JP2023015998A - Defective position removing method, lift method, photomask, and lift system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scanning-type reduced projection optical system that can scan a tiny irradiation area having an energy distribution which is uniform and invariable, extensively, with high accuracy and at high speed, while making up for lack of accuracy of a scanner, without using a fθ and a telecentric reduced projection lens which are expensive and have large calibers, and low-cost lift device or the like for mounting or for re-transfer which is mounted with the system, and to provide an execution method for the system.

SOLUTION: A scanning-type reduced projection optical system, which allows pulse laser light in a lateral multi mode to form an image with a size corresponding to a tiny area on a donor substrate, through a lens array-type zoom homogenizer, an array mask 10, a scanning mirror 4, a photo mask 6 and a telecentric projection lens 8, is used to lift fine elements on the donor substrate onto a receptor substrate opposing thereto, with high positional accuracy. Execution steps for the system include steps for an inspection for obtaining positional information, a lift area division, an irradiation position selection, transfer and a stage movement.

SELECTED DRAWING: Figure 6B

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to a scanning reduction projection optical system and a laser processing apparatus using the same.

As a technique used in the manufacturing process of displays, etc., there is a technique of transferring a large number of minute elements such as micro LEDs arranged in a matrix on a donor substrate to a receptor substrate. There is also a technique for transferring various functional films such as conductive and adhesive films, material films, organic EL films, etc. coated on a donor substrate to a receptor substrate. For example, there are various techniques such as a lift (LIFT: Laser Induced Forward Transfer) technique, a stamp technique, and a roll transfer technique. However, it is not easy to achieve both high-speed processing and high positional accuracy required for the process with any of the techniques, and even at high speeds, transfer omissions and positional deviations occur.

Japanese Patent Application Laid-Open No. 2020-4478 Japanese Patent Application Laid-Open No. 2006-41500

Therefore, the applicant developed a high-speed and high-precision lift device (Patent Document 1). However, defects of up to 1% exist in minute elements, etc. on the donor substrate and receptor substrate that are transferred and mounted by the transfer device that uses the above-mentioned stamp technology and roll transfer technology used in the lift device. There is Therefore, there is a demand for a technique for re-transferring microelements and the like to the defective portion and an apparatus using the technique to achieve both high precision and high speed.

In addition, such techniques can be used not only for retransfer from a donor substrate to a receptor substrate, but also for removal of irradiated objects such as defective micro-elements located on the substrate and portions of unwanted material. It is also expected to be used in the process of removing defects in addition to the process of mounting microelements by transfer.

On the other hand, unlike Patent Document 1, there is a high-precision transfer technique based on a step-and-repeat method. For example, in the technique of re-transferring micro-elements, etc. to non-element areas after removing defective micro-elements on the substrate to be repaired in advance, a beam homogenizer that combines excimer laser light with a lens array is used. The laser beam is shaped into a laser beam with a uniform energy distribution using a photomask and a reduction projection lens, which is then reduced and projected onto a minute element or the like located on the donor substrate (for retransfer), and the minute element or the like is projected. is lifted onto the substrate to be modified. With this technology, it is possible to accurately lift (re-transfer) microelements on a donor substrate onto a substrate to be repaired by means of a stage with high positional accuracy. Since it takes about 2 seconds, it is not practical as a retransfer device used in the manufacturing process of displays, etc., where a large number of defective parts may occur as much as 1%, even in light of its production efficiency. .

As a technology that enables high-speed scanning, an optical system that combines a galvanometer scanner and an fθ lens is well known. It is possible to remove the element from the substrate to be corrected at high speed as long as the positional accuracy of the scanner allows, but the subsequent retransfer, which requires high positional accuracy, is difficult due to the limit of accuracy. .

Therefore, in order to solve the problem of the positional accuracy of the scanner, the scanned laser light is selectively irradiated through an fθ lens or the like toward the openings arranged on the photomask, and the apertures are positioned on the substrate. It is possible to construct a high-speed, high-positional-precision scanning reduction projection optical system with reduced dependence on the scanning accuracy of the scanner. In Patent Document 2, a Nd:YAG laser beam is scanned by a galvanomirror, and reduced projection is performed via an fθ lens and a photomask, thereby correcting positional deviation of an irradiation area on a donor substrate due to low scanning accuracy. Examples of compensating optics are shown.

However, in order to increase the size of each substrate and achieve higher processing speeds, it is necessary to enlarge the irradiation area on the donor substrate and reduce and project the scanned laser beam onto many irradiation targets in a short time. That is, it is necessary to secure a large scannable irradiation area on the photomask. In this case, it is necessary to increase the apertures of the fθ lens and the reduction projection lens used in Patent Document 2, and a telecentric design requires a high cost.

Furthermore, in order to cope with the miniaturization and high density of irradiation objects such as minute elements, it is necessary not only to compensate for the accuracy limit of the scanner, but also to achieve a stable and uniform intensity distribution so as not to interfere with adjacent irradiation objects. A very small irradiation area size of laser light is required on the donor substrate. In addition, it is expected to realize a lift device, a retransfer device, and a defect removal device that replace the device described in Patent Document 1, which are equipped with such an optical system.

Therefore, without using an expensive large-aperture f-theta lens or a telecentric reduction projection lens, while compensating for the lack of accuracy of the scanner, a small irradiation area with a uniform energy distribution without fluctuation is scanned over a wide range with high accuracy and high speed. It is an object of the present invention to provide a scanning type demagnification projection optical system capable of reducing the image, a lift device or the like for mounting or retransfer equipped with the optical system at low cost, and to provide a method for carrying out the same using these.

The first invention is directed to irradiation objects such as microelements such as mini LEDs or micro LEDs arranged in multiple numbers on a substrate, or material films and functional films attached to the substrate by coating or printing. Scanning reduction projection that can be used in a laser processing apparatus that irradiates a multimode pulsed laser beam and induces a reaction directly on an object to be irradiated or through a substance between the substrate and the object to be irradiated An optical system comprising a lens array type zoom homogenizer, a scanning mirror scanned by one or more drive axis controllers, a photomask, and a projection lens system telecentric at least on the image side as constituent optical elements. A plurality of openings having a predetermined shape to be reduced and projected are arranged at a predetermined pitch in the photomask.

Further, the homogenizer is a zoom homogenizer including a first lens array, a second lens array, and a condenser lens, the second lens array and the condenser lens constituting an infinity correction optical system, and one or more lenses on the photomask. An illuminated area of predetermined size covering the adjacent apertures is imaged onto the photomask to compensate, among other things, for variations in the location and size of the illuminated area and the energy intensity distribution within the illuminated area.

“Compensation for fluctuations” means that fluctuations in the oscillation state, for example, are known to cause fluctuations in the beam pointing stability, beam size, and intensity distribution of the beam cross section. A state in which the influence is avoided in the irradiation area imaged on the mask. As a result, a very small area can be imaged on the mask-projected donor substrate with a highly uniform energy distribution.

The predetermined size is a size such that the irradiation area does not extend to any other openings adjacent to the periphery of the opening group. That is, considering the irradiation position accuracy on the photomask due to the scanning accuracy of the scanning mirror, it is assumed that the laser beam passes through the adjacent opening and is irradiated onto the irradiation object (not intended to be irradiated) on the substrate. If so, the boundary (outer edge) of the energy distribution above the threshold at which the reaction is induced has a size that does not reach (do not cover) any openings adjacent to the opening group included in the irradiation area. As an example, in FIG. 1, the irradiation area (DP) enclosed by the dash-dotted line illustrates the maximum allowable size of the irradiation area covering an aperture group consisting of four apertures (61), Small illumination area exemplifies the minimum size of the illumination area that covers one aperture. In the drawing, each example of the irradiation area is shown double to express the deviation due to the positional accuracy of the scanner.

