KR20120100209A - Maskless exposure apparatus and method for stitching exposure using the same - Google Patents

Maskless exposure apparatus and method for stitching exposure using the same Download PDF

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KR20120100209A
KR20120100209A KR1020110018956A KR20110018956A KR20120100209A KR 20120100209 A KR20120100209 A KR 20120100209A KR 1020110018956 A KR1020110018956 A KR 1020110018956A KR 20110018956 A KR20110018956 A KR 20110018956A KR 20120100209 A KR20120100209 A KR 20120100209A
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South Korea
Prior art keywords
exposure
stitching line
spot
virtual
illuminance
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KR1020110018956A
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Korean (ko)
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김자열
장상돈
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삼성전자주식회사
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Priority to KR1020110018956A priority Critical patent/KR20120100209A/en
Publication of KR20120100209A publication Critical patent/KR20120100209A/en

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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F1/00—Originals for photomechanical production of textured or patterned surfaces, e.g., masks, photo-masks, reticles; Mask blanks or pellicles therefor; Containers specially adapted therefor; Preparation thereof
    • G03F1/38—Masks having auxiliary features, e.g. special coatings or marks for alignment or testing; Preparation thereof
    • G03F1/44—Testing or measuring features, e.g. grid patterns, focus monitors, sawtooth scales or notched scales
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/20—Exposure; Apparatus therefor
    • G03F7/2051—Exposure without an original mask, e.g. using a programmed deflection of a point source, by scanning, by drawing with a light beam, using an addressed light or corpuscular source
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70216—Mask projection systems
    • G03F7/70275—Multiple projection paths, e.g. array of projection systems, microlens projection systems or tandem projection systems
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70216—Mask projection systems
    • G03F7/70283—Mask effects on the imaging process
    • G03F7/70291—Addressable masks, e.g. spatial light modulators [SLMs], digital micro-mirror devices [DMDs] or liquid crystal display [LCD] patterning devices
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70216—Mask projection systems
    • G03F7/70308—Optical correction elements, filters or phase plates for manipulating imaging light, e.g. intensity, wavelength, polarisation, phase or image shift
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70375—Multiphoton lithography or multiphoton photopolymerization; Imaging systems comprising means for converting one type of radiation into another type of radiation
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70483—Information management; Active and passive control; Testing; Wafer monitoring, e.g. pattern monitoring
    • G03F7/70605—Workpiece metrology
    • G03F7/70616—Monitoring the printed patterns
    • G03F7/70633—Overlay, i.e. relative alignment between patterns printed by separate exposures in different layers, or in the same layer in multiple exposures or stitching
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70691—Handling of masks or workpieces
    • G03F7/70791—Large workpieces, e.g. glass substrates for flat panel displays or solar panels

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)

Abstract

PURPOSE: A maskless exposure apparatus and a stitching exposure method using the same are provided to substantially omit the physically overlapped region between exposure heads using a virtual stitching line. CONSTITUTION: A maskless exposure apparatus includes a substrate, a plurality of exposure heads, a beam measuring part, a controlling part, and a roughness correcting part. A plurality of exposure heads emits exposure beam in the form of beam spot array to a substrate such that patterns are exposed on the substrate. The beam measuring part measures the beam data of the exposure beam. The controlling part defines the overlapped region of the exposure heads based on the measured beam data and defines a range in which a virtual stitching line(L) exists based on the overlapped region. The roughness correcting part corrects the roughness of the virtual stitching line.

Description

MASKLESS EXPOSURE APPARATUS AND METHOD FOR STITCHING EXPOSURE USING THE SAME}

The present invention relates to a maskless exposure apparatus capable of reducing the visibility of a stitching line in maskless lithography and a stitching exposure method using the same.

In general, a method of forming a pattern on a substrate (or semiconductor wafer) constituting a liquid crystal display (LCD), a plasma display panel (PDP), or a flat panel display (FPD) A pattern material is first formed by applying a pattern material to a substrate, and selectively exposing the pattern material using a photomask to selectively remove portions of the pattern material or other portions whose chemical properties are different.

