Diaphragm pump

Abstract

A diaphragm pump (1) that sucks and discharges a resist solution supplied to a semiconductor wafer by a predetermined amount includes a diaphragm (20), a body (10), a detected portion (3), and a detection portion (4). The diaphragm (20) is formed in a film shape by resin. The body (10) has a space portion (13) in which the diaphragm (20) is arranged to be displaceable, and the space portion (13) is divided into a chemical solution chamber (14) and a drive chamber (15). The detected portion (3) is held in the body (10) so as to be able to contact a face of the diaphragm (20) on the side of the drive chamber (15), and is movable in conjunction with the diaphragm (20). The detection portion (4) detects displacement of the diaphragm (20) based on a position of the detected portion (3).

Description

Technical Field

[0001] The present invention relates to a diaphragm pump installed in a chemical solution supply line of a semiconductor manufacturing apparatus. Background Technology

[0002] A diaphragm pump is installed in the chemical solution supply line of a semiconductor manufacturing apparatus and is used to control the supply of chemical solutions to semiconductor wafers. The diaphragm pump displaces a diaphragm that divides a space formed within its body into a chemical solution chamber and a drive chamber. By changing the pressure within the drive chamber to positive and negative pressure, the diaphragm is alternately displaced between the chemical solution chamber side and the drive chamber side, thereby drawing in and discharging chemical solutions. The diaphragm pump is equipped with a magnet and a magnet position sensor for detecting the displacement of the diaphragm. A connecting portion protrudes from the diaphragm portion at the center of the diaphragm on the drive chamber side, and the magnet is fixed to this connecting portion by screws. The magnet position sensor is located on the body side. By detecting the diaphragm position using this magnet position, the amount of chemical solution discharged can be controlled to a predetermined quantity (for example, see Patent Document 1).

[0003] Furthermore, in order to suppress particulates generated from the surface of the diaphragm, the diaphragm pump uses PFA (a copolymer resin of tetrafluoroethylene and perfluoroalkyl vinyl ether) as the diaphragm material, and smooths its surface by extrusion molding. (For example, please refer to Patent Document 2.)

[0004] Prior technology documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2006-46284

[0007] Patent Document 2: Japanese Patent No. 6602553 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] The diaphragm displacement of a diaphragm pump alternates between an expansion state (suction) from the neutral position towards the drive chamber and an expansion state (discharge) from the neutral position towards the chemical solution chamber. During this displacement, stress concentrates near the boundary between the connector and the membrane, making it prone to deterioration.

[0010] Furthermore, even when the diaphragm is made of a material that is difficult for particles to form, there is still a risk of particles forming from areas that deteriorate due to stress concentration. In recent years, the miniaturization of semiconductor circuits has meant that even tiny particles smaller than 20 nm, which cannot be measured by particle measurement devices, can sometimes affect semiconductor yield. Therefore, in diaphragm pumps used in semiconductor manufacturing, it is desirable to eliminate the causes of particle formation and suppress particle generation as much as possible.

[0011] means of solving problems

[0012] One type of diaphragm pump aimed at solving the above-mentioned problems is (1) a diaphragm pump that draws in and discharges a chemical solution supplied to a semiconductor wafer in a predetermined quantity, comprising a diaphragm, a body, a detection section, and a detection section. The diaphragm is formed into a membrane shape using resin. The body has a space in which the diaphragm is disposed to be displaceable, the space being divided by the diaphragm into a chemical solution chamber into a drive chamber into which the chemical solution flows and a drive chamber into which an operating fluid is supplied to displace the diaphragm. The detection section is located on the side of the body that is held in contact with the diaphragm and is movable following the diaphragm. The detection section detects the displacement of the diaphragm based on the position of the detection section.

[0013] In the diaphragm pump with the above configuration, the position of the diaphragm is detected based on the position of the detection part that moves along with the diaphragm. Since only the detection part is in contact with the diaphragm when the membrane-like diaphragm moves along with it, the detection part can deform freely. Therefore, deterioration of the diaphragm due to stress concentration is difficult to occur, and the generation of particulate matter is suppressed. Thus, in the diaphragm pump with the above configuration, which has the function of detecting diaphragm displacement, the durability of the diaphragm is improved, and the generation of particulate matter can be suppressed.

[0014] (2) In the diaphragm pump described in (1), it is preferable that the diaphragm is formed by extrusion molding, or roll forming, or both extrusion molding and roll forming.

[0015] In the diaphragm pump with the above configuration, because the surface of the diaphragm is not machined, there are no rough edges or unevenness on the surface of the diaphragm, and it is smooth. Therefore, the generation of particles based on the unevenness of the diaphragm is suppressed.

[0016] (3) In the diaphragm pump described in (1) or (2), it is preferable that the diaphragm is made of PFA (a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether).

