TWI911117B - Transfer method, manufacturing method of other substrates to which the object is transferred, and photomask - Google Patents

Abstract

This invention provides a transfer method and a photomask. It achieves large-scale, refined, and shortened cycle time of the recipient substrate of the transfer device while maintaining high transfer position accuracy. In a mechanism constructed on separate platforms, each stage group moving in a state of holding the donor substrate on which the transfer object is placed and/or the beam shaping optical system and the miniaturized projection optical system, and the stage group holding the recipient substrate as the transfer object, minimizes vibrations caused by the relative scanning of each substrate relative to the laser and anomalies in the synchronous position accuracy of the stage bearing the scan.

Description

Transfer method, manufacturing method of other substrates to which the object is transferred, and photomask

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).

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. As such, Patent Document 1 discloses a method of converting a single laser 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 with a predetermined number of overlaps. 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 organic EL layer to the opposing circuit substrate.

The technology uses a structure where a spacer with an appropriate value of 80-100 μm is sandwiched between a donor substrate and a circuit substrate. A component that maintains a fixed gap between the donor substrate and the circuit substrate, and integrates them, 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 substrate, a donor substrate of the same size as the circuit substrate is required. Furthermore, the need for larger circuit substrates increases manufacturing costs and the size of the device.

Similarly, as a technique for transferring an organic EL layer on a donor substrate to an opposing circuit substrate, Patent Document 2 discloses the following method: 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 the opposing circuit substrate with a spacing of 10 to 100 μm. However, Patent Document 2 does not disclose the laser scanning method or the stage structure for implementing it, nor does it disclose the transfer device. Therefore, Patent Document 2 cannot be used as a reference for maintaining and improving the transfer position accuracy that can correspond to the scaling up of circuit substrates.

Furthermore, Patent Document 3 discloses a technique related to step-scan scanning in an exposure apparatus for semiconductor device manufacturing. The basic concept is as follows: a series of irradiation areas along the scanning exposure direction of the wafer stage are exposed intermittently 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 the pattern of the intermediate photomask onto the wafer. Exposure is performed while the intermediate photomask stage and the wafer stage scan together relative to the projection optical system. The pattern of the intermediate photomask is sequentially projected onto multiple irradiation areas of the wafer. Exposure is intermittently performed on the multiple irradiation areas on the wafer, arranged along the scanning direction, while the wafer stage is continuously moved during scanning. 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 shaking caused by stage scanning on exposure accuracy can be reduced.

However, the technology disclosed in Patent Document 3 is a semiconductor exposure apparatus based on reduced projection exposure, and its technical field differs from the transfer technology of this 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 this invention. The stage structure and scanning technology of this invention are used to project the photomask pattern of this invention onto 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 this invention cannot be referenced from the technology disclosed in Patent Document 3.

Existing technical literature

Patent Document 1: Japanese Patent Publication No. 2014-67671

Patent Document 2: Japanese Patent Publication No. 2010-40380

Patent Document 3: Japanese Patent Publication No. 2000-21702

By configuring the donor stage holding the donor substrate and the optical stage of the optical system placed on the donor stage as independent mechanisms, and by configuring the receiver stage holding the receiver substrate as an independent 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 accuracy between stages is minimized. As a result, the present invention aims to provide a transfer device that, while maintaining transfer position accuracy, facilitates the scaling up, refinement, and reduction of cycle time of the receiver substrate.

The first invention is a transfer device that selectively peels off an object from the back of a donor substrate onto the surface of the moving donor substrate by irradiating it with pulsed laser light, and transfers the object to a receiver substrate that moves opposite to the donor substrate. The transfer device includes: a pulsed laser device; a telescope to parallelize the pulsed laser light emitted from the laser device; and a shaping optical system to direct the pulsed laser light passing through the telescope. The system shapes the spatial intensity distribution into a uniform distribution; a mask allows the pulsed laser, shaped by the shaping optical system, to pass through in a prescribed pattern; a field mirror is located between the shaping optical system and the mask; a projection lens projects the laser with the pattern passed through the mask onto the surface of the donor substrate; a mask stage holds the field mirror and the mask; an optical stage holds the shaping optical system, the mask stage, and the projection lens; and a donor stage allows the laser to pass through the mask to form a uniform distribution. The device includes a donor substrate with its back side facing the laser's injection side, a recipient stage holding the recipient substrate, and a programmable multi-axis control device having a trigger output function for the pulsed laser oscillation and a stage control function. The recipient 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 together with the Z-axis stage for the projection lens. On the optical stage, the telescope, the shaping optical system, the field mirror, the photomask, and the projection lens constitute a miniaturized projection optical system. The miniaturized projection optical system projects the pattern of the photomask onto the surface of the donor substrate in a miniaturized manner. The X-axis of the donor stage is set on platform 1 (first platform), and the Y-axis of the recipient 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.