However, as substrates become larger in size and patterns become more precise, maskless exposure can increase exponentially, resulting in the formation of patterns on substrates (or semiconductor wafers) without the use of photomasks. The device is being developed. The maskless exposure apparatus exposes the exposure beam to a substrate by transferring the exposure beam to the substrate with pattern information made of a control signal using a spatial light modulator (SLM) such as a digital micro-mirror device (DMD). It is a principle to expose a pattern on a surface.

Such maskless exposure apparatus aligns the exposure head inclined (θ) with respect to the scanning direction (Y-axis direction) to form a beam spot array tilted at the exposure surface, and while scanning the stage in the main scanning direction, Control of the optical modulation device controls the ON / OFF state of the beam spot array so that a desired pattern is transferred onto the exposure surface. The maskless exposure is performed when the stage is driven in the Y-axis in the scanning direction, and the exposure area is enlarged and reduced by manipulation of the optical system.

However, in the maskless exposure, since the size of the optical modulator for modulating the exposure beam according to the pattern is small, the exposure width in the sub-scanning direction X covered by one of the exposure heads even though the area of the beam spot array is enlarged while passing through the optical system. This generally ranges from 60 to 70 mm. Therefore, in the case of large substrates (eg, 2 m or more), the sub-scan direction (X) is appropriate when the number of exposure heads is insufficient to cover the entire glass. Since stepping must be performed to perform exposure, a stitching line is generated by stepping. This stitching line appears as defective even when the LCD (Liquid Crystal Display) panel is manufactured and operated. Therefore, the stitching line should be exposed so that the stitching line is not visible.

On the other hand, even if the number of exposure heads is sufficient, there is still a problem of how to finely adjust the distance between the exposure heads because a stitching line overlaps the exposure area due to overlap between adjacent exposure heads. In this case, there is a method of attaching equipment to the exposure head that can finely adjust the distance between the exposure heads, but this requires expensive equipment and expensive work.

In the maskless exposure, a virtual stitching line is used to propose a method of substantially eliminating overlapping areas between exposure heads.

To this end, the maskless exposure apparatus according to an aspect of the present invention, the beam measuring unit measurement for measuring the beam data of the plurality of exposure head beam spot array for transferring the exposure beam in the form of a beam spot array to expose the pattern on the substrate substrate On the control panel virtual stitching line L, a region D overlapping between the plurality of exposure heads is determined using the obtained beam data, and a range in which the virtual stitching line L is located based on the overlap region D is determined. And an illuminance correction unit that performs illuminance correction.

The control unit also overlaps the virtual stitching line L by turning off the virtual stitching line L right spot beam of the left exposure head and the virtual stitching line L left spot beam of the right exposure head. Make the length of region D zero.

In addition, the controller determines the overlap region D using Equation 1 below.

[Equation 1]

d = (K-1) * P

D ≥2 * d

In Equation 1, K is the number of beam repetitions on the scan line, and P is a distance between the spot beams 133 and is a predetermined value.

In addition, the controller determines a range in which the virtual stitching line L is located by using Equation 2 below.

&Quot; (2) "

Left position + d ≤ L ≤ right position of overlap region D-d

In addition, the beam data includes position data, intensity data, horizontal size data, and vertical size data of the spot beams constituting the beam spot array.

In addition, the illuminance correcting unit performs digital correction to secure uniformity of illuminance in the virtual stitching line L using the measured beam data.

In addition, the illuminance correction unit calculates the spatial density at each point of the spot beams, and turns off the spot beam of the point with the highest spatial density calculated to ensure uniform illuminance with respect to the virtual stitching line L. FIG.

Also, the illuminance correction unit calculates a residual for the PEG at the Y coordinate position of the spot beams to perform illuminance correction.

