KR20240037500A - Edge exposure aparatus - Google Patents

Abstract

According to the present embodiments, a peripheral exposure device can be provided in which uniformity of light quantity is increased and critical line quality is improved by minimizing light loss.

Description

Peripheral exposure device {EDGE EXPOSURE APARATUS}

The present embodiments relate to a peripheral exposure apparatus, and more specifically, to a peripheral exposure apparatus in which uniformity of light quantity increases and critical line quality is improved by minimizing light loss.

The exposure process, which can be considered a core process in semiconductor or display manufacturing, is a process of forming a specific pattern on a wafer using light of an appropriate wavelength and a mask. That is, a circuit pattern is formed on the wafer by applying photoresist (PR) to the surface of the wafer and exposing and developing the photoresist layer through a mask.

A commonly used method of applying photoresist to the surface of a wafer is a coating method that supplies photoresist to the center of the wafer and rotates the wafer to evenly apply photoresist to the entire surface using centrifugal force.

Generally, because the wafer is formed in a circular shape, a circuit pattern is not formed even if photoresist is applied to the peripheral or edge area. If photoresist is left in the peripheral area, the photoresist applied to the peripheral area will peel off during the subsequent wafer transfer process, generating particles. There is a problem of lowering the yield.

To solve this problem, a peripheral exposure process is essentially performed to remove the photoresist applied to the periphery of the wafer. Conventional peripheral exposure devices mostly adopt an indirect irradiation method, resulting in light loss and low light intensity. There was a problem with poor exposure quality as shadows were generated due to lack of uniform irradiation.

In addition, in particular, in the existing OLED display process, exposure devices using UV lamps were mainly used. UV lamps have a short lifespan, require frequent replacement and are difficult to maintain, and take a lot of time to turn on and off, reducing inspection efficiency. There was a problem of causing environmental pollution by generating ozone and mercury.

The present embodiments were developed against the above-mentioned background and relate to a peripheral exposure apparatus in which uniformity of light quantity is increased and critical line quality is improved by minimizing light loss.

According to the present embodiments, a light source unit including a plurality of unit light sources and a lens for focusing the light of the plurality of unit light sources, a barrel unit including an entrance unit through which light from the light source unit is incident, and an exit unit through which light incident from the entrance unit is emitted. , a peripheral exposure device including a tubular reflector accommodated in the barrel portion and open at both ends to reflect light incident on the entrance portion from the inside and guide the light to the exit portion may be provided.

According to the present embodiments, a peripheral exposure apparatus can be provided in which uniformity of light quantity is increased and critical line quality is improved by minimizing light loss.

1 is a perspective view of a peripheral exposure apparatus according to the present embodiments.
Figure 2a is a cross-sectional view of Figure 1.
Figure 2b is a cross-section of a peripheral exposure device according to another embodiment.
Figures 3 and 4 are perspective views of a portion of Figure 1.
Figure 5 is a diagram schematically showing the optical path inside the peripheral exposure apparatus according to the present embodiments.
6 to 8 are diagrams for explaining the light uniformity of the peripheral exposure apparatus according to the present embodiments.
Figure 9 is a diagram schematically showing the optical path in a conventional peripheral exposure apparatus.
Figure 10 shows the relationship between the size, length, and inclination angle of the reflectors' incident portions, the size of the emitting portions, and the light receiving devices for light irradiated to the outside of the emitting portions.
Figures 11a, 12a, 13a, 14a, 15a, 17a, 18a, 19a, and 20a show reflectors with the inclination angle of the reflector, the size of the entrance part, the length of the reflector, and the size of the exit part shown in Table 1. They are showing the fields.
FIG. 16 shows the light quantity and uniformity when a failure occurs in one or more column or row unit light sources for the reflector shown in FIG. 15A.
Figures 11b, 12b, 13b, 14b, 15b, 17b, 18b, 19a and 19b, and 20b are respectively similar to Figures 11a, 12a, 13a, 14a, 15a, 16a, Figures 17a, 18a, 19a, 20a, and Table 1 show the light uniformity of the reflector.
Figure 21a is a conceptual diagram of analyzing the illuminance at each angle after placing a screen on the emitter (emission part) of the reflector shown in Figure 15a and drilling holes in the left-->center-->right order, and Figures 21b to 21d are These are the results of analyzing the illuminance by angle after drilling holes in the following order: left-->center-->right.

