Mask cleaning device and method

Abstract

The invention discloses a mask plate cleaning device. The mask plate cleaning device comprises a blowing table and an air blowing device. A mask plate placing part is arranged on the first surface of the purging table and is used for placing and fixing a mask plate. And the purging table is also connected with the rotating device. The air blowing device comprises a nozzle which is connected with a nozzle moving device. In the cleaning process, the rotating device drives the purging table and the mask plate to rotate, and the nozzle moving device controls the nozzle to move and enables the purging position of the purging gas sprayed by the nozzle to move along a path from the center of the purged surface of the mask plate to the edge direction. The invention further discloses a mask cleaning method. According to the invention, the purging cleaning effect and efficiency can be improved, and the purging gas flow can be reduced at the same time.

Description

Technical Field

[0001] The present invention relates to the field of manufacturing semiconductor integrated circuits, and in particular to a mask cleaning device and a mask cleaning method. Background Art

[0002] The mask is an essential component in the photolithography process. The pattern on the mask is projected onto the wafer at a certain ratio. If particles fall onto the mask, they will affect the pattern on the wafer when they reach a certain size. It is inevitable that particles will fall onto the mask during use and storage, so removing particles on the mask surface is essential.

[0003] like Figure 1 , which is a schematic diagram of the structure of an existing mask cleaning device; it includes: a robot 102 , a blowing device 104 and a purge platform 103 arranged in a cavity 101 , and a carrier platform 105 arranged outside the cavity 101 .

[0004] The existing mask cleaning method includes the following steps:

[0005] (1) The mask is loaded onto the purge station 103 through the transport of the robot arm, namely the robot 102, and the purge station 103 fixes the mask.

[0006] (2) The air nozzle blows the entire mask in an S-shaped path. Figure 2 , which is a schematic diagram of the purge path of the existing mask cleaning device during the cleaning process; the arrow line 106 represents the S-shaped path.

[0007] (3) After the reverse side is purged in the same manner, the mask is loaded into a mask box by a robotic arm, and the mask box is placed on the carrier 105 . Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a mask cleaning device which can increase the purge cleaning effect and efficiency and reduce the purge gas flow rate. To this end, the present invention also provides a mask cleaning method.

[0009] In order to solve the above technical problems, the mask cleaning device provided by the present invention comprises: a purge platform and an air blowing device.

[0010] A mask placement component is disposed on the first surface of the purge platform, and the mask placement component is used to place and fix the mask during the cleaning process.

[0011] The purge station is also connected to the rotating device.

[0012] The blowing device comprises a nozzle, which is used to spray out the purge gas, and the nozzle is connected to the nozzle moving device.

[0013] During the cleaning process, the rotating device drives the purge platform and the mask to rotate, and the nozzle moving device controls the movement of the nozzle and moves the purge position where the nozzle sprays the purge gas along a path from the center to the edge of the purge surface of the mask.

[0014] A further improvement is that it also includes: a carrying platform and a manipulator.

[0015] The carrier is used for placing the mask before or after cleaning.

[0016] The robot is used to move the mask between the carrying platform and the purge platform or to flip the mask.

[0017] A further improvement is that the purge table, the air blowing device and the manipulator are arranged in the cleaning chamber, and the supporting table is arranged outside the cleaning chamber.

[0018] A further improvement is that the purge gas includes nitrogen.

[0019] A further improvement is that the nozzle moving device includes a nozzle rotating component, which controls the angle of the nozzle and makes the flow direction of the purge gas and the extension direction from the center to the edge of the purge surface of the mask plate form an obtuse angle.

[0020] A further improvement is that, during the cleaning process, the purging position of the purging gas moves along a straight path from the center to the edge of the purged surface of the mask.

[0021] A further improvement is that the swept surface of the mask is the front surface of the mask or the swept surface of the mask is the back surface of the mask.

[0022] A further improvement is that the nozzle moving device includes a telescopic component, and the movement of the nozzle is controlled by the telescopic component.