In addition, the stitching exposure method of the maskless exposure apparatus according to an aspect of the present invention transmits an exposure beam emitted from a plurality of exposure heads on a substrate in the form of a beam spot array, and measures and measures beam data of the beam spot array. The overlapping area D between the plurality of exposure heads is determined using the beam data, and the range where the virtual stitching line L is located based on the overlap area D is defined. And turning off the virtual stitching line L right spot beam of the left exposure head and the virtual stitching line L left spot beam of the right exposure head to zero the length of the overlap area D.

Further, the stitching exposure method of the maskless exposure apparatus according to one aspect of the present invention further includes correcting roughness on the virtual stitching line L when performing the stitching exposure using the virtual stitching line L. FIG. Include.

Further, correcting the illuminance on the virtual stitching line L is to perform digital correction to ensure uniformity of illuminance on the virtual stitching line L using the measured beam data.

In addition, correcting the illuminance on the virtual stitching line L, calculates the spatial density at each point of the spot beams, and calculates the spatial density calculated to ensure uniform illuminance for the virtual stitching line L. It is to turn off the spot beam of the highest point.

Further, correcting the illuminance on the virtual stitching line L is to correct the illuminance by calculating a residual for the PEG at the Y coordinate position of the spot beams.

According to the proposed maskless exposure apparatus and the stitching exposure method using the same, the visibility of the stitching line can be reduced by substantially eliminating the physical overlapping area between the exposure heads in the maskless exposure using the virtual stitching line. In addition, it is possible to eliminate the process of modifying the pattern of the stitching region for each pattern to be exposed, thereby eliminating the cost of modifying the pattern each time the maskless exposure apparatus is calibrated. In addition, there is no need to finely adjust the distance between the exposure heads, thereby reducing the cost of additional equipment, thereby reducing the initial design, fabrication, and setup costs of the maskless exposure apparatus, while reducing maintenance costs.

1 is a schematic configuration diagram of a maskless exposure apparatus according to an embodiment of the present invention.
2 is a view showing an exposure head of a maskless exposure apparatus according to an embodiment of the present invention.
3 is a perspective view showing a DMD configuration of a maskless exposure apparatus according to an embodiment of the present invention.
4 is a detailed configuration diagram of FIG. 2.
5 is a plan view illustrating a beam spot array by a maskless exposure apparatus according to an exemplary embodiment of the present invention.
6 is a control block diagram of a maskless exposure apparatus according to an embodiment of the present invention.
FIG. 7 is a view illustrating overlap regions between exposure heads in the maskless exposure apparatus according to the exemplary embodiment of the present invention. FIG.
FIG. 8 is a conceptual view illustrating a method of eliminating overlap regions between exposure heads using a virtual stitching line in a maskless exposure apparatus according to an embodiment of the present invention.
9 is a view showing roughness in a virtual stitching line in a maskless exposure apparatus according to an embodiment of the present invention.
10 is a flowchart illustrating a control method for performing illuminance correction in the maskless exposure apparatus according to the exemplary embodiment of the present invention.
11 is a conceptual diagram illustrating a method of calculating a spatial density for illuminance correction in a maskless exposure apparatus according to an embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic configuration diagram of a maskless exposure apparatus according to an embodiment of the present invention.

In FIG. 1, the maskless exposure apparatus 10 according to an exemplary embodiment of the present invention includes a stage 20 for moving a substrate 30 to be exposed (all objects to form a predetermined pattern such as a film, a wafer, and a glass). And an exposure head 100 for transferring the exposure beam to the substrate 30 to expose a photosensitive film (pattern forming material) coated on the substrate 30.

The stage 20 also moves the substrate 30 in the X-axis direction, the Y-axis direction, and if necessary, the Z-axis direction. The stage 20 includes guides 22 and 24 extending along the moving direction of the stage 20. The stage 20 is reciprocated by the guides 22 and 24 in the X-axis direction which is a sub-scanning direction, or the Y-axis direction (scanning direction) which is a scanning direction.

In addition, the stage 20 includes a chuck 26 that fixes the substrate 30 to the stage 20, and an isolator 28 that blocks vibration of the stage 20.

The exposure head 100 is fixed to the stage gantry 102 to irradiate the substrate 30 with an exposure beam to form image data in a desired pattern shape. This exposure head 100 is composed of a single head or multiple heads.

