Substrate processing apparatus

Abstract

To provide a substrate processing apparatus capable of suppressing damage to a pattern on the surface of a substrate even when vibrations are transmitted to a liquid on the surface side of the substrate during a process of thawing a frozen film.SOLUTION: A substrate processing apparatus according to an embodiment forms a frozen film on a surface of a substrate, captures foreign matter adhering to the surface of the substrate in the frozen film, and thaws the frozen film containing a foreign matter to remove the foreign matter from the surface of the substrate. The apparatus includes a liquid supply unit which supplies liquid to the frozen film containing the foreign matter, a vibration unit which faces the frozen film, and a controller which controls the vibration unit. The controller controls the vibration unit to transmit vibration to a liquid film containing the liquid supplied to the frozen film and liquid generated by thawing the frozen film, and reduces the energy of the vibration transmitted to the liquid film or stops the vibration depending on the position of the upper surface of the frozen film below the liquid film.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to a substrate processing apparatus. [Background technology]

[0002] Freeze cleaning has been proposed as a method for removing foreign matter such as particles adhering to the surfaces of substrates such as imprint templates, photolithography masks, and semiconductor wafers.

[0003] In freeze cleaning, pure water is generally used as the liquid used for cleaning. For example, in freeze cleaning, first, pure water and cooling gas are supplied to the surface of a rotating substrate. Next, the supply of pure water is stopped, and a part of the supplied pure water is discharged to form a water film on the surface of the substrate. The water film is frozen by the supplied cooling gas. When the water film freezes to form a frozen film, foreign matter such as particles is captured by the frozen film, and the foreign matter is separated from the surface of the substrate. Next, a process of thawing the frozen film is performed. In the thawing process, pure water is supplied to the frozen film to thaw it, and the foreign matter is discharged outside the substrate together with the pure water by centrifugal force.

[0004] By carrying out the freeze cleaning method described above, the removal rate of foreign matter can be increased. However, in recent years, there has been a demand for a further improvement in the removal rate of foreign matter. In this case, if vibrations are transmitted to the liquid on the surface side of the substrate in the process of thawing the frozen film, it is possible to prevent the foreign matter separated from the surface of the substrate from reattaching to the surface of the substrate. This makes it possible to further improve the removal rate of foreign matter. However, since a fine pattern is formed on the surface of the substrate, there is a risk that the pattern may be damaged if vibrations are simply transmitted to the liquid. Therefore, there was a need for the development of a substrate processing apparatus that could suppress damage to the pattern on the surface of the substrate even if vibrations were transmitted to the liquid on the surface side of the substrate during the process of thawing the frozen film. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-026436 A Summary of the Invention [Problem to be solved by the invention]

[0006] The problem that the present invention aims to solve is to provide a substrate processing apparatus that can suppress damage to a pattern on the surface of a substrate even if vibrations are transmitted to the liquid on the surface side of the substrate during the process of thawing a frozen film. [Means for solving the problem]

[0007] A substrate processing apparatus according to an embodiment is a substrate processing apparatus that forms a frozen film on a surface of a substrate, incorporates foreign matter adhering to the surface of the substrate into the frozen film, and thaws the frozen film containing the foreign matter to remove the foreign matter from the surface of the substrate. The substrate processing apparatus includes a liquid supply unit that supplies liquid to the frozen film containing the foreign matter, a vibration unit that faces the frozen film, and a controller that controls the vibration unit. The controller controls the vibration unit to transmit vibration to a liquid film containing the liquid supplied to the frozen film and liquid generated by thawing the frozen film, and reduces the energy of the vibration transmitted to the liquid film or stops the vibration depending on the position of the upper surface of the frozen film below the liquid film. Effect of the Invention

[0008] According to an embodiment of the present invention, a substrate processing apparatus is provided that can suppress damage to a pattern on the surface of a substrate even if vibrations are transmitted to a liquid on the surface side of the substrate during a process of thawing a frozen film. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram illustrating a substrate processing apparatus according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a schematic perspective view of a vibrating body. [Diagram 3] 1A to 1C are schematic diagrams illustrating the functions and effects of grooves. [Figure 4] FIG. 11 is a schematic perspective view of a vibrating body according to another embodiment. [Diagram 5] 5A to 5C are schematic diagrams illustrating the action and effect of the vibrating body. [Figure 6] 13 is a schematic perspective view illustrating a vibrating body according to another embodiment. FIG. [Figure 7] 4 is a timing chart illustrating the operation of the substrate processing apparatus. [Figure 8] 11 is a graph illustrating the change in temperature of liquid supplied to the surface of a substrate. [Figure 9] 1(a) to 1(c) are schematic cross-sectional views illustrating the thawing process. [Figure 10] 11(a) to 11(c) are schematic cross-sectional views illustrating the positions of the upper surface of the frozen film when the vibration energy is switched or the vibration is stopped. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted as appropriate.

[0011] The substrate 100 exemplified below may be, for example, a semiconductor wafer, an imprint template, a photolithography mask, or a plate-like body used in MEMS (Micro Electro Mechanical Systems). The substrate 100 is not limited to the exemplified ones. The substrate 100 may have a pattern (for example, a fine uneven portion) formed on the surface 100b.

[0012] FIG. 1 is a schematic view illustrating a substrate processing apparatus 1 according to the present embodiment. As shown in FIG. 1, the substrate processing apparatus 1 includes, for example, a mounting section 2, a cooling section 3, a first liquid supply section 4, a second liquid supply section 5, a chamber 6, an exhaust section 7, a blower section 8, a vibration section 9, a detection section 10, and a controller 11.

[0013] The mounting unit 2 rotates the mounted substrate 100. The mounting unit 2 has, for example, a mounting table 2a, a rotation shaft 2b, and a drive unit 2c. The mounting table 2a is rotatably provided inside the chamber 6. The mounting table 2a has a plate shape. One main surface of the mounting table 2a is provided with a plurality of supports 2a1 for supporting the substrate 100. When the substrate 100 is supported by the supports 2a1, the surface 100b (the surface to be cleaned) of the substrate 100 faces away from the mounting table 2a. Furthermore, a hole 2aa is provided in the center of the mounting table 2a, penetrating the mounting table 2a in the thickness direction.

[0014] One end of the rotating shaft 2b is provided on the inner wall of the hole 2aa of the mounting table 2a. The other end of the rotating shaft 2b is provided outside the chamber 6. The rotating shaft 2b is connected to a driving unit 2c outside the chamber 6.

[0015] The rotating shaft 2b is cylindrical. An air outlet 2b1 is provided at the end of the rotating shaft 2b on the side of the mounting table 2a. The air outlet 2b1 opens to the surface of the mounting table 2a on which the multiple support parts 2a1 are provided. The end of the opening side of the air outlet 2b1 is connected to the inner wall of the hole 2aa. The opening of the air outlet 2b1 faces the back surface 100a of the substrate 100 placed on the mounting table 2a. In a direction perpendicular to the central axis of the rotating shaft 2b, the cross-sectional area of ​​the air outlet 2b1 increases toward the mounting table 2a side (opening side).

[0016] By providing blowing portion 2b1, it is possible to supply released cooling gas 3a1 to a wider area of ​​rear surface 100a of substrate 100. In addition, it is possible to reduce the release speed of cooling gas 3a1. This makes it possible to prevent partial cooling of substrate 100 and an excessively fast cooling speed of substrate 100 that makes it difficult to cause a supercooled state of liquid 101, which will be described later.

