Wafer transfer device

Abstract

Provided is a wafer transfer device comprising a wafer transfer chamber, a blower, and a blowing path arranged between the wafer transfer chamber and the blower, wherein: a semi-shielding member having a plurality of openings is installed on a gas outflow unit provided to the wafer transfer chamber side of the blowing path; the area of the semi-shielding member is larger than the area of a gas inflow unit provided on the blower side of the blowing path; a diffuser that expands from the gas inflow unit toward the gas outflow unit is formed between the gas inflow unit and the gas outflow unit; and at least a portion of the vertical cross-section of a wall surface of the diffuser has a flat plate shape or a convex shape that protrudes toward the central part of the blowing path. As a result, it is possible to suppress a decrease in the flow velocity of downflow in a region near a side wall surface of the wafer transfer chamber and make the flow velocity distribution of the downflow uniform.

Description

Wafer Transfer Device

[0001] The present disclosure relates to a wafer transport apparatus.

[0002] The wafer transfer device has a wafer transfer chamber and transfers wafers stored in a wafer storage pod (FOUP: Front Opening Unified Pod) to a processing chamber. A fan filter unit (FFU: Fan Filter Unit) is installed upstream of the wafer transfer chamber. The fan generates an airflow toward the wafer transfer chamber.

[0003] Patent Document 1 discloses a mini-environment device having a wafer transfer chamber equipped with a wafer transfer machine and through which wafers transferred to a processing chamber pass, a circulation flow path through which gas within the wafer transfer chamber flows, bypassing the wafer transfer chamber, a blower that creates a circulating airflow that descends within the wafer transfer chamber and ascends through the circulation flow path, a straightening member that is provided in the ceiling of the wafer transfer chamber and laminarizes the circulating airflow to flow into the wafer transfer chamber, a particle removal filter that is provided in the ceiling of the wafer transfer chamber or in the circulation flow path, and a chemical filter that is detachably provided in the circulation flow path separately from the particle removal filter, the chemical filter being provided at a height lower than the lowest position in the wafer transfer chamber through which wafers can pass.

[0004] Japanese Patent Application Laid-Open No. 2017-112137

[0005] Although the amount is small, foreign matter floats inside the wafer transfer chamber. If this foreign matter adheres to the wafer, it can cause problems when the wafer processing equipment inspects the wafer. For this reason, a downflow that flows from the top to the bottom of the wafer transfer chamber is supplied inside the wafer transfer chamber. This downflow is fast in the center of the wafer transfer chamber and slow in the area near the side wall of the wafer transfer chamber. When wafers are transferred to an area where the downflow is slow, foreign matter is likely to adhere to the wafer.

[0006] An object of the present disclosure is to suppress a decrease in the flow velocity of the downflow in the region near the sidewall surface of the wafer transfer chamber and to make the flow velocity distribution of the downflow uniform.

[0007] The wafer transport device of the present disclosure comprises a wafer transport chamber, a blower, and an air flow path installed between the wafer transport chamber and the blower, and a semi-shielding member having multiple openings is installed in the gas outlet section provided on the wafer transport chamber side of the air flow path, the area of ​​the semi-shielding member being larger than the area of ​​the gas inlet section provided on the blower side of the air flow path, and a diffuser expanding from the gas inlet section toward the gas outlet section is formed between the gas inlet section and the gas outlet section, and the vertical cross section of at least a portion of the wall surface of the diffuser is flat or convex toward the center of the air flow path.

[0008] According to the present disclosure, it is possible to suppress a decrease in the flow velocity of the downflow in the region near the sidewall surface of the wafer transfer chamber, and to make the flow velocity distribution of the downflow uniform.

