CN112346304A

CN112346304A - Light shield conveying device

Info

Publication number: CN112346304A
Application number: CN201910724773.7A
Authority: CN
Inventors: 刘波
Original assignee: Changxin Memory Technologies Inc
Current assignee: Changxin Memory Technologies Inc
Priority date: 2019-08-07
Filing date: 2019-08-07
Publication date: 2021-02-09

Abstract

The invention relates to the technical field of semiconductor manufacturing, in particular to a photomask conveying device. The reticle transport apparatus includes: the bearing part is used for bearing the photomask; and the purging part is arranged above the bearing part and is used for performing gas purging on the photomask positioned on the bearing part so as to remove particles on the surface of the photomask. The invention ensures the cleanness of the surface of the photomask, avoids the defects of the photoresist pattern on the wafer during exposure and improves the yield of products.

Description

Light shield conveying device

Technical Field

The invention relates to the technical field of semiconductor manufacturing, in particular to a photomask conveying device.

Background

Photolithography is a crucial step in the manufacturing process of semiconductor devices such as Dynamic Random Access Memories (DRAMs). In a photolithography process, the cleanliness of a photomask is an important factor for ensuring the photolithography quality. However, the existing process technology cannot effectively clean the Reticle, and particularly in the photolithography process, there is no special cleaning System in the photolithography machine to clean the Reticle surface, so that after the Reticle surface is detected by an Integrated particle Inspection System (IRIS), the Reticle must be taken out from the photolithography machine, and the Reticle is cleaned outside the photolithography machine. This way of cleaning: on one hand, the process of taking out the photomask from the machine and then feeding the photomask into the machine consumes a lot of time, and the productivity of the machine is reduced; on the other hand, it is difficult to avoid secondary pollution on the surface of the photomask in the subsequent transmission process.

Therefore, how to improve the cleanliness of the mask, improve the lithography quality of the wafer, and improve the yield of the product is a technical problem to be solved urgently at present.

Disclosure of Invention

The invention provides a photomask conveying device, which is used for solving the problem that a photomask cannot be effectively cleaned in the prior art so as to improve the photoetching quality and the product yield.

In order to solve the above problems, the present invention provides a reticle transferring apparatus comprising:

the bearing part is used for bearing the photomask;

and the purging part is arranged above the bearing part and is used for performing gas purging on the photomask positioned on the bearing part so as to remove particles on the surface of the photomask.

Preferably, the method further comprises the following steps:

the first rotating shaft is connected with the purging part;

and the first driver is connected with the first rotating shaft and used for driving the first rotating shaft to rotate within a first preset angle range so as to adjust the relative position between the purging part and the bearing part.

Preferably, the method further comprises the following steps:

the second rotating shaft is connected with the bearing part;

and the second driver is connected with the second rotating shaft and used for driving the second rotating shaft to rotate within a second preset angle range so as to transmit the photomask.

Preferably, the first rotating shaft is connected with an end of the purging part, the second rotating shaft is connected with an end of the bearing part, and the second rotating shaft is nested inside the first rotating shaft.

Preferably, the method further comprises the following steps:

and the sensor is connected with the first driver and used for detecting the driving parameter of the first driver so as to obtain the rotation angle of the purging part.

Preferably, the purge section comprises a pipe and a filter;

one end of the pipeline is connected with a gas source, and the other end of the pipeline is connected with the filter and is used for transmitting gas to the filter;

the filter is used for removing pollutants in the gas and transmitting the filtered gas to the light shield.

Preferably, the blowing part further comprises an air knife; the air inlet side of the air knife is communicated with the filter;

the air outlet side of the air knife comprises a first area, and when the purging part purges the photomask, the projection of the first area in the vertical direction at least covers the photomask;

the first area is provided with a plurality of first guide plates which incline a preset angle relative to the bearing part and is used for obliquely purging the photomask.

Preferably, the air outlet side further comprises a second area, and when the purging part purges the light shield, a projection of the second area in the vertical direction extends out of the light shield from an end part of the light shield far away from the second rotating shaft;

the second zone has a plurality of second baffles extending in a vertical direction for sweeping gas vertically downward.

Preferably, the preset angle is 45 ° or 135 °.

Preferably, the distance between the purging part and the mask carried by the carrying part is 20mm to 40mm in the vertical direction.

According to the photomask conveying device, the purging part is arranged above the bearing part for bearing the photomask, so that the photomask is subjected to gas purging in the photomask conveying process, on one hand, the surface of the photomask is ensured to be clean, the photoetching defect on a wafer is avoided, and the product yield is improved; on the other hand, the gas purging is carried out while the photomask is transmitted, so that the efficiency of cleaning the photomask is improved, and the productivity of a machine table is improved.

