JP2008196858A - Pressure sensor, differential pressure type flow meter, fluid flow controller and substrate processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the pressure sensor inhibited with the affection of the noise caused by the minute pressure fluctuation. <P>SOLUTION: The pressure sensor is constituted that a secondary pressure receiving chamber 42 being in contact with a diaphragm 13 reserves the air. The pressure of fluid flowing in a piping 2 is received by the liquid in a primary pressure chamber 41, the pressure of which is transmitted to a communication path 45 and finally transmitted to the secondary pressure chamber 42 for pressing the diaphragm 13. When the diaphragm 13 is deformed by the pressure given through the air, the deformation is transmitted through a pushrod 19 to a pressure sensor element 20. The detection mechanism composed of the pressure element 20, a circuit part 28, a displacement amp 31, and an operation part 32 detects the deformation of the diaphragm 13 and converts it into the pressure value. Because the liquid pressure is transmitted to the diaphragm 13 through the compressive fluid, even if the minute pressure fluctuation of the liquid is generated it is smoothed by the air in the secondary pressure chamber 42, therefore the affection of the noise caused by the minute pressure fluctuation is inhibited. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pressure sensor for measuring the pressure of a fluid flowing through a flow path pipe, in particular, the pressure of a treatment liquid rich in corrosiveness such as hydrofluoric acid, and a differential pressure type flow meter, a flow controller and a substrate processing to which the pressure sensor is applied. Relates to the device.

  Currently, semiconductor manufacturing equipment and various chemical plants have strong oxidizing power (corrosiveness) or high permeability (for example, hydrofluoric acid, hydrochloric acid, nitric acid, sulfuric acid, hydrogen peroxide solution, aqueous ammonia, and mixtures thereof) Liquid) is frequently used. Liquid pressure gauges and differential pressure type flow meters used for these chemical solutions are required to have extremely high chemical resistance and penetration resistance (permeation resistance). However, even though conventional liquid pressure gauges and differential pressure type flowmeters are said to have high chemical resistance, they have a short life when used with highly corrosive and penetrating chemicals. It was necessary to calibrate frequently. For example, when a chemical solution having high corrosivity and permeability such as high-concentration hydrofluoric acid is used, it has been said that the lifetime should be about 1 year and calibration should be performed once every 1 to 2 months. Such frequent calibration work and replacement work with a short life are factors that increase the downtime of the semiconductor manufacturing apparatus and various plants and increase the running cost.

  In particular, in a semiconductor manufacturing apparatus, in order to prevent metal contamination, it is necessary to suppress metal elution from a member in contact with a chemical solution to a level as low as possible (for example, less than 1 ppb for sodium). Therefore, materials that cannot clear the problem of metal elution are used as the wetted parts of liquid pressure gauges and differential pressure flowmeters applied to semiconductor manufacturing equipment, no matter how high the chemical resistance and permeation resistance are. I couldn't.

  Considering these problems, the improvement of the contact member of the pressure sensor used for the chemical solution having particularly high corrosiveness and permeability and the improvement of the structure of the pressure receiving element and the pressure receiving portion have been performed. For example, in Patent Document 1, the housing is made of a material mainly composed of fluororesin, the pressure-sensitive part of the sensor element is made of a corrosion-resistant material, and the housing accommodates the diaphragm part and the sensor element. A pressure sensor with improved chemical resistance by using a multi-segmented structure divided into parts is disclosed. In Patent Document 2, a protective cap with excellent chemical resistance is attached to the end of an operating rod housed in a fram that receives fluid pressure, thereby providing a structure with excellent corrosion resistance and a long life. A pressure gauge is disclosed.

Japanese Patent Laid-Open No. 7-72029 JP 2002-310823 A

  There are various types of pressure sensors used in liquid pressure gauges and differential pressure type flow meters that have been used in the past, but the basic principle is common, and the chemicals flowing through the pipes have a diaphragm. The pressure receiving element detects the deformation amount of the diaphragm, and the signal circuit converts the deformation amount into a pressure value signal. Pressure sensors used in semiconductor manufacturing equipment use diaphragms such as PFA (a copolymer of tetrafluoroethylene and perfluoroalkoxyethylene), PTFE (polytetrafluoroethylene), and PCTFE (polychlorotrifluoroethylene). It is made of resin material. These fluororesins have high corrosion resistance and penetration resistance compared to other resins, and the level of the metal elution problem is low enough to meet the required level of semiconductor manufacturing equipment. However, in recent years, it has been found that hydrofluoric acid and hydrochloric acid can permeate even with these fluororesins such as PFA, PTFE, and PCTFE, and the problem that the pressure-receiving element of the pressure sensor deteriorates within a short period of time is a problem. It has not been resolved.