For example, when apertures (square) are arranged in a matrix on the photomask (6) as shown in FIG. ) is within the range of the following formula, where Ma is the side of each opening, Pi is the pitch, and St is the scanning positional accuracy of the scanner on the photomask.
Pi×(n−1)+Ma+St≦DP<Pi×(n+1)−Ma−St
For a given size exceeding this range, laser light having energy above the threshold that passes through (a portion of) an unintended adjacent aperture is reduced and projected onto an unintended object to be irradiated, inducing a reaction. There is a possibility that If the shape of the aperture is not square, or if the range of the predetermined size (DP) in the simultaneous irradiation of n×m pieces is a matter of design.

When a photomask having apertures arranged in a matrix is used for collective irradiation, the pitch (Pi) of the apertures on the photomask is the distance to be lifted onto the receptor substrate, assuming that the reduction magnification of the reduction projection lens is 1/c. It is fixed at c times the pitch of the object to be irradiated.

Depending on the specifications of the reduction projection lens, the number of apertures can be selected from various designs ranging from one in which the apertures are arranged in a row as shown in FIG. 2 to one in which apertures are arranged in a matrix as shown in FIG. These also depend on the scannable range of the scanning mirror.

The lens elements constituting the first lens array and the second lens array are not limited to the fly-eye type, and may be cylindrical or spherical. Therefore, each lens array may be composed of a combination of orthogonal lens elements. In addition, there are zoom homogenizers with the addition of a third lens array.

In a second aspect based on the first aspect, the projection lens system includes a field lens disposed between the condenser lens and the photomask, and a reduction projection lens telecentric at least on the image side. It is a projection optical system.

Here, the specifications of the field lens are determined based on the specifications of the zoom homogenizer, condenser lens (3) and telecentric lens, and the preferred position in the present invention is just before the photomask (6) as shown in FIG. . The focal length of this field lens (5) is such that the laser light from the zoom homogenizer (the number of condensing points corresponding to the number of lens elements in the second lens array (2)) reaches the entrance pupil of the image-side telecentric reduction projection lens (8). It is designed with a curvature that allows it to pass through the aperture (7) placed in position.

A third invention is a scanning reduction projection optical system according to the first or second invention, wherein the scanning mirror (4) is composed of a biaxial galvanometer scanner. Thereby, the irradiation area of the laser beam can be scanned toward the openings arranged in a plurality of rows on the photomask (6). There are various types of control devices for scanning mirrors, such as a dedicated controller or a combination of a dedicated board and a PC. Both can be used to control the oscillation timing of the pulsed laser light.

In a fourth invention, in any one of the first to third inventions, the lens array comprises an aperture group in which apertures each having a size smaller than the size of each lens element constituting the lens array are arranged so as to face each lens element. It is a scanning reduction projection optical system using a zoom homogenizer in which an array mask is arranged immediately before the first lens array or between the first lens array and the second lens array. As a result, a virtual image due to stray light between lens elements can be removed on the donor substrate on which the shape of the aperture on the photomask has been reduced and projected, and extremely fine image formation with stable and highly uniform energy distribution can be obtained. In addition, regardless of the shape of the lens element, an arbitrary shape microscopic image can be obtained in accordance with the shape of the aperture of the photomask.

If the lens elements are cylindrical, they may be used in combination with an elongated aperture array mask. The position of the array mask is determined while checking the irradiation area on the photomask with a beam profiler or the like in the range immediately before or after the first lens array or between the first lens array and the second lens array. matter. Note that the number of lens elements and the number of aperture groups of the array mask do not have to match. For example, the NA of the optical system can be adjusted by reducing the numerical aperture of the outer periphery of the array mask.

As an example of the predetermined size, dA is the element size of the first lens array of fly-eye type, or the size of the aperture of the array mask disposed immediately before the first lens array, f1 is the focal length of the first lens array, The focal length of the second lens array is f2, the distance between the first and second lens arrays is a (here, a=f2), and the focal length of the condenser lens is fC, forming the projection lens system. Assuming that the focal length of the field lens is fF and the distance between these lenses is b, the predetermined size (DP) of the irradiation area imaged on the photomask is expressed by the following equation.

However, this configuration is not suitable because of the influence of the aberration of the first lens array and the diffraction caused by the array mask. These problems are avoided by moving the first lens array toward the light source and placing the array mask near the focal position of the second lens array on the light source side. Furthermore, the utilization efficiency of the pulsed laser light cut out by the array mask can be improved.

In a fifth aspect, the array mask according to the fourth aspect has a plurality of types of openings that enable switching between groups of openings having different sizes, shapes, or numbers of openings within the plane of the substrate. It is a scanning reduction projection optical system in which groups are arranged.

If the number of apertures in the array mask is less than the number of lens elements in the first lens array, the array mask will have the function of profiled illumination. FIG. 4 shows an example of an array mask in which a group of apertures for irregular illumination and a group of apertures facing each other in the same number as the lens elements of the lens array are arranged on one substrate.

A sixth aspect of the present invention is the scanning reduction projection optical system according to the fourth or fifth aspect, wherein the array mask is mounted on a mount including a .theta.-axis that enables fine rotational adjustment around the optical axis.

Light emitted from each lens element of the second lens array is superimposed on the photomask by a condenser lens to obtain an image with high uniformity. Here, in the relative positional relationship between the array mask and the second lens array, the positional deviation within the plane perpendicular to the optical axis does not affect the uniformity. However, if there is a shift in the rotational direction (θ) around the optical axis, the outline of the image formation becomes blurred, resulting in multiple image formation. The situation is shown in FIG. (Here, an array mask having a circular aperture shape is used.) The influence of such rotational shift increases as the image formation becomes smaller.

A seventh invention is a scanning reduction projection optical system according to any one of the first to sixth inventions, wherein the various optical elements correspond to oscillation wavelengths of an excimer laser.

An eighth invention is a laser processing apparatus utilizing multimode pulsed laser light directed to an irradiation target positioned on a substrate to induce a reaction, wherein the multimode pulsed laser oscillates from the laser apparatus. A laser processing apparatus configured to reduce and project light onto a substrate held on a stage having at least X-axis and Y-axis drive axes by the scanning type reduction projection optical system according to any one of 1 to 6. .

Here, there are various types of objects to be irradiated on the substrate, such as the aforementioned defective microelements and unnecessary portions of the functional film on the circuit substrate. Also, induced "reactions" herein include, but are not limited to, mechanical, optical, electrical, magnetic, and thermal reactions.

In a ninth aspect based on the eighth aspect, the substrate is a donor substrate having the object to be irradiated on the surface thereof, and a pulsed laser beam is irradiated from the back surface of the donor substrate toward the object to be irradiated. A laser processing apparatus for mounting, retransfer, or both for selectively peeling or separating an irradiation object and lifting it onto a receptor substrate facing a donor substrate, more specifically a lift apparatus. is.

In addition, the stage is a donor stage that holds the donor substrate with its back surface facing the incident side of the pulsed laser beam, and further holds the receptor substrate in the X-axis, Y-axis, and Z-axis directions in the vertical direction. and a receptor stage having a θ axis that rotates in the XY plane, the scanning reduction projection optical system and the donor stage are installed on a first platen, and the receptor stage is a second platen or The first surface plate and the second surface plate are installed on the foundation surface plate, and the first surface plate and the second surface plate are each independently installed on the foundation surface plate.

Here, selectively exfoliating or separating the irradiation object means, when the irradiation object is a microelement, selectively peeling off the microelement itself from the donor substrate. , In the case of a functional film, etc. printed or coated on a donor substrate, the functional film, etc. of the portion corresponding to the image formation position and size of the laser beam projected in a reduced size through the opening on the photomask. means to selectively peel or separate the Note that this peeling or separation includes a case where a so-called ablation process does not intervene.

In addition, since all stages perform step-and-repeat operations, that is, all stages are stationary when the laser beam is irradiated, there is physical contact between the stages and the guides, making the rolling guides stable. It can be said that the method is preferable to the air bearing method in consideration of cost.