[0023] In order to solve the above technical problems, the mask cleaning method provided by the present invention comprises the following steps:

[0024] The mask is placed and fixed on a placement component arranged on the first surface of the purge stage.

[0025] The rotating device connected to the purge platform drives the purge platform and the mask to rotate.

[0026] The nozzle sprays the purge gas to the swept surface of the mask to clean the mask, and during the cleaning process, the nozzle moving device controls the movement of the nozzle and moves the purge position where the nozzle sprays the purge gas along a path from the center to the edge of the swept surface of the mask.

[0027] A further improvement is that the mask is taken out from the carrying platform by a robot and moved to be placed on the placing component of the purge platform.

[0028] After the cleaning of the mask is completed, the method further includes a step of moving the mask from the purge platform to the carrier platform by the robot.

[0029] The swept surface of the mask is selected by the robot turning over the mask.

[0030] A further improvement is that the purge table, the air blowing device and the manipulator are arranged in the cleaning chamber, and the supporting table is arranged outside the cleaning chamber.

[0031] A further improvement is that the purge gas includes nitrogen.

[0032] A further improvement is that, during the cleaning process, the nozzle moving device also controls the angle of the nozzle through the nozzle rotating component and makes the flow direction of the purge gas and the extension direction from the center to the edge of the purge surface of the mask form an obtuse angle.

[0033] A further improvement is that, during the cleaning process, the purging position of the purging gas moves along a straight path from the center to the edge of the purged surface of the mask.

[0034] A further improvement is that the swept surface of the mask is the front surface of the mask or the swept surface of the mask is the back surface of the mask.

[0035] A further improvement is that both the front and back sides of the mask need to be cleaned, and after one of the front and back sides of the mask is cleaned as the purged side; the mask is turned over, and then the other of the front and back sides of the mask is cleaned as the purged side.

[0036] The present invention adds a rotation function of the purge table, combines the purge table to drive the rotation of the mask and the nozzle moving device to control the movement of the nozzle, wherein the centrifugal force brought by the rotation itself can achieve the removal of some polluted particles with smaller adhesion, and the purge gas sprayed from the nozzle can further increase the force for removing the polluted particles along the direction of the centrifugal force, thereby achieving the removal of particles with greater adhesion. Therefore, the present invention can increase the purging and cleaning effect.

[0037] In addition, the rotation of the mask can also make the movement control of the nozzle simpler. It is only necessary to realize the path movement from the center of the swept surface of the mask to the edge direction. In the simplest case, this path can be a straight line path. Compared with the complex S-shaped path in the prior art, the movement path of the nozzle of the present invention is simpler and easier to control.

[0038] In addition, the rotation of the mask plate and the control of the movement path of the nozzle moving outward from the center of the present invention can also make all positions, including all positions from the center to the edge, be well purged; while in the existing method, the S-shaped path needs to be purged back and forth, which easily causes the center position of the adjacent purging path to not be well purged, so there is a weak purging area. Therefore, the purging effect formed by the purging path of the present invention is better, and finally the purging cleaning effect can be further increased. Moreover, compared with the S path of the existing method, the nozzle movement path of the present invention is short, and the purging of each position on the surface of the mask plate can be achieved in a shorter time, so the purging time is short and the efficiency is higher.

[0039] In addition, the force used by the present invention to finally remove the polluted particles is the combined force of the centrifugal force formed by the rotation and the purge force formed by the flow of the purge gas. Therefore, under the condition that the adhesion force of the polluted particles is the same, compared with the existing method, the flow rate of the purge gas required to remove the polluted particles in the present invention can be reduced, thereby reducing the purge gas flow rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0041] Figure 1 It is a structural schematic diagram of an existing mask cleaning device;

[0042] Figure 2 It is a schematic diagram of the purge path of the existing mask cleaning device during the cleaning process;

[0043] Figure 3 is a schematic structural diagram of a mask cleaning device according to an embodiment of the present invention;

[0044] Figure 4 is a schematic diagram of a purge path of a mask cleaning device during a cleaning process according to an embodiment of the present invention;

[0045] Figure 5 is an enlarged view of a purge station and a nozzle of a mask cleaning device according to an embodiment of the present invention;

[0046] Figure 6 The figure is a flow chart of a mask cleaning method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0047] like Figure 3, which is a schematic diagram of the structure of a mask cleaning device according to an embodiment of the present invention; Figure 4 , which is a schematic diagram of a purge path of a mask cleaning device during a cleaning process according to an embodiment of the present invention; the mask cleaning device according to the embodiment of the present invention comprises: a purge platform 206 and a blowing device 204 .