[0017] In the diaphragm pump having the above-described structure, compared with a diaphragm made of PTFE (polytetrafluoroethylene) that is compressed and molded, the generation of particles at the liquid contact surface is suppressed by using a diaphragm made of PFA as the raw material. Therefore, by using a diaphragm made of PFA as the raw material, the generation of particles that affect the manufacturing of semiconductors can be suppressed.

[0018] (4) In any of the diaphragm pumps described in (1) to (3), it is preferable that the movable distance of the aforementioned tested part is smaller than the maximum stroke of the aforementioned diaphragm.

[0019] In the diaphragm pump configured as described above, since the part being tested follows the diaphragm for a portion of the diaphragm's stroke but does not follow it for the remainder of the stroke, the diaphragm is less likely to wear off due to friction against the part being tested, thus improving the durability of the diaphragm.

[0020] (5) In any of the diaphragm pumps described in (1) to (4), it is preferable that the diaphragm thickness is more than 0.1 mm and less than 0.3 mm.

[0021] In the diaphragm pump configured as described above, because the diaphragm thickness is thin, ranging from 0.1 mm to 0.3 mm, the tension during diaphragm displacement is low, and the diaphragm deforms more easily in response to pressure changes within the drive chamber. Therefore, the diaphragm pump configured as described above can be expected to have good discharge performance. Furthermore, because the diaphragm thickness is thin, stress concentration during deformation is less likely to cause deterioration, thus suppressing the generation of particulate matter.

[0022] (6) The diaphragm pump described in (5) further includes a biasing member that biases the aforementioned detected part toward the space portion. It is preferable that the biasing force of the aforementioned biasing member is 0.05N or more and 0.15N or less.

[0023] In the diaphragm pump configured as described above, the biasing force of the biasing member that biases the part to be tested toward the space is a load that is not significantly greater than the tension of the thinner diaphragm, so the diaphragm is easier to deform freely for the part to be tested.

[0024] (7) In any of the diaphragm pumps described in (1) to (6), it is preferable that the diaphragm is disposed on the body in a state of partial deflection corresponding to the aforementioned space when no load is applied.

[0025] In the diaphragm pump described above, since tension does not act on the diaphragm when it is displaced, pressure loss is unlikely to occur during diaphragm displacement, and the discharge rate of the chemical solution remains stable. Furthermore, stress concentration is less likely to occur on the displaced diaphragm, making diaphragm damage less probable.

[0026] (8) In any one of (1) to (7) of the diaphragm pump, the aforementioned body has a bottomed retaining hole that opens into the inner wall of the aforementioned drive chamber. The aforementioned retaining hole houses the aforementioned detection part and a biasing member that biases the aforementioned detection part toward the space part. It is preferable that the aforementioned detection part is disposed on the outside of the aforementioned retaining hole.

[0027] In the diaphragm pump configured as described above, since the detection section and the detection section are arranged in a state of airtightness of the drive chamber, there is no leakage of the operating fluid from the detection section, and there is no corrosion of the detection section by the chemical solution that permeates the diaphragm.

[0028] (9) In the diaphragm pump described in (8), the aforementioned detection part has a magnet detected by the aforementioned detection part, a movable part on which the aforementioned magnet is mounted and is housed in the aforementioned holding hole in a way that can protrude or retract, and a stop part disposed inside the aforementioned holding hole to restrict the movement of the aforementioned movable part.

[0029] In the diaphragm pump configured as described above, particles generated from the detection unit are suppressed, and the detection unit can be movably disposed in the body in a compact structure, independent of the diaphragm.

[0030] Invention Effects

[0031] Based on the technology disclosed in this specification, in a diaphragm pump that has the function of detecting diaphragm displacement, the durability of the diaphragm is improved, thereby suppressing the generation of particulate matter. Attached Figure Description

[0032] Figure 1 is a cross-sectional view of a diaphragm pump, showing the no-load state.

[0033] Figure 2 is a cross-sectional view of the diaphragm pump, showing the pump at the end of its discharge phase.

[0034] Figure 3 is a cross-sectional view of a diaphragm pump, showing the suction end state.

[0035] Figure 4 is an enlarged view of section A1 of Figure 1.

[0036] Figure 5 is an enlarged view of section A2 of Figure 2.

[0037] Figure 6 is an enlarged view of the part being inspected.

[0038] Figure 7 is an enlarged view of section A3 of Figure 3.

[0039] Figure 8 is a cross-sectional view showing a modified example of a diaphragm pump. Detailed Implementation

[0040] The following description, based on the drawings, describes one embodiment of the present invention. This specification discloses a diaphragm pump incorporated into a semiconductor manufacturing apparatus and used for supplying a resist.