Hereinafter, some embodiments of the present disclosure will be described in detail with reference to illustrative drawings. In adding reference numerals to components in each drawing, the same components may have the same reference numerals as much as possible even if they are shown in different drawings. Additionally, in describing the present embodiments, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present technical idea, the detailed description may be omitted. When “comprises,” “has,” “consists of,” etc. mentioned in the specification are used, other parts may be added unless “only” is used. When a component is expressed in the singular, it can also include the plural, unless specifically stated otherwise.

Additionally, in describing the components of the present disclosure, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, order, or number of the components are not limited by the term.

In the description of the positional relationship of components, when two or more components are described as being “connected,” “coupled,” or “connected,” the two or more components are directly “connected,” “coupled,” or “connected.” ", but it should be understood that two or more components and other components may be further "interposed" and "connected," "combined," or "connected." Here, other components may be included in one or more of two or more components that are “connected,” “coupled,” or “connected” to each other.

In the description of temporal flow relationships related to components, operation methods, production methods, etc., for example, temporal precedence relationships such as “after”, “after”, “after”, “before”, etc. Or, when a sequential relationship is described, non-continuous cases may be included unless “immediately” or “directly” is used.

On the other hand, when a numerical value or corresponding information (e.g., level, etc.) for a component is mentioned, even if there is no separate explicit description, the numerical value or corresponding information is related to various factors (e.g., process factors, internal or external shocks, It can be interpreted as including the error range that may occur due to noise, etc.).

1 is a perspective view of a peripheral exposure device according to the present embodiments, FIG. 2A is a cross-sectional view of FIG. 1, FIGS. 3 and 4 are a perspective view of a portion of FIG. 1, and FIG. 5 is a peripheral exposure device according to the present embodiments. Figures 6 to 8 are diagrams schematically showing the internal optical path, Figures 6 to 8 are diagrams for explaining the light uniformity of the peripheral exposure apparatus according to the present embodiments, and Figure 9 is a schematic diagram of the optical path in the conventional peripheral exposure apparatus. This is the drawing shown.

Referring to FIG. 1 , the peripheral exposure apparatus 100 according to the present embodiments includes a light source unit 110 and a barrel unit 120. The peripheral exposure apparatus 100 according to the present embodiments irradiates the light of the light source unit 110 to the outside through the emitter 121 disposed at one end of the barrel unit 120, and the irradiated light passes through the mask to the wafer. By supplying, a peripheral exposure process is performed.

Referring to FIG. 2, the light source unit 110 includes a plurality of unit light sources 221 and a lens 222 that focuses the light of the plurality of unit light sources 221.

The barrel unit 120 includes an entrance unit 212 through which light from the light source unit 110 is incident, and an exit unit 121 through which light incident on the entrance unit 212 is emitted.

The peripheral exposure device 100 according to the present embodiments is accommodated in the barrel portion 120 and has both ends open, and includes a tubular reflector ( 210) is additionally included.

Referring to FIG. 2A and FIGS. 3 and 4, the light source unit 110 includes a housing that accommodates a plurality of unit light sources 221, lenses 222, etc., and a plurality of unit light sources 221 and lenses 222 inside the housing. ) includes a frame that supports the etc. The housing may have a substantially rectangular parallelepiped shape and has a structure and material for dissipating heat emitted from the plurality of unit light sources 221. For example, the housing may be made of a highly thermally conductive material such as aluminum.

As shown in FIG. 2A, the lens 222 may be in close contact with the entrance unit 212 or may be in close contact with the entrance unit 212, and as shown in FIG. 2B, the lens 222 may be at a certain distance from the entrance unit 212. It may be separated from .

In addition, the light source unit 110 may further include a heat sink 223 and a blowing fan for absorbing and discharging heat generated from the plurality of unit light sources 221. As shown in the figure, the plurality of unit light sources 221 are in direct surface contact with the heat sink 223, so that the heat sink 223 can more efficiently absorb and emit heat generated from the plurality of unit light sources 221. You can.

A plurality of unit light sources 221 are arranged in columns and rows as shown in FIGS. 5 and 7. According to one embodiment, the plurality of unit light sources 221 may be arranged in the same number of columns and rows (see (A) of FIG. 7). According to one embodiment, the plurality of unit light sources may be arranged in 9×9, 10×10, or 16×16. Each unit light source 221 can be driven independently. That is, the control unit that controls the on and off of the plurality of unit light sources 221 can turn on and off each of the unit light sources 221, and the plurality of unit light sources 221 can be turned on or off depending on the number of unit light sources 221 that are turned on or off. The amount of light emitted can be adjusted.

The plurality of unit light sources 221 are arranged in a plurality of columns and rows, and each unit light source may be driven independently on a column or row basis.