On the other hand, the first surface plate, the second surface plate, and the base surface plate on which these stages are installed must be made of a highly rigid member such as steel, stone, or ceramic. . Stone materials typified by granite (granite/granite) are preferably used as the stone material.

With the above configuration, fluctuations in the positional accuracy and positional stability of the irradiation target lifted onto the receptor substrate are suppressed by the scanning reduction projection optical system and the installation structure of each substrate stage that eliminates vibration. It is determined by the relative positional relationship between the mask, the reduction projection lens and the donor substrate, and the arrangement positional accuracy of the object to be irradiated on the donor substrate.

In a tenth aspect based on the ninth aspect, the scanning mirror control device selects based on previously acquired position information of an object to be irradiated on the donor substrate and information on a planned lift position on the receptor substrate. The lift device includes a function of controlling a scanning mirror that scans the optical axis of a pulsed laser and a function of controlling the irradiation of the pulsed laser light toward the opening on the photomask.

In particular, when a lift device is used as a retransfer device, it is undeniable that the donor substrate for retransfer may have an element-free portion or a defective portion where a defective element is mounted. Therefore, the laser beam from the scanning reduction projection optical system is applied only to the irradiation target on the donor substrate to be lifted, which is selected based on the information on the defective portions of the receptor substrate to be lifted and the donor substrate to be lifted. A scanning mirror is controlled to scan the optical axis across an aperture on the photomask opposite the selected object to be illuminated.

An eleventh invention is the lift device according to the ninth or tenth invention, wherein the donor stage can hold two or more donor substrates and can switch between them.

For example, a first donor substrate coated with a conductive paste film is irradiated with a pulsed laser beam of a predetermined size that has been reduced and projected by the scanning reduction projection optical system according to the present invention, and a position on the opposite receptor substrate is irradiated. Then, a portion of the conductive paste film corresponding to the size is lifted (paste printing). Next, by moving the donor stage, the first donor substrate is switched to the second donor substrate (carrier substrate), the microelement (device) on the carrier substrate is lifted to the same position on the receptor substrate, and the conductive paste is applied. It is fixed through the membrane.

A twelfth invention is the lift device according to the ninth to eleventh inventions, wherein the donor stage is suspended from the lower surface of the first surface plate.

The order of installation of the axes constituting the donor stage is a matter of design, but preferably, from the lower surface of the horizontally installed first surface plate, the X-axis and the Y-axis are arranged in this order, and if the θ-axis is included, it is below it. to hang. Incidentally, the axial configuration of the receptor stage is also a matter of design.

A thirteenth invention is the laser processing apparatus according to the eighth invention or the lift apparatus according to any one of the ninth to twelfth inventions, wherein the laser apparatus is an excimer laser apparatus.

A fourteenth invention is a receptor substrate facing an irradiation target on a donor substrate using a lift device according to the present invention equipped with a scanning reduction projection optical system according to any one of the ninth to thirteenth inventions. For mounting on the top or for retransfer, the lift method includes "position information D" which is the position information of the irradiation object on the donor substrate, and the planned lift position of the irradiation object on the receptor substrate. An inspection process for obtaining certain "position information R" in advance, a division process for dividing a region on the donor substrate into "divided areas D" of a predetermined size, and division by lifting based on the position information D and the position information R A selection step of selecting a position of an object to be irradiated within area D, and irradiating the donor substrate through an opening on a photomask opposite (via a reduction projection lens) to the position of the selected object to be irradiated. a transfer step of lifting an irradiation object selected in the divided area D by laser light toward a "divided area R" defined as an area on the receptor substrate facing the divided area D for convenience; a moving step of moving the receptor substrate to the next lift area; thereafter, the transferring step and the moving step are repeated, and the selected irradiation object on the donor substrate is moved to the receptor for the entire area of the receptor substrate to be lifted. This is a lift method for mounting or re-transferring onto a substrate.

In the inspection process, there are various methods of acquiring the position information of the irradiation object that is mounted. It is a design matter. Determination of the origin position of these coordinates is also a matter of design. The position information D and/or the position information R may be inspected using an independent inspection device separate from the lift device, and the result may be acquired by the control device of the lift device via communication means, It may be calculated from design numerical values based on the measurement result when positioning (aligning) the donor substrate and the receptor substrate with this lift device. It is desirable that this inspection process be performed before the division process, although it depends on the total tact time for mounting or retransfer.

The position of the irradiation object selected in the divided area D means, when this lifting method is used for mounting, all the irradiation objects on the donor substrate opposite to the planned lift position in the opposing divided area R (however, , excluding defective areas), and when used for retransfer, the object to be irradiated on the donor substrate (however, defective areas (non-element areas) ) is the position of

In the transfer process, without stopping the scanning of the scanning mirror, the pulse laser light is oscillated in synchronization with the time when the optical axis is scanned at the position of the selected object to be irradiated, or the scanning and stopping are repeated. including any of

Furthermore, the position information D includes not only the positional coordinates of the microelements as the irradiation target, which are normally mounted on the donor substrate, but also the position coordinates of the irradiation target that can be peeled off or separated normally. (as anomalous position information) can also be included (as anomaly position information). The same applies to the position information R when this lift method is used for retransfer.

The maximum size of the divided area D depends on the reduction projection lens that constitutes the scanning reduction projection optical system mounted on the lift device. In particular, telecentric demagnification projection lenses are limited in numerical aperture and magnification in view of their manufacturing costs, and these specifications limit the area on the photomask, and thus on the donor substrate, that can be lifted by a single scan. .

In this lifting method, regardless of whether the lifting device is used for mounting or for retransfer, the divided areas D are set in the region of the donor substrate, and the donor substrate and the receptor substrate are separated from each other. are moved by the step-and-repeat operation of each stage holding the , and when these stages are stopped, vibration is avoided and lifted with high accuracy.

In a fifteenth aspect based on the fourteenth aspect, when the designed mounting pitch of the object to be irradiated on the donor substrate is used for mounting using the lift method, the designed mounting pitch is calculated from the position information R. 1, 1/2, 1/3, etc. of the designed mounting pitch for the irradiation target on the already mounted receptor substrate when used for the pitch or for retransfer. It is a lift method when it is a multiple of an integer of 1 or more, such that

When the planned lift positions on the receptor substrate are arranged in a matrix of X x Y, the mounting pitch on the opposing donor substrate of the same size is 1/n times in the X row and 1/m times in the Y row. (n and m are different integers of 1 or more).

In the sixteenth invention, first, the actual mounting pitch of the object to be irradiated on the donor substrate calculated from the positional information D acquired in the inspection process, and the mounting pitch on the receptor substrate similarly calculated from the positional information R. between the substrates (taking into account differences in packing density on the donor substrate). When this lift method is used for mounting, the mounting pitch on the receptor substrate is calculated from the planned lift position (designed position) of the object to be irradiated. It is the actual implementation pitch of things.

In light of the manufacturing process of the donor substrate, even if the donor substrate does not have defective elements or non-elements on the donor substrate, the actual mounting pitch of the irradiation object mounted is different from the designed mounting pitch. It may have an error (δPi). Even if this error does not tend to fluctuate depending on the location on the same substrate, it can be assumed that there is a difference (has an error) between production lots of donor substrates, and further between donor substrates. It is from. In this case, the error δPi is accumulated according to the number of irradiation objects included in the divided area D.

Therefore, the sixteenth invention is a lift method in which the amount of movement of each substrate in the movement step of the fifteenth invention is set to the amount of movement that offsets this "accumulated error amount".

In the sixteenth invention, when trying to lift the irradiation target in the divided area D using a donor substrate having a certain size or more of the error (δPi), the position of the irradiation target in the area (reference and Depending on the number of irradiation objects from a certain position), the accumulated error amount at that position may exceed the allowable range in terms of lift position accuracy. In addition to the deviation between the planned lift position on the receptor substrate and the position of the object to be irradiated on the donor substrate to be lifted, the planned position where the laser light passing through the opening on the photomask forms an image on the donor substrate and its position. The deviation from the position of the object to be irradiated becomes a problem especially when the object to be irradiated on the donor substrate is densely packed and the pitch is narrow.