[0041] The diaphragm pump 1 shown in Figures 1 to 3 is installed in the chemical solution supply line of a semiconductor manufacturing apparatus and is used for supplying and controlling the chemical solution to a semiconductor wafer (not shown). In this embodiment, the diaphragm pump 1, as an example of a chemical solution, controls a photoresist. The diaphragm pump 1 alternately switches between a positive pressure state and a negative pressure state via the drive chamber 15. As shown in Figure 1, the diaphragm 20 is displaced towards the chemical solution chamber 14 side and the drive chamber 15 side as shown in Figures 2 and 3, and can dispense and draw the photoresist in predetermined quantities.

[0042] As shown in Figure 1, the diaphragm pump 1 includes a body 10, a diaphragm 20, a detection part 3, and a detection part 4.

[0043] The main body 10 consists of a first outer shell 11 and a second outer shell 12 connected by a diaphragm 20. The first outer shell 11 and the second outer shell 12 are formed of a highly corrosion-resistant fluoropolymer. In this embodiment, the first outer shell 11 and the second outer shell 12 are made of PFA.

[0044] On the surfaces of the first outer shell 11 and the second outer shell 12 that abut against each other, the first concave surface 111 and the second concave surface 121 are formed into a generally dome shape. A space 13 is formed between the first outer shell 11 and the second outer shell 12 via the first concave surface 111 and the second concave surface 121. In the space 13, a diaphragm 20 is configured to be displaceable. The diaphragm 20 is membrane-shaped and is held between the first outer shell 11 and the second outer shell 12 by its outer edge, thus airtightly dividing the space 13 into a chemical solution chamber 14 and a drive chamber 15.

[0045] The first housing 11 is formed with an inflow path 16 and an outflow path 17 opening into the first concave surface 111, and a flow path for the flow of resist liquid into and out is formed in the chemical solution chamber 14. The second housing 12 is formed with an operating flow path (not shown) opening into the second concave surface 121, and a flow path for the supply and exhaust of operating air is formed in the drive chamber 15. Operating air is an example of "operating fluid".

[0046] The diaphragm 20 is formed from a resin that is easily moldable. It is preferable that the raw material for the diaphragm 20 is a corrosion-resistant fluororesin. More preferably, it is preferable that the raw material for the diaphragm 20 is PFA. The inventors conducted experiments on a diaphragm pump 1 incorporating a PFA-made diaphragm 20 and a diaphragm pump incorporating a PTFE (polytetrafluoroethylene) diaphragm formed by compression molding. The experiments involved supplying a fixed amount of fluid and counting the number of particles contained in this fixed amount of fluid using a particle counter. The results confirmed that the PFA-made diaphragm generated fewer particles than the PTFE-made diaphragm.

[0047] Furthermore, the raw material for the separator 20 can be any fluoropolymer other than PFA, such as PP (polypropylene), PVDF (vinylidene fluoride), or PVDC (polyvinylidene chloride). Separators formed from these fluoropolymers are expected to have a greater effect on suppressing particulate matter than separators made from PTFE. In addition, separators made from these fluoropolymers can be formed by extrusion molding, roll forming, or both, and the effect of suppressing particulate matter generation is expected to be even higher.

[0048] The diaphragm 20 is formed as a thin membrane. It is preferable that the membrane thickness of the diaphragm 20 is between 0.1 mm and 0.3 mm. This is because if the membrane thickness of the diaphragm 20 is less than 0.1 mm, there is a possibility of it breaking when it comes into contact with the part being detected 3 and rubs against it. On the other hand, if the membrane thickness of the diaphragm 20 is greater than 0.3 mm, there is a possibility of increased tension on the diaphragm 20, reduced pump discharge performance, and the generation of particulate matter due to stress concentration.

[0049] The diaphragm 20 is formed such that the portion disposed in the space 13 is flexed to one side. As shown in Figure 4, when the diaphragm 20 is assembled to the body 10 in a no-load state, the detection part 3 is positioned away from the diaphragm 20 from the predetermined quantity L1, so that tension does not act on the diaphragm 20. In particular, by forming the diaphragm 20 in a flexed manner towards the chemical solution chamber 14, the range of displacement of the diaphragm 20 from the detection part 3 is widened, and wear of the diaphragm 20 can be suppressed. The position of the diaphragm 20 in the no-load state is designated as the "neutral position P1".

[0050] After the diaphragm 20 of this embodiment is formed into the shape shown in Figure 1 by extrusion molding, its surface is smoothed by roll forming. This is to suppress the generation of particles from the surface of the diaphragm 20.

[0051] The main body 10 has a cylindrical retaining hole 122 at the center of the second concave surface 121. The detection part 3 is a separate entity from the diaphragm 20 and is movably housed in the retaining hole 122. The detection part 3 is held on the side of the main body 10 that is in contact with the diaphragm 20 and can move along with the diaphragm 20.