In the exemplary embodiment of the present invention, the stage 20 on which the substrate 30 is mounted is moved with respect to the exposure head 100 as an example. However, the present invention is not limited thereto, and the stage 20 is fixed and the exposure head is fixed. 100 may move, and further, both the stage 20 and the exposure head 100 may move.

The maskless exposure apparatus 10 according to the exemplary embodiment of the present invention is provided with a beam measuring unit 40 for measuring the position of the exposure beam irradiated from the exposure head 100 to the substrate 30.

2 is a view showing an exposure head of a maskless exposure apparatus according to an embodiment of the present invention, Figure 3 is a perspective view showing a DMD configuration of the maskless exposure apparatus according to an embodiment of the present invention.

In FIG. 2, the exposure head 100 includes a light source 110 for emitting the exposure beam 115, an illumination optical system 120 for correcting the exposure beam 115 emitted from the light source 110 with uniform illuminance, and outputting the light. The light modulation element 130 for modulating the exposure beam 115 passing through the illumination optical system 120 according to the pattern information (image data), and the beam spot array for the exposure beam 115 modulated by the light modulation element 130. It includes a projection optical system 140 for transmitting on the substrate 30 in the form of a beam spot array.

The light source 110 emits a beam for exposure, and includes a semiconductor laser or an ultraviolet lamp.

The light modulator 130 includes a spatial light modulator (SLM). The optical modulation device 130 may be, for example, a digital micro-mirror device (DMD) of a MEMS type, a two-dimensional grating light valve (GLV), and a transparent zirconate (PLZT) that is a transparent ceramic. an electro-optic device using a titantate, a ferroelectric liquid crystal (FLC), or the like may be used, and DMD may be preferably used. Hereinafter, the present invention will be described using the optical modulation device 130 made of DMD for convenience of description.

As shown in FIG. 3, the DMD includes a memory cell 132 (eg, an SRAM cell) and a plurality of micro mirrors 134 arranged in a matrix type of L rows and M columns on the memory cell 132. It is a mirror device comprising a. By varying the angle of each micromirror 134 based on the control signal generated in accordance with the image data, the desired light is reflected by the projection optical system 140, and other light is sent by a different angle to block.

When a digital signal is written to the memory cell 132 of the optical modulation element 130 made of the DMD, the micromirror 134 is inclined at a predetermined angle (for example, ± 12 °) around a diagonal line. On / off control of each micromirror 134 is controlled by the control part 46 mentioned later, respectively. Light reflected by the micro mirror 134 in the on state exposes an exposure object (usually PR: Photoresist) on the substrate 30, and light reflected by the micro mirror 134 in the off state is the substrate 30. The above exposure object is not exposed.

4 is a detailed configuration diagram of FIG. 2.

In FIG. 4, the projection optical system 140 includes the first imaging optical system 142 and the second imaging optical system 144, the micro lens array 146, and the aperture array 148 along a path through which the exposure beam 115 passes. Include.

The first imaging optical system 142 is composed of double telecentric optical systems, and enlarges the image passing through the optical modulation device 130 by about 4 times, for example, to open the opening surface of the micro lens array 146 ( It forms in the aperture plane.

The second imaging optical system 144 is also composed of double telecentric optical systems, and is imaged on the substrate 30 by, for example, about one-fold multiple beam spots formed on the focal plane of the micro lens array 146. do. In the exemplary embodiment of the present invention, the magnifications of the first imaging optical system 142 and the second imaging optical system 144 are 4 times and 1 times, respectively. However, the present invention is not limited thereto and the first imaging optical system ( 142 and the magnification of the second imaging optical system 144 depend on the size of the desired beam spot, the minimum feature size of the pattern to be exposed, and the number of exposure heads 100 to be used in the maskless exposure apparatus 10. Therefore, an optimal combination of magnifications can be derived.