  Therefore, instead of bringing the pressure receiving element into direct contact with the diaphragm, the pressure of the structure is such that the pressure received by the diaphragm from the chemical liquid is transmitted to the pressure receiving element via the push rod, and the chemical liquid that has passed through the diaphragm is discharged from the vent to the outside of the pressure sensor. Sensors are being developed. With such a structure, since the chemical gas that has permeated through the diaphragm is discharged to the outside, it is possible to prevent the pressure receiving element from deteriorating.

  However, in the case of such a structure, the amount of deformation that the pressure receiving element receives is smaller than that of the structure that is in direct contact with the diaphragm, and therefore it is necessary to increase the sensitivity of the pressure receiving element for measurement. If it does so, the influence of the noise by the minute pressure fluctuation resulting from precipitation and re-dissolution of the dissolved gas in a chemical | medical solution will become large, As a result, the new problem of having a serious influence on measurement accuracy will arise.

  The present invention has been made in view of the above problems, and a pressure sensor that suppresses the influence of noise caused by minute pressure fluctuations, as well as a differential pressure flow meter, a flow controller, and a substrate processing apparatus to which the pressure sensor is applied. The purpose is to provide.

  In order to solve the above-mentioned problem, the invention of claim 1 is a pressure sensor for measuring a pressure of a fluid flowing through a flow path pipe, and is attached to the flow path pipe so as to retain gas in an interior communicating with the flow path pipe. A pressure-receiving chamber, a diaphragm that is deformed by the pressure of the fluid flowing through the passage pipe that is transmitted through the gas staying inside the pressure-receiving chamber, and a detection that detects the amount of deformation of the diaphragm and converts it into a pressure value And a section.

  The invention according to claim 2 is the pressure sensor according to claim 1, wherein the pressure receiving chamber is disposed so as to face the pipe of the flow path pipe, and a fluid flowing through the flow path pipe is introduced 1. A secondary pressure receiving chamber, a secondary pressure receiving chamber disposed in contact with the diaphragm and filled with gas, and a communication path for connecting the primary pressure receiving chamber and the secondary pressure receiving chamber to each other. To do.

  The invention according to claim 3 is the pressure sensor according to claim 1, wherein the pressure receiving chamber is disposed in contact with the diaphragm and filled with a gas, and the pipe of the flow path pipe And a communication path connecting the secondary pressure receiving chamber to each other.

  According to a fourth aspect of the present invention, in the pressure sensor according to the second or third aspect of the present invention, the secondary pressure receiving chamber and the communication path are cylindrical, and the diameter of the communication path is the secondary pressure receiving chamber. It is characterized by being less than half of the diameter.

  According to a fifth aspect of the present invention, in the pressure sensor according to any one of the first to fourth aspects, the diaphragm is carbonized on a surface in contact with the glassy carbon, silicon carbide, or the gas in the pressure receiving chamber. It is characterized by being formed of graphite on which a silicon film is formed.

  The invention according to claim 6 is the pressure sensor according to claim 5, wherein the detection unit includes a capacitance type detection element, and one electrode of the detection element is connected to the pressure receiving chamber of the diaphragm. Is in contact with the opposite surface.

  The invention according to claim 7 is the pressure sensor according to any one of claims 1 to 6, wherein the fluid contains hydrofluoric acid, hydrochloric acid, nitric acid, sulfuric acid, hydrogen peroxide water or ammonia water. Features.

  The invention according to claim 8 is the differential pressure type flow meter for measuring the flow rate of the fluid flowing through the pipe, wherein the differential pressure type flow meter is provided at an upstream position and a downstream position of the pipe. Pressure difference between the pressure sensor measured by the pressure sensor at the upstream position and the downstream position, and the pressure loss material disposed between the upstream position and the downstream position of the pipe. And a flow rate calculating means for calculating a flow rate of the fluid flowing through the pipe.

  According to a ninth aspect of the invention, in the differential pressure type flow meter according to the eighth aspect of the invention, the pressure loss material is an orifice.

  According to a tenth aspect of the present invention, in the differential pressure type flow meter according to the eighth aspect of the invention, the pressure loss material is a capillary.

  The invention of claim 11 is a flow rate controller for adjusting a flow rate of a fluid flowing through a pipe. The differential pressure type flow meter according to any one of claims 8 to 10 provided in the pipe, and the difference A flow rate adjusting valve provided in the pipe on the downstream side of the pressure type flow meter, and a flow rate control means for controlling the flow rate adjusting valve based on a fluid flow rate obtained by the differential pressure type flow meter. Features.