[0052] The structure of the detection unit 3 will be specifically described with reference to Figures 4 through 7. Figure 4 is an enlarged view of portion A1 in Figure 1. Figure 5 is an enlarged view of portion A2 in Figure 2. Figure 6 is an enlarged view corresponding to Figure 4, showing the state in which the diaphragm 20 abuts against the detection unit 3. Figure 7 is an enlarged view of portion A3 in Figure 3.

[0053] As shown in Figures 4 to 7, the detection part 3 is constructed by a pump screw 32, a magnet 33, and a plunger 34, with the magnet 33 clamped between the pump screw 32 and the plunger 34. The pump screw 32 and the plunger 34 are examples of "movable parts".

[0054] The detection unit 3 is movably held in the holding hole 122 along the displacement direction of the diaphragm 20 (left-right direction in the figure) using the guide member 38 and the bushing 39. The detection unit 3 is constantly biased by the spring 36 in the direction protruding from the holding hole 122.

[0055] As shown in Figure 4, the magnet 33 is cylindrical, including a hollow cavity 331. The pump screw 32 has a head 322 at one end of the leg 321 where the male screw portion 321a is formed. The outer diameter of the head 322 is the same as the outer diameter of the outer peripheral surface 332 of the magnet 33. The plunger 34 is generally cylindrical, and its surface 345, which faces the contact surface 343 that contacts the diaphragm 20, has an opening for a female screw hole 341 for fastening the male screw portion 321a.

[0056] The tested part 3 screws the leg 321 of the pump screw 32, which passes through the hollow hole 331 of the magnet 33, into the plunger 34, thereby holding the magnet 33 in a state where its movement in the axial direction is restricted between the plunger 34 and the head 322 of the pump screw 32. The plunger 34 has a step portion 342 formed in a ring shape along the outer periphery of the opening of the female screw hole 341. The magnet 33 is prevented from loosening in the radial direction by its step portion 342 and the leg 321 of the pump screw 32.

[0057] The movement of the detected part 3 is regulated by the guide member 38. The guide member 38 is cup-shaped, including an opening 381 on one side, and has an insertion hole 383 formed on the closed surface 382. The guide member 38 is inserted into the retaining hole 122 with its open end protruding against the bottom surface of the retaining hole 122.

[0058] The head 322 of the pump screw 32 is configured to protrude radially outward along the outer periphery of the end face opposite to the leg 321. The inner diameter of the insertion hole 383 is larger than the outer diameter of the head 322 and smaller than the outer diameter of the flange 323. The detection part 3 is mounted on the guide member 38 such that the flange 323 can abut against the closed surface 382 from the opening 381 side.

[0059] Spring 36 is compressed between the head 322 of pump screw 32 and the bottom surface of retaining hole 122, and constantly applies a biasing force to the detected part 3 in the direction of protrusion from retaining hole 122 toward drive chamber 15. Spring 36 is an example of a "biasing member". The detected part 3 is locked to the closed surface 382 by flange 323, and the movement in the protruding direction from retaining hole 122 toward drive chamber 15 is restricted. That is, the maximum amount of protrusion of the detected part 3 toward drive chamber 15 is defined. The position of the detected part 3 in this case is referred to as "closed position P11".

[0060] As shown in Figure 7, the detected part 3 is locked to the bottom surface of the retaining hole 122 by the flange 323, thus restricting its movement in the retraction direction from the drive chamber 15 toward the retaining hole 122. In other words, the minimum amount of protrusion of the detected part 3 toward the drive chamber 15 is defined. The position of the detected part 3 in this case is referred to as the "open position P12". In this embodiment, the flange 323, the closing surface 382, ​​and the bottom surface of the retaining hole 122 constitute an example of a "stopping part".

[0061] The contact surface 343 of the plunger 34 of the detection part 3, which is in contact with the diaphragm 20, is set to be flat, and the corners 344 of the contact surface 343 are processed with R-corner (rounded corner processing) to form a smooth curved surface. In this way, the frictional resistance generated between the detection part 3 and the diaphragm 20 is reduced.

[0062] The distance L3 by which the tested part 3 moves from the closed position P11 to the open position P12 is smaller than the maximum stroke L4 of the diaphragm 20. The maximum stroke L4 is the distance between the discharge end position P2 of the diaphragm 20 deforming along the first concave surface 111 and the full stroke position P4 of the diaphragm 20 deforming along the second concave surface 121. The tested part 3 contacts the diaphragm 20 during a portion of its stroke, as shown in Figures 6 and 7, and does not contact the diaphragm 20 during the remainder of its stroke, as shown in Figures 4 and 5, thus reducing the area of ​​contact between the diaphragm 20 and the tested part 3. This is to suppress wear on the diaphragm 20.