The microlens array 146 is formed by arranging a plurality of microlenses corresponding to the micromirrors 134 of the light modulation element 130 in two dimensions. For example, when the light modulation element 130 is composed of 1920 × 400 micromirrors 134, correspondingly, 1920 × 400 microlenses are also disposed. In addition, the arrangement pitch of the microlenses may be substantially the same as the value obtained by multiplying the arrangement pitch of the micromirrors 134 of the light modulation device 130 by the magnification of the first imaging optical system 142.

The aperture array 148 is a two-dimensional array of a plurality of pin holes in the focal plane of the micro lens corresponding to the micro lens. The pin hole serves to shape the size of the beam spot focused through the micro lens to a certain size or to block noise generated in the projection optical system 140. The diameter of the pinhole is, for example, 6 mu m.

5 is a plan view illustrating a beam spot array by a maskless exposure apparatus according to an exemplary embodiment of the present invention.

In FIG. 5, the exposure beam 115 focused on the focal plane of the microlens array 146 from the light modulation element 130 via the first imaging optical system 142 may have a circular or elliptic shape. An image of the exposure beam 115 formed on the exposure surface on the substrate 30 via the second imaging optical system 144 is called a beam spot array 131, and the beam spot array 131 is formed in a matrix form. It consists of a number of spot beams 133 arranged. For example, the arrangement pitch of the spot beam 133 may be about 55 μm, and the spot beam 133 may have a circular shape having a Gaussian distribution having a full width at half maximum (FWHM) of about 2.5 μm.

The arrangement direction of the beam spot array 131 is arranged to be inclined at a predetermined alignment angle () with respect to the scanning direction (Y-axis direction). This is to increase the resolution of the maskless exposure apparatus 10.

As such, the exposure beam 115 emitted from the light source 110 is formed as an exposure image in the form of a beam spot array 131 on the substrate 30 via the light modulation device 130 and the projection optical system 140. However, when using a plurality of (eg, two) exposure heads 100, there is a physical overlap region between the exposure heads 100, so that a stitching line overlapping the exposure areas is formed. Will be created.

Accordingly, an embodiment of the present invention proposes a method of reducing the visibility of the stitching line by eliminating a region that is physically overlapped between the exposure heads 100 using the virtual stitching line. This will be described with reference to FIG.

6 is a control block diagram of a maskless exposure apparatus according to an embodiment of the present invention.

In FIG. 6, the maskless exposure apparatus 10 includes a beam measuring unit 40, a calculating unit 42, an illuminance correcting unit 43, an exposure data generating unit 44, and a control unit 46.

The beam measuring unit 40 is a position (X coordinate, Y coordinate) of the plurality of spot beams 133 arranged in a matrix in the beam spot array 131 where the exposure beam 115 is formed on the exposure surface on the substrate 30. Coordinates), the intensity of the spot beam 133, the horizontal size of the spot beam 133, and the vertical size of the spot beam 133 are measured.

The calculation unit 42 determines a region D that is physically overlapped between the exposure heads 100 using the beam position data measured by the beam measuring unit 40. This overlap area D serves as a reference for determining the position of the virtual stitching line L. FIG.

The illuminance correcting unit 43 uses a virtual stitching line L using beam position data (X coordinate, Y coordinate), beam intensity data, and beam size data (horizontal direction and vertical direction) measured by the beam measuring unit 40. ), Digital correction is performed to ensure uniformity of illuminance. The key to performing digital calibration is to avoid line edge roughness (LER) degradation. In this case, the beam data used for illuminance correction may be data measured by the beam measuring unit 40 in its entirety, or after measuring only some sample beams for shortening the time, the total data may be predicted from the beam data.

The exposure data generation unit 44 generates exposure data of the optical modulation device 130 according to the exposure pattern. The exposure data generation unit 44 switches exposure on / off for turning off some of the micromirror 134 rows of the optical modulation device 130. Generate off data or generate exposure on / off data to turn off some rows of the micro lens array 146.

The control unit 46 determines the position of the virtual stitching line L based on the overlap area D determined by the calculation unit 42, and stores the exposure off data corrected by the illuminance correction unit 43 as an optical modulator ( 130).