Drawings

FIG. 1 is a schematic diagram of the overall structure of a reticle transport apparatus according to an embodiment of the present invention;

FIG. 2A is a schematic cross-sectional view of a mask delivery apparatus in a first state in accordance with an embodiment of the present invention;

FIG. 2B is a schematic cross-sectional view of a mask transport apparatus in a second state in accordance with an embodiment of the present invention;

FIG. 3 is a schematic top view of a mask delivery apparatus according to an embodiment of the present invention;

FIG. 4 is another schematic cross-sectional view of the mask delivery apparatus in a second state in accordance with an embodiment of the present invention;

FIG. 5 is a schematic top view of the air outlet side of the air knife in accordance with the preferred embodiment of the present invention;

FIG. 6 is a schematic view of the first region on the air outlet side of the air knife in accordance with the preferred embodiment of the present invention;

FIG. 7 is a schematic view of a second region on the air outlet side of the air knife in accordance with the preferred embodiment of the present invention;

FIG. 8 is a schematic view of the range of motion of a reticle transport apparatus in a reticle transport system according to an embodiment of the present invention;

FIG. 9 is a graph comparing a reticle being transported by the reticle transport apparatus of the present invention with particulate matter on a reticle of the prior art.

Detailed Description

The following describes the mask transfer apparatus according to an embodiment of the present invention in detail with reference to the accompanying drawings.

In order to improve the cleaning effect of the mask and avoid the photolithography defect on the wafer, the present embodiment provides a mask transferring apparatus, and fig. 1 is a schematic diagram of the overall structure of the mask transferring apparatus according to the embodiment of the present invention. As shown in fig. 1, the mask transferring apparatus according to the present embodiment includes:

a carrier 11 for carrying a mask 12;

and the purging part 13 is arranged above the bearing part 11 and is used for performing gas purging on the photomask 12 on the bearing part 11 so as to remove particles on the surface of the photomask 12.

Specifically, the reticle transferring apparatus includes a base 10 and an arm body 14 connected to the base 10, and the carrier 11 is connected to an end of the arm body 14. After the mask 12 is carried by the carrying part 11, the arm body 14 performs a stretching and/or rotating motion according to a predetermined path, so as to realize the transmission of the mask 12 between different structural components. The purging part 13 is located above the carrying part 11 so as to purge the mask 12 from top to bottom.

Since the reticle 12 is transferred between the structural components by the reticle conveying device during reticle transportation, in the present embodiment, the purging portion 13 is disposed in the reticle conveying device, so that the reticle 12 on the bearing portion 11 can be purged with gas in real time by the purging portion 13, on one hand, the reticle 12 can be purged for many times during transportation of the reticle 12, thereby improving the cleaning effect of the reticle 12, and effectively reducing, even completely removing, particles on the surface of the reticle 12; on the other hand, since the purging part 13 is disposed on the reticle transferring device, the reticle 12 can be purged in real time during the transferring process, thereby effectively preventing the secondary pollution on the surface of the reticle 12. Both of the two aspects are beneficial to reducing the occurrence of photoetching defects on the wafer, improving the product yield and improving the machine productivity. In addition, the blowing part 13 is arranged above the bearing part 11 and connected with the arm body 14, so that extra space in a machine table is not occupied, and the space of the machine table is saved.

Fig. 2A is a schematic cross-sectional view of a mask conveying device in a first state according to an embodiment of the present invention, fig. 2B is a schematic cross-sectional view of a mask conveying device in a second state according to an embodiment of the present invention, and fig. 3 is a schematic top view of the mask conveying device according to an embodiment of the present invention. In order not to affect the taking and placing of the reticle with respect to the reticle transporting apparatus, it is preferable that, as shown in fig. 2A, 2B and 3, the reticle transporting apparatus further includes:

a first shaft 20 connected to the purge unit 13;

and the first driver 22 is connected to the first rotating shaft 20 and is used for driving the first rotating shaft 20 to rotate within a first preset angle range so as to adjust the relative position between the purging part 13 and the bearing part 11.

Preferably, the reticle transport apparatus further comprises:

a second rotating shaft 21 connected to the bearing part 11;

and a second driver 23 connected to the second rotating shaft 21, for driving the second rotating shaft 21 to rotate within a second predetermined angle range, so as to transmit the mask 12.

Preferably, the first rotating shaft 20 is connected to an end of the purging unit 13, the second rotating shaft 21 is connected to an end of the supporting unit 11, and the second rotating shaft 21 is nested inside the first rotating shaft 20.

