Diaphragm pump

Abstract

To provide a diaphragm pump that has a function of detecting a displacement of a diaphragm, and restrains occurrence of particles by improving durability of the diaphragm.SOLUTION: A diaphragm pump 1 for sucking and discharging resist liquid to be supplied to a semiconductor wafer by a predetermined amount is provided with a diaphragm 20, a body 10, a detected part 3, and a detecting part 4. The diaphragm 20 is made by forming a resin in a film shape. The body 10 comprises a space part 13 in which the diaphragm 20 is arranged so as to be displaceable. The space part 13 is partitioned into a chemical liquid chamber 14 and a driving chamber 15. The detected part 3 is held by the body 10 so as to be capable of coming into contact with a surface of the diaphragm 20 located on the side of the driving chamber 15, and can move by following the diaphragm 20. The detecting part 4 detects a displacement of the diaphragm 20 on the basis of the position of the detected part 3.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a diaphragm pump installed in a chemical liquid supply line of a semiconductor manufacturing device. [Background technology]

[0002] A diaphragm pump is installed in a chemical supply line of a semiconductor manufacturing device and is used to control the supply of chemical liquid to be supplied to semiconductor wafers. A diaphragm pump displaceably houses a diaphragm that divides a space formed inside a body into a chemical chamber and a drive chamber, and alternately displaces the diaphragm toward the chemical chamber side and the drive chamber side by changing the pressure inside the drive chamber to positive pressure and negative pressure, thereby sucking in and discharging the chemical liquid. A magnet and a magnet position sensor for detecting the displacement of the diaphragm are attached to the diaphragm. A connecting part is provided at the center of the drive chamber side of the diaphragm so as to protrude from the membrane part, and a magnet is fixed to the connecting part by a screw, and a magnet position sensor is installed on the body side. The discharge amount of the chemical liquid can be controlled to a predetermined amount by detecting the diaphragm position based on the magnet position (see, for example, Patent Document 1).

[0003] In addition, in order to suppress particles from being generated on the surface of the diaphragm, the diaphragm of the diaphragm pump is made of PFA (tetrafluoroethylene-perfluoroalkylvinylether copolymer resin) and the surface is smoothed by extrusion molding (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-46284 A [Patent Document 2] Patent No. 6602553 Summary of the Invention [Problem to be solved by the invention]

[0005] The diaphragm of a diaphragm pump is displaced by alternately expanding from a neutral position toward the drive chamber (suction) and expanding from a neutral position toward the chemical chamber (discharge). When the diaphragm is displaced, stress is concentrated near the boundary between the connection part and the membrane part, which makes the diaphragm prone to deterioration.

[0006] Even if a material that is less likely to generate particles is selected for the diaphragm, there is a risk that particles will be generated from areas that have deteriorated due to stress concentration. In recent years, semiconductor circuits have become increasingly finer, and even minute particles less than 20 nm in size that cannot be measured by particle measuring devices can affect semiconductor yields. Therefore, in diaphragm pumps used in semiconductor manufacturing, it is desirable to eliminate causes of particle generation as much as possible and suppress particle generation. [Means for solving the problem]

[0007] One aspect of a diaphragm pump made for the purpose of solving the above problems is (1) a diaphragm pump that sucks in and discharges a predetermined amount of chemical liquid to be supplied to a semiconductor wafer, comprising a membrane-like diaphragm formed from resin, and a space in which the diaphragm is displaceably positioned, the space being partitioned by the diaphragm into a chemical liquid chamber into which the chemical liquid flows and a drive chamber into which an operating fluid that displaces the diaphragm is supplied, a detectable portion held by the body so as to be able to come into contact with a surface of the diaphragm located on the drive chamber side and which can move in accordance with the diaphragm, and a detection portion that detects the displacement of the diaphragm based on the position of the detectable portion.

[0008] In a diaphragm pump having the above configuration, the position of the diaphragm is detected based on the position of the detected part that moves following the diaphragm. When the detected part moves following the diaphragm, the film-like diaphragm can freely deform relative to the detected part because the detected part and the diaphragm are only in contact with each other. Therefore, the diaphragm is less likely to deteriorate due to stress concentration, and the generation of particles is suppressed. Therefore, according to the diaphragm pump having the above configuration, in a diaphragm pump having a function of detecting the displacement of the diaphragm, the durability of the diaphragm can be improved and the generation of particles can be suppressed.

[0009] (2) In the diaphragm pump described in (1), it is preferable that the diaphragm is formed by extrusion molding, roll molding, or both.

[0010] In the diaphragm pump having the above configuration, the surface of the diaphragm is not machined, so there are no irregularities due to machined marks on the surface of the diaphragm, and the surface is smooth. This reduces the generation of particles due to the irregularities on the diaphragm.

[0011] (3) In the diaphragm pump described in (1) or (2), the material of the diaphragm is preferably PFA.