Hereinafter, an operation process and an effect of the maskless exposure apparatus configured as described above and the stitching exposure method using the same will be described.

First, the substrate 30 is placed on the stage 20 and fixed with the chuck 26.

The upper stage gantry 102 of the stage 20 is provided with a plurality of (two A and B) exposure heads 100 for transferring the exposure beam 115 to the substrate 30 so that the desired substrate 30 can be provided. The pattern shape is exposed.

Two (A, B) exposure heads 100 are provided with an optical modulator 130 for modulating the exposure beam 115 according to a desired pattern shape, and thus modulates the exposed exposure beam 115 in the form of a beam spot array 131. The image is formed on the furnace substrate 30 (see FIG. 5).

The maskless exposure apparatus 10 which exposes the beam spot array 131 on which the exposure beam 115 is formed on the substrate 30 is inclined at a predetermined rotational angle with respect to the scanning direction (Y-axis direction). The exposure is performed when the stage 20 is driven in the Y-axis direction, which is the scanning direction.

In this exposure, there is a region D that is physically overlapped between the two (A, B) exposure heads 100. This will be described with reference to FIG.

FIG. 7 is a view illustrating overlap regions between exposure heads in the maskless exposure apparatus according to the exemplary embodiment of the present invention. FIG.

In FIG. 7, the length in which the leftmost part of the right exposure head B 100 further extends from the rightmost part of the left exposure head A 100 is regarded as the overlapping area D between the exposure heads 100 and overlapped. The virtual stitching line L is located somewhere in the area D.

Then, the right side of the virtual stitching line L of the left exposure head A 100 turns off the micromirror 134 so that the beam does not come out, and the left side of the virtual stitching line L of the right exposure head B 100. Again, the micro mirror 134 is turned off so that the beam does not come out. This is shown in FIG. 8.

FIG. 8 is a conceptual view illustrating a method of eliminating overlap regions between exposure heads using a virtual stitching line in a maskless exposure apparatus according to an embodiment of the present invention.

In FIG. 8, the part shown in black has the micromirror 134 turned off. The part shown in black is the micromirror 134 of the part which passed to the right side of the virtual stitching line L at the left exposure head A 100, and to the left side of the virtual stitching line L at the right exposure head B 100. It is the micromirror 134 of the part which fell.

In this case, although the overlap area D exists physically between the exposure heads A and B 100, there is virtually no overlapping part between the exposure heads A and B 100. Nevertheless, the pattern data need to be corrected. There is no.

In addition, since the length of the overlap region D is expressed in an inequality form as shown in Equation 1 below, it is not necessary to finely adjust the distance between the exposure heads A and B 100 and the maskless exposure apparatus 10. It is not affected by the calibration.

The constraint condition of the overlap region D for applying this method is as shown in [Equation 1].

[Equation 1]

d = (K-1) * P

D ≥2 * d

In Equation 1, K is the number of beam repetitions on the scan line, and P is a distance between the spot beams 133 and is a predetermined value.

In addition, the virtual stitching line L should be located somewhere in the overlap area D. The range in which the virtual stitching line L can be located is based on the overlap area D below [Equation 2]. ] Is determined.

&Quot; (2) "

Left position + d ≤ L ≤ right position of overlap region D-d

In the maskless exposure apparatus 10 according to an exemplary embodiment of the present invention, in order to prevent the stitching line from being visually recognized, the reason for having the constraints as shown in Equations 1 and 2 above is a virtual stitching line. (L) By turning off the micromirror 134 on both sides, the spot beam 133 will not be formed in the board | substrate 30. FIG.

In addition, in the above [Equation 1], [Equation 2], the d value is the value of the section in which the K value falls due to the installation angle of the micromirror 134. In other words, it is not the exposure head 100 but the length of the section in which roughness falls due to the characteristics of the maskless exposure. Therefore, the overlap area D between the exposure heads A and B 100 must be secured at least 2 * d, and the virtual stitching line L is located at a distance d from both left and right ends of the overlap area D. Should be.