[0017] A cooling nozzle 3d is attached to the end of the rotating shaft 2b opposite to the mounting table 2a side. A rotating shaft seal (not shown) is provided between the end of the rotating shaft 2b opposite to the mounting table 2a side and the cooling nozzle 3d. Therefore, the end of the rotating shaft 2b opposite to the mounting table 2a side is sealed so as to be airtight.

[0018] The driving unit 2c is provided outside the chamber 6. The driving unit 2c is connected to the rotation shaft 2b. The rotation force of the driving unit 2c is transmitted to the mounting table 2a via the rotation shaft 2b. Therefore, the driving unit 2c can rotate the mounting table 2a, and further the substrate 100 mounted on the mounting table 2a.

[0019] Furthermore, the driving unit 2c can change not only the start and stop of rotation but also the number of rotations (rotation speed). The driving unit 2c can be equipped with a control motor such as a servo motor, for example.

[0020] The cooling unit 3 supplies a cooling gas 3a1 that cools the liquid 101 on the front surface 100b of the substrate 100. The cooling unit 3 supplies the cooling gas 3a1 to a space between the mounting table 2a and the rear surface 100a of the substrate 100. The cooling unit 3 has, for example, a cooling liquid unit 3a, a filter 3b, a flow rate control unit 3c, and a cooling nozzle 3d. The cooling liquid unit 3a, the filter 3b, and the flow rate control unit 3c are provided outside the chamber 6.

[0021] The cooling liquid section 3a stores the cooling liquid and generates the cooling gas 3a1. The cooling liquid is a liquefied cooling gas 3a1. There are no particular limitations on the cooling gas 3a1 as long as it is a gas that does not easily react with the material of the substrate 100. The cooling gas 3a1 can be, for example, an inert gas such as nitrogen gas, helium gas, or argon gas.

[0022] The cooling liquid section 3a has a tank for storing the cooling liquid and an evaporation section for evaporating the cooling liquid stored in the tank. The tank is provided with a cooling device for maintaining the temperature of the cooling liquid. The evaporation section increases the temperature of the cooling liquid to generate cooling gas 3a1 from the cooling liquid. The evaporation section may, for example, utilize the outside air temperature or perform heating by a heat medium. The temperature of the cooling gas 3a1 may be any temperature below the freezing point of the liquid 101, and may be, for example, −170° C.

[0023] The cooling gas 3a1 can also be generated by cooling an inert gas such as nitrogen gas using a chiller, etc. In this way, the cooling liquid section can be simplified.

[0024] The filter 3b is connected to the cooling liquid section 3a via a pipe. The filter 3b prevents foreign matter such as particles contained in the cooling liquid from flowing out to the substrate 100 side.

[0025] The flow rate control unit 3c is connected to the filter 3b via a pipe. The flow rate control unit 3c controls the flow rate of the cooling gas 3a1. The flow rate control unit 3c may be, for example, a mass flow controller (MFC). The flow rate control unit 3c may indirectly control the flow rate of the cooling gas 3a1 by controlling the supply pressure of the cooling gas 3a1. In this case, the flow rate control unit 3c may be, for example, an auto pressure controller (APC).

[0026] The temperature of the cooling gas 3a1 generated from the cooling liquid in the cooling liquid section 3a is approximately a predetermined temperature. Therefore, by controlling the flow rate of the cooling gas 3a1 with the flow rate control section 3c, the temperature of the substrate 100, and therefore the temperature of the liquid 101 on the surface 100b of the substrate 100, can be controlled. In this case, by controlling the flow rate of the cooling gas 3a1 with the flow rate control section 3c, a supercooled state of the liquid 101 can be created in the cooling step described below.

[0027] The cooling nozzle 3d has a cylindrical shape. One end of the cooling nozzle 3d is connected to the flow rate control unit 3c. The other end of the cooling nozzle 3d is provided inside the rotating shaft 2b. The other end of the cooling nozzle 3d is located near the end of the blowing unit 2b1 on the opposite side to the mounting table 2a side (opening side).

[0028] Cooling nozzle 3d supplies cooling gas 3a1, the flow rate of which is controlled by flow rate control unit 3c, to substrate 100. Cooling gas 3a1 emitted from cooling nozzle 3d is supplied directly to rear surface 100a of substrate 100 via blowing unit 2b1.

[0029] When the cooling gas 3a1 is supplied to the rear surface 100a side of the substrate 100, freezing starts from the rear surface (the surface facing the substrate 100) of the film of the liquid 101 formed on the front surface 100b of the substrate 100. When freezing starts from the rear surface of the film of the liquid 101, foreign matter adhering to the front surface 100b of the substrate 100 becomes easier to separate from the front surface 100b of the substrate 100.

[0030] Therefore, it is sufficient that the substrate processing apparatus 1 is one that supplies the cooling gas 3a1 at least to the back surface 100a side of the substrate 100. For example, the substrate processing apparatus 1 may also supply the cooling gas 3a1 to the front surface 100b side of the substrate 100. When the cooling gas 3a1 is also supplied to the front surface 100b side of the substrate 100, the cooling nozzle 3d may be provided also on the front surface 100b side of the substrate 100.

[0031] The first liquid supply unit 4 supplies liquid 101 to the surface 100b of the substrate 100. The liquid 101 is used in a preliminary process and a process for forming a film of the liquid 101, which will be described later. There are no particular limitations on the liquid 101 as long as it is unlikely to react with the material of the substrate 100. For example, the liquid 101 can be water (e.g., pure water or ultrapure water), a liquid containing water as a main component, a liquid having gas dissolved therein, or the like.

[0032] The first liquid supply unit 4 has, for example, a liquid storage unit 4a, a supply unit 4b, a flow rate control unit 4c, and a liquid nozzle 4d. The liquid storage unit 4a, the supply unit 4b, and the flow rate control unit 4c are provided outside the chamber 6.

[0033] Liquid storage portion 4a stores liquid 101. The temperature of liquid 101 stored in liquid storage portion 4a is higher than the freezing point of liquid 101. The temperature of liquid 101 stored in liquid storage portion 4a is, for example, room temperature (for example, 20° C.).

[0034] The supply unit 4b is connected to the liquid storage unit 4a via a pipe. The supply unit 4b supplies the liquid 101 stored in the liquid storage unit 4a toward the liquid nozzle 4d. The supply unit 4b can be, for example, a pump that is resistant to the liquid 101.

[0035] The flow rate control unit 4c is connected to the supply unit 4b via a pipe. The flow rate control unit 4c controls the flow rate of the liquid 101 supplied by the supply unit 4b. The flow rate control unit 4c can be, for example, a flow rate control valve. The flow rate control unit 4c can also start and stop the supply of the liquid 101.

[0036] The liquid nozzle 4d is provided inside the chamber 6. The liquid nozzle 4d has a cylindrical shape. One end of the liquid nozzle 4d is connected to the flow rate control unit 4c via a pipe.

[0037] The other end of the liquid nozzle 4d (the side from which the liquid 101 is discharged) is provided above the surface 100b of the substrate 100 placed on the mounting table 2a. The liquid 101 discharged from the liquid nozzle 4d is supplied to the surface 100b of the substrate 100. The other end of the liquid nozzle 4d can be provided near the rotation center of the substrate 100. In this manner, the liquid 101 can be supplied to approximately the center of the surface 100b of the substrate 100. The liquid 101 supplied to approximately the center of the surface 100b of the substrate 100 spreads to the peripheral side of the surface 100b of the substrate 100, and a film of the liquid 101 having an approximately constant thickness is formed on the surface 100b of the substrate 100.