Here, the "moving" substrate includes a case in which it moves without stopping during irradiation by a pulsed laser (referred to as "LS" in FIG1A; however, although FIG1A shows the main structure 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). When only one irradiation is used in the peeling of the object from the donor substrate and a high cycle time is required, it is suitable to choose a structure in which the donor substrate and the receiver substrate move continuously at the same or different speeds. 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 and the receiver substrate stops during a certain number of irradiations is sometimes chosen.

Furthermore, the term "object" is not particularly limited and can refer to any transfer 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 multiple objects arranged in a regular pattern as tiny units, but is not limited to these objects. Additionally, the transfer mechanism includes the following: the light-absorbing layer, irradiated by a laser, generates a shock wave, thereby causing the object to peel off from the donor substrate and transfer towards 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.

The material of the donor substrate only needs to be transparent to the wavelength of the laser, and ideally it should be a material with minimal bending due to 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 on the donor stage (Yd, θd) can include, for example, mechanical correction by setting an adsorption area near the center of the donor substrate; or correction using a gap sensor formed by a combination of height sensors described later.

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 specified 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.

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 entity, but more specifically, it could be configured as two platforms arranged along the Y-axis, with a linear scale and a 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).

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.

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, detailed structures of the movable worktable and linear guide rails are not shown in any of the figures.

The placement method of the optical stage (Xo) on the platform or other devices is not limited; various mechanisms can be selected, such as placing it on the Xd, placing it on the same platform as the platform on which the Xd is placed, or placing it on a different platform from the Xd. Xo and Xd move simultaneously along the X-axis, while the relative positions of the shaping optical system (H), field mirror (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.

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.

The photomask is held on a photomask stage, which has at least a W-axis that moves along the X-axis 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.

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 between the donor and recipient substrates during the transfer process and ensuring extremely high parallelism. Furthermore, according to the aforementioned structure of the movement method of each stage assembly 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 the interference and vibration of the substrates' movement areas can be suppressed, and the size and precision of the recipient substrates can be accommodated.

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.

Figure 1A shows the main structural parts of the transfer device of the second invention (side view). Figure 1B shows the case where Xo is placed on Xd and 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 a top view of Figure 1C.

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.

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).

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.

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.

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.

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 for screws to pass through, 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 installation process.

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, two rows of holes on the outer side are used for fixing to Xd and have "clearance" for rotational adjustment. Furthermore, two rows of holes arranged along the Y-axis are used for fixing to Yd.

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

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 the two, 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 the two, 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 the two.

For example, the RP used between G1 and Xd shown in FIG3A, the RP used between Xd and Xo shown in FIG3C, and the RP used between Xd and Yd shown in FIG3B can be used as the aforementioned RP.

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 the two, a rotation adjustment mechanism between the optical stage and the platform 1 for fine-tuning the setting angle in the XY plane between the two, 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 the two.

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 unit, is adjusted.

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 the two, a rotation adjustment mechanism between the optical stage and the platform 3 for fine-tuning the setting angle in the XY plane between the two, 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 the two.

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

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

The tenth invention is based on the ninth invention, wherein the transfer device includes a pulsed light gate that cuts off any pulse train of laser pulses emitted from the excimer laser.

As is known to the public, pulse-oscillating laser devices receive trigger signals from the programmable multi-axis control device and begin oscillation. However, the energy of the pulses after a certain number of oscillations or within a certain time period becomes unstable to the point that they are unusable due to different applications. Therefore, in order to eliminate this unstable pulse group, it is necessary to eliminate the pulse group by mechanical optical gate action. Specifically, for example, in the case of an excimer laser oscillating at 1 kHz, the time window between adjacent laser pulses is approximately 1 ms, requiring a high-speed optical gate function that can move (cross) a certain distance within this time. This specific distance depends on the size of the laser space in the area where the light gate operates. If the distance is 5 mm, the required light gate operating speed is 5 m/s, necessitating the use of an ultra-high-speed light gate with a voice coil or similar device to allow optical elements to enter and exit the optical path. Furthermore, even if the size of this space is reduced by using a shaping optical system or similar device to shorten the distance the light gate components traverse, they are still susceptible to damage due to the energy density of the laser.