[0048] A placement component for the mask 203 is provided on the first surface of the purge station 206, and the placement component is used to place and fix the mask 203 during the cleaning process. In some embodiments, the mask 203 is directly placed on the first surface of the purge station 206, and the mask 203 is fixed by vacuum adsorption or electrostatic adsorption. In this case, the placement component is directly composed of the first surface of the purge station 206 and the vacuum adsorption device or the electrostatic adsorption device. In other embodiments, multiple clamps can also be used to fix the mask 203.

[0049] like Figure 5 , which is an enlarged view of the purge platform 206 and the nozzle 204a of the mask cleaning device according to an embodiment of the present invention; the purge platform 206 is also connected to the rotating device, Figure 5 The rotation arrow line 208 indicates rotation. In some embodiments, the rotating device includes a motor, and the rotation is achieved by the motor.

[0050] The blowing device 204 includes a nozzle 204a, which is used to eject the purge gas, and the nozzle 204a is connected to a nozzle moving device (not shown). Usually, the blowing device 204 also includes an air inlet pipe, which is connected to a purge gas source, and the nozzle 204a is connected to the air inlet pipe.

[0051] During the cleaning process, the rotating device drives the purge stage 206 and the mask plate 203 to rotate, and the nozzle moving device controls the movement of the nozzle 204a and moves the purge position where the nozzle 204a sprays the purge gas along a path from the center to the edge of the purge surface of the mask plate 203. Figure 4As shown, arrow line 207 indicates the moving path of the purging position. The nozzle 204a is usually spaced a certain distance from the purged surface of the mask 203, so the movement of the nozzle 204a is completely controlled according to the actual needs of the arrow line 207. In the embodiment of the present invention, during the cleaning process, the purging position of the purging gas moves along a straight path from the center to the edge of the purged surface of the mask 203, that is, the moving path of the nozzle 204a is a straight path, and the purging path is an outward straight path without considering the rotation; in the case of considering the rotation, the straight line will eventually sweep the entire purged surface of the mask 203, thereby achieving comprehensive purging of the purged surface of the mask 203 without dead angles. In other embodiments, the purge path may be an outward curved path, that is, the nozzle 204a is moved from the center to the outside. Without considering the rotation, the purge path is an outward curved path. Considering the rotation, the curved path will eventually sweep across the entire purged surface of the mask 203.

[0052] In the embodiment of the present invention, the nozzle moving device includes a telescopic component, and the movement of the nozzle 204a is controlled by the telescopic component.

[0053] In the embodiment of the present invention, it further includes: a carrying platform 205 and a robot arm 202 .

[0054] The carrier 205 is used to place the mask 203 before or after cleaning.

[0055] The robot 202 is used to move the mask 203 between the carrier 205 and the purge stage 206 or to flip the mask 203 .

[0056] In the embodiment of the present invention, the purge table 206, the blowing device 204 and the manipulator 202 are arranged in the cleaning chamber 201, and the carrying table 205 is arranged outside the cleaning chamber 201. The cleaning chamber 201 only needs to separate the inside and outside environments of the chamber to prevent the external environment from polluting the inside environment of the chamber.

[0057] In the embodiment of the present invention, the purge gas includes nitrogen. In other embodiments, the purge gas can also be any chemically stable gas such as an inert gas or CDA gas, as long as the purge can be achieved through gas flow.