[0038] 1, the opening (discharge port) at the other end of the liquid nozzle 4d can be directed toward the side surface of the vibration body 91 (main body 91a) (described later) on the rotation center side of the substrate 100. In this way, the liquid 101 discharged from the liquid nozzle 4d is supplied to the surface 100b of the substrate 100 after hitting the side surface of the vibration body 91 (main body 91a) on the rotation center side of the substrate 100. Therefore, the liquid 101 can be supplied to a wider area of ​​the surface 100b of the substrate 100, and the collision speed between the liquid 101 and the substrate 100 can be reduced. As a result, a film of the liquid 101 is easily formed on the entire surface 100b of the substrate 100.

[0039] Also, a hole can be provided in the vibration body 91 (main body 91a) and the liquid 101 can be supplied to the surface 100b of the substrate 100 through the hole in the vibration body 91 (main body 91a). In other words, the vibration body 91 can have the function of the liquid nozzle 4d.

[0040] The second liquid supply unit 5 supplies liquid 102 to the frozen film 101a including the foreign matter 300 in a thawing step described below. The liquid 102 may be any liquid that does not easily react with the material of the substrate 100 and does not easily remain on the surface 100b of the substrate 100 in a drying step described below. The liquid 102 may be, for example, water (e.g., pure water or ultrapure water), a liquid containing water as a main component, or a liquid having gas dissolved therein, similar to the liquid 101 described above. In this specification, the film of liquid 101 formed on surface 100b of substrate 100 that is completely frozen in a freezing step (solid-liquid phase) described later is referred to as frozen film 101a.

[0041] In this case, liquid 102 may be the same as liquid 101, or may be different from liquid 101. When liquid 102 is the same as liquid 101, second liquid supply unit 5 can be omitted. When second liquid supply unit 5 is omitted, first liquid supply unit 4 is also used in the thawing step described below. That is, liquid 101 is also used in the thawing step.

[0042] Furthermore, the temperature of liquid 102 can be set to a temperature higher than the freezing point of liquid 102. For example, the temperature of liquid 102 may be any temperature that can thaw frozen liquid 101. The temperature of liquid 102 is, for example, about room temperature (e.g., 20°C). Furthermore, if the temperature of liquid 102 is set to a temperature higher than room temperature, the thawing time can be shortened. When the temperature of liquid 102 is set to a temperature higher than room temperature, for example, a heater and a temperature control device are provided in liquid storage section 5a, which will be described later.

[0043] When liquid 101 is used in the thawing step as well, if the temperature of liquid 101 exceeds room temperature, the temperature of the film of liquid 101 formed before the cooling step described below will be high. If the temperature of the film of liquid 101 increases, the time required for the cooling step will be longer. Therefore, when the temperature of the liquid used in the thawing step exceeds room temperature, it is preferable to provide a second liquid supply unit 5 even if liquid 102 is the same as liquid 101.

[0044] The second liquid supply unit 5 has, for example, a liquid storage unit 5a, a supply unit 5b, a flow rate control unit 5c, and a liquid nozzle 4d. The liquid storage unit 5a may be the same as the liquid storage unit 4a described above. The supply unit 5b may be the same as the supply unit 4b described above. The flow rate control unit 5c may be the same as the flow rate control unit 4c described above.

[0045] 1 shows an example in which the nozzle 4d is used as both the first liquid supply unit 4 and the second liquid supply unit 5. However, a liquid nozzle for supplying liquid 101 and a liquid nozzle for supplying liquid 102 may be provided separately. In the following, a case where liquid nozzle 4d is used for supplying both liquid 101 and liquid 102 will be described.

[0046] The chamber 6 is box-shaped. A cover 6a is provided inside the chamber 6. The cover 6a receives the liquid 101 (liquid 102) that is supplied to the substrate 100 and is discharged to the outside of the substrate 100 as the substrate 100 rotates. A partition plate 6b is provided inside the chamber 6. The partition plate 6b is provided between the outer surface of the cover 6a and the inner surface of the chamber 6.

[0047] A plurality of exhaust ports 6c are provided on the side surface on the bottom side of the chamber 6. The used cooling gas 3a1, liquid 101, and liquid 102, and air 8a supplied by the blower 8 are exhausted to the outside of the chamber 6 from the exhaust ports 6c. An exhaust pipe 6c1 is connected to the exhaust ports 6c. In addition, an exhaust pipe 6c2 for exhausting the liquid 101 and the liquid 102 is connected to the exhaust ports 6c.

[0048] The exhaust unit 7 is connected to the exhaust pipe 6c1. The exhaust unit 7 exhausts the used cooling gas 3a1 and air 8a. The exhaust unit 7 is, for example, a pump or a blower.

[0049] The blower 8 is provided on the ceiling surface of the chamber 6. The blower 8 can also be provided on the side surface of the chamber 6, so long as it is on the ceiling side. The blower 8 includes, for example, a blower such as a fan and a filter. The filter is, for example, a HEPA filter (High Efficiency Particulate Air Filter).

[0050] The vibration unit 9 is used in the thawing process described below. In the thawing process, the vibration unit 9 transmits vibrations to a liquid film 103 including the liquid 102 (liquid 101) supplied to the frozen film 101a and the liquid (liquid 101) generated by thawing the frozen film 101a. For example, the vibration unit 9 transmits vibrations to the liquid film 103 from a direction intersecting with the surface 100b of the substrate 100.

[0051] The vibration section 9 includes, for example, a vibrating body 91, a vibrator 92, a circuit 93, a holder 94, and a cover 95. FIG. 2 is a schematic perspective view of the vibrating body 91. As shown in FIG. 2, arrows X, Y, and Z represent three mutually orthogonal directions. The X direction is a horizontal direction, and the Y direction is a horizontal direction orthogonal to the X direction.

[0052] 2, the vibrating body 91 has, for example, a main body 91a and a flange 91b. The main body 91a and the flange 91b are integrally formed. The vibrating body 91 is made of a material that easily transmits vibrations from the vibrator 92 and is unlikely to generate particles. The vibrating body 91 is made of, for example, quartz.

[0053] The main body 91a has, for example, a rectangular parallelepiped shape. A dimension L of the main body 91a in the X direction can be larger than the maximum dimension between the center of rotation of the substrate 100 and the periphery of the substrate 100. For example, when the planar shape of the substrate 100 is a circle, the dimension L of the main body 91a can be larger than the radius of the substrate 100. For example, when the planar shape of the substrate 100 is a rectangle, the dimension L of the main body 91a can be larger than half the diagonal dimension of the substrate 100.

[0054] In the thawing step described later, the substrate 100 rotates. Therefore, if the dimension L of the main body 91a is larger than the maximum dimension between the center of rotation of the substrate 100 and the periphery of the substrate 100, vibrations can be transmitted to the entire area of ​​the liquid film 103 without moving the vibrating body 91 during the thawing step.

[0055] An end 91aa of the main body 91a on the substrate 100 side can be a flat surface, or a groove 91a1 can be provided in the end 91aa as shown in FIG. 2. The groove 91a1 opens to the end 91aa of the main body 91a. At least one groove 91a1 can be provided. The groove 91a1 extends in the X direction. In the X direction, the groove 91a1 opens to both side surfaces of the main body 91a. When multiple grooves 91a1 are provided, the multiple grooves 91a1 can be arranged side by side in the Y direction. The function and effect of the groove 91a1 will be described later.