According to one embodiment, the unit light source 221 may be a UV LED. UV LED emits light in the ultraviolet range required for the exposure process, for example, may emit light with a wavelength of 365 nm, 405 nm, or 436 nm. By using UV LED, energy efficiency is improved and lifespan is increased compared to conventional UV lamps, and it is eco-friendly as it does not generate ozone or mercury.

Light emitted from the plurality of unit light sources 221 is focused by the lens 222 and is incident on the entrance portion 212 of the barrel portion 120. According to one embodiment, lens 222 may be a fly eye lens. The fly eye lens improves uniformity by focusing light emitted from a plurality of unit light sources 221.

In addition, the light incident on the entrance unit 212 passes through the reflector 210 and is emitted to the exit unit 121. Inside the reflector 210, the light is reflected on the inner surface of the reflector 210 and moves forward. It is possible to form more uniform light.

The barrel unit 120 includes an entrance unit 212 through which light emitted from the light source unit 110 is incident, and an exit unit 121 through which the light incident on the entrance unit 212 is emitted. The barrel portion 120 is formed in a substantially rectangular parallelepiped shape, and is provided with frames 211 and 214 that form an entrance portion 212 and an exit portion 121 at one end and the other end, respectively. The reflector 210 is formed in a tubular shape and is accommodated inside the barrel portion 120. The reflector 210 is open at both ends, and one end of the reflector 210 can be inserted into the entrance part 212 and protrude from the barrel part 120, as shown in the drawing, and the other end of the reflector 210 is an exit part. It may be coupled to the inner surface of the frame 214 forming (121). Accordingly, light emitted from the light source unit 110 may be incident on the entrance unit 212 through one end of the reflector 210 and may be emitted from the emission unit 121 through the other end of the reflector 210. Additionally, the barrel portion 120 may be provided with a support frame 213 that supports the middle part of the reflector 210. The entrance unit 212 and the exit unit 121 may be formed in a rectangular shape, and accordingly, the reflector 210 may also be formed to have a rectangular cross-section.

The reflector 210 may have a cross-sectional area that increases from one end to the other. That is, the entrance part 212 is formed to be smaller than the emission part 121, and accordingly, the reflector 210 has a cross-sectional area of one end connected to the entrance part 212 smaller than the cross-sectional area of the other end connected to the emission part 121. can be formed. The cross-sectional area of the reflector 210 may increase linearly from one end to the other.

Referring to FIG. 5 , light incident into the reflector 210 is reflected from the inner surface of the reflector 210 and is guided to the emitter 121. Inside the reflector 210, light is guided through internal reflection and total reflection. FIG. 6 is a diagram showing the uniformity of light emitted by the peripheral exposure apparatus 100 according to the present embodiments, and it can be confirmed that very uniform light is emitted in the x and y directions.

Referring to FIG. 9, when uniform light is formed using only the fly-eye lens 901, as in a conventional peripheral exposure device, the light passing through the fly-eye lens 901 spreads, resulting in light loss and preventing precise exposure. There is a problem that is difficult to perform. In addition, the conventional peripheral exposure device uses an indirect irradiation method, which has the limitation of creating a shadow (gray zone) during exposure. In other words, the intensity of the irradiated light gradually decreases as it approaches the center of the wafer, and peripheral exposure is performed. It has the limitation of having a low critical linewidth quality where the boundary between the area and the area forming the circuit pattern is unclear.

However, the peripheral exposure apparatus 100 according to the present embodiments has a structure in which the light focused by the lens 222 is reflected on the inside of the reflector 210 and is directly irradiated through the emitter 121, thereby improving the uniformity of light. increases and has a high critical linewidth quality. In comparison with the conventional peripheral exposure device, the limitation of the conventional peripheral exposure device was to expose with a critical line width of about 200 μm, but according to the peripheral exposure device 100 according to the present embodiments, exposure with high quality of about 100 μm is possible. possible.

Additionally, the peripheral exposure apparatus 100 according to the present embodiments has the advantage that uniformity does not deteriorate even if the amount of light decreases when a failure occurs in some of the plurality of unit light sources 221. In an embodiment in which the plurality of unit light sources 221 are arranged in a 10×10 arrangement, the normal state and the case where a failure occurs in one row of the plurality of unit light sources 221 as shown in (A) of FIG. In comparison, as shown in (B) of Figure 7, the amount of light decreased from 2.95 W/cm^2 to 2.66 W/cm^2, but the uniformity was confirmed to be almost the same at about 84%.