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 a device for correcting the movement position error using pre-made two-dimensional distribution correction value data for correcting the movement position error of the stage.

For example, two-dimensional distribution correction data in the XY plane, analogous to any combination of Xd or Xo and Yr or Yd, can be used to correct the positions of the recipient and donor substrates during laser irradiation. The main causes of positional errors in the correction include, but are not limited to, pitting, yawing, and rolling that 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 include the movement speeds of Yr and Yd and their ratio.

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.

Here, the portion 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 rotation positions. Furthermore, in the inspection of parallelism and perpendicularity when assembling each stage, the amount of deviation in the direction perpendicular to it is monitored using a high-magnification, high-resolution camera relative to the moving distance of each stage relative to the alignment substrate, and the perpendicularity is adjusted using the aforementioned rotation adjustment mechanism. Furthermore, in adjusting the parallelism between Yr and Yd, the two stages are moved synchronously (parallel) by the same distance. Using a high-magnification camera mounted on one stage, the position of the alignment mark image (crosshairs, etc.) attached to the opposing stage, which has undergone pattern matching, is observed to see if it remains stationary. In this case, movement in the Y-axis direction indicates an abnormal synchronization of Yd and Yr, while movement in the X-axis direction indicates an error in the parallelism adjustment of Yd and Yr.

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.

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.

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 measured values and the height information from the height sensors, the gap between the donor substrate and the receiver substrate is calculated.

The fourteenth invention is based on the thirteenth invention, and includes a position measuring device using a laser interferometer for both the Y-axis of the receiver stage and the Y-axis of the donor stage.

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

Based on the 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 and as a calibration when finely adjusting the gear ratio in the gear mode operation of Yr and Yd described later.

The structure of the Y-axis (Yd) laser interferometer, which serves as the donor stage, can utilize a structure including the following components: Ic, held on a plane that moves together with Yd, which is suspended on Xd; IL, fixed to Xd in the same manner; and a quarter-wavelength plate, etc. (not shown). Here, a triaxial tapered prism (retroreflector) is suitable as the reflector, preferably positioned 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 any detection method for the interferometer laser can be based on choosing the most suitable method according to the required transfer position accuracy.

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 with the position where the pattern of the photomask is projected and imaged through the projection lens.

This confocal beam profiler can monitor the position and spatial intensity distribution of the laser projected onto the donor substrate surface, as well as its imaging status, in real time with the same accuracy as the imaging resolution of the reduced imaging optical system.

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 bending amount of the donor substrate is measured in advance along 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 adjusting the Z-axis (Zr) of the recipient stage or the Z-axis stage of the projection lens.

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 receiving stage and the Y-axis of the donor stage in the assembly process of the transfer device. The method for adjusting the transfer device is based on the Y-axis of the receiving stage, which has been adjusted for straightness along with the Z-axis and θ-axis of the receiving stage, and includes the following steps in sequence: adjusting the Y-axis of the receiving stage by means of a rotation adjustment mechanism located between the platform 1 and the X-axis of 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, suspended on the X-axis of the donor stage with its perpendicularity adjusted, and the Y-axis of the recipient stage are aligned synchronously; the alignment mark on the Y-axis of the opposing donor stage is observed using 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 using a rotation adjustment mechanism between the X-axis and the Y-axis of the donor stage.

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

This invention enables the scaling up of the receiver substrate and the reduction of cycle time of the transfer device while maintaining high transfer position accuracy, based on the high synchronous position accuracy of the donor substrate and the receiver substrate.

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

[Implementation Example 1]

In this embodiment 1, the following embodiment is shown: On a donor substrate with dimensions of 200×200 [mm], a layered (solid film) object formed as a sheet with a light absorption layer is used as a transfer object with each unit shape of 10×10 [μm], and is transferred to a receiver substrate with dimensions of 400×400 [mm] in a matrix pattern of 144 million matrix objects with dimensions of 12000 [length] × 12000 [width]. The position of the above 144 million transfer objects has a positional accuracy of ±1 [μm], and the interval between each matrix is 30 [μm].