[0056] The flange 91b is plate-shaped and is provided on the side opposite to the end 91aa side of the main body 91a. The flange 91b protrudes from the side surface of the main body 91a. The flange 91b can be in contact with the upper surface of the holding part 94. The flange 91b can be omitted. However, if the flange 91b is provided, it becomes easier to position the vibrating body 91 and stabilize the posture of the vibrating body 91 when the vibrating body 91 is attached to the holding part 94.

[0057] Next, the function and effect of the groove 91a1 of the vibrating body 91 will be described. FIG. 3 is a schematic diagram illustrating the function and effect of the groove 91a1. In addition, the arrows X, Y, and Z in FIG. 3 are the same as those in FIG. 3, a side surface 91a1a of the groove 91a1 in the Y direction is inclined with respect to an end portion 91aa. One side surface 91a1a is inclined in the opposite direction to the opposing side surface 91a1a.

[0058] 3, vibration 92a from vibrator 92 propagates through vibrating body 91 (main body 91a) and enters side surface 91a1a of groove 91a1. The propagation direction of vibration 92a that has entered side surface 91a1a to liquid film 103 changes depending on the inclination angle of side surface 91a1a.

[0059] Here, if the end 91aa of the vibrating body 91 were a flat surface, the direction of propagation of the vibration 92a to the liquid film 103 would be approximately perpendicular to the surface 100b of the substrate 100. Therefore, the direction of the force acting on the foreign object 300 would be approximately perpendicular to the upper surface of the frozen film 101a or the surface 100b of the substrate 100, making it difficult for the foreign object 300 to move in a direction parallel to the upper surface of the frozen film 101a or the surface 100b of the substrate 100. If it becomes difficult for the foreign object 300 to move in a direction parallel to the upper surface of the frozen film 101a or the surface 100b of the substrate 100, it becomes difficult to separate or discharge the foreign object 300.

[0060] In contrast, if the groove 91a1 is provided at the end 91aa of the vibrating body 91, the direction of the force acting on the foreign object 300 is likely to be inclined with respect to the upper surface of the frozen film 101a or the surface 100b of the substrate 100, as shown in FIG. 3. If a force in a direction inclined with respect to the upper surface of the frozen film 101a or the surface 100b of the substrate 100 is applied to the foreign object 300, a component force in a direction parallel to the upper surface of the frozen film 101a or the surface 100b of the substrate 100 acts on the foreign object 300. Therefore, the foreign object 300 is likely to move in a direction parallel to the upper surface of the frozen film 101a or the surface 100b of the substrate 100. If the foreign object 300 is likely to move in a direction parallel to the upper surface of the frozen film 101a or the surface 100b of the substrate 100, the removal rate of the foreign object 300 can be improved.

[0061] In this case, it is preferable that the angle θ between the side surface of the groove 91a1 and the extension line 91a1b of the end 91aa of the vibration body 91 is set to 20°≦θ≦87°. In this way, the foreign matter 300 becomes more easily movable, and the removal rate of the foreign matter 300 can be further improved.

[0062] 3, the cross-sectional outline of the groove 91a1 is trapezoidal, but the cross-sectional outline of the groove 91a1 may be, for example, triangular. The side surface of the groove 91a1 may be flat or curved. When the side surface of the groove 91a1 is curved, the angle between the tangent to the curved surface and the extension line of the end 91aa of the vibrating body 91 may be the angle θ described above.

[0063] Next, returning to FIG. 1, the vibrator 92, the circuit 93, the holder 94, and the cover 95 provided in the vibrating section 9 will be described. The vibrator 92 is provided on the vibrating body 91 (flange 91b). The vibrator 92 can be, for example, adhered to the vibrating body 91. The vibrator 92 converts an applied voltage into a force. The vibrator 92 is, for example, a piezoelectric element.

[0064] The circuit 93 is electrically connected to the vibrator 92. The circuit 93 applies a voltage of a predetermined frequency to the vibrator 92. In this case, the frequency is, for example, about 1.6 MHz to 4 MHz. The circuit 93 can also control the energy of the vibration and control the start and stop of the vibration. The circuit 93 controls the energy of the vibration by changing at least one of the amplitude and the angular frequency, for example.

[0065] The holder 94 holds the vibrating body 91 at a predetermined position above the substrate 100. In this case, it is preferable that the distance between the end 91aa of the vibrating body 91 (main body 91a) and the surface 100b of the substrate 100 is 1.8 mm or less. In this way, it becomes easy to hold the liquid film 103 between the end 91aa of the vibrating body 91 (main body 91a) and the surface 100b of the substrate 100. Therefore, vibration can be efficiently transmitted from the vibrating body 91 (main body 91a) to the liquid film 103.

[0066] The holding portion 94 is, for example, plate-shaped and has a hole penetrating in the thickness direction. The main body 91a of the vibrating body 91 can be inserted into the hole. When the main body 91a is inserted into the hole, the flange 91b of the vibrating body 91 can be brought into contact with the upper surface of the holding portion 94. The flange 91b can be attached to the holding portion 94 using a fastening member such as a screw.

[0067] The holding unit 94 can also be movable in a direction parallel to the surface 100b of the substrate 100. For example, a rotation axis can be provided in the vicinity of the end of the holding unit 94 opposite to the side where the vibrating body 91 is provided, and the holding unit 94 holding the vibrating body 91 can be rotated. For example, in a thawing step described later, the holding unit 94 can be rotated so that the vibrating body 91 is positioned above the surface 100b of the substrate 100, and in other steps, the holding unit 94 can be rotated so that the vibrating body 91 moves to a retracted position outside the substrate 100. Therefore, in the thawing step described later, the vibration part 9 (vibrator 91) faces the frozen film 101a.

[0068] The cover 95 is provided on the upper surface of the holding portion 94. The cover 95 covers the transducer 92. The cover 95 can be attached to the holding portion 94 using a fastening member such as a screw.

[0069] The detection unit 10 detects the thawing state (dissolving state) of the frozen film 101a in a thawing process described below. When thawing of the frozen film 101a starts in the thawing process, the above-mentioned liquid film 103 is formed on the remaining frozen film 101a that has not yet been thawed. Therefore, the thawing state can be detected by detecting the position of the upper surface of the remaining frozen film 101a (the position of the interface between the liquid film 103 and the frozen film 101a).

[0070] For example, the detection unit 10 can be a reflective optical sensor. In this case, the detection unit 10 irradiates the liquid film 103 with light and receives the light reflected at the interface between the liquid film 103 and the frozen film 101a. The detection unit 10 then detects the position of the interface based on the received reflected light. If the detection unit 10 is a reflective optical sensor, it can directly detect the position of the upper surface of the frozen film 101a.

[0071] Furthermore, the detection unit 10 may be configured to indirectly detect the position of the upper surface of the frozen film 101a. For example, in the freezing process described below, when the film of the liquid 101 is completely frozen to form the frozen film 101a, the thickness of the frozen film 101a becomes thicker than the thickness of the film of the liquid 101 before freezing due to volume expansion. Then, in the thawing process, when the frozen film 101a is thawed, the thickness of the frozen film 101a gradually becomes thinner. The thickness of the film of the liquid 101 generated by thawing the frozen film 101a becomes thinner than the thickness of the thawed frozen film 101a. Therefore, as the thawing of the frozen film 101a progresses, the total thickness of the remaining frozen film 101a and the liquid film 103 on the frozen film 101a gradually becomes thinner.

