CN112764325A

CN112764325A - Baffle device and exposure machine

Info

Publication number: CN112764325A
Application number: CN202110035248.1A
Authority: CN
Inventors: 王虎
Original assignee: TCL Huaxing Photoelectric Technology Co Ltd
Current assignee: TCL Huaxing Photoelectric Technology Co Ltd
Priority date: 2021-01-12
Filing date: 2021-01-12
Publication date: 2021-05-07
Anticipated expiration: 2041-01-12
Also published as: CN112764325B

Abstract

The invention provides a baffle device and an exposure machine, wherein the exposure machine comprises a mask plate positioned above the baffle device, the baffle device comprises a plurality of baffle devices, the baffle devices enclose a light transmission area positioned below the mask plate, and the baffle device is provided with a height adjusting mechanism. The baffle device moves in the horizontal direction according to the light shielding area to be formed, and the longitudinal distance between the edge of the baffle device and the mask plate can be different when the baffle device is at different positions, and the larger the longitudinal distance is, the larger the range of the generated gray area is. The height adjusting mechanism can control the longitudinal distance between the edge of the baffle device and the mask plate in the horizontal moving process to be larger than zero and smaller than a first preset distance, so that the baffle device does not scratch the mask plate, the longitudinal distance between the mask plate and the edge of the baffle device can be kept in a small range, the range of an ash area can be further reduced, and the precision of the baffle device is improved.

Description

Baffle device and exposure machine

Technical Field

The invention relates to a photoetching device, in particular to a baffle device and an exposure machine.

Background

In lithography, an exposure machine typically includes a light source, a reticle, and a lens. The mask is a glass plate with a surface covered by various patterns, and a light source can project the patterns onto a wafer coated with photoresist through the mask to generate three-dimensional relief patterns for assisting in etching circuit patterns on the wafer.

In actual use, there may be a need to project, i.e. to perform a partial exposure, a pattern portion on the reticle. Therefore, a baffle plate can be additionally arranged between the mask plate and the wafer, the part which does not need to be exposed is covered by the baffle plate to block the light from transmitting, the light is limited to the part which needs to be exposed, and the area of the light irradiation area is controlled by the baffle plate, so that partial exposure can be realized.

However, diffraction of light occurs at the edge of the shutter, and a certain distance of gray areas are generated at the edge of the shutter during the pattern transfer, and the pattern is distorted to some extent in the areas, which is a difficult disadvantage in production.

Disclosure of Invention

The invention aims to provide a baffle device and an exposure machine, which can reduce a dust area, thereby improving the precision of the baffle and simultaneously reducing the scratch of a mask.

In one aspect, the invention provides a baffle device, which is applied to an exposure machine, wherein the exposure machine comprises a mask plate positioned above the baffle device, a plurality of baffle devices enclose a light transmission area positioned below the mask plate, the baffle device is provided with a height adjusting mechanism, and the height adjusting mechanism is used for controlling the longitudinal distance between the edge of the baffle device and the mask plate in the horizontal moving process to be larger than zero and smaller than a first preset distance.

Preferably, the baffle device comprises a transverse baffle body arranged perpendicular to the longitudinal direction, a fixed vertical baffle body arranged in the longitudinal direction and connected with the transverse baffle body, and a movable vertical baffle body connected with the fixed vertical baffle body through the height adjusting mechanism, wherein the fixed vertical baffle body is arranged at one end, close to the light transmission area, of the transverse baffle body;

the height adjusting mechanism controls the movable vertical blocking body to move in the longitudinal direction, so that the longitudinal distance between the edge of the movable vertical blocking body and the mask plate in the horizontal moving process is larger than zero and smaller than the first preset distance.

Further preferably, a distance meter is arranged at the top of the fixed vertical baffle and used for measuring the longitudinal distance from the top of the fixed vertical baffle to the bottom surface of the reticle.

Further preferably, the reticle has a maximum sag value at a center of the reticle lower than an edge, and the height of the fixed vertical barrier is greater than the maximum sag value.

Further preferably, when the movable vertical baffle is located at the edge of the reticle, the longitudinal distance detected by the distance meter is the largest, and the movable vertical baffle is at a first height; when the longitudinal distance detected by the range finder decreases by a first distance, the movable vertical stop moves downward by the first distance.

Further preferably, the distance between the fixed vertical baffle and the edge of the transverse baffle main body close to the light-transmitting area is smaller than a second preset distance.