  The invention of claim 12 is a substrate processing apparatus for performing processing by immersing a substrate in a processing liquid, a processing tank for storing the processing liquid and immersing the substrate, a pipe for guiding the processing liquid to the processing tank, A pressure sensor according to any one of claims 1 to 7 provided in the pipe.

  The invention of claim 13 is a substrate processing apparatus for performing processing by immersing a substrate in a processing liquid, a processing tank for storing the processing liquid and immersing the substrate, a pipe for guiding the processing liquid to the processing tank, A differential pressure type flow meter according to any one of claims 8 to 10 provided in the pipe.

  The invention of claim 14 is a substrate processing apparatus for performing processing by immersing a substrate in a processing liquid, a processing tank for storing the processing liquid and immersing the substrate, and a pipe for guiding the processing liquid to the processing tank, And a flow rate controller according to the invention of claim 11 provided in the pipe.

  According to a fifteenth aspect of the present invention, in a substrate processing apparatus for performing processing by supplying a processing liquid to a substrate, a substrate holding unit that holds the substrate in a horizontal posture, and an axis center along the vertical direction of the substrate holding unit A rotating means that rotates around, a discharge nozzle that discharges the processing liquid onto the substrate held by the substrate holder, a pipe that guides the processing liquid to the discharge nozzle, and the pipe are provided in the pipe. A pressure sensor according to any one of Items 7 is provided.

  According to a sixteenth aspect of the present invention, in a substrate processing apparatus for performing processing by supplying a processing liquid to a substrate, a substrate holding unit that holds the substrate in a horizontal posture, and an axis center along the vertical direction of the substrate holding unit 9. A rotating device that rotates around, a discharge nozzle that discharges a processing liquid onto a substrate held by the substrate holding unit, a pipe that guides the processing liquid to the discharge nozzle, and the pipe. The differential pressure type flow meter according to any one of Items 10 is provided.

  According to a seventeenth aspect of the present invention, in a substrate processing apparatus for performing processing by supplying a processing liquid to a substrate, a substrate holding portion for holding the substrate in a horizontal posture, and an axis center along the vertical direction of the substrate holding portion. The invention of claim 11 provided in the rotating means for rotating around, a discharge nozzle for discharging the processing liquid onto the substrate held by the substrate holding portion, a pipe for guiding the processing liquid to the discharge nozzle, and the pipe. And a flow rate controller according to claim 1.

  According to the present invention, since the pressure of the fluid flowing through the flow path pipe is transmitted to the diaphragm via the gas that is a compressible fluid, it is possible to suppress the influence of noise caused by minute pressure fluctuations in the fluid. .

  In particular, according to the third aspect of the present invention, since there is no fluid retention portion, it is possible to mitigate the occurrence of a change in the concentration of the fluid to be measured and the accompanying pressure fluctuation.

  In particular, according to the invention of claim 4, since the diameter of the communication path is less than or equal to half of the diameter of the secondary pressure receiving chamber, the outflow of gas from the secondary pressure receiving chamber can be suppressed.

  In particular, according to the invention of claim 5, since the diaphragm is formed of glassy carbon, silicon carbide, or graphite having a silicon carbide film formed on the surface in contact with the gas in the pressure receiving chamber, It is possible to reliably prevent the generated corrosive gas from permeating the diaphragm and degrading the detection unit.

  In particular, according to the invention of claim 6, since one electrode of the detection element is in contact with the surface of the diaphragm opposite to the pressure receiving chamber, pressure can be measured with higher accuracy.

  In addition, according to the eighth to tenth aspects of the present invention, it is possible to measure the flow rate of the fluid flowing through the pipe with high accuracy while suppressing the influence of noise caused by minute pressure fluctuations in the fluid.

  According to the eleventh aspect of the present invention, it is possible to adjust the flow rate of the fluid flowing through the pipe with high accuracy while suppressing the influence of noise caused by minute pressure fluctuations in the fluid.

  According to the twelfth aspect of the present invention, the pressure of the processing liquid flowing through the pipe can be measured with high accuracy, the substrate can be appropriately immersed, and the processing uniformity between the substrates can be improved.

  According to the thirteenth aspect of the present invention, the flow rate of the processing liquid flowing through the pipe can be measured with high accuracy, the substrate can be appropriately immersed, and the processing uniformity between the substrates can be improved.

  In addition, according to the fourteenth aspect of the present invention, the flow rate of the processing liquid flowing through the pipe can be adjusted with high accuracy, and the substrate can be appropriately immersed to improve the processing uniformity between the substrates.