Specifically, the first driver 22 and the second driver 23 may be both motors. The first shaft 20 has a first gear 201 on the top and the first driver 22 has a second gear 221 on the top. The first driver 22 drives the second gear 221 on the top portion thereof to rotate, and the second gear 221 is meshed with the first gear 201, so that the rotation of the second gear 221 drives the first gear 201 to rotate, and further drives the first rotating shaft 20 to rotate around the axis thereof within the first preset angle range. The second shaft 21 has a third gear 211 at the top thereof, and the second driver 23 has a fourth gear 231 at the top thereof. The second driver 23 drives the fourth gear 231 at the top thereof to rotate, and the fourth gear 231 is meshed with the third gear 211, so that the rotation of the fourth gear 231 drives the third gear 211 to rotate, thereby driving the second rotating shaft 21 to rotate around the axis thereof within the second preset angle range.

Specific numerical values of the first preset angle and the second preset angle may be set by a person skilled in the art according to actual needs, and the specific embodiment does not limit the specific numerical values. For example, in the process of taking and placing the mask 12 by the mask conveying device, the first driver 22 drives the first rotating shaft 20 to rotate, so that the purging portion 13 rotates to the right back of the carrying portion 11 (i.e. the included angle between the purging portion 13 and the carrying portion 11 is 180 °), as shown in fig. 2A, so that the carrying portion 11 can freely take and place the mask 12, and the mask 12 is prevented from colliding with the purging portion 13. After the mask 12 is transferred to the carrying part 11, the first driver 22 drives the first rotating shaft 20 to rotate again, so that the purging part 13 rotates to a position right above the carrying part 11 (i.e. an included angle between the purging part 13 and the carrying part 11 is 0 °), as shown in fig. 2B, so that the purging part 13 performs gas purging on the mask 12 on the carrying part 11.

In order to further ensure the safety of the reticle transporting device in the process of taking and placing the reticle 12, preferably, the reticle transporting device further comprises:

and the sensor is connected with the first driver 22 and used for detecting the driving parameter of the first driver 22 so as to obtain the rotation angle of the purging part 13.

For example, the first driver 22 is a motor and the Sensor is an Encoder Sensor (Encoder Sensor). The sensor detects a drive parameter (for example, a degree of motor operation) of the first actuator 22, and thereby indirectly determines the rotation angle of the purge portion 13.

FIG. 8 is a schematic view of the movement range of the reticle transport apparatus during reticle transport according to the embodiment of the present invention. Specifically, in the photolithography tool, a coordinate system as shown in fig. 8 is established with a central position of a movement range of the mask conveying device in the mask conveying process as an origin, the movement range of the mask conveying device includes a conveying area 81 and a pick-and-place area 82, and the pick-and-place area 82 is disposed around the periphery of the conveying area 81. In the positive direction along the X axis, the turntable is located outside said pick-and-place area 82; on opposite sides of the pick-and-place area 82 in the direction along the Y-axis are an integrated mask inspection system and a load port, respectively. The carrier 11 of the reticle transporting apparatus carries out the taking and placing of the reticle 12 in the taking and placing area 82, for example, the reticle 12 is taken out from the load port or the reticle 12 is placed on the turntable; the carrier 11 of the mask transfer device transfers and purges the mask 12 in the transfer area 81.

When the carrying part 11 is located in the conveying area 81, the purging part 13 rotates to a position right above the carrying part 11 to purge the mask 12; when the carrying part 11 is located in the pick-and-place area 82, the purging part 13 rotates to a position right behind the carrying part 11, so as to facilitate the pick-and-place of the mask 12. The sensor detects the driving parameter of the first driver 22 in real time to obtain the rotation angle of the purge part 13. When the carrying part 11 is located at the edge of the pick-and-place area 82 adjacent to the conveying area 81, if the detection result of the sensor still indicates that the purging part 13 does not rotate to the right back of the carrying part 11, the mask conveying device stops moving and gives an alarm to avoid damage to the mask to be picked and placed.

FIG. 4 is another schematic cross-sectional view of the mask delivery apparatus in a second state in accordance with an embodiment of the present invention. Preferably, as shown in fig. 4, the purge part 13 includes a pipe 40 and a filter 41;

one end of the pipeline 41 is connected with a gas source, and the other end of the pipeline 41 is connected with the filter 41 and is used for transmitting gas to the filter 41;

the filter 41 is used to remove contaminants from the gas and deliver the filtered gas to the reticle 12.

In particular, one end of the duct 41 communicates with a source of gas for providing a purge gas, which is conveyed to the filter 41 in the direction of the arrows in fig. 4. The filter 41 is used to remove contaminants such as particles from the gas, thereby avoiding secondary contamination of the reticle 12. The gas used for purging in this embodiment may be Clean Dry Air (CDA), nitrogen gas, or an inert gas such as argon gas.