[0012] In a diaphragm pump having the above configuration, a diaphragm made from PFA reduces the generation of particles at the liquid contact surface compared to a diaphragm made from compression molded PTFE, so by using a diaphragm made from PFA, it is possible to reduce the generation of particles that can affect semiconductor manufacturing.

[0013] (4) In the diaphragm pump according to any one of (1) to (3), it is preferable that the distance that the detected part can move is smaller than the maximum stroke amount of the diaphragm.

[0014] In the diaphragm pump configured as described above, the detected portion follows the diaphragm during part of the diaphragm's stroke and does not follow the diaphragm during the remaining stroke, so that the diaphragm is less likely to rub against the moving portion and wear out, improving the durability of the diaphragm.

[0015] (5) In the diaphragm pump described in any one of (1) to (4), it is preferable that the diaphragm has a membrane thickness of 0.1 mm or more and 0.3 mm or less.

[0016] In the diaphragm pump with the above configuration, the thickness of the diaphragm is thin, between 0.1 mm and 0.3 mm, so the tension when the diaphragm is displaced is small and the diaphragm is easily deformed in response to fluctuations in the internal pressure of the drive chamber. Therefore, the diaphragm pump with the above configuration can be expected to have good discharge performance. In addition, the diaphragm is thin and is less likely to deteriorate due to stress concentration when deforming, so the generation of particles can be suppressed.

[0017] (6) In the diaphragm pump described in (5), it is preferable that a biasing member that biases the detected portion toward the space portion is provided, and the biasing force of the biasing member is 0.05 N or more and 0.15 N or less.

[0018] In the diaphragm pump having the above configuration, the biasing force of the biasing member that biases the detected portion toward the space portion is a load that is not significantly greater than the tension of the thin diaphragm, so that the diaphragm can easily deform freely relative to the detected portion.

[0019] (7) In the diaphragm pump described in any one of (1) to (6), it is preferable that the diaphragm is arranged in the body in a state in which the portion corresponding to the space is deflected when the diaphragm is in an unloaded state.

[0020] In the diaphragm pump having the above configuration, tension does not act on the diaphragm when it is displaced, so pressure loss is unlikely to occur when the diaphragm is displaced, and the discharge amount of the liquid medicine is stable. In addition, in the diaphragm pump, stress concentration is unlikely to occur on the displaced diaphragm, and the diaphragm is unlikely to be damaged.

[0021] (8) In the diaphragm pump described in any one of (1) to (7), it is preferable that the body has a bottomed retaining hole that opens to an inner wall of the drive chamber, the retaining hole accommodates the detectable portion and a biasing member that biases the detectable portion toward the space portion, and the detection portion is arranged outside the retaining hole.

[0022] In the diaphragm pump of the above configuration, the detected part and the detection part are arranged with the drive chamber kept airtight, so there is no leakage of operating fluid from the detected part and the detection part is not corroded by chemical solutions that have permeated the diaphragm.

[0023] In the diaphragm pump described in (9)(8), it is preferable that the detected part has a magnet that is detected by the detection part, a movable part to which the magnet is attached and which is housed in the retaining hole so as to be able to protrude or retract, and a stopper part that is disposed inside the retaining hole and limits the movement of the movable part.

[0024] In the diaphragm pump having the above configuration, particles generated from the detected portion can be suppressed, while the detected portion can be movably disposed in the body in a compact structure and independent from the diaphragm. Effect of the Invention

[0025] According to the technology disclosed in this specification, in a diaphragm pump having a function of detecting the displacement of a diaphragm, it is possible to improve the durability of the diaphragm and suppress the generation of particles. [Brief description of the drawings]

[0026] [Figure 1]FIG. 2 is a cross-sectional view of the diaphragm pump, showing the unloaded state. [Diagram 2] FIG. 2 is a cross-sectional view of the diaphragm pump, showing a discharge completion state. [Diagram 3] FIG. 2 is a cross-sectional view of the diaphragm pump, showing a suction completion state. [Figure 4] FIG. 2 is an enlarged view of part A1 in FIG. [Diagram 5] FIG. 3 is an enlarged view of part A2 in FIG. [Figure 6] FIG. [Figure 7] FIG. 6 is an enlarged view of part A3 in FIG. 5. [Figure 8] FIG. 11 is a cross-sectional view showing a modified example of the diaphragm pump. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the accompanying drawings. This specification discloses a diaphragm pump that is incorporated in a semiconductor manufacturing device and is used to supply a resist liquid.