In FIG. 8, if there is no physically overlapping area D between the exposure heads A and B 100, the roughness of the ends of the exposure heads A and B 100 is lowered even though the roughness is due to the off of the micromirror 134. Will fall further. Therefore, it is difficult to secure uniformity of illuminance.

Accordingly, even if the exposure heads A and B 100 are installed to satisfy the above two conditions and the virtual stitching line L is positioned, a problem remains.

When exposed under the above conditions, the roughness at the stitched portion is shown in three cases, as shown in FIG. 9.

9 is a view showing the roughness in the virtual stitching line in the maskless exposure apparatus according to an embodiment of the present invention, (A) is a case where the roughness in the virtual stitching line (L) is high, (B) Denotes a case in which illuminance is normal in the virtual stitching line L, and (C) illustrates a case in which illuminance is low in the virtual stitching line L. FIG.

In the case of FIG. 9B, the exposure may be performed without any further action in the cases of (A) and (C), and the over and under exposures occur, respectively, and the virtual stitching line (L) is performed. The line width becomes thinner or thicker at the site.

Therefore, in case of (A) and (C), partial compensation is performed by turning off or turning on the micromirror 134 closest to the virtual stitching line L. FIG. When the micromirror 134 is operated in this manner, the LER (Line Edge) is considered in consideration of the residual spatial density of the position event generator (PEG) at the Y-beam position of the spot beam 133 corresponding to the micromirror 134. To prevent degradation of roughness. This will be described with reference to FIGS. 10 and 11.

10 is a flowchart illustrating a control method for performing illuminance correction in a maskless exposure apparatus according to an embodiment of the present invention, and FIG. 11 is a diagram illustrating an illumination method of the maskless exposure apparatus according to an embodiment of the present invention. Conceptual diagram illustrating how to calculate spatial density.

In FIG. 10, a residual for the PEG (Position Event Generator) of the Y coordinate of each spot beam 133 is calculated using Equation 3 below (200).

For example, when the Y coordinate position of the spot beam 133 is 76.1 μm and the PEG is 1.0 μm, the residual becomes 0.1.

&Quot; (3) "

Residual = mod (76.1, 1.0) = 0.1

Subsequently, the spatial density within the Gaussian range (see FIG. 11) at each point of the spot beams 133 is calculated using Equation 4 below (202).

&Quot; (4) "

Figure pat00001

In FIG. 11, the area indicated by the circle based on the spot beam 133 displayed in black is an effective area of influence within the Gaussian range.

Using the distance (d1, d2, d3, d4) from the other spot beams 133 in the Gaussian range with respect to the spot beam 133 shown in black, as shown in Equation 4 above, the spatial density Calculate At this time, the spatial density is calculated within the Gaussian range for each spot beam 133.

In addition, the spot beams 133 having the highest spatial density, that is, the spot beams 133 having the most dense spatial density, are compared by comparing the spatial densities of the respective spot beams 133 calculated using Equation 4 below. ) To prevent the deterioration of LER (Line Edge Roughness) (204).

As described above, the maskless exposure apparatus 10 according to the exemplary embodiment of the present invention can secure the uniform illuminance without causing a decrease in the line edge roughness (LER) during exposure by software-correcting the illuminance.

10: maskless exposure apparatus 20: stage
30 substrate 40 beam measuring unit
42: calculator 43: illuminance correction unit
44: exposure data generation unit 46: control unit
100: exposure head 110: light source
115: exposure beam 130: light modulation element
131: beam spot array 133: spot beam
140: projection optical system

Claims (14)

