xo and Xd have moved the same distance relative to G1. This allows the position relative to Yd in the X-axis direction to be changed without altering the relative positions of Xo and Xd on the X-axis. Figure 2C also shows a side view of the case where only Xo has moved relative to G1. This allows the relative positions of Xd and Xo on the X-axis to be changed.

[0136] The details of the field lens (F), photomask (M), and projection lens (Pl) of the other reduced projection optical system are the same as in Embodiment 1. The laser emitted from the projection lens enters from the back of the donor substrate and is projected accurately toward the transfer object formed on its surface (lower surface) at a scaled-down size of 1 / 5 of the pattern drawn on the photomask. Furthermore, the imaging on the surface of the donor substrate is performed by a confocal beam profilometer, as in Embodiment 1.

[0137] Based on the photomask pattern that projects a reduced image onto the object to be transferred on the surface of the donor substrate in the manner described above, when the object to be transferred is transferred to the opposite recipient substrate, the manner in which the donor and recipient substrates are scanned and the manner in which the object to be transferred is transferred onto the recipient substrate are the same as in Figures 6, 10, 11 and 13A to 13C. Furthermore, the positional synchronization accuracy of the movement of the Y-axis (Yr) of the recipient stage and the Y-axis (Yd) of the donor stage is the same as in Figure 12 described in Example 1.

[0138] Furthermore, the methods for adjusting the parallelism between the Y-axis and X-axis of each stage, as well as the perpendicularity between the Y-axis and X-axis, are the same as in Example 3. That is, the Y-axis (Yr) of the recipient stage, after straightness adjustment, is used as the adjustment reference. The perpendicularity of Yr to the X-axis (Xd) of the donor stage suspended from the stone platform 1 (G1) is observed using a high-magnification CCD camera fixed to the Z-axis (Zr) of the recipient stage, and adjusted using the rotation adjustment mechanism (RP) between G1 and Xd. Similarly, the parallelism between the Y-axis (Yd) of the donor stage suspended on the adjusted Xd is observed using the same high-magnification CCD camera, and adjusted using the RP between Xd and Yd. Finally, the perpendicularity between the optical stage (Xo) and Yr is observed using a high-magnification CCD that moves together with Xo, and adjusted using the RP between G1 and Xo.

[0139] [Industrial Applicability]

[0140] This invention can be used as a manufacturing apparatus for displays.

[0141] Platform 1 2 platforms 3 platforms 11 Platform 12 platforms AD Donor Stage Adjustment Board AR receptor stage adjustment substrate BP confocal beam profiler CCD high-magnification camera D donor substrate F field lens G base platform G1 Platform 1 G11 Platform 11 G12 Platform 12 G2 Platform 2 G3 Platform 3 H Shaping Optical System Ic laser interferometer corner pyramid prism IL laser interferometer laser LS Laser M light 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, the Y-axis of the donor stage Yl Projection lens and camera switcher Yr, the Y-axis of the receptor platform Z-axis stage of the Zl projection lens Z-axis of the Zr receptor stage θd is the θ-axis of the donor stage. θr is the θ-axis of the receptor stage.

Claims

1. A laser processing method for removing a portion of a substrate using a laser, characterized in that: a laser emitted from a laser device is made parallel by passing it through a telescope; the laser is shaped into a region with substantially uniform spatial intensity distribution by a shaping optical system; the shaped laser is irradiated onto a photomask; and the pattern of the photomask is projected onto the removed portion of the substrate through a projection lens; the shaping optical system moves along the optical axis during the processing operation, and within the range of the movement, the laser light entering the shaping optical system from the telescope is adjusted to substantially become parallel light.

2. The laser processing method as claimed in claim 1, wherein the substrate moves relative to the pattern of the photomask in a direction within the plane of the substrate during the processing action.

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

4. The laser processing method as claimed in claim 1 or 2, wherein the spatial intensity distribution of the laser projected onto the substrate in a reduced manner has a substantially uniform region.

5. The laser processing method as claimed in claim 1 or 2, wherein the photomask has a region with a spatial intensity distribution uniformity of the laser within ±5%.

6. The laser processing method as described in claim 1 or 2, wherein the laser is an excimer laser.

7. A reduction projection optical system, which is a laser processing apparatus for removing a portion of a substrate using a laser, comprising: a laser device for emitting a laser; a telescope for aligning the emitted laser into parallel light; and a shaping optical system for shaping the aligned laser into a laser having a region with substantially uniform spatial intensity distribution. A photomask is used to allow the shaped laser irradiation to pass through a specified pattern; And a projection lens, which reduces the laser's defined pattern and projects it onto the removed portion of the substrate; During the processing, the shaping optical system moves along the optical axis. Within the range of movement, the laser beam entering the shaping optical system is adjusted by the telescope to become substantially parallel light.

8. The reduction projection optical system as claimed in claim 7, wherein the substrate moves relative to a predetermined pattern of the laser in a direction within the substrate plane during the processing action.

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

10. The reduction projection optical system as claimed in claim 7 or 8, wherein the spatial intensity distribution of the laser projected onto the substrate in a reduced manner has a substantially uniform region.

11. The reduced projection optical system as claimed in claim 7 or 8, wherein the photomask has a region on which the spatial intensity distribution uniformity of the laser is within ±5%.

12. The reduced projection optical system as claimed in claim 7 or 8, wherein the laser is an excimer laser.

13. A method for manufacturing a substrate, wherein a portion of the substrate is removed by a laser processing method as described in any one of claims 1 to 6.

14. A method for peeling an object located on the surface of a donor substrate from the donor substrate by means of a laser processing method as described in any one of claims 1 to 6.

15. A laser processing apparatus having a reduction projection optical system as described in any one of claims 7 to 12, for removing a portion of a substrate by laser.

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