[0028] The diaphragm pump 1 shown in Figures 1 to 3 is disposed in a chemical liquid supply line of a semiconductor manufacturing device, and is used to control the supply of chemical liquid to be supplied to a semiconductor wafer (not shown). The diaphragm pump 1 of this embodiment controls a resist liquid as an example of a chemical liquid. The diaphragm pump 1 can discharge and suck up a predetermined amount of resist liquid by alternately putting the drive chamber 15 into a positive pressure state and a negative pressure state, so that the diaphragm 20 shown in Figure 1 is displaced toward the chemical liquid chamber 14 side and the drive chamber 15 side as shown in Figures 2 and 3.

[0029] As shown in FIG. 1, the diaphragm pump 1 includes a body 10, a diaphragm 20, a detected part 3, and a detection part 4.

[0030] In the body 10, a first housing 11 and a second housing 12 are connected via a diaphragm 20. The first housing 11 and the second housing 12 are formed of a fluororesin having high corrosion resistance. The material of the first housing 11 and the second housing 12 in this embodiment is PFA.

[0031] First housing 11 and second housing 12 have a first concave surface 111 and a second concave surface 121 formed in a substantially dome shape on their mutually abutting surfaces. Body 10 has space 13 formed between first housing 11 and second housing 12 by first concave surface 111 and second concave surface 121. Diaphragm 20 is displaceably disposed in space 13. Diaphragm 20 is in the form of a film, and an outer edge portion of diaphragm 20 is sandwiched between first housing 11 and second housing 12 to airtightly divide space 13 into drug solution chamber 14 and driving chamber 15.

[0032] In the first housing 11, an inflow passage 16 and an outflow passage 17 are formed so as to open to the first concave surface 111, and passages are formed for flowing the resist liquid in and out of the chemical liquid chamber 14. In the second housing 12, an operation passage (not shown) is formed so as to open to the second concave surface 121, and a passage is formed for supplying and exhausting operation air to and from the drive chamber 15. The operation air is an example of an "operation fluid".

[0033] The diaphragm 20 is formed of a resin that is easy to mold. The raw material of the diaphragm 20 is preferably a corrosion-resistant fluororesin. More preferably, the raw material of the diaphragm 20 is PFA. The inventors conducted a test in which a fixed amount of fluid was supplied to a diaphragm pump 1 incorporating a PFA diaphragm 20 and a diaphragm pump incorporating a compression-molded PTFE (polytetrafluoroethylene) diaphragm, and the number of particles contained in the fixed amount of fluid was counted using a particle counter, and it was confirmed that the PFA diaphragm generated fewer particles than the PTFE diaphragm.

[0034] The raw material of the diaphragm 20 may be fluororesin other than PFA, such as PP (polypropylene), PVDF (vinylidene fluoride resin), or PVDC (polyvinylidene chloride). Diaphragms made of these fluororesins are also expected to have a greater effect of suppressing particles than PTFE diaphragms. Furthermore, diaphragms made of these fluororesins are expected to have a greater effect of suppressing particle generation by forming them by extrusion molding, rolling molding, or both.

[0035] The diaphragm 20 is formed in a thin film shape. The thickness of the diaphragm 20 is preferably 0.1 mm or more and 0.3 mm or less. If the thickness of the diaphragm 20 is less than 0.1 mm, it may be torn when it comes into contact with and rubs against the detected part 3. On the other hand, if the thickness of the diaphragm 20 is more than 0.3 mm, the tension acting on the diaphragm 20 becomes large, which may reduce the pump discharge performance or generate particles due to stress concentration.

[0036] The diaphragm 20 is formed so that the portion disposed in the space 13 bends in one direction. This is because, when the diaphragm 20 is assembled in an unloaded state to the body 10 as shown in Fig. 4, the detected part 3 is disposed at a position away from the diaphragm 20 by a predetermined distance L1, so that tension is not applied to the diaphragm 20. In particular, by forming the diaphragm 20 to bend toward the liquid medicine chamber 14, the range in which the diaphragm 20 separates from the detected part 3 and is displaced is expanded, and wear of the diaphragm 20 can be suppressed. The position of the diaphragm 20 in an unloaded state is referred to as the "neutral position P1."

[0037] The diaphragm 20 of this embodiment is formed into the shape shown in Fig. 1 by extrusion molding, and then the surface is smoothed by roll molding. This is to prevent particles from being generated from the surface of the diaphragm 20.

[0038] The body 10 has a cylindrical retaining hole 122 formed in the center of the second concave surface 121. The detected part 3 is provided separately from the diaphragm 20 and is movably housed in the retaining hole 122. The detected part 3 is held by the body 10 so as to be able to come into contact with a surface of the diaphragm 20 located on the driving chamber 15 side, and can move following the diaphragm 20.

[0039] The configuration of the detected part 3 will be specifically described with reference to Figs. 4 to 7. Fig. 4 is an enlarged view of part A1 in Fig. 1. Fig. 5 is an enlarged view of part A2 in Fig. 2. Fig. 6 is an enlarged view corresponding to Fig. 4, showing a state in which the diaphragm 20 abuts against the detected part 3. Fig. 7 is an enlarged view of part A3 in Fig. 3.