[0072] Therefore, by detecting the position of the upper surface of the liquid film 103, it is possible to obtain the position of the upper surface of the frozen film 101a below the liquid film 103. Note that the relationship between the position of the upper surface of the liquid film 103 and the position of the upper surface of the frozen film 101a below the liquid film 103 can be obtained in advance by performing experiments or simulations. When detecting the position of the upper surface of the liquid film 103, the detection unit 10 can be, for example, a non-contact type displacement meter such as a laser displacement meter or an ultrasonic displacement meter.

[0073] In addition, by detecting the temperature of the upper surface of the liquid film 103, the position of the upper surface of the frozen film 101a below the liquid film 103 can also be indirectly detected. For example, in the thawing process, as the frozen film 101a thaws, the volume of the liquid film 103 on the frozen film 101a increases. Since the temperature of the liquid film 103 is higher than the temperature of the frozen film 101a, as the volume of the liquid film 103 increases (as thawing progresses), the temperature of the upper surface of the liquid film 103 increases. Therefore, by detecting the temperature of the upper surface of the liquid film 103, the position of the upper surface of the frozen film 101a below the liquid film 103 can be indirectly detected. Note that the relationship between the temperature of the upper surface of the liquid film 103 and the position of the upper surface of the frozen film 101a below the liquid film 103 can be found in advance by performing experiments or simulations. When detecting the temperature of the upper surface of the liquid film 103, the detection unit 10 can be, for example, a non-contact thermometer such as a radiation thermometer or a thermograph.

[0074] The position of the upper surface of the frozen film 101a below the liquid film 103 can also be obtained from the time from the start of thawing. For example, the temperature of liquid 101 (liquid 102) used in the thawing process is set within a predetermined range, and the relationship between the time from the start of thawing (e.g., the start of supply of liquid 101 (liquid 102)) and the position of the upper surface of frozen film 101a below liquid film 103 is determined in advance by conducting experiments or simulations. In this way, the position of the upper surface of frozen film 101a below liquid film 103 can be indirectly detected from the time from the start of thawing (e.g., the time from the start of supply of liquid 102 by second liquid supply unit 5).

[0075] If the position of the upper surface of the frozen film 101a is obtained by time management, it is possible to omit the detection unit 10. If the detection unit 10 can be omitted, it is possible to simplify the configuration of the substrate processing apparatus 1 and reduce the manufacturing cost.

[0076] However, if the detection unit 10 detects the position of the upper surface of the frozen film 101a, the position of the upper surface of the frozen film 101a can be obtained more accurately. The purpose and effect of detecting the position of the upper surface of the frozen film 101a in the thawing process will be described in detail later.

[0077] The controller 11 controls the operation of each element provided in the substrate processing apparatus 1. The controller 11 has, for example, a calculation unit such as a CPU (Central Processing Unit) and a storage unit such as a semiconductor memory. The controller 11 is, for example, a computer. The storage unit stores a control program that controls the operation of each element provided in the substrate processing apparatus 1. Based on the control program stored in the storage unit, the calculation unit sequentially executes a preliminary process, a process of forming a film of the liquid 101, a cooling process, a thawing process, and a drying process, which will be described later.

[0078] FIG. 4 is a schematic perspective view of a vibrating body 96 according to another embodiment. In addition, the arrows X, Y, and Z in FIG. 4 are the same as those in FIG. 4, the vibrating body 96 has, for example, a main body 96a and a flange 96b. The main body 96a and the flange 96b are integrally formed. The material of the vibrating body 96 can be, for example, the same as the material of the vibrating body 91 described above.

[0079] Flange 96b may be similar to flange 91b described above.

[0080] The dimension L1 of the main body 96a in the X direction can be the same as the dimension L of the main body 91a described above. The side surface 96a1 of the main body 96a in the Y direction is connected to the end portion 96aa of the vibrating body 96 (main body 96a). The side surface 96a1 is inclined with respect to the end portion 96aa of the vibrating body 96 (main body 96a). The angle θ1 between the side surface 96a1 of the main body 96a and the extension line 96ab of the end portion 96aa of the vibrating body 96 (main body 96a) can be the same as the angle θ described above.

[0081] FIG. 5 is a schematic diagram illustrating the action and effect of the vibrating body 96. In FIG. As shown in FIG. 5, in the vibrating body 96, the vibration 92a from the vibrator 92 propagates inside the vibrating body 96 (main body 96a) and enters the side surface 96a1 of the main body 96a. In the region of the side surface 96a1 that is not in contact with the liquid film 103 (the region in contact with the outside air), total reflection is likely to occur due to Snell's law. Therefore, in the region of the side surface 96a1 that is not in contact with the liquid film 103, the vibration 92a propagates while being repeatedly reflected. For example, in FIG. 5, the vibration 92a that is incident on the side surface 96a1 from above in a direction inclined with respect to the Z direction is a vibration that is reflected once by the side surface 96a1. The vicinity of the end portion 96aa of the vibrating body 96 (main body 96a) is in contact with the liquid film 103. For example, the vicinity of the end portion 96aa of the vibrating body 96 (main body 96a) is inserted into the liquid film 103. The liquid film 103 comes into contact with the vicinity of the end 96aa of the vibrating body 96 (main body 96a) due to the surface tension of the liquid film 103 and the flow of the liquid film 103 accompanying the rotation of the substrate 100. The vibration 92a incident on the portion of the side surface 96a1 that is in contact with the liquid film 103 is easily emitted from the vibrating body 96 (main body 96a) according to Snell's law. In this case, the propagation direction of the vibration 92a changes according to the angle θ1.

[0082] As shown in FIG. 5, there are also vibrations 92a that enter the side surface 96a1 from above in a direction substantially parallel to the Z direction and are emitted from the vibrating body 96 (main body 96a) without ever being reflected by the side surface 96a1.

[0083] In the vibrating body 96, as shown in Fig. 5, the direction of the force acting on the foreign object 300 tends to be inclined with respect to the upper surface of the frozen film 101a or the surface 100b of the substrate 100. Therefore, as described in Fig. 3, a component of force in a direction parallel to the upper surface of the frozen film 101a or the surface 100b of the substrate 100 acts on the foreign object 300, so that the foreign object 300 tends to move in a direction parallel to the upper surface of the frozen film 101a or the surface 100b of the substrate 100. If the foreign object 300 tends to move in a direction parallel to the upper surface of the frozen film 101a or the surface 100b of the substrate 100, the removal rate of the foreign object 300 can be improved.

[0084] 5 shows an end 96aa of the vibrating body 96 (main body 96a) as a flat surface, the end 96aa may be provided with the groove 91a1 having the inclined surface described above. Also, the side surface of the vibrating body 91 (main body 91a) described above may be made into an inclined surface.