[0058] In the embodiment of the present invention, Figure 5As shown, the nozzle moving device includes a nozzle rotating component, which controls the angle of the nozzle 204a and is used to control the flow direction of the purge gas and the extension direction from the center to the edge of the purge surface of the mask 203 to form an obtuse angle. The obtuse angle can ensure that the force provided by the flow of the purge gas includes an outward force, that is, a force in the same direction as the centrifugal force.

[0059] The swept surface of the mask plate 203 is the front surface of the mask plate 203 or the swept surface of the mask plate 203 is the back surface of the mask plate 203 .

[0060] The embodiment of the present invention adds a rotation function to the purge table 206, combines the purge table 206 to drive the rotation of the mask 203 and the nozzle moving device to control the movement of the nozzle 204a, wherein the centrifugal force brought by the rotation itself can achieve the removal of some contamination particles with less adhesion. Figure 5 As shown, due to the inertia of the rotation itself, the polluted particle 209 has an outward centrifugal force (not shown). The centrifugal force is a virtual force. In order to achieve force balance, the centripetal force 210 actually received by the polluted particle 209 needs to be equal to the centrifugal force. The centripetal force 210 is determined by the adhesion between the polluted particle 209 and the purge stage 206. The greater the adhesion, the greater the centripetal force that can be provided. If the centripetal force is smaller than the centrifugal force, the polluted particle 209 cannot maintain balance, so the polluted particle 209 will move in the direction of the centrifugal force and finally be removed from the outside of the mask 203. In addition, in the embodiment of the present invention, the purge gas sprayed by the nozzle 204a can further increase the force of removing the polluted particles along the direction of the centrifugal force, and remove the particles with greater adhesion. Therefore, the present invention can increase the purge cleaning effect.

[0061] In addition, the rotation of the mask 203 can also make the movement control of the nozzle 204a simpler. It is only necessary to realize the path movement from the center of the swept surface of the mask 203 to the edge direction. In the simplest case, this path can be a straight line path. Compared with the complex S-shaped path in the prior art, the movement path of the nozzle 204a in the embodiment of the present invention is simpler and easier to control.

[0062] In addition, the rotation of the mask 203 of the embodiment of the present invention and the control of the movement path of the nozzle 204a moving outward from the center can also make all positions, including all positions from the center to the edge, be well purged; while in the existing method, the S-shaped path needs to be purged back and forth, which can easily cause the center position of the adjacent purging path to not be well purged, so there is a weak purging area. Therefore, the purging effect formed by the purging path of the embodiment of the present invention is better, and finally the purging cleaning effect can be further increased. Moreover, compared with the S path of the existing method, the nozzle movement path of the embodiment of the present invention is short, and the purging of each position on the surface of the mask can be achieved in a shorter time, so the purging time is short and the efficiency is higher.

[0063] In addition, the force used to finally remove the polluted particles in the embodiment of the present invention is the combined force of the centrifugal force formed by the rotation and the purge force formed by the flow of the purge gas. Therefore, under the condition that the adhesion force of the polluted particles is the same, compared with the existing method, the flow rate of the purge gas required to remove the polluted particles in the embodiment of the present invention can be reduced, thereby reducing the purge gas flow rate.

[0064] like Figure 6 FIG. 2 is a flow chart of a mask cleaning method according to an embodiment of the present invention. The mask cleaning method according to an embodiment of the present invention comprises the following steps:

[0065] Step S101 , placing the mask on the carrier 205 .

[0066] The mask 203 is placed and fixed on a placement component provided on the first surface of the purge table 206. In the method of the embodiment of the present invention, the mask 203 is taken out from the carrier table 205 by the robot 202 and moved and placed on the placement component of the purge table 206. This step is Figure 6 In step S102, the robot arm clamps the mask to the purge station and fixes the mask in step S103. The rotating device connected to the purge station 206 drives the purge station 206 and the mask 203 to rotate. This step is the high-speed rotation of the purge station in step S103.

[0067] In the method of the embodiment of the present invention, the swept surface of the mask 203 is the front side of the mask 203 or the swept surface of the mask 203 is the back side of the mask 203. The swept surface of the mask 203 is selected by the robot 202 flipping the mask 203.