Board
A plurality of exposure heads for transferring an exposure beam in the form of a beam spot array to expose a pattern on the substrate
A beam measuring unit measuring beam data of the beam spot array
The control unit determines a region D overlapping between the plurality of exposure heads using the measured beam data, and determines a range in which the virtual stitching line L is located based on the overlap region D.
And an illuminance correction unit for performing illuminance correction on the virtual stitching line (L). The method of claim 1,
The control unit turns off the virtual stitching line L right spot beam of the left exposure head and the virtual stitching line L left spot beam of the right exposure head with the virtual stitching line L as the center. To make the length of the overlap region D zero. The method of claim 2,
The control unit is a maskless exposure apparatus for determining the overlap region (D) by using the equation (1).
[Equation 1]
d = (K-1) * P
D ≥2 * d
In Equation 1, K is the number of beam repetitions on the scan line, and P is a distance between the spot beams 133 and is a predetermined value. The method of claim 2,
And the control unit determines a range in which the virtual stitching line (L) is located by using Equation (2).
&Quot; (2) "
Left position + d ≤ L ≤ right position of overlap region D-d The method of claim 2,
And the beam data includes position data, intensity data, horizontal size data, and vertical size data of the spot beams constituting the beam spot array. The method of claim 5,
And the illumination correction unit performs digital correction to secure the uniformity of the illumination in the virtual stitching line (L) by using the measured beam data. The method of claim 6,
The illuminance correcting unit calculates a spatial density at each point of the spot beams, and turns off the spot beam of the point having the highest spatial density calculated to ensure uniform illuminance with respect to the virtual stitching line (L). Maskless exposure device. The method of claim 7, wherein
And the illuminance correcting unit calculates a residual for the PEG at the Y coordinate position of the spot beams to perform the illuminance correction. The exposure beam emitted from the plurality of exposure heads is transferred onto the substrate in the form of a beam spot array;
Measure the beam data of the beam spot array
The overlapping area D between the plurality of exposure heads is determined using the measured beam data.
Determine the range where the virtual stitching line (L) is located on the basis of the overlap area (D)
With respect to the virtual stitching line L, the virtual stitching line L right spot beam of the left exposure head and the virtual stitching line L left spot beam of the right exposure head are turned off and the overlap is performed. The stitching exposure method of the maskless exposure apparatus which performs the stitching exposure which makes the length of the area | region D zero. 10. The method of claim 9,
And the beam data includes position data, intensity data, horizontal size data, and vertical size data of the spot beams constituting the beam spot array. The method of claim 10,
Stitching exposure method of the maskless exposure apparatus, further comprising correcting the roughness on the virtual stitching line (L) when performing the stitching exposure using the virtual stitching line (L). The method of claim 11,
Correcting the illuminance on the virtual stitching line L,
Stitching exposure method of the maskless exposure apparatus using the measured beam data to perform digital correction to ensure the uniformity of the illuminance in the virtual stitching line (L). The method of claim 12,
Correcting the illuminance on the virtual stitching line L,
A maskless exposure apparatus for calculating a spatial density at each point of the spot beams and turning off the spot beam of the point having the highest spatial density calculated to ensure uniform illuminance with respect to the virtual stitching line (L). Stitching exposure method. The method of claim 13,
Correcting the illuminance on the virtual stitching line L,
Stitching exposure method of the maskless exposure apparatus for correcting the illuminance by calculating the residual for the PEG at the Y coordinate position of the spot beams.
KR1020110018956A 2011-03-03 2011-03-03 Maskless exposure apparatus and method for stitching exposure using the same KR20120100209A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20140035198A (en) * 2012-09-13 2014-03-21 엘지디스플레이 주식회사 Maskless exposure apparatus and method
KR20140120697A (en) * 2013-04-04 2014-10-14 삼성디스플레이 주식회사 Digital exposure device using glv and digital exposure device using dmd
US9535333B2 (en) 2015-01-13 2017-01-03 Samsung Display Co., Ltd. Maskless exposure device and maskless exposure method using the same

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20140035198A (en) * 2012-09-13 2014-03-21 엘지디스플레이 주식회사 Maskless exposure apparatus and method
KR20140120697A (en) * 2013-04-04 2014-10-14 삼성디스플레이 주식회사 Digital exposure device using glv and digital exposure device using dmd
US9535333B2 (en) 2015-01-13 2017-01-03 Samsung Display Co., Ltd. Maskless exposure device and maskless exposure method using the same

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