[0085] FIG. 6 is a schematic perspective view illustrating a vibrating body 97 according to another embodiment. As shown in FIG. 6, the vibration body 97 has a side surface 97a that is inclined with respect to the end of the vibration body 97. For example, the vibration body 97 can be a vibration body 96 having a smaller dimension L1 than the vibration body 96 described above. The vibration body 97 may be a vibration body 91 having a smaller dimension L than the vibration body 91 described above. The dimension L3 of the vibration body 97 can be smaller than the minimum dimension between the rotation center of the substrate 100 and the periphery of the substrate 100. In this way, the vibration body 97 can be made smaller and less expensive. However, if the dimension L3 is made smaller, the vibration is transmitted to a part of the liquid film 103. Therefore, it is necessary to move the position of the vibration body 97 between the rotation center of the substrate 100 and the periphery of the substrate 100. For example, a holding part that can move the vibration body 97 in a direction parallel to the surface 100b of the substrate 100 may be provided.

[0086] As described above, the substrate processing apparatus 1 according to this embodiment forms the frozen film 101a on the surface 100b of the substrate 100. Then, the foreign matter 300 adhering to the surface 100b of the substrate 100 is captured in the frozen film 101a, and the frozen film 101a containing the foreign matter 300 is thawed, thereby removing the foreign matter 300 from the surface 100b of the substrate 100.

[0087] Next, the operation of the substrate processing apparatus 1 will be further described. FIG. 7 is a timing chart illustrating the operation of the substrate processing apparatus 1. As shown in FIG. FIG. 8 is a graph for illustrating the temperature change of the liquid 101 supplied to the surface 100b of the substrate 100. In FIG. 7 and 8 show the case where the substrate 100 is a 6025 quartz (Qz) substrate (152 mm×152 mm×6.35 mm) and the liquids 101 and 102 are pure water. The liquid 102 used for thawing is the same as the liquid 101. Therefore, in Fig. 7 and Fig. 8, the liquid 101 is also used in the thawing step.

[0088] First, the substrate 100 is carried into the chamber 6 through a loading / unloading port (not shown) of the chamber 6. The carried-in substrate 100 is placed and supported on the multiple supports 2a1 of the mounting table 2a.

[0089] After the substrate 100 is supported on the mounting table 2a, a freeze-cleaning process is performed, including a preliminary process, a process of forming a film of the liquid 101, a cooling process, a thawing process, and a drying process, as shown in FIGS.

[0090] First, a preliminary step is carried out as shown in FIG. 7 and FIG. In the preliminary step, the controller 11 controls the supply unit 4b and the flow rate control unit 4c to supply the liquid 101 at a predetermined flow rate to the front surface 100b of the substrate 100. The controller 11 also controls the flow rate control unit 3c to supply the cooling gas 3a1 at a predetermined flow rate to the rear surface 100a of the substrate 100. The controller 11 also controls the drive unit 2c to rotate the substrate 100 at a second rotation speed.

[0091] Here, when the cooling gas 3a1 is supplied to cool the atmosphere inside the chamber 6, frost containing dust in the atmosphere may adhere to the substrate 100, causing contamination. For this reason, in the preliminary step, the liquid 101 is continuously supplied to the surface 100b of the substrate 100. That is, in the preliminary step, the substrate 100 is cooled and frost is prevented from adhering to the surface 100b of the substrate 100.

[0092] The second rotation speed is, for example, about 50 rpm to 500 rpm. The flow rate of the liquid 101 is, for example, about 0.1 L / min to 1.0 L / min. The flow rate of the cooling gas 3a1 is, for example, about 40 NL / min to 200 NL / min. The process time of the preliminary process is about 1800 seconds.

[0093] The temperature of the film of liquid 101 in the preliminary step is approximately the same as the temperature of the supplied liquid 101 because liquid 101 is continuously supplied. For example, when the temperature of the supplied liquid 101 is approximately room temperature (20° C.), the temperature of the film of liquid 101 is approximately room temperature (20° C.).

[0094] Next, a process of forming a film of liquid 101 is carried out as shown in FIG. 7 and FIG. In the step of forming the film of liquid 101, the supply of liquid 101 that was supplied in the preliminary step is stopped. Since the rotation of substrate 100 is maintained, liquid 101 on surface 100b of substrate 100 is discharged. In this case, the rotation speed of substrate 100 is decelerated to a first rotation speed that can suppress variations in thickness of the film of liquid 101 due to centrifugal force. The first rotation speed is, for example, 0 rpm to 50 rpm.

[0095] After the rotation speed of the substrate 100 is set to a first rotation speed, a predetermined amount of liquid 101 is supplied to the substrate 100 to form a film of the liquid 101. The thickness of the film of the liquid 101 (the thickness of the film of the liquid 101 when the cooling step is performed) is, for example, about 300 μm to 1300 μm.

[0096] During the process of forming the film of liquid 101, the flow rate of cooling gas 3a1 is maintained at the same flow rate as in the preliminary process. In the preliminary process described above, the in-plane temperature of substrate 100 is approximately uniform. If the flow rate of cooling gas 3a1 is maintained at the same flow rate as in the preliminary process during the process of forming the film of liquid 101, the in-plane temperature of substrate 100 can be maintained in an approximately uniform state.

[0097] Next, a cooling step is carried out as shown in FIGS. In this specification, the cooling process includes a "supercooling process," a "freezing process (solid-liquid phase)," and a "freezing process (solid phase)." The "supercooling process" is a process in which the liquid 101 is in a supercooled state and before the liquid 101 in the supercooled state starts to freeze. In the supercooling process, only the liquid 101 exists on the entire surface 100b of the substrate 100. The "freezing process (solid-liquid phase)" is a process in which the freezing of the liquid 101 in the supercooled state starts and before the freezing is completely completed. In the freezing process (solid-liquid phase), the liquid 101 and the liquid 101 that has frozen exist on the entire surface 100b of the substrate 100. The "freezing process (solid phase)" is a process after the liquid 101 is completely frozen. In the freezing process (solid phase), only a frozen film 101a in which the liquid 101 is frozen exists on the entire surface 100b of the substrate 100.

[0098] Also, after the film formation process of the liquid 101, the freezing process (solid-liquid phase) may be performed without the supercooling process, and the thawing process may be performed before the frozen film 101a is formed. Also, after the film formation process of the liquid 101, the freezing process (solid-liquid phase), the freezing process (solid phase), and the thawing process may be performed in sequence without the supercooling process. That is, the supercooling process and the freezing process (solid phase) may be omitted. Even if the supercooling process and the freezing process (solid phase) are omitted, the foreign matter 300 can be separated from the surface 100b of the substrate 100. If the supercooling process and the freezing process (solid phase) are omitted, the cooling process can be simplified, and the time required for the cooling process can be shortened.

[0099] In the supercooling step, the temperature of the liquid 101 film on the front surface 100b of the substrate 100 is further lowered than the temperature of the liquid 101 film in the liquid 101 film formation step by the cooling gas 3a1 continuously supplied to the rear surface 100a of the substrate 100, and the liquid 101 is in a supercooled state. In this case, if the cooling speed of the liquid 101 becomes too fast, the liquid 101 will not be in a supercooled state and will immediately freeze. Therefore, the controller 11 controls at least one of the rotation speed of the substrate 100, the flow rate of the cooling gas 3a1, and the flow rate of the liquid 101, so that the liquid 101 on the front surface 100b of the substrate 100 is in a supercooled state.

[0100] The control conditions under which liquid 101 is in the supercooled state are affected by the size of substrate 100, the viscosity of liquid 101, the specific heat of cooling gas 3a1, etc. Therefore, it is preferable to appropriately determine the control conditions under which liquid 101 is in the supercooled state by performing experiments or simulations in advance.