Therefore, in the seventeenth invention, the distance between adjacent irradiation objects on the donor substrate is set as the upper limit, and the irradiation size of the laser beam irradiated toward the irradiation object on the donor substrate and the size of the irradiation object Considering the difference and the effect of these positional deviations on the lift position accuracy, the range of the allowable cumulative error amount is determined, and the position where the cumulative error amount in the divided area D is the maximum (for example, the upper left corner as a reference case), if this allowable range is exceeded, the size of the divided area D in the dividing step of the sixteenth invention is further reduced to a size that allows the cumulative error amount at that position to fall within the allowable range. divided area D”.

Then, the irradiation object selected in the correction divided area D is mounted or re-transferred in the "correction divided area R", which is also determined to have the same size for the sake of convenience, on the opposing receptor substrate. After that, a transfer step is performed in which the donor substrate and the receptor substrate are moved by a stage in order to be lifted to the next correction division area R. FIG. At that time, the amount of movement of each stage is adjusted so as to offset the accumulated error amount.

When determining the allowable range of the accumulated error amount, even if the accumulated error amount exceeding the above-mentioned maximum value does not occur in one divided area D, the donor substrate (or Assuming that the maximum value may be exceeded as a result of repeating the movement process according to the design pitch (on the receptor substrate), or by simulating in advance, this allowable range (size of the corrected divided area D) is determined. Good.

In an eighteenth aspect based on the seventeenth aspect, the positional information D, the positional information R, the size of the divided area D, and the allowable range are used as parameters by a simulation program to perform mounting or retransfer of the entire receptor substrate. In this lift method, the size of the corrected divided area D, the combination of the movement amounts of each stage, and the execution order of each process are determined so as to minimize the time.

A small and stable irradiation area with a uniform energy distribution without fluctuation is directed to the opening arranged on the photomask while compensating for the scanning accuracy deficiency of the scanning mirror without using a large-diameter f-theta lens or telecentric projection lens. To achieve at low cost a scanning type reduction optical system that scans at high speed and performs reduction projection on an object to be irradiated with high uniformity and precision, a defect removal device equipped with the system, and a lift device for mounting or retransfer.

FIG. 2 is a conceptual diagram illustrating a state of a photomask having openings arranged in a matrix. FIG. 2 is a conceptual diagram illustrating a state of a photomask in which openings are arranged in a line; FIG. 2 is a conceptual diagram exemplifying how the constituent elements of the scanning reduction projection optical system are arranged; (without array mask) FIG. 4 is a schematic diagram illustrating the appearance of an array mask in which a plurality of aperture groups are arranged; Beam profiler image of the (θ-off-axis) irradiated area on the photomask. FIG. 2 is a schematic conceptual diagram (three-dimensional) of a lift device equipped with a scanning reduction projection optical system. FIG. 2 is a schematic conceptual diagram of a lift device equipped with a scanning reduction projection optical system; FIG. 2 is a conceptual diagram of the element configuration of a zoom homogenizer; A conceptual diagram of an array mask. Photo of the array mask. FIG. 4 is a conceptual diagram regarding the arrangement of each optical element from the zoom homogenizer to the donor substrate. A beam profile image showing an imaging state on a photomask when a rectangular array mask is inserted. A beam profile image showing the imaging state on the photomask when a circular array mask is inserted. FIG. 2 is a conceptual diagram of a photomask used in Example 1; A beam profile image of laser light projected on a donor substrate in a reduced scale. A conceptual diagram of an area in which microelements are mounted over the entire effective area of the donor substrate. FIG. 4 is a conceptual diagram showing how a region on a 6-inch donor substrate is divided into 27 divided areas. FIG. 4 is a conceptual diagram showing the relationship between the position on the donor substrate and the amount of accumulated error; FIG. 4 is a conceptual diagram showing how defect location information D and defect location information R overlap; FIG. 4 is a conceptual diagram showing how divided areas of opposing substrates are made to face each other and lifted. FIG. 10 is a conceptual diagram showing how substrate division areas that do not face each other are lifted while being opposed to each other.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated using a specific example and figure. In addition, in the following description, the above-described conceptual diagrams and the like may be used for the sake of convenience.

In Example 1, microelements (micro LED elements) with a size of 30×60 [μm] (X axis×Y axis) are arranged in a matrix without defects on a 6-inch donor substrate. An embodiment of a lift device for mounting irradiation objects in a matrix of 222×225 (49950 in total) on a receptor substrate of the same size is shown. The lift position accuracy required for the approximately 50,000 minute elements mounted on the receptor substrate is ±2 [μm], and the pitch in each axial direction is 450 [μm]. On the donor substrate, minute elements are arranged without defects (no element-free portions) at a pitch that is 1/2 times the mounting pitch of the positions to be lifted on the receptor substrate, and the total number is about 200,000. be. The distance (interval) between adjacent microelements is X: 195 [μm] and Y: 165 [μm]. In this embodiment, for the sake of simplicity, the size of the receptor substrate is the same as that of the donor substrate, and the arrangement pitch of the microelements is the same on both the X axis and the Y axis.

First, FIG. 6A shows an example of the appearance of a lift device according to the implementation of the present invention. The configuration shown in this external view can be applied to receptor substrates of 55 inches or more in size. Also, FIG. 6B shows a conceptual diagram of the layout of the main components. In FIG. 6B, illustration of the laser device, various control devices, mounts of other optical elements, etc. is omitted, and the X-axis, Y-axis, and Z-axis directions are shown in the figure. The first surface plates (G11, G12) and the second surface plate (G2) were all stone surface plates using granite. And iron with high rigidity was used for the foundation surface plate (G).

Moreover, it is desirable to have a rotation adjustment mechanism for finely adjusting the installation angle (perpendicular/parallel) between each surface plate and between each surface plate and each stage. Specifically, the rotation adjusting mechanism described in Patent Document 1 is suitable. Furthermore, it is desirable that the high-magnification camera for monitoring the position of each substrate is installed at a location different from the vibration system such as the stage that holds the substrate.

The laser device used in Example 1 is an excimer laser with an oscillation wavelength of 248 [nm]. The spatial distribution of the emitted laser light is approximately 8×24 [mm], and the beam divergence angle is 1×3 [mrad]. Both are notation of (vertical x horizontal), and numerical values are FWHM. There are various specifications of excimer lasers, and there are differences in output, repetition frequency, beam size, beam divergence angle, etc. In addition, the emitted laser light is vertically elongated (the vertical and horizontal are reversed). ), but there are many excimer lasers that can be used in this embodiment by adding, omitting, or changing the design of the optical system. Also, depending on the size of the laser device, there are cases where it is installed on a surface plate different from the foundation on which the stage group of the lift device is generally installed.

Emitted light from the excimer laser enters the telescope optical system and propagates to the zoom homogenizer beyond it. Here, as shown in FIG. 6B, the zoom homogenizer is arranged on the first platen (G11) so that its optical axis is along the X-axis. The laser light immediately before entering this zoom homogenizer is adjusted by a telescope optical system so that it becomes roughly parallel light. Incident. In this embodiment, the size is approximately 25×25 [mm] (Z×Y).

Each lens array (1, 2) constituting the zoom homogenizer in this embodiment, as shown in the conceptual diagram shown in FIG. It is a combination of cylindrical lens arrays at right angles. The laser light enters the first lens array (1) in the first stage and passes through an array mask (10) placed near the focal position of the second lens array (2) in the rear stage on the light source side while condensing. , the second lens array (2), and the condenser lens (3).
In Example 1, an array mask in which 0.75 [mm] square openings are arranged in a matrix was used. A conceptual diagram thereof is shown in FIG. 8A. In this conceptual diagram, the positional relationship between the array mask (10) placed immediately before the fly-eye type lens array (1) and its aperture (101) is conceptually illustrated to show the state of facing the lens array. is shown. The state of the array mask used in this example is shown in FIG. 8B.