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

The configuration of the transfer device in Embodiment 1 of the present invention will be described sequentially according to the transmission order of the laser from the pulsed laser emitted from the laser device to the object irradiating 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 (vertical × horizontal) measurements, and the values are in FWHM.

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 (causing longitudinal and transverse inversion). However, through the addition, omission, or design modification of the optical system, there are various types of excimer lasers that can be used in this embodiment 1. In addition, although the laser device depends on its size, it is generally mounted on a different base (laser platform) than the base of the stage assembly with the transfer device.

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. The 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 X-axis of the donor stage. Therefore, regardless of the movement of Xd and/or Xo in the X-axis direction, 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 (width × width).

The shaping optical system (H) of this embodiment combines two sets of single-axis cylindrical lens arrays into two right angles in a plane perpendicular to the optical axis. The configuration is such that the lens array of the pre-stage in each set is imaged on the photomask (M) through the lens array of the subsequent stage and the condenser lens (not shown) located behind it.

The laser beams from the shaping optical system are incident on the photomask via a field lens (F) that forms a telecentric projection optical system in combination with a projection lens (Pl). The laser beams on the photomask are 1 × 50 mm (FWHM), and the area with a spatial intensity distribution uniformity within ±5% maintains a size of 0.5 × 45 mm or larger.

The photomask is fixed on the photomask stage, as described above. The photomask stage has a total of six-axis adjustment mechanism. The six axes are: the W axis, which moves along the X-axis direction 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 serves as 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.

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

In addition, when switching between multiple patterns on a single photomask, photomasks with different patterns can be used if the size of the laser irradiating the photomask from the shaping optical system is within the range of motion of the photomask stage.

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 a single scan of the acceptor 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 within this photomask pattern; shown in Figure 7 as a 3×2 column matrix). This allows the use of a donor substrate that is smaller than the acceptor substrate.

The laser beam passing through the aforementioned photomask pattern is redirected by a reflector to be directed downwards (in the -Z direction) towards the lead and then into the projection lens. This projection lens is equipped with an anti-reflection coating for 248nm and has a 1/5 magnification. Details are shown in Table 1 below.

[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 (lines and space) [μm] 2 NA 0.13 Distance from the photomask to the projection surface [mm] 1050

A laser beam emitted from the projection lens enters from the back of the donor substrate and is projected precisely onto a predetermined position on 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.

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 Z-axis stage (Zl) of the projection lens and the W-axis position of the photomask stage on which the field mirror (F) is placed are adjusted. Additionally, while an adjustment function (Z-axis stage) for the donor substrate in the Z-axis direction can be added, the decrease in transfer position accuracy caused by increasing the load on the X-axis (Xd) of the donor stage needs to be considered.

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 profiler (BP) with a plane on the focal plane that is conytically related to the image plane is effective. Figure 8 shows the adjustment screen. In this embodiment 1, real-time and high-resolution monitoring reduces the spatial intensity distribution of the laser imaged on the donor substrate surface and the edge interface of the light-absorbing layer.

The above describes the functions implemented by the device structure of this embodiment 1 in relation to the transmission of pulsed lasers emitted from the laser device.

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.

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 structure is built on a base platform (G). Additionally, a rotation adjustment mechanism (RP) is located between G1 and Xd, between Xo and Xd, and between Xd and Yd (not shown).

In addition, in order to adjust the perpendicularity and parallelism of the axes of each stage, an adjustment board AD held on the donor stage is used instead of the donor board, and an adjustment board AR placed on the recipient stage is used instead of the recipient board. On any one of the adjustment boards, lines indicating the accurate formation of right angles of 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).

1) Parallelism between Yr and AR(Y) (Perpendicularity between Yr and AR(X))

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 on 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 stroke of the stage, and the allowable deviation varies depending on the required transfer accuracy. (The same applies below.)

2) Parallelism between AR(X) and Xd (perpendicularity between Yr and Xd)

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 set on the Z-axis stage of the projection lens on the optical stage (Xo). The Xd axis is moved by 400 mm so that the deviation of the alignment line X in the Y-axis direction is within 1 μm. The installation angle of the two is adjusted using the rotation adjustment mechanism between G1 and Xd, and the installation angle of G1 and Xd, i.e., Xd relative to Yr, is also adjusted.