FIG. 8 shows a comparison of light quantity and uniformity when a failure occurs in the unit light source 221 of one or more columns or rows. As shown in the figure, the amount of light gradually decreased, but the uniformity was confirmed to be almost the same at about 84%. This is because the light emitted from the light source unit 110 is reflected inside the reflector 210 and is formed as uniform light. According to the present embodiments, even if a failure occurs in some of the plurality of unit light sources 221, the light is always constant. Uniformity can be maintained, enabling continuous production.

According to the peripheral exposure device having such a shape, a peripheral exposure device that minimizes light loss, increases uniformity of light quantity, and improves critical line quality can be provided.

FIG. 10 shows the size, length, and inclination angle of the incident portion 212 of the reflectors 210, the size of the emitter 121, and light receiving devices for light irradiated to the outside of the emitter 121. It shows the relationship of (Receiver 1, Receiver2).

Referring to FIG. 10 , the plurality of unit light sources 221 are spaced apart from the incident portion 212 of the reflector 210 at a certain distance, for example, at intervals of 8 mm. The size of the incident unit 212 may be determined by considering the number of unit light sources 221, the length of the reflector 210, the size of the exit unit 121, etc. Below, the size of the incident portion 212 is exemplarily described as 40*40 (mm), but is not limited thereto.

11A, 12A, 13A, 14A, 15A, 17A, 18A, 19A, and 20A show the inclination angle of the reflector 210, the size of the incident portion 212, and the reflector 210 shown in Table 1. Shows reflectors 210 having a length of ) and the size of the emitting unit 121.

The sizes of the entrance portions 212 of the reflectors 210 shown in FIGS. 11A to 20A are the same, but the length and inclination angle of the reflectors 210 and the size of the exit portion 121 are different from each other as shown in Table 1. Different.

Figure 11a Figure 12a Figure 13a Figure 14a Figure 15a Figure 16a Figure 17a Figure 18a Figure 19a Figure 20a
Entrance area (mm ² ) 40*40 40*40 40*40 40*40 40*40 40*40 40*40 40*40 40*40 40*40 Length (mm) 312.5 360 300 312.5 365.6 330.6 330.6 330.6 330.6 330.6 Tilt angle (°) 3.3 3 4 3.3 3.3 3.5 3.3 3.4 3.6 3.7 Exit part (mm ² ) 76.*76 77.7*77.7 82*82 76*76 82*82 80*80 78*78 79*79 81.5*81.5 82.5*82.5

As can be seen from Table 1, as described above, the cross-sectional area of the reflector 210 may increase from one end to the other end. At this time, when the cross-sectional area of the reflector 210 increases from one end to the other end, as shown in FIG. 10, the inclination angle of the reflectors 210 may be 3.3° to 4°, but is not limited thereto.

Additionally, the length of the reflectors 210 may be 312.5 mm to 365.6 mm, and the size of the emitting unit 121 may be 76*76 mm ² to 82.5*82.5 mm ² , but is not limited thereto.

FIG. 16 shows the light quantity and uniformity when a failure occurs in one or more column or row unit light sources 221 for the reflector 210 shown in FIG. 15A.

As described above with reference to FIG. 8, the peripheral exposure apparatus 100 according to the present embodiments has the advantage that uniformity does not deteriorate even if the amount of light decreases when a failure occurs in some of the plurality of unit light sources 221. .

As can be seen from Figure 16, it was confirmed that the amount of light gradually decreased, but the uniformity was substantially the same as that of Figure 15b. As described above, because the light emitted from the light source unit 110 is reflected inside the reflector 210 shown in FIG. 15A and is formed as uniform light, even if a failure occurs in some of the plurality of unit light sources 221 Continuous production is possible because constant uniformity can always be maintained.

As shown in FIG. 10, the size of the incident unit 212 is fixed, and the length of the reflector 210, the inclination angle of the reflector 210, and the size of the exit unit 121 are changed, and the plurality of unit light sources 221 are used. The uniformity of the irradiated light passing through the reflector 210 and reaching the 75*75 receiving device and the 100*100 receiving device was investigated.

Figures 11b, 12b, 13b, 14b, 15b, 17b, 18b, 19a and 19b, and 20b are respectively similar to Figures 11a, 12a, 13a, 14a, 15a, 16a, 17A, 18A, 19A, 20A, and Table 1 show the light uniformity of the reflector 210.

Table 2 shows the maximum light uniformity of the reflectors 210 shown in FIGS. 11B, 12B, 13B, 14B, 15B, 16B, 17B, 18B, 19A and 19B, and 20B. It is organized into minimum value, average value, maximum value-minimum value (P_devi), and average value (P_devi rate).