FIG. 9 shows a conceptual diagram of the arrangement of each optical element from the zoom homogenizer to the donor substrate. The detailed arrangement position is a matter of design. The laser light emitted from the zoom homogenizer is scanned by a two-axis scanning mirror (4) and its control device, propagates to a field lens (5), and forms an image on a photomask (6).

The image plane on the photomask (6) is the infinity correction optical system composed of the second lens array (2) and the condenser lens (3) with the aperture (101) of the array mask (10) as the object plane. image plane.
A laser beam is scanned by a scanning mirror (4), propagated toward one selected aperture (61) on the photomask (6), and imaged in an irradiation area of a predetermined size. FIG. 10A is the beam profile image. This predetermined size is the boundary (periphery/outer edge) of the energy distribution that has a threshold value or more at which a reaction is induced when an unintended irradiation target is irradiated through an unselected adjacent photomask opening. , which is approximately 1 [mm] (FWHM) in this embodiment. FIG. 10B also shows the beam profile on the photomask (6) when the array mask (10) having a circular opening is used.

As the photomask (6) in Example 1, a synthetic quartz plate on which a pattern is drawn (applied) by chromium plating is used. FIG. 11 shows a conceptual diagram thereof. The laser light passes through the non-chrome-plated window portion (61) shown in white and is blocked by the chrome-plated colored portion (62). The size of the apertures is 60×100 [μm], and 74 apertures are arranged at a pitch of 600 [μm] in the X-axis direction, and 25 apertures are arranged at the same pitch in the Y-axis direction, for a total of 1850 apertures. The surface to be plated with chromium is the laser light emitting side, and the incident side is coated with an antireflection film for 248 [nm]. Further, instead of chromium plating, aluminum vapor deposition or dielectric multilayer film can be used.

The photomask (6) and the array mask (10) are respectively fixed to dedicated mounts (not shown), and the mounts move in the X-, Y-, and Z-axis directions respectively. , V-axis, and R-axis (θ-axis), which is the rotation axis (around the optical axis) in the YZ plane, TV-axis that adjusts the tilt with respect to the V-axis, and TU-axis that adjusts the tilt with respect to the U-axis. have a mechanism

The laser beam (optical axis) passing through the zoom homogenizer scans the apertures on the photomask at high speed by the scanning mirror (4), and the excimer laser device scans the optical axis to the position of each aperture. Pulses are oscillated in synchronization with the timing.

After passing through the photomask pattern, the laser light propagates through the diaphragm (7) to the image-side telecentric projection lens (8) having a reduction ratio of 3/4, and then toward the donor substrate (91) from its back surface to its front surface ( (lower surface) is reduced and projected to a position where a minute element having a size of 30×60 [μm] (X×Y) is mounted. FIG. 12 is a beam profile image of the projected laser light. The minute elements on the donor substrate irradiated with the scanning laser light are lifted and mounted in a matrix on the opposing receptor substrate one after another at a pitch of 450 [μm].

The number of lifted irradiation objects of 30×60 [μm] corresponds to the aforementioned 74×25 apertures on the photomask, and the lift range is about 33×11 [mm].

The reduction projection lens (8) is telecentric on the image side, and in addition to adjustment by means of a Z-axis drive stage that holds it, a function for adjusting the donor substrate in the Z-axis direction (Z-axis stage (Zd)) is added. , can also be configured to support imaging on the light absorbing layer. However, it is necessary to consider the decrease in lift position accuracy due to the increased weighted load on the donor stage.

Also, when adjusting the imaging position at the interface between the surface of the donor substrate and the light absorbing layer, etc., a confocal beam profiler (BP) having a plane in a conjugate relationship with the mask surface and the reduction projection lens as the imaging surface is used. Real-time monitoring using In Example 1, the spatial intensity distribution of laser light projected in a reduced scale onto the interface between the surface of the donor substrate and the minute elements is monitored in real time and with high resolution.

A laser beam is scanned toward all the openings on the photomask (6), and the laser beam is sequentially irradiated toward the minute elements arranged on the donor substrate whose imaging position is adjusted. As a result, 1850 microelements corresponding to the numerical aperture on the photomask are mounted on the same number of planned lift positions on the receptor substrate. The 1,850 lift regions are divided into three parts (A to C) in the X-axis direction and nine parts (1 to 9) in the Y-axis direction, for a total of 27 parts (A1 to A9, B1 to B9, C1 to C9) corresponds to one area. Its size is about 33×11 [mm] determined by the scanning angle of the scanning mirror and the aperture diameter of the reduction projection lens. After completing the lift for one area, the donor and receptor substrates are moved to the next lift area. For example, the movement is 33.3 [mm] in the X-axis direction and 11.25 [mm] in the Y-axis direction. Thereafter, 1,850 lifts are performed again, and thereafter, this is repeated over the entire planned lift positions, completing the mounting of 49,950 microelements from the donor substrate to the receptor substrate. On the donor substrate, as mentioned above, microelements are mounted without defects at a density of 1/2 times the pitch of the intended lift position on the receptor substrate. It can be mounted on the receptor substrate.

Depending on the relationship between the image size of each opening of the laser light on the donor substrate and its energy density, the predetermined size (DP) of the irradiation area of the laser light on the photomask is indicated, for example, by a dashed line in FIG. As shown, if four openings can be sized to be collectively irradiated, the time required for mounting can be reduced to about 1/4.

Further, as shown in FIG. 13, when the donor substrate has a wafer shape and microelements are mounted on the entire effective area, the lift along the mounting area of the microelements is used. By setting an area (the hatched area in the figure) and scanning the scanning range of the scanning mirror in accordance with this area, it is also possible to lift minute elements positioned at every corner.

The above are specific examples of the lifting device and the mounting method for mounting the minute elements on the donor substrate onto the opposing receptor substrate.

In Example 2, 495×495=245025 microelements of 40 μm square are mounted in a matrix at a pitch of 200 μm with adjacent elements, assuming that there is no transfer failure. A 6-inch receptor substrate to be repaired (hereinafter simply referred to as "receptor substrate" in this second embodiment) was corrected by retransfer to a defective portion corresponding to about 1%. Shown with a lifting device. Also, similar to the receptor substrate, about 1% of microelements used for retransfer (correction) arranged on a 6-inch donor substrate for correction (hereinafter simply referred to as "donor substrate" in this embodiment). Assume that non-element locations (and defective locations) are distributed. Incidentally, on the donor substrate in Example 2, the microelements are mounted on the receptor substrate at a pitch of 50 μm, which is 1/4 times the design mounting pitch of the microelements mounted on the receptor substrate. arrayed, totaling more than 3.9 million. Therefore, the interval between adjacent microelements is 10 [μm]. In addition, the general configuration of the scanning reduction projection optical system mounted on the lift apparatus of the second embodiment and the structure of the apparatus are the same as those of the first embodiment, but the specifications of each optical element and their arrangement position are determined by these. Beam profile shape is a matter of design.

On the photomask (6) in the second embodiment, as shown in FIG. 200 [μm] square apertures (Ma), which are one size larger, are arranged in a matrix of 165×55 at a pitch (Pi) of 800 [μm]. This array corresponds to the array of microelements mounted on the receptor substrate. The size of the irradiation area imaged on this photomask by the scanning reduction projection optical system is about 1 [mm] square, which is the same as in the first embodiment. It is a size that can be irradiated. The laser light passing through this aperture forms an image through an image-side telecentric demagnification projection lens (8) toward a minute element used for retransfer (correction) on a donor substrate (9).