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

Using the alignment line X of the adjustment substrate AR adjusted in the above manner, the parallelism between the optical stage (Xo) and the donor stage's X-axis (Xd) is adjusted while observing with a high-magnification CCD camera, which is fixed on the optical stage (Xo) or mounted on the Z-axis stage 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 donor stage's X-axis (Xd) 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.

4) Parallelism between 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 on an optical stage (Xo) or mounted on the Z-axis stage 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.

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

To adjust the perpendicularity of the X-axis (Xd) and Y-axis (Yd) of the donor stage, the 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 the Z-axis stage of the projection lens on the optical stage (Xo). The optical stage (Xo) is moved 200 mm, and the perpendicularity of the Y-axis (Yd) of the donor stage, suspended on the X-axis (Xd), to the donor stage is adjusted by a rotation adjustment mechanism between the two, ensuring that the deviation of the alignment line X in the Y-axis direction is within 0.5 μm.

6) Parallelism between AD(Y) and Yr (parallelism between Yd and Yr)

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 opposite 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. Then, the Y-axis (Yd) of the donor stage is moved by 400 mm, and it is confirmed that the deviation in the X-axis direction of the alignment line Y is within 1 μm. In addition, to confirm the same process at the other end of the stage, after moving Xd to that end, move Yd by 400 mm to confirm that the deviation in the X-axis direction of the alignment line Y is within 1 μm. Alternatively, Yd and Yr can be moved in parallel to observe the positional changes of the alignment mark.

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, depending on the position of the X-axis of the donor stage and the shape (opening) of the stone platform 1. 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 the X-axis direction.

Since stone platform 1 (G1) and stone platform 2 independently support each stage, and Yd is suspended from Xd mounted 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 according to the adjustment steps described in 1) to 6), it is ideal to perform the adjustment in a way that minimizes the allowable deviation in the initial stage. In addition, although the adjustment steps described in 1) to 6) record the adjustment of the parallelism and perpendicularity of each stage in the XY plane, adjustments to other axes (X-axis and Y-axis) are also required.

Next, referring to Figures 9A to 9C, the scanning of the donor substrate and recipient substrate during the transfer in this embodiment 1 will be described. Here, the top view of Figures 9A to 9C shows the operator positioned to the left of these figures and the donor substrate (D) and recipient substrate (R) being scanned back and forth relative to the operator.

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 this bending, along with position information, is used as two-dimensional data for mapping. This information is used as a correction amount for the Z-axis (Zr) of the recipient stage, corresponding to the X-axis (Xd) and Y-axis (Yd) of the donor stage as it moves during the transfer process.

Furthermore, in the following explanation, for ease of explanation, the designated position on the left side of the receiver substrate (R) and donor substrate (D) 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 respectively defined as origins. Furthermore, in the donor substrate, the positions of the donor stages (Xd, Yd, θd) during laser (LS) irradiation 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 the position that allows for the travel portion of the journey during subsequent transfer processes and substrate removal.

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 the laser irradiating the object (S) through a reduced-projection optical system. The light-absorbing layer (not shown) in the 10 × 10 [μm] region receiving the irradiation absorbs the laser, ablates, and generates a shock wave, thereby transferring the object in the same region to the opposing acceptor substrate. Although three objects are shown, in the case of Example 1, a total of 300 objects are transferred to the acceptor substrate at once.

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

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.

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

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

As described above, each stage accelerates from its position one side in front of the origin, maintaining a stable, constant velocity. During this acceleration period and until the stage reaches the origin, the laser pulses need to be interrupted to prevent the laser from irradiating the donor substrate. Therefore, a programmable multi-axis control device sends external oscillation trigger signals or high-speed optical gate actions, along with stage drive signals, to the laser device with high precision.

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.

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

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.

Figure 11 shows the situation before returning to the position of 15 μm (shown as a solid line) in the -X direction from the previous origin (shown as a dashed line) after completing the -9 mm × 20 step movement in Xd, using that point as the new origin, and starting the same operation. Thereafter, the Y-axis scans (180 mm (Yd) and 360 mm (Yr)) of both stages and the -9 mm × 20 step operation in Xd are repeated. Thus, by irradiating the unirradiated area (the area to be irradiated by the next laser (LS) is indicated by a single-dot dashed line in the figure) during the initial 180 mm scan of Xd (20 steps of -9 mm), the object on the donor substrate can be transferred to the recipient substrate more efficiently and effectively.