[0009] FIG. 1 is a longitudinal sectional view showing a wafer transport apparatus of Example 1. FIG. 2 is a longitudinal sectional view showing a wafer transport apparatus of Modified Example 1. FIG. 3 is a longitudinal sectional view showing a wafer transport apparatus of Example 2. FIG. 4 is a longitudinal sectional view showing a wafer transport apparatus of Modified Example 2. FIG. 5 is a longitudinal sectional view showing a wafer transport apparatus of Example 3. FIG. 6 is a longitudinal sectional view showing a wafer transport apparatus of Modified Example 3. FIG. 7 is a longitudinal sectional view showing a wafer transport apparatus of Example 4. FIG. 8 is a longitudinal sectional view showing a wafer transport apparatus of Example 5. FIG. 9 is a longitudinal sectional view showing a wafer transport apparatus of Example 6.

[0010] Hereinafter, examples of the present disclosure will be described with reference to the drawings.

[0011] FIG. 1 is a vertical cross-sectional view showing a wafer transfer device according to a first embodiment.

[0012] The wafer transfer device shown in this figure comprises a wafer transfer chamber 1 and a blower 3 (FFU). A robot 2 is installed in the wafer transfer chamber 1, which removes wafers stored in a wafer storage pod (FOUP) and transfers them to a processing chamber where the wafers are processed. This robot 2 also removes wafers that have been processed in the processing chamber from the processing chamber and returns them to the FOUP. The blower 3 is installed at the top of the wafer transfer chamber 1. The blower 3 draws in gas from the outside and sends it into the wafer transfer chamber 1. The blower 3 is housed in the FFU room 4.

[0013] Typically, the wafer transfer chamber 1 has a roughly rectangular parallelepiped shape. Therefore, the cross section of the wafer transfer chamber 1 is roughly rectangular. The long side of this roughly rectangular cross section may be more than twice as long as the short side of the cross section. In some cases, two or more blowers 3 are installed in a row in the long side direction above the wafer transfer chamber 1 having such a shape. This figure shows a cross section parallel to the short side.

[0014] An air flow path 5 is provided between the wafer transfer chamber 1 and the blower 3. The air flow path 5 protrudes into the wafer transfer chamber 1 from the outlet 31 of the blower 3. A semi-shielding member 6 composed of a punched metal plate or a plate-like member with multiple openings arranged in a lattice pattern is installed at the outlet (gas outlet portion) of the air flow path 5. As described above, since the wafer transfer chamber 1 has a substantially rectangular parallelepiped shape, the air flow path 5 also has a substantially rectangular parallelepiped shape. The semi-shielding member 6 also has a substantially rectangular shape. By installing the semi-shielding member 6, the pressure distribution within the air flow path 5 can be made uniform. As a result, the flow velocity of the downflow 7, which is the airflow flowing out from the semi-shielding member 6, becomes substantially uniform within the wafer transfer chamber 1.

[0015] In this figure, the area of ​​the semi-shielding member 6, which is the gas outflow portion from the air blowing path 5 to the wafer transfer chamber 1, is larger than the area of ​​the outlet 31 of the blower 3, i.e., the gas inflow portion from the blower 3 to the air blowing path 5. To accommodate this flow path configuration, a tapered wall 8 is installed between the outlet 31 of the blower 3 and the semi-shielding member 6 so that the flow path expands from the outlet 31 of the blower 3 toward the semi-shielding member 6. The tapered wall 8 has a long, thin, flat plate shape and is installed parallel to the long side direction of the cross section of the wafer transfer chamber 1.

[0016] Here, the area of ​​the semi-shielding member 6 is not the total area of ​​the openings of the semi-shielding member 6, but an area calculated from the dimensions of the upper or lower surface of the semi-shielding member 6. Therefore, the value of the area of ​​the semi-shielding member 6 is the sum of the area of ​​the semi-shielding member 6 itself and the total area of ​​its openings.

[0017] Furthermore, the area of ​​the gas inlet portion from the blower 3 to the air duct 5 is the sum of the total area of ​​the openings and the area of ​​the rectifier itself, even if a filter, a punched metal plate, or other such rectifier is installed on the surface of the gas inlet portion. In other words, the area of ​​the gas inlet portion from the blower 3 to the air duct 5 is the area calculated from the overall dimensions of the part where the gas inlet portion intersects with the airflow.