The excimer laser light having the irradiation area size, which is pulse-oscillated in synchronization with the operation of the scanning mirror (4), is irradiated to the 200 [μm] square opening on the photomask (6). After passing through this aperture, the laser light passes through an image-side telecentric projection lens (8) with a reduction ratio of 1/4, and is directed from the back surface of the donor substrate to the microelements arranged thereon with a distance of 10 [μm]. Microelements adjacent to each other at intervals are irradiated without interfering with each other. In this embodiment, the irradiated pulsed laser light forms an image on the surface (lower surface) of the donor substrate at a 50 [μm] angle, which is one size larger than the microelement size, induces a reaction, and causes a microscopic image at that position. The device is lifted toward the non-device location on the receptor substrate.

Hereinafter, a specific lift method for retransfer (correction) will be shown by dividing into each step.
(1) Inspection process As the positional information of the minute elements mounted on the donor substrate and the receptor substrate, design positional information and actual mounting positions obtained from image processing are acquired. The specific coordinates are the center of gravity obtained from the shape of the minute element, and the origin of the coordinates is determined with reference to the position of the orientation flat of the substrate. Here, the positional information on the donor substrate is referred to as "positional information D" and the positional information on the receptor substrate is referred to as "positional information R".

The position information D includes microelements recognized as defective that should not be used for retransfer and non-element locations that are not mounted in the first place. Their positional coordinates are calculated from adjacent microelements and obtained as "defective position information D". The same applies to the "defective position information R" in the position information R.

In this embodiment, the design pitch of the microelements arranged on the donor substrate is 1/4 times the design pitch of the microelements mounted on the receptor substrate. have errors between donor substrates and even between receptor substrates. Therefore, this error is calculated from the position information D and R in advance. In this embodiment, for the sake of simplicity, the positional information R is the design pitch, and the value of the donor substrate pitch error δPi with respect to the pitch is +0.0075 [μm].

(2) Dividing Step A region on a 6-inch donor substrate is divided into 27 divided areas (“divided areas D”) as in the first embodiment. As shown in FIG. 14, each area is 33×11 [mm], and each divided area is shown as A1 to A9, B1 to B9, and C1 to C9 in the figure for convenience. The receptor substrate is similarly divided into 27 "divided areas R", and the lift is performed between the opposed divided areas.

As in the first embodiment, the size of the divided area D is a design item determined by the effective aperture diameter of the reduction projection lens, the size of the photomask limited by other specifications, and the reduction projection magnification. .

Here, the permissible range of the cumulative error amount obtained by multiplying the 660 (-1) irradiation objects in the long axis (X-axis) direction of the irradiation target contained in the divided area D by the aforementioned error δPi is ± It was set to 5 [μm].
As shown in FIG. 15, when the upper left end of the divided area D (one-dot chain line) is used as a reference for alignment, this allowable range is such that the laser light that has passed through the opening (61) on the photomask (6) reaches the donor substrate. The 50 [μm] square (dashed line in the figure), which is the size to be imaged on the upper 40 [μm] microelement, is the entire surface of the microelement (solid line) at the rightmost position where the accumulated error amount is maximum. is arbitrarily set based on the limit of irradiation. Note that the 40 [μm] square of the two-dot chain line in the figure is the design mounting position of the minute element on the donor substrate, and is located in the center of the imaging size of the dashed line. In this embodiment, any minute element mounted in the divided area D has a cumulative error amount within the allowable range (659×0.0075≈4.94) with respect to the design position there. Therefore, there is no need to set a reduced "correction division area D" in this division step.

(3) Selection process With respect to the divided area R of the same size facing the divided area D, the non-element locations corresponding to about 1% of the 9075 microelements mounted in the divided area R (defective position information of about 91 locations) R), among the micro-elements arranged in the divided area D, the micro-elements located opposite to the micro-elements are selectively lifted on a one-to-one basis.

However, among the microelements (660×220=145200) mounted in the divided area D, there are 1452 defective elements, which is about 1%, and these (defective location information D) are based on the defective location information R may overlap with FIG. 16 shows the situation. Here, it is an image of observing the receptor substrate through the donor substrate. A partial area of an array of microelements arranged on a donor substrate is shown. In this figure, the vicinity of the upper left surrounded by the dashed line in the divided area A1 is shown in an enlarged manner, and the state of arrangement of microelements on the donor substrate located within this area is illustrated.

Here, for the sake of convenience, the positions of non-element locations where defective elements have been removed from the receptor substrate in advance by the removal step are indicated by white rectangles (Mr), and likewise the positions of microelements normally mounted on the receptor substrate are indicated. The black squares (Er) indicate the positions of the microelements on the donor substrate, which is 16 times denser than the receptor substrate, and the gray squares (Ed). (Ed overlapping Er and Mr is not shown.) As mentioned above, the pitch of the microelements Ed on the donor substrate is 50 [μm], and the pitch of the microelements Er on the receptor substrate is 200 [μm]. be.

First, the case of correcting the first receptor substrate with the donor substrate used for the first correction will be described.
(3-1) Collate the defect position information D and the defect position information R for each board, and confirm in advance the position where the non-element location (Mr) overlaps the defect element position (Md). The presence or absence of overlap to be confirmed here is the position where the β row group aligned in the X-axis direction of the donor substrate shown in the figure and the α row group aligned in the Y-axis direction intersect (a total of 245,025 points/substrate). means an overlap of substrate units (all 27 areas) in . Note that the other groups of α', α'', α''', β', β'' and β''' columns are similar to those of other microelements on the donor substrate that are packed at 16 times the density. Represents an array position. (In the figure, the α column group is indicated by arrows only in the three columns from the left, the β column group is indicated by arrows in only the two columns from the top, and the other "'" column groups are similarly illustrated by arrows in a limited manner. .)

If there is no overlap, the selection step selects the microelement location (Ed) on the donor substrate relative to the no element location (Mr). If duplication is confirmed, it will be described later.

(3-2) On the other hand, in the case of a combination of a donor substrate that has already been used for repair and a (first or) second or subsequent receptor substrate, the position of about 1% of the defective elements that the donor substrate originally had In addition to the information (Md), all the position information (1% Md + used Md), which is the used position information where the microelements are missing due to being used for retransfer in the past, and the unused position information on the receptor substrate. The distribution position information (Mr) of the element location is collated, and the presence or absence of duplication is checked in advance. As a result, if there is no overlap, the micro-element locations (Ed) on the donor substrate relative to the no-element locations (Mr) are selected for the selection step.

(4) Transfer process In the case of (3-1) or (3-2) above, after the positions of the microelements on the donor substrate to be used for retransfer are selected, the first or second and subsequent receptors Re-transfer is started from the divided area A1 to correct the substrate. The scanning mirror (4) scans the optical axis of the laser light along the rows of β on the donor substrate through the photomask (6) and the reduction projection lens (8). In this area, excimer laser light oscillated at the timing when the optical axis is scanned at the selected position, and the minute element mounted at the selected position on the donor substrate is moved to the opposite position on the receptor substrate. is lifted toward a non-element location (Mr) where

(5) Moving Step After finishing the correction of the area A1 of the receptor substrate by the microelements in the selected position in the area A1 of the donor substrate, the next area A2 is similarly corrected. Areas are moved to correct all areas in an arbitrary order (eg, A1 to A9→B1 to B9→C1 to C9) by moving the stage holding each substrate. Note that the amount of stage movement during movement of each divided area is set so as to cancel out the aforementioned cumulative error amount (approximately +4.95 [μm]). After completing the correction of all divided areas that need to be corrected, this receptor substrate is replaced with the next receptor substrate to be corrected.

On the other hand, if it is confirmed that there is overlap in the collation by substrate unit in the above (3-1) or (3-2), the column group to be collated is changed from α to α' column group or from β Change to the β' column group, and in the combination of the column group after the change (intersection point of the changed column group), collate by substrate unit as in (3-1) or (3-2) above, and there is no duplication. Check whether In this case, there are 15 possible column group combinations. When a combination of row groups that do not overlap is found in the substrate unit, the micro-element position (Ed) on the donor substrate corresponding to the no-element location (Mr) is selected based on the combination. Before the transfer process, the substrate is moved according to the combination of the row groups. FIG. 17 shows the state of the position between the substrates at the time of retransfer between the divided areas (A1).