[0040] 4 to 7, the detected part 3 is composed of a pump screw 32, a magnet 33, and a plunger 34, and the magnet 33 is sandwiched between the pump screw 32 and the plunger 34. The pump screw 32 and the plunger 34 are examples of a "movable part."

[0041] The detected part 3 is held in the holding hole 122 by a guide member 38 and a bush 39 so as to be movable along the displacement direction (left-right direction in the figure) of the diaphragm 20. The detected part 3 is constantly biased by the spring 3 in a direction protruding from the holding hole 122.

[0042] 4, the magnet 33 has a cylindrical shape with a hollow hole 331. The pump screw 32 has a head 322 at one end of a leg 321 on which a male thread 321a is formed. The outer diameter of the head 322 is approximately the same as the outer diameter of an outer circumferential surface 332 of the magnet 33. The plunger 34 has a substantially cylindrical shape, and a female screw hole 341 into which the male thread 321a is fastened is provided on a surface 345 opposite to a contact surface 343 that contacts the diaphragm 20.

[0043] In the detected part 3, the leg 321 of the pump screw 32 inserted into the hollow hole 331 of the magnet 33 is screwed into the plunger 34, so that the magnet 33 is held in a state where the axial movement between the plunger 34 and the head 322 of the pump screw 32 is restricted. The plunger 34 has a stepped portion 342 formed in an annular shape along the outer periphery of the opening of the female screw hole 341. The stepped portion 342 and the leg 321 of the pump screw 32 suppress radial wobble of the magnet 33.

[0044] The amount of movement of the detected part 3 is regulated by a guide member 38. The guide member 38 is cup-shaped with an opening 381 that opens on one side, and an insertion hole 383 is formed in a closed surface 382. The guide member 38 is fitted into the holding hole 122 with the open end abutting against the bottom surface of the holding hole 122.

[0045] Head 322 of pump screw 32 has flange 323 protruding radially outward along the outer periphery of the end face located opposite leg 321. The inner diameter of insertion hole 383 is larger than the outer diameter of head 322 and smaller than the outer diameter of flange 323. Detectable part 3 is attached to guide member 38 from the opening 381 side so that flange 323 can abut against closing surface 382.

[0046] The spring 36 is compressed between the head 322 of the pump screw 32 and the bottom surface of the retaining hole 122, and constantly applies a biasing force to the detected part 3 in a direction that causes the detected part 3 to protrude from the retaining hole 122 into the drive chamber 15. The spring 36 is an example of a "biasing member." The detected part 3 has its flange 323 engaged with the closing surface 382, ​​so that its movement in the protruding direction from the retaining hole 122 into the drive chamber 15 is limited. In other words, a maximum protruding amount by which the detected part 3 protrudes into the drive chamber 15 is defined. The position of the detected part 3 in this case is referred to as the "off position P11."

[0047] 7, the movement of the detected part 3 in the retraction direction from the drive chamber 15 to the retaining hole 122 is restricted by the engagement of the flange part 323 with the bottom surface of the retaining hole 122. In other words, a minimum protrusion amount of the detected part 3 into the drive chamber 15 is specified. The position of the detected part 3 in this case is referred to as "ON position P12." In this embodiment, the flange part 323, the closing surface 382, ​​and the bottom surface of the bottomed hole 122 constitute an example of a "stopper part."

[0048] In the detected part 3, the contact surface 343 of the plunger 34 that comes into contact with the diaphragm 20 is provided flat, and the corners 344 of the contact surface 343 are rounded to form a smooth curved surface. This reduces the frictional resistance generated between the detected part 3 and the diaphragm 20.

[0049] A moving distance L3 over which the detected part 3 moves from the OFF position P11 to the ON position P12 is set to be smaller than a maximum stroke amount L4 of the diaphragm 20. The maximum stroke amount is the distance between the discharge completion position P2 where the diaphragm 20 deforms along the first concave surface 111 and the full stroke position P4 where the diaphragm 20 deforms along the second concave surface 121. The detected part 3 contacts the diaphragm 20 during a part of the stroke of the diaphragm 20 as shown in Figs. 6 and 7, and does not contact the diaphragm 20 during the remaining part of the stroke of the diaphragm 20 as shown in Figs. 4 to 6, thereby reducing the range over which the diaphragm 20 contacts the detected part 3 and suppressing wear of the diaphragm 20.

[0050] The movement distance L3 is preferably 50% or less of the maximum stroke amount. This is to reduce the range of displacement of the diaphragm 20 when it is in contact with the detected part 3, and to suppress wear of the diaphragm 20. More preferably, the movement distance L3 is preferably 30% or less of the maximum stroke amount. This is because the diaphragm 20 comes into contact with the detected part 3 just before reaching the full stroke position P4, thereby reducing the load that the diaphragm 20 receives from the detected part 3, and improving the durability of the diaphragm 20.