Preferably, the height adjusting mechanism is a gear and a rack which are engaged with each other, the gear is mounted on the fixed vertical blocking body, and the rack is mounted on the movable vertical blocking body.

Further preferably, the right end of the transverse baffle body has a vertical corner.

Further preferably, the upper end of the movable vertical barrier has a vertical corner.

In another aspect, the present invention provides an exposure machine including the shutter device described in any one of the above.

The invention has the beneficial effects that: the invention provides a baffle device and an exposure machine, wherein the exposure machine comprises a mask plate positioned above the baffle device, a plurality of baffle devices enclose a light transmission area positioned below the mask plate, and a height adjusting mechanism is arranged on each baffle device. The baffle device moves in the horizontal direction according to the light shielding area to be formed, and the longitudinal distance between the edge of the baffle device and the mask plate can be different when the baffle device is at different positions, and the larger the longitudinal distance is, the larger the range of the generated gray area is. The height adjusting mechanism can control the longitudinal distance between the edge of the baffle device and the mask plate in the horizontal moving process to be larger than zero and smaller than a first preset distance, so that the baffle device does not scratch the mask plate, the longitudinal distance between the mask plate and the edge of the baffle device can be controlled in a smaller range, the range of an ash area can be reduced, and the precision of the control exposure area of the baffle device is improved.

Drawings

The technical solution and other advantages of the present invention will become apparent from the following detailed description of specific embodiments of the present invention, which is to be read in connection with the accompanying drawings.

FIG. 1 is a schematic cross-sectional view of an exposure machine according to a first embodiment of the present invention;

FIG. 2 is a schematic diagram of the diffraction path of light at the edge of the baffle means provided by the first embodiment of the present invention;

FIG. 3 is a schematic structural view of a baffle unit according to a second embodiment of the present invention;

FIG. 4 is a schematic diagram of a second embodiment of the invention, showing the same shutter device in two positions on a reticle.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

As used herein, the term "longitudinal" refers to a direction perpendicular to the substrate, denoted by "a"; the term "horizontal direction" refers to a direction parallel to the substrate, denoted by "b"; the term "longitudinal distance" refers to a perpendicular distance.

Referring to fig. 1, fig. 1 is a schematic cross-sectional structure diagram of an exposure machine according to a first embodiment of the invention. The exposure machine 100 comprises a light source (not shown in the figure), a mask 10 and a plurality of baffle devices 20 which are sequentially arranged from top to bottom along a longitudinal direction (a), wherein the baffle devices 20 enclose a light-transmitting area A positioned below the mask 10, and the baffle devices 20 are provided with height adjusting mechanisms 30. The height adjustment mechanism 30 is used for controlling the longitudinal distance between the edge of the shutter device 20 and the reticle 10 in the horizontal (b) moving process to be larger than zero and smaller than a first preset distance.

The exposure machine 100 further comprises a base plate 40 positioned below the baffle device 20 and a material layer 41 to be exposed positioned on the base plate 40, wherein the material layer 41 to be exposed is exposed in the light-transmitting area a to obtain the pattern of the corresponding mask 10, and the baffle device 20 is further arranged to enable one mask to achieve the application of diversified patterns.

The exposure machine 100 further comprises a correction unit 50 located between the layer 41 of material to be exposed and the baffle means 20, which correction unit 50 may be a lens, the ability of which lens to collect diffracted light may be expressed in terms of numerical aperture NA.

In this embodiment, the exposure machine 100 may include four of the shutter devices 20, i.e., one for each of the front, rear, left, and right sides, to define a light-transmissive area a. Fig. 1 shows only two flap arrangements 20 as a cross-sectional view, the two flap arrangements 20 being displaceable in the horizontal direction (b). Specifically, the lower surface of the mask plate 10 is connected with a first supporting pad 11, the upper surface of the baffle device 20 is connected with a second supporting pad 21, the lower surface of the first supporting pad 11 is provided with a rack, the upper surface of the second supporting pad 21 is provided with a gear, and the relative motion of the gear and the rack can enable the baffle device 20 to move in the horizontal direction (b) relative to the mask plate 10 so as to change the position of the baffle device 20, thereby changing the position of the light transmission area a and further adjusting the position of the exposure area. Alternatively, the horizontal movement of the shutter device 20 may be achieved by other driving mechanisms.