In addition, in the above-described (3-1) or (3-2) board-by-board collation, if a combination of non-overlapping column groups is not found in any of the 15 combinations, narrow board units rather than wide board units are found. Verification is performed in units of opposing divided areas. For example, the matching is limited to area A1 of the receptor substrate and area A1 of the donor substrate facing thereto. As a result, if there is no overlap at the position where the α-row group and the β-row group intersect, the process proceeds to the transfer step as it is. Search for a combination of column groups (eg, α' column group and β'' column group). There are 16 combinations at most. In the combination of the found non-overlapping column groups, after the correction of the divided area A1 of the receptor substrate by the divided area A1 of the donor substrate is completed, the next area A2 is subjected to similar collation, and the non-overlapping column group is determined. Modify area A2 of the receptor substrate in combination. Thereafter, donor A3 and receptor A3, donor A4 and receptor A4, etc. are repeated. For example, if there is an overlap only between the divided areas B5, and there is no overlap for each substrate except for this area, it is not necessary to collate the areas before and after.

In the collation of the opposing divided areas (A1 and A1, B1 and B1, etc.), if no combination of column groups without overlap is found, at that point, the area on the donor substrate to be collated are limited to the divided areas facing each other, and the other 26 divided areas of the donor substrate are removed from the limitation, and combinations of non-overlapping column groups are searched for in area units. FIG. 18 shows the situation. Here, in the combination of the dividing area C5 of the donor substrate and the dividing area A3 of the receptor substrate, the retransfer is performed at the intersection position of the α''' group and the β''' group, for example. However, considering the defect position information (Md) reflecting the defect position of the minute element used for correction by the time the divided area to be collated is changed, the combination of non-overlapping column groups is divided. Note that you have to grope between areas. In addition, it is necessary to consider (calculate) whether a reasonable takt time can be achieved, taking into comprehensive account the time required to move the stage for frequent movement of the row group and movement to the divided area to be opposed. . According to the result of the calculation, selection of overlapping collation range and judgment of replacement timing of the donor substrate are performed as appropriate.

As long as the direct irradiation of the laser beam onto the receptor substrate does not have an adverse effect, the transfer process may be performed regardless of whether or not the defective position information overlaps. As for the location, options such as entrusting it to the second and subsequent corrections using a different donor substrate will also arise. In addition, it is possible to perform matching for each board and matching for each divided area in a timely manner based on takt time simulation. It is also possible to define each collation method with the shortest tact time and a combination of ranges thereof.

As in the present embodiment, when retransfer is performed for each divided area R, that is, each numerical aperture (165×55) on the photomask is scanned at once with a scanning mirror having a scanning speed of about 30/sec. In the case of re-transferring, assuming that there is no overlapping of defective positions between substrates, the time required to correct (about 90 locations) per divided area is about 3 seconds, which is the time to perform this on 27 divided areas. Then, even if the movement time of each board for moving the divided area is taken into consideration, the time required from the time the board is set until the correction is completed is approximately 90 seconds.

Compared to the takt time of about 2,450 seconds when using the above-mentioned conventional apparatus, which requires about one second to re-transfer a minute element at one location, it is possible to repair up to 1% of defective elements at an overwhelming speed. . In addition, even when considering the calculation time required for collation (duplication confirmation) and the stage movement time required for the row group movement and division area movement for avoiding overlap, the overwhelming superiority of the tact time in this embodiment is can be maintained.

In addition, when randomly collating divided areas without being limited to opposing divided areas, or when considering the amount of accumulated error, the position information D and the position information R obtained in the inspection process, the size of the divided area D and the Using a simulation program using the allowable range of accumulated error as a parameter, the combination of the size of the modified divided area D, the amount of movement of each stage, and the size of each process are determined so as to minimize the time required for mounting or re-transferring the entire receptor substrate. It is recommended to determine the order of implementation and optimize each process.