[0063] It is preferable that the travel distance L3 is 50% or less of the maximum stroke L4. This is to reduce the displacement range of the diaphragm 20 when in contact with the detection part 3 and to suppress wear of the diaphragm 20. More preferably, the travel distance L3 is 30% or less of the maximum stroke L4. By having the diaphragm 20 contact the detection part 3 before reaching the full stroke position P4, the load on the diaphragm 20 from the detection part 3 is reduced, thereby improving the durability of the diaphragm 20.

[0064] The diaphragm pump 1 discharges and draws the corrosion-resistant liquid by maintaining a positive pressure state and a negative pressure state in the drive chamber 15. Therefore, the spring 36 is not configured to displace the diaphragm 20, but rather to return the detected part 3 from the open position P12 to the closed position P11. Thus, the biasing force of the spring 36 is set to apply a load to the diaphragm 20 that is not significantly greater than the tension of the diaphragm 20. In this embodiment, since the diaphragm 20 has a thickness of 0.1 mm to 0.3 mm and low tension, the biasing force of the spring 36 is 0.05 N to 0.15 N.

[0065] The bushing 39 is pressed into the retaining hole 122 until it abuts against the guide member 38, thus positioning and holding the guide member 38, which is acted upon by the biasing force of the spring 36, within the retaining hole 122. Since the guide member 38 and the bushing 39 are embedded into the retaining hole 122 by pressing, the detected part 3 can be installed in the retaining hole 122 without twisting the spring 36. The bushing 39 is disposed between the inner circumferential surface of the retaining hole 122 and the outer circumferential surface of the plunger 34, thus holding the plunger 34 in a slidable position.

[0066] Furthermore, the pump screw 32, plunger 34, guide member 38, and bushing 39 are formed using fluoropolymer resin. These are preferably formed using processing methods other than machining, such as extrusion molding and injection molding. This is to suppress the generation of microparticles from cutting marks and to ensure that the detected part 3 can move responsively to the displacement of the diaphragm 20.

[0067] Returning to Figure 1, the detection unit 4 is a magnetic sensor that detects the position of the detected unit 3. The detection unit 4 is positioned outside the holding hole 122 and detects the displacement of the diaphragm 20 based on the position of the detected unit 3. The detection unit 4 is connected to a main controller (not shown) that manages the process performed on the semiconductor wafer. When the detected unit 3 is positioned in the open position P12, the detection unit 4 sends a detection signal to the main controller (not shown); when the detected unit 3 is not positioned in the open position P12, the detection unit 4 does not send a detection signal to the main controller (not shown).

[0068] Next, the operation of the diaphragm pump 1 will be explained. If the diaphragm pump 1 shown in Figure 1 is in a positive pressure state where the drive chamber 15 is supplied with operating air, then as shown in Figure 2, the diaphragm 20 is deformed along the first concave surface 111 and positioned at the discharge end position P2. Herein, the volume of the chemical solution chamber 14 is minimized.

[0069] As shown in Figure 5, when the diaphragm 20 is positioned at the discharge end position P2, the flange portion 323 of the pump screw 32 is engaged with the closed surface 382 of the guide member 38 and positioned at the closed position P11.

[0070] The diaphragm 20 is positioned away from the detection section 3, which is positioned in the closed position P11, and is placed in the dispensing end position P2. Furthermore, the diaphragm 20 is assembled to the body 10 in a flexed state towards the first concave surface 111 when there is no load. Therefore, the tension acting on the diaphragm 20 at the dispensing end position P2 is smaller compared to a diaphragm assembled to the body 10 in a flat state when there is no load.

[0071] The detection unit 4 shown in Figure 2 did not detect the magnet 33 of the detected unit 3 in the closed position P11. Therefore, the detection unit 4 did not send a detection signal to the main controller (not shown).

[0072] As shown in Figure 2, if the operating air is exhausted from the drive chamber 15 and the internal pressure of the drive chamber 15 decreases, the diaphragm 20 will deform towards the second concave surface 121 (drive chamber 15 side) by its own elasticity, and the sealing force of the diaphragm 20 sealing the first concave surface 111 will decrease.

[0073] As shown in Figure 5, the first concave surface 111 has a plurality of grooves 112 formed in the circumferential direction, and a plurality of grooves 113 formed in the radial direction. Therefore, if the sealing force decreases, the anti-corrosion liquid input into the inflow path 16 begins to flow towards the outflow path 17 after passing through the grooves 112 and 113. This results in a force acting on the diaphragm 20 in the direction away from the first concave surface 111 (towards the second concave surface 121).

[0074] Thus, when the diaphragm pump 1 starts to exhaust operating air from the drive chamber 15, the diaphragm 20 responds well to the first concave surface 111 by its own elasticity and the pressure of the anti-corrosion liquid, and can move towards the second concave surface 121 side (drive chamber 15 side).