[0101] As described above, there are cases where the supercooling step is not performed. In this case, the controller 11 controls at least one of the rotation speed of the substrate 100, the flow rate of the cooling gas 3a1, and the flow rate of the liquid 101 to increase the cooling rate of the liquid 101. By increasing the cooling rate of the liquid 101, the freezing step (solid-liquid phase) is performed without going through the supercooling step.

[0102] When the liquid 101 in the supercooled state starts to freeze, the process transitions from the supercooling process to the freezing process (solid-liquid phase). In the supercooled state, the liquid 101 starts to freeze due to, for example, the temperature of the film of the liquid 101, the presence of foreign matter 300 such as particles or air bubbles, vibration, etc. For example, in the presence of foreign matter 300 such as particles, the liquid 101 starts to freeze when the temperature T of the liquid 101 falls to -35°C or higher and -20°C or lower. The liquid 101 can also start to freeze by applying vibration to the liquid 101, for example by varying the rotation of the substrate 100.

[0103] As described above, in the supercooled liquid 101, a certain percentage of the starting points of freezing become foreign matter 300. The foreign matter 300 that became the starting points of freezing are likely to be captured by the frozen film 101a. Therefore, by performing the supercooling process, the removal rate of the foreign matter 300 can be improved. It is also considered that the foreign matter 300 attached to the surface 100b of the substrate 100 is separated by pressure waves associated with the volume change when the liquid 101 turns into a solid, physical forces associated with the volume increase, and the like.

[0104] Next, a decompression process is performed as shown in FIG. The start of the thawing process can be determined, for example, by the time that has elapsed since the start of the preliminary process or the start of the freezing process (solid-liquid phase). Depending on the length of this elapsed time, it is determined whether thawing starts in the middle of the freezing process (solid-liquid phase) or in the middle of the freezing process (solid phase). The surface state of the liquid 101 (frozen film 101a) on the surface 100b side of the substrate 100 may be detected, and the timing to start thawing may be determined from the change in the surface state.

[0105] In the thawing step, vibration 92a is transmitted by vibration unit 9 to liquid film 103, which contains liquid 101 (liquid 102) supplied for thawing and liquid 101 produced by thawing frozen film 101a. The defrosting process will be described in detail later.

[0106] Next, a drying process is carried out as shown in FIGS. In the drying process, the controller 11 controls the supply unit 4b and the flow rate control unit 4c to stop the supply of the liquid 101. When the liquids 101 and 102 are different liquids, the controller 11 controls the supply unit 5b and the flow rate control unit 5c to stop the supply of the liquid 102. Moreover, the controller 11 controls the flow rate control unit 3c to stop the supply of the cooling gas 3a1.

[0107] Moreover, the controller 11 controls the circuit 93 to stop the generation of the vibration 92a. The controller 11 can also control the holder 94 to move the vibrating body 91 (vibrating body 96, vibrating body 97) to a retreat position outside the substrate 100.

[0108] Furthermore, the controller 11 controls the driving unit 2c to set the rotation speed of the substrate 100 to a fourth rotation speed that is faster than the rotation speed of the substrate 100 in the thawing step (a third rotation speed described below). If the rotation speed of the substrate 100 is faster, the drying time of the substrate 100 can be shortened. The fourth rotation speed is not particularly limited as long as drying is possible.

[0109] In this manner, the freeze-cleaning process is completed. The freeze-cleaning process can be carried out multiple times. After the freeze cleaning process, the substrate 100 is transferred to the outside of the chamber 6 through a transfer port (not shown) of the chamber 6 .

[0110] Next, the thawing step will be further described. In the thawing step, the controller 11 controls the supply unit 4b and the flow rate control unit 4c to supply the liquid 101 to the frozen film 101a. When the liquid 101 and the liquid 102 are different, the controller 11 controls the supply unit 5b and the flow rate control unit 5c to supply the liquid 102 to the frozen film 101a.

[0111] There is no particular limitation on the flow rate of liquid 101 or liquid 102 as long as thawing is possible. The temperature of liquid 101 or liquid 102 may be room temperature (e.g., 20° C.). As described above, the temperature of liquid 101 may be room temperature (e.g., 20° C.), and the temperature of liquid 102 used for thawing may be a temperature higher than room temperature.

[0112] Furthermore, the controller 11 controls the driving unit 2c to increase the rotation speed of the substrate 100 from the first rotation speed to the third rotation speed. The third rotation speed is, for example, about 200 rpm to 700 rpm. If the rotation speed of the substrate 100 is increased, the liquid 101 and the frozen liquid 101 can be thrown off by centrifugal force. Therefore, the liquid 101 and the frozen liquid 101 can be easily discharged from the surface 100b of the substrate 100. At this time, the foreign matter 300 separated from the surface 100b of the substrate 100 is also discharged together with the liquid 101 and the frozen liquid 101.

[0113] Moreover, the controller 11 controls the circuit 93 to cause the oscillator 92 to generate vibrations 92a. The generated vibrations 92a are transmitted to the liquid film 103 via the oscillator 91 (oscillating bodies 96 and 97).

[0114] As shown in Fig. 7, the timing for generating vibration 92a may be simultaneous with the start of supply of liquid 101 (liquid 102) used for thawing, or may be after the start of supply of liquid 101 (liquid 102) as shown by the dashed line in Fig. 7. The timing for stopping vibration 92a may be simultaneous with the stop of supply of liquid 101 (liquid 102) used for thawing, or may be before the stop of supply of liquid 101 (liquid 102) as shown by the dashed line in Fig. 7.

[0115] If the vibration 92a is transmitted to the liquid film 103, it is possible to suppress reattachment of the foreign matter 300 separated from the surface 100b of the substrate 100 to the surface 100b of the substrate 100. Therefore, it is possible to improve the removal rate of the foreign matter 300.

[0116] Next, the purpose and effect of detecting the position of the upper surface of the frozen film 101a in the thawing process will be further described. As described above, if the vibration 92a is transmitted to the liquid film 103, it is possible to suppress reattachment of the separated foreign matter 300. In this case, if the energy of the vibration 92a is increased, it is possible to more effectively suppress reattachment of the separated foreign matter 300.

[0117] 9(a) to 9(c) are schematic cross-sectional views illustrating the thawing process. As shown in FIG. 9(a), a foreign object 300 separated from a surface 100b of a substrate 100 is captured in a frozen film 101a.

[0118] 9(b), when the thawing of the frozen film 101a starts, a liquid film 103 is formed on the remaining frozen film 101a that has not yet been thawed. In addition, vibration 92a is transmitted to the liquid film 103. If the vibration 92a is transmitted to the liquid film 103, reattachment of the separated foreign matter 300 can be suppressed.

[0119] However, a pattern 100c is formed on the surface 100b of the substrate 100. The pattern 100c is, for example, a fine uneven portion. Therefore, as shown in Fig. 9(c), when the frozen film 101a is completely thawed and a vibration 92a is transmitted to the liquid film 103, the vibration 92a is transmitted to the pattern 100c.

[0120] The pattern 100c has low rigidity due to minute unevenness etc. Therefore, if the vibration 92a is transmitted to the pattern 100c, there is a risk that the pattern 100c may be damaged, as shown in FIG.

[0121] In this case, simply reducing the energy of vibration 92a to prevent damage to pattern 100c would result in the separated foreign matter 300 becoming more likely to reattach to surface 100b of substrate 100.