[0018] In summary, a semi-shielding member 6 having multiple openings is installed in the gas outlet section provided on the wafer transport chamber 1 side of the air flow path 5, and the area of ​​the semi-shielding member 6 is larger than the area of ​​the gas inlet section provided on the blower 3 side of the air flow path 5.

[0019] With the above-described configuration, a tapered flow path is formed in the air flow path 5, and it is possible to prevent the air flowing into the air flow path 5 from the outlet 31 of the blower 3 from flowing back in the region near the side wall surface (the long side in cross section) of the air flow path 5. Furthermore, since the structure of the air flow path 5 is a diffuser flow path structure in which the flow path cross-sectional area expands toward the downstream side, uniformity of the pressure distribution in the air flow path 5 is promoted, and the flow velocity of the airflow formed in the air flow path 5 is also uniform. Therefore, the flow velocity of the airflow flowing out from the semi-shielding member 6 is also approximately equal between the center and the region near the side wall surface, and the flow velocity of the downflow 7 in the wafer transfer chamber 1 is uniform.

[0020] In this way, by forming a diffuser flow path structure with tapered walls 8 in the air supply path 5, the flow rate of the downflow 7 within the wafer transfer chamber 1 can be made uniform, and foreign matter can be prevented from adhering to the wafer no matter where the wafer is transferred within the wafer transfer chamber 1.

[0021] In contrast, if the tapered wall 8 is not provided, turbulence may occur in the airflow flowing from the outlet of the blower 3 into the air passage 5 in the vicinity of the side wall surface of the air passage 5, causing local backflow and a drop in pressure. In this case, even within the wafer transfer chamber 1, the speed of the downflow 7 is fast in the center and slower in the vicinity of the side wall surface.

[0022] (Modification 1) FIG. 2 is a vertical cross-sectional view showing a wafer transfer device according to modification 1. As shown in FIG.

[0023] In this figure, a triangular prism-shaped tapered wall 9 is provided instead of the flat plate-shaped tapered wall 8 in Figure 1. The other configurations in Figure 2 are the same as those in Figure 1.

[0024] With this configuration, the same diffuser flow path structure as that in FIG. 1 is formed in FIG.

[0025] Therefore, the same effects as those of the first embodiment can be obtained in the first modification.

[0026] FIG. 3 is a vertical cross-sectional view showing a wafer transfer device according to a second embodiment.

[0027] The basic configuration of this embodiment is the same as that of the first embodiment, so only the configuration that differs from the first embodiment will be described.

[0028] In the wafer transport device shown in this figure, a curved, plate-like tapered wall 10 is installed instead of the flat, plate-like tapered wall 8 in Figure 1. The tapered wall 10 has a convex shape that protrudes toward the center of the air passage 5.

[0029] Here, the term "convex shape" refers to a curved shape or a polygonal shape with an interior angle of less than 180 degrees. This convex shape may have recesses such as dimples or recesses formed during the manufacturing process, as long as it is macroscopically convex as a whole. The interior angle is preferably 120 degrees or more. This is because if the interior angle is less than 120 degrees, turbulence is likely to occur downstream. Furthermore, the interior angle is more preferably 150 degrees or more. This is because the polygonal shape approaches a curved shape, further stabilizing the airflow.

[0030] With this configuration, a diffuser flow path structure similar to that of FIG. 1 is formed in FIG. 3 as well, and it is possible to prevent backflow in the area near the side wall surface in the air passage 5.

[0031] (Modification 2) FIG. 4 is a vertical cross-sectional view showing a wafer transfer device according to modification 2. In FIG.

[0032] In this figure, instead of the curved tapered wall 10 in Figure 3, a columnar tapered wall 11 having a curved surface that protrudes toward the center of the air passage 5 is installed. The other configurations in Figure 4 are the same as those in Figure 3.

[0033] With this configuration, the same diffuser flow path structure as that in FIG. 3 is formed in FIG.

[0034] Therefore, the same effects as those of the second embodiment can be obtained in the second modification.