[0068] The nozzle 204a sprays the purge gas to the swept surface of the mask 203 to clean the mask 203, and during the cleaning process, the nozzle moving device controls the movement of the nozzle 204a to move the purge position of the nozzle 204a spraying the purge gas along a path from the center to the edge of the swept surface of the mask 203. In the method of the embodiment of the present invention, the purge gas includes nitrogen. This step is Figure 6 In step S104, the N2 nozzle purges the mask.

[0069] In the method of the embodiment of the present invention, the nozzle moving device includes a telescopic component, and the movement of the nozzle 204a is controlled by the telescopic component.

[0070] In the method of the embodiment of the present invention, during the cleaning process, the nozzle moving device controls the angle of the nozzle 204a through the nozzle rotating component and makes the flow direction of the purge gas and the extension direction from the center to the edge of the purge surface of the mask 203 form an obtuse angle.

[0071] In some embodiment methods, during the cleaning process, the purging position of the purging gas moves along a straight path from the center to the edge of the purged surface of the mask 203 .

[0072] In the method of the embodiment of the present invention, the purge platform 206 , the air blowing device 204 and the manipulator 202 are arranged in the cleaning chamber 201 , and the carrying platform 205 is arranged outside the cleaning chamber 201 .

[0073] In the method of the embodiment of the present invention, both the front and back sides of the mask 203 need to be cleaned. After cleaning one of the front and back sides of the mask 203 as the purged side, the mask 203 is flipped over, and then the other of the front and back sides of the mask 203 is used as the purged side to complete the cleaning. The step of flipping the mask 203 corresponds to Figure 6 In step S108, the mask is turned over and placed back on the purge station.

[0074] After the mask 203 is cleaned, the process further includes moving the mask 203 from the purge stage 206 to the carrier stage 205 by the robot 202. Figure 6 In step S107, the mask is withdrawn to the carrier platform.

[0075] That is, the method of the embodiment of the present invention mainly includes the following steps: (1) The mask is loaded onto the purge table through the carrier and the robotic arm, and the purge table fixes the mask. (2) The motor under the purge table drives the purge table and the mask to rotate at high speed. (3) After the speed of the purge table reaches a stable value, the air nozzle sprays N2 onto the mask at a certain angle, while moving from the center of the mask to the edge of the mask. (4) After the purge is completed, the mask is turned over by the robotic arm to purge the back side. (5) After both sides are purged, the mask is reloaded onto the carrier.

[0076] It is inevitable that the surface of the mask is contaminated with particles during use. The method of the embodiment of the present invention can effectively remove the contaminated particles on the surface of the mask, reducing the frequency of manual opening of the box to remove particles. The method of blowing the mask in the embodiment of the present invention has the following advantages over the existing S-shaped blowing method: (1) In the existing method, the nozzle moves while the mask is fixed, and the nozzle blows in an S shape, which has a slow blowing speed and a long time. The blowing method of the method of the embodiment of the present invention is that the mask rotates at high speed, and the nozzle moves from the center of the mask to the outside to blow, which has a short relative displacement, a short blowing time, and a higher efficiency. (2) When the existing method performs S-shaped blowing, the interval between adjacent blowing paths is longer than the blowing interval of the embodiment of the present invention, so the traditional method easily causes the center position of the adjacent blowing paths to not be well purged. In the method of the embodiment of the present invention, the middle mask rotates at high speed so that the adjacent paths are very short, and the center position can also be well purged. (3) In the method of the embodiment of the present invention, the mask rotates at high speed. If the adhesion of the particles on the surface is low and the maximum static friction is insufficient to provide the required centripetal force, the particles will be thrown out. When particles with large adhesion force rotate, part of the static friction provides centripetal force, so the particles can be removed from the surface with a small force, that is, the gas flow rate is small. In the existing method, the particles will be blown away only when the force is greater than the maximum static friction, that is, the gas flow rate is large. Therefore, compared with the existing S-shaped purge method, the method of the embodiment of the present invention improves the work efficiency and particle removal rate, while reducing the number of manual opening of the POD (box for storing mask plates), effectively reducing the risks brought by manual purge.