[0075] As shown in Figure 6, the diaphragm 20 moves from the dispensing end position P2 to the contact position P3 where it abuts the contact surface 343 of the detected part 3 while separated from the detected part 3. Therefore, the detected part 3 does not move with the diaphragm 20 between the dispensing end position P2 and the contact position P3, and is positioned in the closed position P11.

[0076] When the diaphragm 20 deforms by expanding from the abutment position P3 toward the second concave surface 121 (drive chamber 15 side), the contact surface 343 of the detected part 3 is pushed toward the holding hole 122. The biasing force of the spring 36 biasing the detected part 3 is generally small, between 0.05N and 0.15N. Therefore, the detected part 3 follows the diaphragm 20 without impairing its displacement and can move in the retracting direction.

[0077] As shown in Figure 3, in diaphragm pump 1, the diaphragm 20 deforms along the second concave surface 121 and is displaced to the full-stroke position P4. Corresponding to the deformation of the diaphragm 20 in the manner of expansion along the second concave surface 121, the corrosion resist flows into the chemical solution chamber 14. When the diaphragm 20 is displaced to the full-stroke position P4, the volume of the chemical solution chamber 14 becomes maximum.

[0078] As shown in Figure 7, the movement of the detected part 3 in the retraction direction is restricted by the head 322 of the pump screw 32 protruding against the bottom surface of the retaining hole 122, and it is positioned in the open position P12. At this time, the plunger 34 of the detected part 3 protrudes only slightly towards the drive chamber 15. Thus, the detected part 3 is pushed into the retaining hole 122 by the diaphragm 20, which is positioned in the full stroke position P4, and is stably positioned in the open position P12.

[0079] The contact surface 343 of the detected part 3 is set to be flat, and the corner 344 of this contact surface 343 is a smooth curved surface. Therefore, the diaphragm 20, which is positioned at the full stroke position P4, deforms slowly between the contact surface 343 and the second concave surface 121, and it is difficult for stress concentration to occur in the part that contacts the detected part 3. Thus, it is possible to suppress the occurrence of particles from the deteriorated part caused by stress concentration.

[0080] When the detection unit 4 shown in Figure 3 is configured in the open position P12, the detected unit 33 is detected, and a detection signal is sent to the main controller (not shown). Based on the detection signal, the main controller (not shown) detects that the diaphragm pump 1 has drawn a predetermined amount of resist solution.

[0081] If the diaphragm pump 1 shown in Figure 3 is supplied with positive pressure by operating air to the drive chamber 15, then as shown in Figure 2, the diaphragm 20 will be displaced to the discharge end position P2. The predetermined amount of corrosion resist that flows into the chemical solution chamber 14 is discharged from the outflow path 17 by the expansion of the diaphragm 20 towards the first concave side 111.

[0082] As shown in Figure 6, if the diaphragm 20 begins to displace towards the first concave surface 111 (the chemical solution chamber 14 side), the detected part 3 is biased by the spring 36 and moves in the protruding direction. In other words, the detected part 3 can move along with the diaphragm 20.

[0083] The part to be detected 3 and the diaphragm 20 are separate entities, and the part to be detected 3 only contacts the diaphragm 20. Therefore, when the part to be detected 3 moves in accordance with the diaphragm 20, the diaphragm 20 can freely deform in response to the part to be detected 3, and the tension acting on the part in contact with the part to be detected 3 is small.

[0084] Furthermore, the bias force of the spring 36 is generally small, ranging from 0.05N to 0.15N. Therefore, the load acting on the portion of the detected part 3 that contacts the diaphragm 20 is relatively small. Consequently, even if the detected part 3 contacts the diaphragm 20 and moves along with it, the portion of the diaphragm 20 in contact with the detected part 3 is less prone to wear and particle generation.

[0085] As shown in Figure 5, the tested part 3 is engaged with the closed surface 382 of the guide member 38 by the flange 323 of the pump screw 32, and cannot move in the protruding direction beyond the closed position P11. Therefore, during the period from the contact position P3 to the discharge end position P2, the diaphragm 20 is displaced due to separation from the tested part 3, so it will not bear a load other than the operating air, and deterioration caused by stress concentration is unlikely to occur.

[0086] If the detection unit 4 shown in Figure 2 moves from the open position P12 to the closed position P11, the detection unit 3 cannot detect the magnet 33, and therefore does not send a detection signal to the main controller (not shown). The main controller (not shown) detects that the diaphragm pump 1 has supplied a predetermined amount of resist to the semiconductor wafer (not shown) because it has not received a detection signal.

[0087] Because the discharge end position P2 and the full stroke position P4 of the diaphragm pump 1 are defined by the first concave surface 111 and the second concave surface 121, the maximum and minimum volumes of the chemical solution chamber 14 are stable. Therefore, even with repeated discharge and suction, the diaphragm pump 1 can accurately supply a predetermined amount of resist to the semiconductor wafer (not shown).