[0035] FIG. 5 is a vertical cross-sectional view showing a wafer transfer device according to a third embodiment.

[0036] The basic configuration of this embodiment is the same as that of the first embodiment, so only the configuration that differs from the first embodiment will be described.

[0037] In the wafer transfer device shown in this figure, the tapered wall 8 is installed only on the right side of the figure. The tapered wall 8 is a long, thin, flat plate. Since no tapered wall is installed on the left side of the figure, the cross section has a rectangular flow path shape and is recessed. Therefore, a backflow occurs in the area near the side wall surface on the left side of the figure of the air flow path 5. Therefore, the flow velocity of the downflow 7 flowing from the air flow path 5 through the semi-shielding member 6 into the wafer transfer chamber 1 tends to be slower in the left part of the figure.

[0038] However, depending on the internal structure of the wafer transfer chamber 1, the downflow 7 may be more likely to flow in the region on the left side of the wafer transfer chamber 1 in the drawing. In this case, it may not be necessary to improve the flow path structure of the air flow path 5 to prevent backflow.

[0039] In this way, the shape of the side area of ​​the airflow path 5 is improved in accordance with the internal structure of the wafer transfer chamber 1.

[0040] In FIG. 5, the tapered wall 8 is installed on the right side of the figure, but if the structure inside the wafer transfer chamber 1 is such that the airflow flows easily on the right side of the figure and difficult on the left side of the figure, the tapered wall 8 is installed on the left side of the air flow path 5 in the figure.

[0041] (Modification 3) FIG. 6 is a vertical cross-sectional view showing a wafer transfer device according to modification 3. In FIG.

[0042] In this figure, a plate-shaped tapered wall 10 having a curved surface that is convex toward the center of the air passage 5 is installed instead of the flat tapered wall 8 in Figure 5. The other configurations in Figure 6 are the same as those in Figure 5.

[0043] With this configuration, the same diffuser flow path structure as that in FIG. 5 is formed in FIG.

[0044] Therefore, the same effects as those of the third embodiment can be obtained in the third modification.

[0045] Whether the tapered wall 10 is disposed on the right side or the left side in the drawing may be determined based on the ease of airflow, as in the third embodiment.

[0046] FIG. 7 is a vertical cross-sectional view showing a wafer transfer device according to a fourth embodiment.

[0047] The basic configuration of this embodiment is the same as that of the first embodiment, so only the configuration that differs from the first embodiment will be described.

[0048] In the wafer transfer device shown in this figure, a flat tapered wall 8 is installed on the right side of the figure, and a plate-like tapered wall 10 having a convex curved surface is installed on the left side of the figure.

[0049] This figure shows a case where the inside of the wafer transfer chamber 1 has a flow path structure in which the airflow is easy to flow on the right side of the figure and difficult to flow on the left side of the figure. For this reason, as described above, tapered walls with different backflow prevention effects are selected. In this way, by selecting the tapered wall based on the ease of airflow, the flow velocity of the downflow 7 can be made uniform.

[0050] When the ease of airflow inside the wafer transfer chamber 1 is reversed, it is desirable to reverse the positions of the tapered wall 8 and the tapered wall 10 .

[0051] FIG. 8 is a vertical cross-sectional view showing a wafer transfer device according to a fifth embodiment.

[0052] The basic configuration of this embodiment is the same as that of the first embodiment, so only the configuration that differs from the first embodiment will be described.

[0053] In the wafer transfer device shown in this figure, a flat tapered wall 12 is installed between the semi-shielding member 6 at the outlet of the air flow path 5 and the side wall surface of the wafer transfer chamber 1. This allows the airflow flowing out from the semi-shielding member 6 to gradually expand inside the wafer transfer chamber 1, preventing it from flowing back in the area near the side wall surface (long side in cross section) of the wafer transfer chamber 1. Therefore, it is possible to prevent the downflow 7 from slowing down in the area near the side wall surface of the wafer transfer chamber 1.

[0054] In this embodiment, a flat tapered wall 8 is installed inside the air passage 5, but the tapered wall inside the air passage 5 is not limited to this, and any of the tapered walls shown in Examples 1 to 4 may be applied.