One of the baffle devices 20 comprises two parts: a transverse baffle body 201 arranged perpendicular to the longitudinal direction (a), and a movable vertical baffle body 202 connected to the transverse baffle body 201 through the height adjusting mechanism 30. The movable vertical baffle 202 is arranged along the longitudinal direction (a) and has a vertical corner at the top to form an inverted L shape, so that the movable vertical baffle 202 can better block light compared with a completely vertical baffle without a corner. The edge of the barrier device 20 refers to the position of the top of the barrier device 20 near the light-transmitting area a, and in this embodiment, the edge of the barrier device 20 is the edge B of the movable vertical barrier 223.

Since diffraction occurs at the edge B of the light near the transparent area a at the top of the shutter device 20, the area irradiated by the diffracted light may form gray areas on the reticle 10, that is, the position corresponding to the gray areas on the material layer 41 to be exposed may be underexposed, so that the pattern corresponding to the reticle 10 may be distorted to some extent.

Referring to fig. 2, fig. 2 is a schematic diagram of a diffraction path of light at an edge of a baffle device according to a first embodiment of the invention. The light from the light source is diffracted at the edge B of the shutter device 20, and thus underexposure occurs when the diffracted light is directed down to the material layer 41 to be exposed. From the perspective of the mask 10, the area corresponding to the diffracted light may be referred to as a gray area C, in which the pattern of the mask 10 may be distorted to some extent, and the distortion of the pattern may be reflected on the underlying material layer 41 to be exposed, that is, the portion of the material layer 41 to be exposed corresponding to the gray area C may be underexposed or the pattern may be blurred, which has a great influence on the process accuracy. Since the gray area C is caused by the barrier device 20, if the gray area C is larger, the accuracy of the barrier device 20 is poor, and the real pattern corresponding to the light-transmitting area enclosed by the barrier device 20 cannot be obtained because the gray area C is larger.

Here, the length of the gray zone C in the horizontal direction (B) is equal to the longitudinal distance (Z0) × tan θ × 2 from the edge B of the shutter device 20 to the reticle 10, and θ is equal to the vertical aperture NA of the lens, so that when NA is constant, the length of the gray zone C in the horizontal direction (B) is proportional to the longitudinal distance Z0, and thus it is known that the smaller the longitudinal distance Z0 from the edge B of the shutter device 20 to the reticle 10, the smaller the gray zone C. It is noted that the longitudinal distance Z0 from edge B of the shutter arrangement 20 to the reticle 10 refers to the perpendicular distance from edge B to the bottom surface of the reticle 10.

The longitudinal distance Z0 from edge B to reticle 10 during horizontal movement of shutter arrangement 20 may be different because the shape of reticle 10 may not be perfectly horizontal. The size of the ash zone C created by the baffle device 20 at different locations therefore varies, with the greater the longitudinal distance Z0, the greater the ash zone C. If the longitudinal distance Z0 from edge B to reticle 10 is fixed, then to ensure that the lowest part of reticle 10 is not scratched, the longitudinal distance Z0 from edge B to reticle 10 is increased higher on reticle 10 and the gray zone becomes larger.

In this embodiment, the height adjustment mechanism 30 may control the movable vertical baffle 202 to move up and down relative to the transverse baffle body 201, so as to ensure that the longitudinal distance Z0 between the edge B of the baffle device 20 and the reticle 10 is kept within a certain range, such as greater than zero and less than a first preset distance, during the horizontal (B) movement, so that the edge B does not scratch the bottom surface of the reticle 10, and the ash area is also reduced.

Referring to fig. 3, fig. 3 is a schematic structural diagram of a baffle device according to a second embodiment of the present invention. The shutter device 220 is located below the reticle 210.

It has been found that a large-format reticle 210 may always sag to some extent during operation, with the reticle 210 having a maximum sag value at the center below the edges of the reticle 210, which is related to the size of the reticle 210 and also to the time of use. For larger size reticles, the maximum sag value can be up to 10 mm. The mask 210 may include a glass plate, a chromium layer, and a film stacked from top to bottom, and the film is easily scratched by the baffle device 220.

It will be appreciated that to ensure the safety of the bottom surface film of the reticle 210, the longitudinal distance from the edge G of the top of the shutter arrangement 220 near the light transmitting region D to the reticle 210 may be greater than a maximum sag value of 10mm when the shutter arrangement 220 is moved to the edge of the reticle 210.