It was confirmed that light uniformity was improved in the reflector 210 shown in FIG. 13A when compared with the reflectors 210 shown in FIGS. 11A and 12A.

However, because the exposure area and the light transmission area at the end of the mirror were almost the same, it was too sensitive to tolerance. To solve this problem, the length of the reflectors 210 shown in FIG. 14A was adjusted to increase the light transmission area at the end of the mirror while leaving the inclination angle of the reflectors 210 the same, but the light uniformity was lower than that of the reflectors shown in FIGS. 11A and 12A. It was confirmed that although it was not as high as 210, it was clearly falling.

Therefore, like the reflectors 210 shown in FIG. 15A, the light transmission area at the end of the mirror is set to 80*80 mm ² and then the length + inclination angle optimization is performed again to achieve a similar level of light uniformity as the reflector 210 shown in FIG. 13A. It was confirmed that there was improvement.

Table 3 shows the results of tolerance analysis for the inclination angles of the reflectors 210 shown in FIG. 15A.

As can be seen from Table 3, when the inclination angle of 0.1° or more becomes smaller as in the reflectors 210 shown in FIGS. 17A and 18A, the light transmission area at the end of the mirror narrows and the irradiance at the center tends to increase. It can be seen that the light uniformity is decreasing.

It was confirmed that when the inclination angle becomes larger, as in the reflectors 210 shown in FIGS. 19A and 20A, the light transmission area at the end of the mirror expands, the irradiance at the edge tends to increase, and uniformity decreases. In addition, it was confirmed that the light uniformity decreases more sensitively as the tolerance of the inclination angle of the reflectors 210 increases.

In summary, the inclination angle of the reflectors 210 is 3.3° to 4°, the length of the reflectors 210 is 312.5mm to 365.6mm, and the size of the emitter 121 is 76*76mm ² to 82.5*82.5mm. In the case of ^2, as shown in FIG. 9, it can be confirmed that light uniformity is improved compared to the conventional peripheral exposure device using only the fly eye lens 901.

In addition, it was confirmed that the light uniformity of the reflectors 210 shown in FIGS. 13A, 15A, and 18A was relatively improved compared to other reflectors 210.

FIG. 21A is a conceptual diagram of analyzing the illuminance at each angle after placing a screen on the emitter 121 for the reflector 210 shown in FIG. 15A and drilling holes in the order of left-->center-->right. Figures 21b to 21d show the results of analyzing the illuminance by angle after drilling holes in the following order: left-->center-->right.

After setting the mirror end light transmission area to 80*80 mm ² for the reflectors 210 shown in FIG. 15a and analyzing the angle of the light ray at each exposure area position, it was confirmed that the average peak reference half width angle was about 12°. . Additionally, the reflectors 210 shown in other drawings can be expected to have a similar average peak reference half width as the reflectors 210 shown in FIG. 15A.

The above description is merely an illustrative explanation of the technical idea of the present disclosure, and those skilled in the art will be able to make various modifications and variations without departing from the essential characteristics of the present disclosure. In addition, the present embodiments are not intended to limit the technical idea of the present disclosure, but rather to explain it, so the scope of the present technical idea is not limited by these embodiments. The scope of protection of this disclosure should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of rights of this disclosure.

100: peripheral exposure device 110: light source unit
120: Light transmission department 121: Projection department
211: frame 212: entrance part
213: support frame 214: frame
221: unit light source 222: lens
223: heat sink

Claims (5)

a light source unit including a plurality of unit light sources and a lens that focuses the light of the plurality of unit light sources;
a barrel unit including an entrance unit through which light from the light source unit is incident, and an exit unit through which light incident on the entrance unit is emitted; and
A tubular reflector accommodated in the barrel portion and open at both ends to reflect the light incident on the entrance portion from the inside and guide the light to the exit portion;
A peripheral exposure device wherein the cross-sectional area of the reflector increases from one end to the other, and the reflectors have an inclination angle of 3.3° to 4°. According to claim 1,
The length of the reflectors is 312.5mm to 365.6mm, and the size of the emitting portion is 76*76mm ² to 82.5*82.5mm ² . According to claim 1,
A peripheral exposure apparatus wherein the plurality of unit light sources are arranged in a plurality of columns and rows, and each unit light source is driven independently. According to claim 1,
A peripheral exposure apparatus wherein the plurality of unit light sources are arranged in a plurality of columns and rows, and each unit light source is independently driven on a column or row basis. According to claim 1,
Peripheral exposure apparatus, characterized in that the barrel portion is provided with a support frame that supports the middle part of the reflector.

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