[0088] Since the diaphragm 20 is assembled to the body 10 in a no-load state, with the portion corresponding to the space 13 flexing towards the first concave surface 111, tension does not act during displacement. Therefore, the diaphragm pump 1 experiences minimal pressure loss during diaphragm 20 displacement, and the discharge rate of the corrosion-resistant fluid remains stable.

[0089] Because the diaphragm 20 is thin and experiences less tension, it deforms more easily in response to pressure changes in the drive chamber 15. Therefore, the diaphragm pump 1 can be expected to have good discharge performance. Furthermore, even with repeated deformation, stress concentration-induced degradation is unlikely to occur in the diaphragm 20, and particulate generation can be suppressed.

[0090] The diaphragm 20 uses PFA, which is difficult for microparticles to form, as a raw material. Furthermore, the diaphragm 20 is formed through extrusion molding and roll forming, eliminating the unevenness caused by cutting marks, thus minimizing microparticle formation. Therefore, even with repeated deformation, microparticles are unlikely to be generated from the surface of the diaphragm 20.

[0091] Furthermore, since the diaphragm 20 is designed to be a separate entity from the detection section 3 and can be displaced separately from the detection section 3, loads other than operating air do not apply. As a result, the tension acting on the diaphragm 20 is relatively small, stress concentration on the diaphragm 20 is unlikely to cause deterioration, and particles are unlikely to be generated from the deteriorated parts.

[0092] As shown in Figures 5 to 7, in the diaphragm pump 1, the detected part 3 moves in contact with the diaphragm 20 during a portion of the diaphragm 20's stroke. Therefore, compared to the case where the detected part contacts the diaphragm 3 throughout its entire stroke, the diaphragm pump 1 is less likely to experience wear due to friction against the detected part 3, thus improving the durability of the diaphragm 20.

[0093] Assuming that even if the diaphragm 20 wears down due to friction with the detection part 3 and particles are generated, since the detection part 3 is located on the drive chamber 15 side, the particles are sealed in the drive chamber 15 and do not mix into the resist solution.

[0094] The diaphragm pump 1 has the detection section 3 disposed inside the holding hole 122, and the detection section 4, which detects the detection section 3, disposed outside the holding hole 122. In other words, the diaphragm pump 1 configures the detection section 3 and the detection section 4 in an airtight state within the drive chamber 15. Therefore, there is no leakage of operating air from the detection section 3, and no corrosion of the detection section 4 by the resist liquid permeating the diaphragm 20.

[0095] Furthermore, the diaphragm pump 1, with the detection part 3 slidably disposed in the holding hole 122 and the flange portion 323 of the pump screw 32 abutting against the closed surface 382 of the guide member 38 and the bottom surface of the holding hole 122, can suppress particles generated from the detection part 3 by regulating the movement range of the detection part 3. In addition, the diaphragm pump 1 can allow the detection part 3 to be movably disposed in the body 10 in a compact structure, independent of the diaphragm 20.

[0096] As explained above, in the diaphragm pump 1 of this embodiment, the position of the diaphragm 20 is detected based on the position of the detection part 3, which moves in tandem with the diaphragm 20. Since only the detection part 3 is in contact with the diaphragm 20 when the membrane 20 moves in tandem with the detection part 3, the detection part 3 can deform freely. Therefore, stress concentration-induced deterioration of the diaphragm 20 is difficult to occur, and the generation of particulate matter is suppressed. Thus, in the diaphragm pump 1 according to this embodiment, which has the function of detecting the displacement of the diaphragm 20, the durability of the diaphragm 20 is improved, and the generation of particulate matter can be suppressed.

[0097] The present invention is not limited to the above embodiments, and various applications are possible. For example, the contact surface 343 of the detected part 3 may not be a flat surface, but a gently convex surface or a gently concave surface.

[0098] For example, the diaphragm 20 can be formed by either extrusion molding or roll forming. Alternatively, the diaphragm 20 can be formed by injection molding. Furthermore, the diaphragm 20 can also be formed by extruding molten, plasticized resin through a tube forming die in an extruder to form a thin film tube, and then cutting this thin film tube extrusion molded product to become a sheet.

[0099] For example, the membrane thickness of the diaphragm 20 may be between 0.1 mm and 0.3 mm. However, a thin diaphragm 20 with a membrane thickness of 0.1 mm to 0.3 mm can be formed by extrusion molding, roll forming, or both, and the effect of suppressing the generation of particulate matter can be expected to be higher.