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

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

As described above, the transfer pattern of the object to the acceptor substrate in this embodiment 1 is to transfer 10×10[μm] in a matrix with an interval of 30[μm]. However, if the interval is set to 60[μm], it is possible to transfer four acceptor substrates with one donor substrate.

[Implementation Example 2]

In this embodiment 2, unlike the layered state where the objects on the surface of the donor substrate are a single sheet in embodiment 1, the following embodiment is used: 144 million objects, each with a shape of 10×10μm and a spacing of 15μm, formed in a matrix on a donor substrate of the same size of 200×200[mm], are transferred to a recipient substrate of size 400×400[mm] at half the density of the donor substrate, i.e., at a spacing of 30[μm] and in the same matrix.

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

Figures 13A to 13C show the process from the initial pulse of the irradiation laser (LS) to the third irradiation on the donor substrate (D) and recipient substrate (R) located at the origin, similar to Embodiment 1.

[Implementation Example 3]

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. On the other hand, the method for adjusting the parallelism between the Y axes and the X axes of each stage, as well as the perpendicularity between each Y axis and the X axis, is different from the embodiments described above. That is, the adjustment method described in embodiment 1 is as follows: in order to adjust the parallelism between the Y axis (Yr) of the recipient stage and the Y axis (Yd) of the donor stage, the adjustment steps 1) to 6) are performed. In contrast, in this embodiment 3, the parallelism between Yr and Yd is adjusted in the early stage of the adjustment steps.

1) Straightness of Yr, θr, and Zr

This adjustment step is a common premise to both Embodiment 1 and Embodiment 2. The straightness of the Y-axis (Yr) and θ-axis (θr) of the receiver stage mounted on the platform 2 (G2), as well as the Z-axis (Zr) and the support of the receiver substrate (relative to the straightness of the Z-axis in the vertical direction when the horizontal plane is taken as the XY plane) of the receiver stage are adjusted using a laser interferometer or similar device. Furthermore, essentially after this adjustment, no adjustments that could affect the verticality of the receiver stage assembly are made; all adjustments to the other stages are performed based on, for example, the uppermost surface of the aforementioned receiver stage assembly.

2) Parallelism between Yr and AR(Y) (Perpendicularity between Yr and AR(X))

Similar to adjustment step 1) in Embodiment 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, adjustment step 1 can be omitted.

3) Parallelism between AR(X) and Xd (perpendicularity between Yr and Xd)

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, but 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 by 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 Xd in the Y-axis direction of the alignment line X is within 0.3 μm.

4) Parallelism of Yr and Yd in the YZ plane

In the description of Embodiment 1, the adjustment steps for other axes (X-axis and Y-axis) are omitted. Here, the adjustment steps for the parallelism in the X-axis system, i.e., the YZ plane, are briefly explained. Observe the lower surface of the donor stage's Y-axis (Yd) using a height sensor installed on the Z-axis (Zr) or other part of the recipient stage. Move Yr and Yd simultaneously (parallel) by the same distance of more than 200 mm and observe the change in the gap sensor's measurement value (distance between Zr and Yd). To ensure that the change is within 5 [μm] or within a sufficiently small range compared to the focal depth of the projection lens, the pad is inserted between the rotation adjustment mechanism and Yd or Yd, adjusting the parallelism in the YZ plane between Yr and Yd.

5) Parallelism between Yr and Yd

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

6) Perpendicularity of Yr and Xo

Using a high-magnification CCD camera mounted on an 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 via 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.

[Implementation Example 4]

Figure 2A shows the main structural parts of the transfer device of Embodiment 4. It is an embodiment based on the seventh invention of the present invention as its basic structure. In addition, in Figures 2A to 2C, the laser device, control device, and other monitors are omitted (these are all the same as in Embodiment 1), and the X-axis, Y-axis, and Z-axis directions are shown in the figures. Furthermore, the arrangement of the donor substrate, the recipient substrate, and the donor substrate of the transfer object used in Embodiment 4, as well as the arrangement after transfer to the recipient substrate, are the same as in Embodiment 2.

The optical system in which pulsed lasers are emitted from an excimer laser device and irradiate the transfer target on the donor substrate is the same as in Embodiment 1, except for the differences arising from the different constructions of the stages shown in Figures 1A and 2A. 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 sequentially arranged on the platform 1 (G1) and the optical stage (Xo) is arranged on it. 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.