Fig. 5 is a schematic top view of the air outlet side of the wind knife in the embodiment of the present invention, fig. 6 is a schematic structural view of the first region of the air outlet side of the wind knife in the embodiment of the present invention, and fig. 7 is a schematic structural view of the second region of the air outlet side of the wind knife in the embodiment of the present invention. Preferably, the blowing part 13 further comprises an air knife 42; the air inlet side of the air knife 42 is communicated with the filter 41;

the air outlet side of the air knife 42 comprises a first area a, and when the purging part 13 purges the photomask 12, the projection of the first area a in the vertical direction at least covers the photomask 12;

the first area a has a plurality of first flow deflectors 61 inclined by a predetermined angle with respect to the carrier 11, for performing inclined purge on the mask 12.

Preferably, the air outlet side further includes a second area B, and when the purging portion 13 purges the light shield 12, a projection of the second area B in the vertical direction extends out of the light shield 12 from an end of the light shield 12 far away from the second rotating shaft 21;

the second zone B has a plurality of second baffles 71 extending in a vertical direction for sweeping the gas vertically downward.

Specifically, the gas is sequentially transmitted to the surface of the mask 12 through the pipe 40, the filter, and the air knife 42 to perform gas purging on the mask 12. The first region a has a plurality of first baffles 61 as shown in fig. 6, and the direction of the arrows in fig. 6 indicate the flow direction of the gas. The end 60 of the first deflector 61 is inclined by the predetermined angle γ with respect to the carrier 11, so that the gas ejected from the first area a obliquely blows the surface of the reticle 12 to blow the particles on the surface of the reticle 12 away from the surface of the reticle 12. The second area B has a plurality of second flow deflectors 71 as shown in fig. 7, so that the gas ejected from the second area B flows vertically downward, and particles blown off from the surface of the optical cover 12 are prevented from splashing around. Wherein, the gap between two adjacent second deflectors 71 in the second area B (i.e. the aperture of the blowing holes in the second area B) may be 3 mm. Preferably, an exhaust port is disposed below the carrier part 11 to exhaust the purged gas. The vertical downward gas ejected from the second region B is beneficial to discharging the particles blown off from the surface of the light shield 12.

Preferably, the preset angle γ is 45 ° or 135 °.

For example, the end 60 of the first baffle 61 is inclined by the predetermined angle γ of 135 ° with respect to the bearing part 11, the first area a blows the particles on the surface of the reticle 12 away from the second rotating shaft 21, and the second area B blows the particles blown off from the surface of the reticle 12 downward, so that the reticle 12 is cleaned and the secondary pollution of the particles is avoided.

Preferably, the distance H between the purge portion 13 and the mask 12 supported by the support portion 11 in the vertical direction is 20mm to 40 mm.

Specifically, the distance H between the air outlet side of the air knife 41 and the light shield 12 in the vertical direction is 20mm to 40 mm. In order to further improve the purging effect, it is more preferable that the distance H between the air outlet side of the air knife 41 and the mask 12 is 30 mm.

In the photomask conveying device provided by the embodiment of the invention, the purging part is arranged above the bearing part for bearing the photomask, so that the photomask is purged by gas in the process of conveying the photomask by the photomask conveying device, on one hand, the cleanness of the surface of the photomask is ensured, the photoetching defect on the surface of a wafer is avoided, and the product yield is improved; on the other hand, the gas purging is carried out while the photomask is transmitted, so that the efficiency of cleaning the photomask is improved, and the productivity of a machine table is improved.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A reticle transport apparatus comprising:

the bearing part is used for bearing the photomask;

2. The reticle transport apparatus of claim 1, further comprising:

the first rotating shaft is connected with the purging part;

3. The reticle transport apparatus of claim 2, further comprising:

the second rotating shaft is connected with the bearing part;

4. The reticle transport apparatus of claim 3, wherein the first shaft connects an end of the purge section, the second shaft connects an end of the carrier section, and the second shaft nests inside the first shaft.

5. The reticle transport apparatus of claim 2, further comprising:

6. The reticle transport of claim 3, wherein the purge comprises a conduit and a filter;

7. The reticle transport of claim 6, wherein the purge portion further comprises a wind knife; the air inlet side of the air knife is communicated with the filter;

8. The reticle transport device of claim 7, wherein the air outlet side further comprises a second region, and when the purging portion purges the reticle, a projection of the second region in a vertical direction extends out of the reticle from an end of the reticle away from the second rotation axis;

9. The reticle transport of claim 7, wherein the predetermined angle is 45 ° or 135 °.

10. The reticle transport apparatus of claim 1, wherein a distance between the purge portion and the reticle carried by the carrier portion in a vertical direction is 20mm to 40 mm.