[0051] The diaphragm pump 1 discharges and sucks the resist liquid by putting the driving chamber 15 into a positive pressure state and a negative pressure state. Therefore, the spring 36 is arranged not for the purpose of displacing the diaphragm 20, but for the purpose of returning the detected part 3 from the ON position P12 to the OFF position P11. Therefore, the biasing force of the spring 36 is set to a degree that applies a load to the diaphragm 20 that is not significantly larger than the tension of the diaphragm 20. The diaphragm 20 in this embodiment is thin, with a film thickness of 0.1 mm or more and 0.3 mm or less, and has a small tension, so the biasing force of the spring 36 is set to 0.05 N or more and 0.15 N or less.

[0052] The bush 39 is press-fitted into the retaining hole 122 up to a position where it abuts against the guide member 38, and positions and holds the guide member 38, on which the biasing force of the spring 36 acts, within the retaining hole 122. Because the guide member 38 and the bush 39 are press-fitted into the retaining hole 122, the detected part 3 can be attached to the retaining hole 122 without twisting the spring 36. The bush 39 is disposed between the inner circumferential surface of the retaining hole 122 and the outer circumferential surface of the plunger 34, and holds the plunger 34 slidably.

[0053] The pump screw 32, plunger 34, guide member 38, and bush 39 are made of fluororesin. It is preferable to form these by a processing method other than cutting, such as extrusion molding or injection molding. This is to prevent particles from being generated from cutting marks and to enable the detected part 3 to move with good responsiveness in response to the displacement of the diaphragm 20.

[0054] Returning to FIG. 1, the detection unit 4 is a magnetic sensor that detects the position of the detected part 3. The detection unit 4 is disposed outside the holding hole 122, and detects the displacement of the diaphragm 20 based on the position of the detected part 3. The detection unit 4 is connected to a host controller (not shown) that manages the process performed on the semiconductor wafer. When the detected part 3 is disposed in the ON position P12, the detection unit 4 transmits a detection signal to the host controller (not shown), and when the detected part 3 is not disposed in the ON position P12, the detection unit 4 does not transmit a detection signal to the host controller (not shown).

[0055] Next, a description will be given of the operation of the diaphragm pump 1. In the diaphragm pump 1 shown in Fig. 1, when the operating air is supplied to the driving chamber 15 and the driving chamber 15 is put into a positive pressure state, the diaphragm 20 deforms so as to follow the first concave surface 111 and is positioned at the discharge completion position P2 as shown in Fig. 2. This minimizes the volume of the liquid chamber 14.

[0056] As shown in FIG. 5, when the diaphragm 20 is located at the discharge completion position P2, the flange 323 of the pump screw 32 is engaged with the closing surface 382 of the guide member 38, and the detected part 3 is located at the OFF position P11.

[0057] The diaphragm 20 is disposed at the discharge completion position P2 away from the detected portion 3 disposed at the off position P11. Moreover, the diaphragm 20 is assembled to the body 10 in a state where it is bent toward the first concave surface 111 in the no-load state. Therefore, the tension acting on the diaphragm 20 at the discharge completion position P2 is smaller than that of a diaphragm assembled to the body 10 in a flat state in the no-load state.

[0058] 2 does not detect the magnet 33 of the detected part 3 in the OFF position P11. Therefore, the detection part 4 does not transmit a detection signal to a higher-level controller (not shown).

[0059] In the diaphragm pump 1 shown in FIG. 2, when the operating air is exhausted from the drive chamber 15 and the internal pressure of the drive chamber 15 decreases, the diaphragm 20 deforms toward the second concave surface 121 (the drive chamber 15 side) due to its own elastic force, and the sealing force of the diaphragm 20 to the first concave surface 111 decreases.

[0060] 5, the first concave surface 111 has a plurality of grooves 112 formed in the circumferential direction, and further has a plurality of grooves 113 formed in the radial direction. Therefore, when the sealing force decreases, the resist liquid that has entered the inflow flow path 16 passes through the grooves 112 and 113 and starts to flow toward the outflow flow path 17. As a result, a force acts on the diaphragm 20 in a direction away from the first concave surface 111 (toward the second concave surface 121).

[0061] In this way, when the operating air begins to be exhausted from the driving chamber 15 of the diaphragm pump 1, the diaphragm 20 responsively moves away from the first concave surface 111 due to its own elastic force and the pressure of the resist liquid, and is displaced toward the second concave surface 121 (the driving chamber 15 side).

[0062] 6, the diaphragm 20 displaces from the discharge completion position P2 to a contact position P3 where it contacts the contact surface 343 of the detected part 3 while being separated from the detected part 3. Therefore, while the diaphragm 20 displaces from the discharge completion position P2 to the contact position P3, the detected part 3 does not move following the diaphragm 20, but is disposed at the OFF position P11.