The light emitted from the excimer laser enters the telescope optical system and propagates to the shaping optical system in front of it. As shown in Figure 2A, the shaping optical system is positioned parallel to the optical axis on 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 platform 2 (G2) different from G1, 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 optical system to a shape that is substantially the same as the movement of Xo (approximately 25 × 25 mm (WHM)).

The donor stage's X-axis (Xd) is suspended below G1, and its Y-axis (Yd) is also suspended there. Furthermore, a rotation adjustment mechanism is provided between them. Figure 2B shows, in a side view, 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 shows, in a side view, 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.

The details of the field mirror (F), photomask (M), and projection lens (Pl) as other components of the reduced-size 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 projects 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 profiler, as in Embodiment 1.

Based on the photomask pattern that performs a scaled-down projection onto the transfer object disposed on the surface of the donor substrate in the manner described above, when the transfer object is transferred to the opposing receiver substrate, the manner in which the donor substrate and receiver substrate are scanned and the manner in which the transfer object is transferred onto the receiver 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 receiver stage and the Y-axis (Yd) of the donor stage is the same as in Figure 12 described in Embodiment 1.

Furthermore, the adjustment methods for 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 Embodiment 3. That is, the Y-axis (Yr) of the recipient stage, which has undergone 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 on the Z-axis (Zr) of the recipient stage, and adjustment is performed using the rotation adjustment mechanism (RP) between G1 and Xd. In addition, the parallelism between the Y-axis (Yd) and Yr of the donor stage suspended on the adjusted Xd is observed using the same high-magnification CCD camera, and adjustment is performed using the RP between Xd and Yd. Finally, the perpendicularity of the optical stage (Xo) and Yr was observed using a high-magnification CCD that moved together with Xo, and adjusted using RP between G1 and Xo.

[Industrial Practicality]

This invention can be used as a manufacturing device for a display.

Platform 1 Platform 2 Platform 3 Platform 11 Platform 12 Platform AD Donor stage adjustment substrate AR Receiver stage adjustment substrate BP Confocal beam profiler CCD High-magnification camera D Donor substrate F Field mirror G Basic platform G1 Platform 1 G11 Platform 11 G12 Platform 12 G2 Platform 2 G3 Platform 3H Shaping optical system Ic Radiation interferometer cone prism IL Radiation interferometer LS Radiation M Photomask Pl Projection lens R Receiver 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 Switching stage for projection lens and camera Yr Y-axis of the receiver stage Zl Z-axis stage Zr of the projection lens; Z-axis θd of the recipient stage; θ-axis θr of the donor stage; θ-axis of the recipient stage.

Figure 1A shows the main structural parts of the transfer device of the present invention (side view). (Second Invention) Figure 1B shows the X-axis of the donor stage after the optical stage has been placed on it and moved from the state of Figure 1A (side view). Figure 1C shows the optical stage after it has moved along the X-axis of the donor stage from the state of Figure 1B (side view). Figure 1D is a top view of Figure 1C. Figure 2A shows the main structural parts of the transfer device of the present invention (side view). (Third Invention) Figure 2B shows the X-axis of the donor stage and the optical stage after they have moved the same distance on platform 1 from the state of Figure 2A (side view). Figure 2C shows only the X-axis of the optical stage after it has moved on platform 1 from the state of 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 to which the donor stage should move according to the size of the acceptor substrate. Figure 5A shows a Y-axis laser interferometer with a acceptor stage. Figure 5B shows a Y-axis laser interferometer with a donor stage. Figure 6 shows an example of a pattern formed on a photomask. Figure 7 shows a transfer process using multiple rows of photomask patterns. Figure 8 shows the monitoring of a confocal beam profiler. Figure 9A shows the first illumination in the transfer process. Figure 9B shows the second illumination in the transfer process. Figure 9C shows the third illumination in the transfer process. Figure 10 shows the acceptor substrate after one scan with a gear ratio of 1:2. Figure 11 shows the X-axis step scan of the donor stage. Figure 12 shows the synchronization error when the Y-axis of the acceptor stage and the Y-axis of the donor stage are moved in parallel. 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.