[0100] If the diaphragm 20 and the detected part 3 are separate entities and separable, the moving distance L3 of the detected part 3 can be the same as the maximum stroke L4 of the diaphragm 20. However, by making the moving distance L3 smaller than the maximum stroke L4, the diaphragm 20 is moved away from the detected part 3, and wear due to friction with the detected part 3 can be suppressed.

[0101] For example, as shown in Figure 8, the diaphragm 20 can be arranged in a flattened state in the space 13 when there is no load applied.

[0102] For example, the diaphragm 20 may be formed into a flat sheet shape. However, by shaping the diaphragm 20 such that the portion disposed in the space 13 is bent, it can be easily disposed on the body 10 in a state of partial deflection corresponding to the space 13 when there is no load.

[0103] For example, the detection section 4 may be configured to connect to the holding hole 122.

[0104] For example, the pump screw 32 may be divided into a first part that engages with the guide member 38 and a second part that includes a male screw portion 321a that is fastened to the female screw hole 341 of the plunger 34.

[0105] For example, the movable part can be formed by a single component, and the magnet 33 can be assembled into this movable part by insert molding.

[0106] Symbol Explanation

[0107] 1: Diaphragm pump

[0108] 3: The part being tested

[0109] 4: Detection Department

[0110] 10: Ontology

[0111] 20: Diaphragm

Claims

1. A diaphragm pump for drawing in and discharging a chemical solution supplied to a semiconductor wafer in a predetermined manner, comprising: A membrane-like diaphragm is formed using resin; The body has a space in which the diaphragm is configured to be displaceable, the space being divided by the diaphragm into a chemical solution chamber into which the chemical solution flows in, and a drive chamber into which an operating fluid is supplied to displace the diaphragm; The detected part is located on the side of the body that is held in contact with the diaphragm on the side of the drive chamber and is movable following the diaphragm; as well as The detection unit detects the displacement of the diaphragm based on the position of the detected part. The movable distance of the detected part is smaller than the maximum stroke of the diaphragm.

2. The diaphragm pump as claimed in claim 1, wherein, The diaphragm is formed by extrusion molding, roll forming, or both extrusion molding and roll forming.

3. The diaphragm pump as described in claim 1 or 2, wherein, The diaphragm is made of PFA.

4. The diaphragm pump as described in claim 1 or 2, wherein, The membrane thickness is between 0.1 mm and 0.3 mm.

5. A diaphragm pump for drawing in and discharging a chemical solution supplied to a semiconductor wafer in a predetermined manner, comprising: A membrane-like diaphragm is formed using resin; The body has a space in which the diaphragm is configured to be displaceable, the space being divided by the diaphragm into a chemical solution chamber into which the chemical solution flows in, and a drive chamber into which an operating fluid is supplied to displace the diaphragm; The detected part is located on the side of the body that is held in contact with the diaphragm on the side of the drive chamber and is movable following the diaphragm; The detection unit detects the displacement of the diaphragm based on the position of the detected part; as well as A biasing member biases the detected part toward the space portion; The membrane thickness is 0.1 mm to 0.3 mm. The biasing force of the biasing member is between 0.05N and 0.15N.

6. A diaphragm pump for drawing in and discharging a chemical solution supplied to a semiconductor wafer in a predetermined manner, comprising: A membrane-like diaphragm is formed using resin; The body has a space in which the diaphragm is configured to be displaceable, the space being divided by the diaphragm into a chemical solution chamber into which the chemical solution flows in, and a drive chamber into which an operating fluid is supplied to displace the diaphragm; The detected part is located on the side of the body that is held in contact with the diaphragm on the side of the drive chamber and is movable following the diaphragm; as well as The detection unit detects the displacement of the diaphragm based on the position of the detected part; When the diaphragm is in an unloaded state without any applied load, it is disposed on the body in a state of partial deflection corresponding to the space portion.

7. A diaphragm pump for drawing in and discharging a chemical solution supplied to a semiconductor wafer in a predetermined manner, comprising: A membrane-like diaphragm is formed using resin; The body has a space in which the diaphragm is configured to be displaceable, the space being divided by the diaphragm into a chemical solution chamber into which the chemical solution flows in, and a drive chamber into which an operating fluid is supplied to displace the diaphragm; The detected part is located on the side of the body that is held in contact with the diaphragm on the side of the drive chamber and is movable following the diaphragm; as well as The detection unit detects the displacement of the diaphragm based on the position of the detected part; The body has a bottomed retaining hole that opens into the inner wall of the drive chamber; The retaining hole houses the part to be detected and a biasing member that biases the part to be detected toward the space portion. The detection part is disposed on the outside of the retaining hole.

8. The diaphragm pump as claimed in claim 7, wherein, The detected part has: The magnet was detected by the detection unit. The movable part, on which the magnet is mounted, is received in the retaining hole in a way that allows it to protrude or retract. as well as A stop is disposed inside the retaining hole to restrict the movement of the movable part.

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