[0063] When the diaphragm 20 deforms so as to bulge from the contact position P3 towards the second concave surface 121 (towards the drive chamber 15), it presses the contact surface 343 of the detected part 3 towards the retaining hole 122. The biasing force of the spring 36 that biases the detected part 3 is small, at not less than 0.05 N and not more than 0.15 N. Therefore, the detected part 3 can move in the retracting direction following the diaphragm 20 without impairing the displacement of the diaphragm 20.

[0064] 3, in the diaphragm pump 1, the diaphragm 20 is displaced to a full stroke position P4 where the diaphragm 20 deforms along the second concave surface 121. As the diaphragm 20 deforms to bulge toward the second concave surface 121, the resist liquid flows into the chemical liquid chamber 14. When the diaphragm 20 is displaced to the full stroke position P4, the volume of the chemical liquid chamber 14 becomes maximum.

[0065] 7, the head 322 of the pump screw 32 hits the bottom surface of the retaining hole 122, restricting movement of the detected part 3 in the retracting direction, and the detected part 3 is disposed in the ON position P12. At this time, the plunger 34 of the detected part 3 protrudes slightly toward the drive chamber 15. Therefore, the detected part 3 is pushed into the retaining hole 122 by the diaphragm 20 disposed in the full stroke position P4, and is disposed stably in the ON position P12.

[0066] The detected part 3 has a flat contact surface 343, and corners 344 of the contact surface 343 are smoothly curved. Therefore, the diaphragm 20 disposed at the full stroke position P4 is gently deformed between the contact surface 343 and the second concave surface 121, and deterioration due to stress concentration is unlikely to occur in the portion in contact with the detected part 3. Therefore, it is possible to suppress generation of particles from the deteriorated portion due to stress concentration.

[0067] 3 detects the magnet 33 when the detected part 3 is placed in the ON position P12, and transmits a detection signal to a higher-level controller (not shown). Based on the detection signal, the higher-level controller (not shown) detects that the diaphragm pump 1 has sucked up a predetermined amount of resist liquid.

[0068] In the diaphragm pump 1 shown in Fig. 3, when the driving chamber 15 is supplied with operating air and put into a positive pressure state, the diaphragm 20 is displaced to the discharge completion position P2 as shown in Fig. 2. By forming the diaphragm 20 to bulge toward the first concave surface 111, a predetermined amount of resist liquid that has flowed into the chemical liquid chamber 14 is discharged from the outflow passage 17.

[0069] 6, when the diaphragm 20 starts to be displaced toward the first concave surface 111 (the liquid medicine chamber 14), the detected part 3 is biased by the spring 36 and moves in the protruding direction.

[0070] The detected part 3 and the diaphragm 20 are separate bodies, and the detected part 3 is simply in contact with the diaphragm 20. Therefore, when the detected part 3 moves following the diaphragm 20, the diaphragm 20 can freely deform relative to the detected part 3, and the tension acting on the part in contact with the detected part 3 is small.

[0071] Moreover, the biasing force of the spring 36 is small, at 0.05 N or more and 0.15 N or less. Therefore, a small load acts on the portion of the detected part 3 that contacts the diaphragm 20. Therefore, even if the detected part 3 contacts the diaphragm 20 and moves following the diaphragm 20, the portion of the diaphragm 20 that contacts the detected part 3 is unlikely to wear out and is unlikely to generate particles.

[0072] 5, the detected part 3 cannot move in the protruding direction beyond the OFF position P11 because the flange 323 of the pump screw 32 is engaged with the closing surface 382 of the guide member 38. Therefore, the diaphragm 20 is displaced separately from the detected part 3 while displacing from the abutment position P3 to the discharge completion position P2, so that the diaphragm 20 is not subjected to any load other than the operating air and is less likely to deteriorate due to stress concentration.

[0073] 2, when the detected part 3 moves from the ON position P12 to the OFF position P11, the detection part 4 can no longer detect the magnet 33 and therefore no longer transmits a detection signal to a higher-level controller (not shown). When the higher-level controller (not shown) no longer receives the detection signal, it detects that the diaphragm pump 1 has supplied a predetermined amount of resist liquid to a semiconductor wafer (not shown).

[0074] In the diaphragm pump 1, the discharge completion position P2 and the full stroke position P4 of the diaphragm 20 are determined by the first concave surface 111 and the second concave surface 121, so that the maximum volume and the minimum volume of the chemical liquid chamber 14 are stable. Therefore, even if the diaphragm pump 1 repeats discharge and suction, it can supply a predetermined amount of resist liquid to a semiconductor wafer (not shown) with high accuracy.