BP Confocal Beam Profiler (CCD) High-Magnification Camera (D) Donor Substrate (F) Field Mirror (G) Base Platform (G1) Platform 1 (G11) Platform 11 (G12) Platform 12 (G2) Platform 2 (H) Shaping Optical System (LS) Laser (M) Photomask (Pl) Projection Lens (R) Receiving Substrate (TE) Telescope (Xd) X-axis of Donor Stage (Xo) Optical Stage (X-axis) (Yd) Y-axis of Donor Stage (Yl) Switching Stage between Projection Lens and Camera (Yr) Y-axis of Receiving Stage (Zl) Z-axis Stage of Projection Lens (Zr) Z-axis of Receiving Stage (θd) θ-axis of Donor Stage (θr) θ-axis of Receiving Stage

Claims (19)

A transfer method involves irradiating an object arranged in a matrix on the surface of a substrate from the back of the substrate with a laser mask pattern, peeling the object off the substrate, and transferring the object in a matrix to another substrate. This method utilizes displacement of the laser mask pattern irradiated on the substrate relative to the substrate and the other substrates, such that the spacing of the objects transferred to the other substrates in the displacement direction is greater than the spacing of the objects on the substrate. Furthermore, the spacing of the windows in the photomask used to acquire the laser mask pattern ensures that the spacing of the objects transferred to the other substrates in a direction perpendicular to the displacement direction is greater than the spacing of the objects on the substrate. The transfer method as described in claim 1, wherein the interval between objects transferred to the other substrate in the displacement direction is more than twice the interval between the objects on the substrate. The transfer method as described in claim 1, wherein the interval between objects transferred to the other substrate in the displacement direction is 2 to 4 times the interval between the objects on the substrate. The transfer method as described in any of claims 1 to 3, wherein the interval between objects transferred to the other substrate in a direction perpendicular to the displacement direction is more than twice the interval between objects on the substrate. The transfer method of any of claims 1 to 3, wherein the interval between objects transferred to the other substrate in a direction perpendicular to the displacement direction is 2 to 4 times the interval between objects on the substrate. A transfer method involves irradiating an object arranged in a matrix on the surface of a substrate from the back side of the substrate, peeling the object off the substrate, and transferring the object to another substrate in a matrix. The method involves simultaneously displacing the laser irradiating the substrate, the substrate, and the other substrates relative to each other in the row direction of the matrix, while the laser irradiates multiple objects that are not adjacent to each other and are spaced apart in the column direction of the matrix, thereby transferring the object in such a way that the density of the object on the other substrates is lower than the density of the object on the substrate. The transfer method as described in claim 6, wherein the density of the matrix of objects transferred to the other substrate in the row direction is less than 1/2 of the density of the objects on the substrate. The transfer method as described in claim 6, wherein the density of the matrix of objects transferred to the other substrate in the row direction is 1/4 to 1/2 of the density of the objects on the substrate. The transfer method as described in any of claims 6 to 8, wherein the density of the matrix of objects transferred to the other substrate in the column direction is less than 1/2 of the density of the objects on the substrate. The transfer method as described in any of claims 6 to 8, wherein the density of the matrix of objects transferred to the other substrate in the column direction is 1/4 to 1/2 of the density of the objects on the substrate. The transfer method as described in claim 1, wherein the substrate and the other substrates are moved in the same direction relative to the laser photomask pattern irradiating the substrate. The transfer method as described in claim 11, wherein the substrate and the other substrates are moved at different speeds relative to a laser photomask pattern irradiated on the substrate. The transfer method as described in claim 12, wherein the other substrate moves faster than the substrate relative to the laser photomask pattern irradiated on the substrate. The transfer method of claim 11, wherein the transfer is stopped when the laser irradiates the substrate. The transfer method as described in claim 11, wherein the movement is performed continuously while the laser is irradiating the substrate. A method of manufacturing an object onto another substrate by means of a transfer method as described in any one of claims 1 to 15. A photomask for use in a transfer method, wherein a laser photomask pattern is irradiated from the back of a substrate onto an object arranged in a matrix on the surface of the substrate, thereby peeling the object off the substrate and transferring the object in a matrix to another substrate, the photomask having a plurality of windows arranged in a row, the windows being separated in such a way that the laser photomask pattern irradiates a plurality of objects on the substrate that are not adjacent to each other and are spaced apart. The photomask as described in claim 17, wherein the window is separated in such a manner that the spacing between objects transferred to the other substrate is more than twice the spacing between objects on the substrate. The photomask as described in claim 17, wherein the windows are spaced 2 to 4 times apart in such a way that the spacing between objects transferred to the other substrates is more than twice the spacing between objects on the substrates.