[0055] FIG. 9 is a vertical cross-sectional view showing a wafer transfer device according to a sixth embodiment.

[0056] The basic configuration of this embodiment is the same as that of the fifth embodiment, so only the configuration that differs from the fifth embodiment will be described.

[0057] In this figure, a curved plate-shaped tapered wall 13 is installed instead of the flat plate-shaped tapered wall 12. The tapered wall 13 is formed to be convex toward the center of the air flow path 5. This provides the same effect as in Example 5.

[0058] In this embodiment, as in the fifth embodiment, any of the tapered walls shown in the first to fourth embodiments may be used as the tapered wall inside the air passage 5 .

[0059] The configurations and effects of the above-described embodiment and modified examples will be described below.

[0060] In the air flow path, a diffuser is formed between the gas inlet and outlet ports, expanding from the gas inlet port toward the gas outlet port, and at least a portion of the wall surface of the diffuser has a vertical cross section that is flat or convex toward the center of the air flow path 5. This configuration makes it possible to prevent turbulence, backflow, etc. from occurring in the air flow path, and to make the flow velocity distribution of the downflow within the wafer transfer chamber uniform.

[0061] The wall surface constituting the longitudinal cross section of the diffuser is composed of two surfaces, one of which may be flat and the other of which may be convex.

[0062] The air flow path may be configured to protrude from the outlet of the blower into the interior of the wafer transfer chamber. In this case, the cross-sectional area of ​​the flow path in the wafer transfer chamber may be larger than the area of ​​the semi-shielding member. In this case, it is desirable that another diffuser be formed between the semi-shielding member and the inner wall surface of the wafer transfer chamber, expanding from the semi-shielding member toward the inner wall surface of the wafer transfer chamber. It is desirable that at least a portion of the vertical cross section of the wall surface of the another diffuser be flat or convex toward the center of the wafer transfer chamber. This configuration can prevent turbulence, backflow, etc. from occurring in the wafer transfer chamber and can uniform the flow velocity distribution of the downflow in the wafer transfer chamber.

[0063] 1: wafer transfer chamber, 2: robot, 3: blower, 4: FFU chamber, 5: air passage, 6: semi-shielding member, 7: downflow, 8, 9, 10, 11, 12, 13: tapered wall, 31: outlet.

Claims

1. A wafer transport device comprising: a wafer transport chamber; a blower; and an air flow path installed between the wafer transport chamber and the blower, wherein a semi-shielding member having a plurality of openings is installed at a gas outlet portion installed on the wafer transport chamber side of the air flow path, the area of ​​the semi-shielding member being larger than the area of ​​a gas inlet portion installed on the blower side of the air flow path, a diffuser expanding from the gas inlet portion toward the gas outlet portion is formed between the gas inlet portion and the gas outlet portion, and the vertical cross section of at least a part of the wall surface of the diffuser is flat or convex toward the center of the air flow path.

2. The wafer transport device according to claim 1, wherein the semi-shielding member is a perforated metal plate or a plate-like member in which the openings are arranged in a lattice pattern.

3. The wafer transport device according to claim 1, wherein the convex shape is a curved shape or a polygonal shape with an interior angle of less than 180 degrees.

4. A wafer transport device according to claim 1, wherein the wall surface constituting the longitudinal cross section of the diffuser is composed of two surfaces, one of the two surfaces being flat, and the other of the two surfaces being convex.

5. A wafer transport device as claimed in claim 1, wherein the air flow path is configured to protrude from the outlet of the blower into the interior of the wafer transport chamber, the cross-sectional area of ​​the flow path within the wafer transport chamber is larger than the area of ​​the semi-shielding member, another diffuser is formed between the semi-shielding member and the inner wall surface of the wafer transport chamber, expanding from the semi-shielding member towards the inner wall surface of the wafer transport chamber, and the vertical cross section of at least a part of the wall surface of the other diffuser is flat or convex towards the center of the wafer transport chamber.

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