[0122] 9(b), the pattern 100c on the surface 100b of the substrate 100 is held by the frozen film 101a below the liquid film 103. If the pattern 100c is held by the frozen film 101a, even if the vibration 92a is transmitted to the pattern 100c, damage to the pattern 100c can be suppressed.

[0123] Therefore, in the substrate processing apparatus 1 according to this embodiment, the detection unit 10 directly or indirectly detects the position of the upper surface of the remaining frozen film 101a below the liquid film 103. Also, as described above, when the detection unit 10 is not provided, the position of the upper surface of the remaining frozen film 101a below the liquid film 103 is indirectly detected based on the time from the start of thawing.

[0124] When the distance between the upper surface of the frozen film 101a and the surface 100b of the substrate 100 is greater than a predetermined value, the energy of the vibration 92a is increased as shown in Fig. 7. If the energy of the vibration 92a is large, it is possible to effectively prevent the separated foreign matter 300 from reattaching to the surface 100b of the substrate 100. In this case, since the pattern 100c is held by the frozen film 101a, it is possible to prevent damage to the pattern 100c.

[0125] Then, when the distance between the upper surface of frozen film 101a and surface 100b of substrate 100 becomes smaller than a predetermined value, the energy of vibration 92a is reduced as shown in FIG. 7, or vibration 92a is stopped as shown by the dotted line in FIG. 7. That is, the controller 11 controls the vibrating unit 9 to reduce the energy of the vibration 92a transmitted to the liquid film 103 or to stop the vibration 92a depending on the position of the upper surface of the frozen film 101a below the liquid film 103. By reducing the energy of the vibration 92a or stopping the vibration 92a, it is possible to prevent damage to the pattern 100c even if the pattern 100c is exposed from the frozen film 101a.

[0126] In this case, the controller 11 controls the circuit 93 to switch the energy of the vibration 92a in the vibrator 92 or to stop the vibration 92a in the vibrator 92. The energy of the vibration 92a can be controlled by changing at least one of the amplitude and the angular frequency, for example. In addition, when the energy of the vibration 92a is reduced, it may be set to, for example, 10% to 50% of the energy of the vibration 92a at the start of thawing of the frozen film 101a. In addition, the energy of the vibration 92a may be gradually or stepwise reduced according to the change in the position of the upper surface of the frozen film 101a.

[0127] 10(a) to 10(c) are schematic cross-sectional views illustrating the positions of the upper surface of the frozen film 101a when the energy of the vibration 92a is switched or the vibration 92a is stopped. When the substrate 100 is, for example, an EUV (Extreme Ultraviolet) mask or a semiconductor wafer, the pattern 100c may have a multi-layer structure in which a plurality of films are laminated. In this case, when the tip of the pattern 100c is exposed from the upper surface of the frozen film 101a, the layer at the tip of the pattern 100c may peel off. Therefore, when the pattern 100c has a multi-layer structure, as shown in FIG. 10(a), the energy of the vibration 92a can be reduced or the vibration 92a can be stopped at the point when the distance between the upper surface of the frozen film 101a and the surface 100b of the substrate 100 becomes slightly larger than the distance between the tip of the pattern 100c and the surface 100b of the substrate 100. 10(b), the energy of the vibration 92a can be reduced or the vibration 92a can be stopped when the distance between the upper surface of the frozen film 101a and the surface 100b of the substrate 100 becomes the same as the distance between the tip of the pattern 100c and the surface 100b of the substrate 100. In this way, even if the pattern 100c has a multi-layer structure, damage to the pattern 100c can be suppressed.

[0128] In addition, when the substrate 100 is, for example, a phase shift mask, an imprint template, or a plate-like body used in MEMS, the pattern 100c may have a single-layer structure. If the pattern 100c has a single-layer structure, for example, as shown in FIG. 10(c), when the distance between the upper surface of the frozen film 101a and the surface 100b of the substrate 100 becomes smaller than the distance between the tip of the pattern 100c and the surface 100b of the substrate 100, the energy of the vibration 92a can be reduced or the vibration 92a can be stopped. If the pattern 100c has a single-layer structure, there is no peeling as in the case of a multi-layer structure, so that even if the tip of the pattern 100c is somewhat exposed from the upper surface of the frozen film 101a, damage to the pattern 100c can be suppressed. Even when the pattern 100c has a single-layer structure, the energy of the vibration 92a can be reduced or the vibration 92a can be stopped when the pattern 100c reaches the position of the upper surface of the frozen film 101a illustrated in Figures 10(a) and (b).

[0129] In other words, when the position of the upper surface of the frozen film 101a becomes close to the position of the tip of the pattern 100c, the controller 11 controls the vibration unit 9 to reduce the energy of the vibration 92a transmitted to the liquid film 103 or to stop the vibration 92a.

[0130] As described above, the position of the upper surface of the frozen film 101a when the energy of the vibration 92a is switched or the vibration 92a is stopped can be changed depending on the structure of the pattern 100c. In this case, if the energy of the vibration 92a is switched or the vibration 92a is stopped at the position of the upper surface of the frozen film 101a illustrated in FIG. 10(b), it becomes possible to accommodate various structures of the pattern 100c.

[0131] The above are examples of the embodiments. However, the present invention is not limited to these descriptions. Regarding the above-mentioned embodiments, those in the art who have appropriately added or removed components or modified the design, or added or omitted steps or modified conditions, are also included within the scope of the present invention as long as they have the characteristics of the present invention.

[0132] For example, the shape, size, number, arrangement, and the like of each element included in the substrate processing apparatus 1 are not limited to those exemplified, and can be changed as appropriate. [Explanation of symbols]

[0133] 1 substrate processing apparatus, 3 cooling section, 3a1 cooling gas, 4 first liquid supply section, 5 second liquid supply section, 6 chamber, 9 vibration section, 10 detection section, 11 controller, 91 vibration body, 92 transducer, 92a vibration, 93 circuit, 96 vibration body, 97 vibration body, 100 substrate, 100a back surface, 100b front surface, 100c pattern, 101 liquid, 101a frozen film, 102 liquid, 103 liquid film, 300 foreign matter

Claims

1. 1. A substrate processing apparatus that forms a frozen film on a surface of a substrate, traps foreign matter adhering to the surface of the substrate in the frozen film, and thaws the frozen film containing the foreign matter to remove the foreign matter from the surface of the substrate, A liquid supply unit that supplies liquid to the frozen film containing the foreign matter; A vibration part facing the frozen film; A controller for controlling the vibration unit; Equipped with The controller controls the vibration unit, Vibrations are transmitted to a liquid film including the liquid supplied to the frozen film and the liquid generated by thawing the frozen film, The substrate processing apparatus reduces the energy of the vibration transmitted to the liquid film or stops the vibration depending on the position of the upper surface of the frozen film below the liquid film.

2. The substrate processing apparatus according to claim 1 , further comprising a detection unit that directly or indirectly detects the position of the upper surface of the frozen film.

3. 2 . The substrate processing apparatus according to claim 1 , wherein the position of the upper surface of the frozen film is detected based on the time from when the liquid supply part starts to supply the liquid.

4. 4. The substrate processing apparatus according to claim 1, wherein the controller controls the vibration unit to gradually or stepwise reduce the energy of the vibration.

5. The surface of the substrate is provided with a pattern; A substrate processing apparatus as described in any one of claims 1 to 3, wherein when the position of the upper surface of the frozen film becomes close to the position of the tip of the pattern, the controller controls the vibration unit to reduce the vibration energy transmitted to the liquid film or to stop the vibration.

Images