[0075] Since the diaphragm 20 is attached to the body 10 in a state where the portion corresponding to the space 13 is bent toward the first concave surface 111 under no load, no tension is applied when the diaphragm 20 is displaced. Therefore, the diaphragm pump 1 is less likely to cause pressure loss when the diaphragm 20 is displaced, and the discharge amount of the resist liquid is stabilized.

[0076] The diaphragm 20 is thin and the tension acting on the diaphragm 20 is small, so it is easily deformed in response to pressure fluctuations in the driving chamber 15. Therefore, good discharge performance can be expected from the diaphragm pump 1. Furthermore, even if the diaphragm 20 is repeatedly deformed, it is not prone to deterioration due to stress concentration, and the generation of particles can be suppressed.

[0077] The diaphragm 20 is made of PFA, which is less likely to generate particles. The diaphragm 20 is formed by extrusion and rolling, and is free of unevenness caused by cutting marks, making it less likely to generate particles. Therefore, the diaphragm 20 is less likely to generate particles on its surface even if it is repeatedly deformed.

[0078] Moreover, since the diaphragm 20 is provided separately from the detected part 3 and can be displaced separately from the detected part 3, no load other than the operating air acts on the diaphragm 20. Therefore, the tension acting on the diaphragm 20 is small, the diaphragm 20 is less susceptible to deterioration due to stress concentration, and particles are less likely to be generated from the deteriorated parts.

[0079] 5 to 7, in the diaphragm pump 1, the detected portion 3 moves in contact with the diaphragm 20 during part of the stroke of the diaphragm 20. Therefore, in the diaphragm pump 1, the diaphragm 20 is less likely to rub against the detected portion 3 and wear out, and the durability of the diaphragm 20 is improved, compared to a case in which the detected portion contacts the diaphragm over the entire stroke of the diaphragm.

[0080] Even if the diaphragm 20 rubs against the detected part 3 and wears away, generating particles, the detected part 3 is provided on the driving chamber 15 side, so the particles are contained within the driving chamber 15 and do not mix with the resist liquid.

[0081] In the diaphragm pump 1, the detectable part 3 is disposed inside the holding hole 122, and the detection part 4 that detects the detectable part 3 is provided outside the holding hole 122. That is, in the diaphragm pump 1, the detectable part 3 and the detection part 4 are disposed in a state in which the drive chamber 15 is kept airtight. Therefore, there is no leakage of operating air from the detectable part 3, and the detection part 4 is not corroded by the resist liquid that has permeated the diaphragm 20.

[0082] Furthermore, in the diaphragm pump 1, the detected part 3 is slidably disposed in the retaining hole 122, and the movement range of the detected part 3 is restricted by abutting the flange part 323 of the pump screw 32 against the closing surface 382 of the guide member 38 and the bottom surface of the retaining hole 122, thereby suppressing particles generated from the detected part 3. Furthermore, the diaphragm pump 1 has a compact structure and the detected part 3 can be movably disposed in the body 10 in a state independent of the diaphragm 20.

[0083] As described above, in the diaphragm pump 1 of this embodiment, the position of the diaphragm 20 is detected based on the position of the detected part 3 that moves following the diaphragm 20. When the detected part 3 moves following the diaphragm 20, the film-like diaphragm 20 can freely deform relative to the detected part 3 because the detected part 3 and the diaphragm 20 are only in contact with each other. Therefore, the diaphragm 20 is less likely to deteriorate due to stress concentration, and the generation of particles is suppressed. Therefore, according to the diaphragm pump 1 of this embodiment, in the diaphragm pump 1 having the function of detecting the displacement of the diaphragm 20, the durability of the diaphragm 20 can be improved and the generation of particles can be suppressed.

[0084] The present invention is not limited to the above-described embodiment, and various applications are possible. For example, the contact surface 343 of the detected part 3 may be a gently convex or concave surface instead of a flat surface.

[0085] For example, the diaphragm 20 may be formed by either extrusion molding or roll molding. The diaphragm 20 may also be formed by injection molding. Furthermore, the diaphragm 20 may be formed by extruding a resin melted and plasticized in an extruder into a thin-film tube through a tube forming die, and then cutting the thin-film tube-shaped extrusion into a sheet shape.

[0086] For example, the thickness of the diaphragm 20 does not have to be 0.1 mm or more and 0.3 mm or less. However, a thin diaphragm 20 having a thickness of 0.1 mm or more and 0.3 mm or less is expected to be more effective in suppressing particle generation by forming the diaphragm 20 by extrusion molding, rolling molding, or both.

[0087] If the diaphragm 20 and the detected part 3 are separate and separable, the movement distance L3 of the detected part 3 may be the same as the maximum stroke amount of the diaphragm 20. However, by making the movement distance L3 smaller than the maximum stroke amount L4, it is possible to suppress the diaphragm 20 from moving away from the detected part 3 and rubbing against the detected part 3 and becoming worn.