In the present embodiment, the barrier device 220 includes a transverse barrier body 221 disposed perpendicular to the longitudinal direction (a), a fixed vertical barrier 222 disposed in the longitudinal direction (a) and connected to the transverse barrier body 221, and a movable vertical barrier 223 connected to the fixed vertical barrier 222 through the height adjusting mechanism 230. The edge G of the baffle means 220 is the edge of the movable vertical barrier 223.

In this embodiment, the fixed vertical barrier 222 is disposed at an end of the transverse barrier body 221 near the light-transmitting region D. In one embodiment, the fixed vertical barrier 222 may be disposed at the right end E of the transverse baffle body 221 near the light-transmitting region D. Preferably, in another embodiment, the distance between the fixed vertical barrier 222 and the right end E of the lateral barrier main body 221 is less than a second predetermined distance, that is, the fixed vertical barrier 222 may be shifted to the left by the second predetermined distance relative to the right end E, so that light leakage at the height adjustment mechanism 230 may be reduced.

In a preferred embodiment, the right end E of the transverse baffle body 221 near the light-transmitting region D has a vertical corner, i.e., the transverse baffle body 221 is in a flat L-shape, and the vertical part in the longitudinal direction (a) can reduce the reflection of light on the transverse baffle body 221.

In a preferred embodiment, the movable vertical stopper 223 has a vertical corner near the upper end F of the reticle 210 so that the movable vertical stopper 223 has an inverted L shape, and a vertical portion in the horizontal direction (a) has a good light shielding effect.

In this embodiment, a distance meter 240 is further disposed on top of the fixed vertical barrier 222 for measuring a longitudinal distance from the top of the fixed vertical barrier 222 to a bottom surface of the reticle 210. The range finder 240 may be an infrared range finder.

The distance from the distance meter 240 to the movable vertical blocking body 223 is less than 3mm, and the closer distance represents that the horizontal positions of the distance meter and the movable vertical blocking body 223 are approximately the same, so that the height adjustment is more accurate when the height of the movable vertical blocking body 223 is adjusted according to the result of the distance meter 240. The height adjusting mechanism 230 controls the movable vertical stopper 223 to move in the longitudinal direction (a) according to the result measured by the distance measuring device 240, so that the longitudinal distance between the edge G of the movable vertical stopper 223 and the reticle 10 in the horizontal (b) moving process is greater than zero and smaller than the first preset distance.

Alternatively, the distance meter 240 may be provided on the lateral fence body 221, since this also measures the distance that the reticle 210 sags at different levels. If infrared ranging is used, there should be no other obstacle in the middle of the distance measured by rangefinder 240.

In another embodiment, if the sensitivity of the range finder 240 is large enough, it can be placed directly at the edge G of the movable vertical barrier 223, directly measuring the longitudinal distance of the edge G to the reticle 210, and thus the error will be smaller.

Preferably, the height adjusting mechanism 230 is a gear and a rack engaged with each other, the gear is mounted on the fixed vertical stopper 222, and the rack is mounted on the movable vertical stopper 223. Alternatively, the height adjustment mechanism 230 may be implemented by other driving mechanisms to move the movable vertical stop 223 up and down relative to the fixed vertical stop 222.

Referring to fig. 4, fig. 4 is a schematic structural diagram of a same shutter device provided in a second embodiment of the invention in two positions on a reticle. When the moveable vertical block 223 is located at both edges of the reticle 210, the longitudinal distance detected by the range finder 240 is the largest, and the moveable vertical block 223 is at a first height H0; when the longitudinal distance detected by the rangefinder 240 decreases by the first distance H1, the movable vertical stop 223 also moves downward by the first distance H1.

For example, when the baffle device 220 is located at the edge of the reticle 210, infrared ranging knows the distance from the reticle 210 to the top of the fixed vertical block 222, and the movable vertical block 223 adjusts the height so that the longitudinal distance from the edge G to the reticle 210 is 1 mm; when the baffle device 220 is located at the center of the mask 210, the infrared distance measurement shows that the distance from the mask 210 to the top of the fixed vertical baffle 222 is reduced by 3mm, the height of the movable vertical baffle 223 is reduced by 3mm, the longitudinal distance from the edge C to the mask 210 is still 1mm, and the film cannot be scraped while the minimum ash area is maintained.

As shown in fig. 4, the height adjustment mechanism 230 may be considered as a gear, where the lower end of the movable vertical stopper 223 is located when the baffle device 220 is at the edge of the reticle 210; when the blocker device 220 is at the center of the reticle 210 (having the maximum sag value), the moveable vertical stop 223 moves downward a first distance H1, where the first distance H1 of the descent of the moveable vertical stop 223 equals the maximum distance of descent of the moveable vertical stop 223, which equals the maximum sag value of the reticle 10.