[0077] The present invention has been described in detail above through specific embodiments, but these do not constitute limitations of the present invention. Without departing from the principle of the present invention, those skilled in the art may also make many variations and improvements, which should also be considered as the protection scope of the present invention.

Claims

1. A mask cleaning device, characterized in that: include: Purge tables and air blowing devices; A mask placement component is provided on the first surface of the purge table, and the mask placement component is used to place and fix the mask during the cleaning process; The purge platform is also connected to the rotating device; The blowing device comprises a nozzle, the nozzle is used to spray the purge gas, and the nozzle is connected to the nozzle moving device; During the cleaning process, the rotating device drives the purge platform and the mask to rotate, and the nozzle moving device controls the movement of the nozzle and moves the purge position where the nozzle sprays the purge gas along a path from the center to the edge of the purge surface of the mask.

2. The mask cleaning device according to claim 1, characterized in that: Also includes: Carrying platform and manipulator; The carrier is used to place the mask before or after cleaning; The robot is used to move the mask between the carrying platform and the purge platform or to flip the mask.

3. The mask cleaning device according to claim 2, characterized in that: The purge platform, the air blowing device and the robot are arranged in a cleaning chamber, and the supporting platform is arranged outside the cleaning chamber.

4. The mask cleaning device according to claim 1, characterized in that: The purge gas includes nitrogen.

5. The mask cleaning device according to claim 1, characterized in that: The nozzle moving device comprises a nozzle rotating component, through which the angle of the nozzle is controlled so that the flow direction of the purge gas and the extension direction from the center to the edge of the purge surface of the mask form an obtuse angle.

6. The mask cleaning device according to claim 1, characterized in that: During the cleaning process, the purging position of the purging gas moves along a straight path from the center to the edge of the purged surface of the mask.

7. The mask cleaning device according to claim 1 or 2, characterized in that: The swept surface of the mask is the front surface of the mask or the swept surface of the mask is the back surface of the mask.

8. The mask cleaning device according to claim 1, characterized in that: The nozzle moving device includes a telescopic component, and the movement of the nozzle is controlled by the telescopic component.

9. A mask cleaning method, characterized in that: The steps include: placing and fixing the mask on a placing component disposed on the first surface of the purge table; A rotating device connected to the purge stage drives the purge stage and the mask to rotate; The nozzle sprays the purge gas to the swept surface of the mask to clean the mask, and during the cleaning process, the nozzle moving device controls the movement of the nozzle and moves the purge position where the nozzle sprays the purge gas along a path from the center to the edge of the swept surface of the mask.

10. The mask cleaning method according to claim 9, characterized in that: The mask is taken out from the carrier table by a robot and moved to be placed on the placement component of the purge table; After the cleaning of the mask is completed, the step of moving the mask from the purge platform to the carrier platform by the robot is also included; The swept surface of the mask is selected by the robot turning over the mask.

11. The mask cleaning method according to claim 10, wherein: The purge platform, the air blowing device and the robot are arranged in a cleaning chamber, and the supporting platform is arranged outside the cleaning chamber.

12. The mask cleaning method according to claim 9, wherein: The purge gas includes nitrogen.

13. The mask cleaning method according to claim 9, wherein: During the cleaning process, the nozzle moving device controls the angle of the nozzle through the nozzle rotating component and makes the flow direction of the purge gas and the extension direction from the center to the edge of the purge surface of the mask form an obtuse angle.

14. The mask cleaning method according to claim 9, wherein: During the cleaning process, the purging position of the purging gas moves along a straight path from the center to the edge of the purged surface of the mask.

15. The mask cleaning method according to claim 9 or 10, characterized in that: The swept surface of the mask is the front surface of the mask or the swept surface of the mask is the back surface of the mask.

16. The mask cleaning method according to claim 15, characterized in that: Both the front and back sides of the mask need to be cleaned. After cleaning one of the front and back sides of the mask as the purged side, the mask is turned over, and then the other of the front and back sides of the mask is cleaned as the purged side.

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