The embodiments of the present invention have been described in detail above. On the other hand, the present invention can be expressed from different viewpoints as follows (1) to (19).
(1) A scanning reduction projection optical system used in a laser processing apparatus that irradiates a laser beam toward an irradiation target to induce a reaction, comprising an infinity correction optical system, a scanning mirror, and a photomask. a scanning reduction projection optical system.
(2) A laser processing apparatus that utilizes irradiating a laser beam toward an object to be irradiated to induce a reaction, the laser having a laser device that oscillates the laser beam, an infinity correction optical system, and a scanning mirror. processing equipment.
(3) A lift device for irradiating a donor substrate provided with an irradiation target with laser light and moving the irradiation target from the donor substrate to a receptor substrate, wherein the laser light is oscillated. Lift device with laser device, infinity correction optics and scanning mirror.
(4) A laser processing method for irradiating an object to be irradiated with a laser beam to induce a reaction, wherein the irradiation is performed using a scanning reduction projection optical system having an infinity correction optical system, a scanning mirror and a photomask. A laser processing method characterized by irradiating a laser beam toward an object.
(5) A lift method for irradiating a donor substrate provided with an irradiation target with a laser beam and moving the irradiation target from the donor substrate to a receptor substrate, comprising an infinity correction optical system and a scanning mirror. and a scanning reduction projection optical system having a photomask to irradiate the object with a laser beam.
(6) A method for manufacturing a substrate mounted with an irradiation target, wherein a donor substrate provided with an irradiation target is irradiated with a laser beam, and the irradiation target is moved from the donor substrate to a receptor substrate, A method of manufacturing a substrate on which an object to be irradiated is mounted, comprising irradiating the object with a laser beam using a scanning reduction projection optical system having an infinity correcting optical system, a scanning mirror, and a photomask.
(7) The method of manufacturing a substrate mounted with an irradiation target according to (6), wherein the irradiation target is a minute device.
(8) The method of manufacturing a substrate on which an irradiation object is mounted according to (7), wherein the minute elements are micro LEDs.
(9) The method of manufacturing a substrate mounted with an irradiation object according to (7) or (8), wherein the microelements are arranged in a matrix on the donor substrate.
(10) The method for manufacturing a substrate mounted with an irradiation target according to (6), wherein the irradiation target is a film.
(11) The method of manufacturing a substrate on which an irradiation target is mounted according to (10), wherein the film is a conductive film or an adhesive film.
(12) The method for manufacturing a substrate on which an irradiation object is mounted according to (10), wherein the film is an organic EL film.
(13) A step of irradiating a first donor substrate provided with a film with a laser beam to move the film from the first donor substrate to a receptor substrate to obtain a substrate on which the film is mounted; Manufacture of a substrate on which microelements are mounted, comprising a step of irradiating a provided second donor substrate with a laser beam to move the microelements from the second donor substrate onto the film of the substrate on which the film is mounted. A method for mounting a micro-element, characterized by irradiating a laser beam toward the film or the micro-element using a scanning reduction projection optical system having an infinity correction optical system, a scanning mirror and a photomask. A method for manufacturing a printed circuit board.
(14) A method of removing a defective portion by irradiating a laser beam onto the defective portion of a donor substrate to remove the defective portion from the donor substrate, comprising an infinity correction optical system, a scanning mirror, and A method of removing a defective portion, comprising irradiating the defective portion with a laser beam using a scanning reduction projection optical system having a photomask.
(15) A retransfer method of irradiating a donor substrate provided with an irradiation target with a laser beam and transferring the irradiation target from the donor substrate to a receptor substrate, wherein the receptor substrate Using a scanning reduction projection optical system having an area where the irradiation object is mounted and a defective area where the irradiation object is not mounted in the mounting planned area, and having an infinity correction optical system, a scanning mirror, and a photomask. A retransfer method, comprising: irradiating a laser beam onto an object to be irradiated provided on the donor substrate to move the object to the defective region of the receptor substrate.
(16) A lift method for irradiating a donor substrate provided with an irradiation target with a laser beam and moving the irradiation target from the donor substrate to a receptor substrate, wherein the The object to be irradiated has a defective area, and a scanning reduction projection optical system having an infinity correction optical system, a scanning mirror, and a photomask is used to irradiate the object to be irradiated other than the defective area with a laser beam, A lifting method, characterized in that it is moved to the receptor substrate.
(17) A laser processing method in which a laser beam is directed at an object to be irradiated to induce a reaction, wherein the laser beam is scanned by a scanning mirror and focused on a photomask as an image plane of an infinity correction optical system. A laser processing method, wherein the laser beam imaged and passed through the photomask is reduced and projected onto the object to be irradiated.
(18) A lift method for irradiating a donor substrate provided with an irradiation target with a laser beam and moving the irradiation target from the donor substrate to a receptor substrate, wherein the laser beam is scanned by a scanning mirror. and forming an image on a photomask as an image plane of an infinity correcting optical system, and reducing and projecting the laser light that has passed through the photomask onto the object to be irradiated.
(19) A method for manufacturing a substrate mounted with an irradiation target, wherein a donor substrate provided with an irradiation target is irradiated with a laser beam, and the irradiation target is moved from the donor substrate to a receptor substrate, The laser beam is scanned by a scanning mirror, an image is formed on a photomask as an image plane of an infinity correction optical system, and the laser beam passing through the photomask is reduced and projected onto the object to be irradiated. A method for manufacturing a board on which an irradiation object to be irradiated is mounted.
(20) A scanning reduction projection optical system for use in a laser processing apparatus that irradiates an object to be irradiated with a laser beam to induce a reaction,
A scanning reduction projection optical system having a first lens array, a second lens array, a scanning mirror and a photomask.
(21) The scanning reduction projection optical system according to (20), wherein the first lens array or the second lens array comprises an array of lens elements.
(22) The scanning reduction projection optical system according to (21), wherein the lens element is fly-eye type, cylindrical type or spherical type.
(23) The scanning reduction projection optical system according to any one of (20) to (22), wherein the first lens array or the second lens array is a perpendicular combination of uniaxial cylindrical lenses.
(24) The scanning reduction projection optical system according to any one of (20) to (23), wherein an array mask is arranged immediately before the first lens array.
(25) The scanning reduction projection optical system according to any one of (20) to (24), wherein an array mask is arranged between the first lens array and the second lens array.
(26) A scanning reduction projection optical system according to (24) or (25), wherein the array mask has an aperture group.
(27) The scanning reduction projection optical system according to (26), wherein the apertures forming the aperture group are circular, elliptical, square, or rectangular.
(28) The scanning reduction projection optical system according to (26) or (27), wherein the size of the apertures forming the aperture group is smaller than the size of the lens element.
(29) The scanning reduction projection optical system according to any one of (24) to (28), wherein the array mask has at least two kinds of aperture groups.
(30) The scanning reduction projection optical system according to (29), wherein the at least two types of aperture groups are different in aperture size, aperture shape, number of apertures, or arrangement of apertures forming each aperture group. .
(31) A scanning reduction projection optical system for use in a laser processing apparatus that irradiates an object to be irradiated with a laser beam to induce a reaction,
A scanning reduction projection optical system that is telecentric only on the image side.
(32) A method of removing a defective portion by irradiating a laser beam onto the defective portion of a donor substrate having the defective portion to remove the defective portion from the donor substrate, comprising:
A method of removing a defective portion, comprising irradiating the defective portion with a laser beam using a scanning reduction projection optical system having a galvanometer scanner and a photomask.
(33)
The method of removing defective portions according to (32), wherein the photomask has circular, elliptical, square or rectangular openings.
(34) The method of removing a defective portion according to (32) or (33), wherein the photomask has a region in which openings are arranged in a matrix.
(35) The method of removing defective portions according to any one of (32) to (34), wherein the photomask has at least two kinds of opening groups.
(36) The method of removing defective portions according to (35), wherein the at least two types of aperture groups are different in size, shape, number of apertures, or arrangement of apertures forming each aperture group.
(37) A retransfer method of irradiating a donor substrate provided with an irradiation target with a laser beam and moving the irradiation target from the donor substrate to a receptor substrate, comprising:
The receptor substrate has an area in which the object to be irradiated is mounted in advance and a defective area in which the object to be irradiated is not mounted in the planned mounting area,
A laser beam is applied to an irradiation target provided on the donor substrate by using a scanning reduction projection optical system having a galvanometer scanner and a photomask, and the object is moved to the defective region of the receptor substrate. retransfer method.
(38) A lift method for irradiating a donor substrate provided with an irradiation target with a laser beam and moving the irradiation target from the donor substrate to a receptor substrate, comprising:
The irradiation target provided on the donor substrate has a defective region,
A lift method comprising: irradiating a laser beam onto an irradiation object other than the defective region by using a scanning reduction projection optical system having a galvanometer scanner and a photomask, and moving the object to the receptor substrate.

Each component in many of the above-described embodiments can be subdivided, and subdivided components can be introduced into (1) to (38) individually or in combination. For example, usage and layout of various lenses, types of laser light, various configurations and control methods in laser processing equipment, types and shapes of photomasks, shapes and layouts of openings, types and shapes of irradiation targets, laser lift-off Reaction mechanisms, optical system mechanisms, and the like are typical examples.

It can be used as part of the manufacturing process of micro LED displays.

Claims (16)

A method for removing a defective portion by irradiating a laser beam onto the defective portion of a substrate having the defective portion to remove the defective portion from the substrate,
irradiating a laser beam toward the defective portion using a scanning reduction projection optical system having a galvanometer scanner and a photomask;
A method of removing a defective portion, wherein the photomask has at least two kinds of opening groups. 2. The method of removing a defective portion according to claim 1, wherein said photomask has a circular, elliptical, square or rectangular opening. 3. The method of removing a defective portion according to claim 1, wherein said photomask has a region in which openings are arranged in a matrix. The at least two types of opening groups are different in size, shape, number of openings, or arrangement of openings forming each opening group. removal method. A lift method for irradiating a substrate provided with an irradiation target with a laser beam and moving the irradiation target from the substrate to another substrate,
A lift method, comprising: irradiating a laser beam onto the irradiation object using a scanning reduction projection optical system having a photomask having at least two kinds of aperture groups. 6. The lifting method according to claim 5, wherein said photomask has circular, elliptical, square or rectangular openings. 7. The lifting method according to claim 5, wherein said photomask has a region in which openings are arranged in a matrix. 8. The lifting method according to any one of claims 5 to 7, wherein the at least two types of opening groups are different in size, shape, number of openings, or arrangement of openings forming each opening group. A photomask used in a lift method for irradiating a substrate provided with an irradiation target with a laser beam and moving the irradiation target from the substrate to another substrate,
A photomask having at least two types of apertures. 10. A photomask according to claim 9, having circular, elliptical, square or rectangular openings. 11. The photomask according to claim 9, wherein the openings have regions arranged in a matrix. 12. The photomask according to any one of claims 9 to 11, wherein said at least two kinds of aperture groups are different in aperture size, aperture shape, number of apertures, or arrangement of apertures forming each aperture group. A lift system that irradiates a substrate provided with an irradiation target with a laser beam and moves the irradiation target from the substrate to another substrate,
1. A lift system comprising: an optical system for irradiating a substrate provided with an irradiation target with laser light; and a photomask having at least two kinds of aperture groups. 14. The lift system of claim 13, wherein the photomask has circular, elliptical, square or rectangular openings. 15. A lift system according to claim 13 or 14, wherein said photomask has a region in which openings are arranged in a matrix. 16. The lift system according to any one of claims 13 to 15, wherein the at least two types of aperture groups differ in aperture size, aperture shape, aperture number, or aperture arrangement forming each aperture group.

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