In one aspect, height H2 of fixed vertical barrier 222 is greater than the maximum sag value of reticle 210 because height H2 of fixed vertical barrier 222 is greater than the maximum descent distance of movable vertical barrier 223. On the other hand, since the height H3 of the movable vertical stop 223 is also greater than the maximum lowering distance, the height H3 of the movable vertical stop 223 is greater than the maximum sag value of the reticle 210, which ensures that the movable vertical stop 223 has sufficient lowering space.

In this embodiment, the exposure machine including the shutter device 220 further includes a control unit (not shown in the figure) connected to the distance meter 240 and the height adjustment mechanism 230, and configured to receive the result measured by the distance meter 240 and send a height adjustment command to the height adjustment mechanism 230 according to the measured result, so as to feed back and accurately control the longitudinal distance between the edge G of the shutter device 220 and each position of the reticle 210 in real time.

The baffle device provided by the embodiment of the invention comprises a transverse baffle main body which is arranged in a manner of being vertical to the longitudinal direction, a fixed vertical baffle body which is arranged in the longitudinal direction and is connected with the transverse baffle main body, and a movable vertical baffle body which is connected with the fixed vertical baffle body through the height adjusting mechanism, wherein the edge height of the baffle device can be automatically adjusted. When the mask plate sags and the shape is changed, the height of the movable vertical baffle body can be automatically adjusted when the baffle device is positioned at different positions in the horizontal direction, so that the longitudinal distance between the edge of the baffle device and the mask plate is larger than zero and smaller than a first preset distance. The baffle device can not scratch the film on the bottom surface of the mask plate, can ensure the safety of the film of the mask plate, and can greatly reduce the range of an ash area, thereby improving the precision of the baffle plate and the precision of the manufacturing process.

The above description of the embodiments is only for helping understanding the technical solution of the present invention and its core idea; those of ordinary skill in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. The baffle device is applied to an exposure machine and is characterized in that the exposure machine comprises a mask plate located above the baffle device, the baffle device is characterized in that the baffle device is arranged in a light transmission area located below the mask plate in a surrounding mode, a height adjusting mechanism is arranged on the baffle device and used for controlling the edge of the baffle device to be larger than zero and smaller than a first preset distance from the longitudinal distance of the mask plate in the horizontal moving process.

2. The baffle device of claim 1, wherein the baffle device comprises a transverse baffle body disposed perpendicular to the longitudinal direction, a fixed vertical baffle body disposed in the longitudinal direction and connected to the transverse baffle body, and a movable vertical baffle body connected to the fixed vertical baffle body through the height adjustment mechanism, the fixed vertical baffle body being disposed at an end of the transverse baffle body adjacent to the light-transmitting zone;

the height adjusting mechanism is used for controlling the movable vertical baffle to move in the longitudinal direction, so that the longitudinal distance between the edge of the movable vertical baffle and the mask is larger than zero and smaller than the first preset distance in the horizontal moving process.

3. The baffle device of claim 2, wherein the top of the fixed vertical baffle is provided with a distance meter for measuring a longitudinal distance from the top of the fixed vertical baffle to the bottom surface of the reticle.

4. The shutter arrangement of claim 3, wherein the reticle has a maximum sag value at a center of the reticle below an edge, the fixed vertical stops having a height greater than the maximum sag value.

5. The shutter arrangement of claim 4, wherein the range finder detects a maximum longitudinal distance when the moveable vertical stop is at an edge of the reticle, the moveable vertical stop being at a first height; when the longitudinal distance detected by the range finder decreases by a first distance, the movable vertical stop moves downward by the first distance.

6. The baffle device of claim 2 wherein the fixed vertical baffle is less than a second predetermined distance from the edge of the transverse baffle body proximate the light transmissive region.

7. The barrier device of claim 2, wherein the height adjustment mechanism is an intermeshing gear and rack, the gear being mounted on the fixed vertical barrier and the rack being mounted on the movable vertical barrier.

8. The baffle device of claim 2 wherein the right end of the transverse baffle body has a vertical corner.

9. The baffle device of claim 2 wherein the upper end of the movable vertical baffle has a vertical corner.

10. An exposure machine, characterized by comprising a shutter device according to any one of claims 1 to 9.