[0088] For example, as shown in FIG. 8, the diaphragm 20 may be disposed in the space 13 in a flat state when no load is applied.

[0089] For example, the diaphragm 20 may be formed in a flat sheet shape. However, by forming the portion of the diaphragm 20 to be placed in the space 13 in a curved shape, the diaphragm 20 can be easily placed in the body 10 with the portion corresponding to the space 13 bent in an unloaded state.

[0090] For example, the detection unit 4 may be disposed so as to communicate with the holding hole 122 .

[0091] For example, the pump screw 32 may be divided into a first part that is engaged with the guide member 38 and a second part that has a male threaded portion 321a that is fastened to the female threaded hole 341 of the plunger 34.

[0092] For example, the movable portion may be formed as a single part, and the magnet 33 may be assembled to the movable portion by insert molding. [Explanation of symbols]

[0093] 1 Diaphragm Pump 3. Detected part 4. Detection section 10. Body 20 Diaphragm

Claims

1. A diaphragm pump that sucks and discharges a predetermined amount of chemical liquid to be supplied to a semiconductor wafer, a film-like diaphragm formed from resin; a body having a space in which the diaphragm is displaceably disposed, the space being partitioned by the diaphragm into a chemical solution chamber into which the chemical solution flows and a drive chamber to which an operating fluid for displacing the diaphragm is supplied; a detected portion that is held by the body so as to be able to come into contact with a surface of the diaphragm that is located on the drive chamber side and that is movable following the diaphragm; a detection unit that detects a displacement of the diaphragm based on the position of the detected portion; and The movable distance of the detection part is smaller than the maximum stroke amount of the diaphragm. A diaphragm pump configured as follows.

2. 2. The diaphragm pump according to claim 1, The diaphragm is formed by extrusion, rolling, or both. A diaphragm pump configured as follows.

3. 3. The diaphragm pump according to claim 1, The diaphragm is made of PFA. A diaphragm pump configured as follows.

4. 3. The diaphragm pump according to claim 1, The diaphragm has a film thickness of 0.1 mm or more and 0.3 mm or less. A diaphragm pump configured as follows.

5. A diaphragm pump that sucks and discharges a predetermined amount of chemical liquid to be supplied to a semiconductor wafer, a film-like diaphragm formed from resin; a body having a space in which the diaphragm is displaceably disposed, the space being partitioned by the diaphragm into a chemical solution chamber into which the chemical solution flows and a drive chamber to which an operating fluid for displacing the diaphragm is supplied; a detected portion that is held by the body so as to be able to come into contact with a surface of the diaphragm that is located on the drive chamber side and that is movable following the diaphragm; a detection unit that detects a displacement of the diaphragm based on the position of the detected portion; and the diaphragm has a film thickness of 0.1 mm or more and 0.3 mm or less; a biasing member that biases the detected portion toward the space portion, The biasing force of the biasing member is 0.05 N or more and 0.15 N or less. A diaphragm pump configured as follows.

6. A diaphragm pump that sucks and discharges a predetermined amount of chemical liquid to be supplied to a semiconductor wafer, a film-like diaphragm formed from resin; a body having a space in which the diaphragm is displaceably disposed, the space being partitioned by the diaphragm into a chemical solution chamber into which the chemical solution flows and a drive chamber to which an operating fluid for displacing the diaphragm is supplied; a detected portion that is held by the body so as to be able to come into contact with a surface of the diaphragm that is located on the drive chamber side and that is movable following the diaphragm; a detection unit that detects a displacement of the diaphragm based on the position of the detected portion; and The diaphragm is disposed in the body in a state where a portion of the diaphragm corresponding to the space portion is deflected when the diaphragm is in an unloaded state. A diaphragm pump configured as follows.

7. A diaphragm pump that sucks and discharges a predetermined amount of chemical liquid to be supplied to a semiconductor wafer, a film-like diaphragm formed from resin; a body having a space in which the diaphragm is displaceably disposed, the space being partitioned by the diaphragm into a chemical solution chamber into which the chemical solution flows and a drive chamber to which an operating fluid for displacing the diaphragm is supplied; a detected portion that is held by the body so as to be able to come into contact with a surface of the diaphragm that is located on the drive chamber side and that is movable following the diaphragm; a detection unit that detects a displacement of the diaphragm based on the position of the detected portion; and the body has a bottomed retaining hole that opens to an inner wall of the drive chamber, The holding hole accommodates the detected portion and a biasing member that biases the detected portion toward the space portion, The detection unit is disposed outside the holding hole. A diaphragm pump configured as follows.

8. 8. The diaphragm pump according to claim 7, The detected part is a magnet to be detected by the detection unit; a movable portion to which the magnet is attached and which is accommodated in the holding hole so as to be able to protrude or retract; a stopper portion disposed inside the holding hole and limiting movement of the movable portion; having A diaphragm pump configured as follows.

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