  According to the fifteenth aspect of the present invention, the pressure of the processing liquid flowing through the pipe can be measured with high accuracy, the substrate can be appropriately processed, and the processing uniformity between the substrates can be improved.

  According to the sixteenth aspect of the present invention, the flow rate of the processing liquid flowing through the pipe can be measured with high accuracy, the substrate can be appropriately processed, and the processing uniformity between the substrates can be improved.

  According to the seventeenth aspect of the present invention, the flow rate of the processing liquid flowing through the pipe can be adjusted with high accuracy, and appropriate processing of the substrate can be performed, so that the uniformity of processing between the substrates can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<1. First Embodiment>
FIG. 1 is a longitudinal sectional view showing a configuration of a pressure sensor 1 according to the present invention. 2 is a cross-sectional view taken along the line AA in FIG. The pressure sensor 1 is a measuring instrument that measures the pressure of the fluid flowing through the flow path pipe 2. In the present embodiment, a hydrogen fluoride (HF) solution (hereinafter simply referred to as “hydrofluoric acid”) flows through the flow path pipe 2.

  The pressure sensor 1 includes a diaphragm 13 having elastic deformability, a pressure receiving element 20 that detects a deformation amount of the diaphragm 13, a circuit unit 28 that outputs an interelectrode capacitance of the pressure receiving element 20 as an electric signal, and a diaphragm 13. A lower support member 12 for supporting, and an upper support member 11 for holding the pressure receiving element 20 and the circuit unit 28 are provided. Further, the pressure sensor 1 includes a displacement amount amplifier 31 and a calculation unit 32 outside the upper support member 11 and the lower support member 12.

  The upper support member 11 and the lower support member 12 are formed of a resin (for example, a fluororesin) having excellent chemical resistance. The upper support member 11 and the lower support member 12 are sandwiched between the flow pipe 2 by PEEK (polyetheretherketone) or metal fastening screws (not shown) and mounted on a PVC (polyvinyl chloride) base (not shown). The diaphragm 13 and the pressure receiving element 20 are fixed to the flow pipe 2 by this. 1 is the upstream side of the fluid, and the right side is the downstream side.

  The diaphragm 13 is stretched on the inner side of the lower support member 12 by holding the peripheral edge portion of the diaphragm 13 by the lower support member 12. The diaphragm 13 of the first embodiment is formed of a fluororesin such as PFA, PTFE, PCTFE, etc. having high corrosion resistance and penetration resistance. The portion where the lower support member 12 holds the peripheral edge of the diaphragm 13 is sealed by an O-ring (not shown) so that liquid and gas do not leak beyond the diaphragm 13.

The inside of the lower support member 12 has a columnar cavity, and is partitioned vertically by a partition member 12a below the diaphragm 13, and a primary pressure receiving chamber 41 and a secondary pressure receiving chamber 42 are formed. The lower primary pressure receiving chamber 41 is a space disposed so as to face the pipe of the flow path pipe 2, and hydrofluoric acid flowing through the flow path pipe 2 flows into the primary pressure receiving chamber 41. On the other hand, the upper secondary pressure receiving chamber 42 is a space that directly contacts the lower surface of the diaphragm 13 and is filled with gas (for example, air). The secondary pressure receiving chamber 42 has a vertical height (gap between the diaphragm 13 and the partition member 12a) of about 1 mm and a capacity of about 1 cm ³ .

  The primary pressure receiving chamber 41 and the secondary pressure receiving chamber 42 are connected to each other by a communication path 45 that is a through hole formed in the partition member 12a. As shown in FIG. 2, the secondary pressure receiving chamber 42 and the communication path 45 are both cylindrical, and the diameter of the communication path 45 is not more than half the diameter of the secondary pressure receiving chamber 42. The primary pressure receiving chamber 41 also has a cylindrical shape, and its diameter is larger than the diameter of the communication path 45.

  Returning to FIG. 1, the pressure receiving element 20 held by the upper support member 11 and the diaphragm 13 held by the lower support member 12 are connected by a push rod 19. The push rod 19 is a rod-like member that mechanically transmits the deformation amount of the diaphragm 13 to the pressure receiving element 20. Here, the amount of deformation of the diaphragm 13 means the amount of displacement of a specific part of the diaphragm 13, and in the present embodiment, the amount of displacement of the center portion of the diaphragm 13 that is displaced the most is assumed. For this reason, the push rod 19 connects the upper surface center portion of the diaphragm 13 and the lower portion of the pressure receiving element 20. Since the pressure receiving element 20 is fixed and held by the upper support member 11 and the upper support member 11 and the lower support member 12 are fixed by fastening screws, the load applied to the diaphragm 13 by the weight of the pressure receiving element 20 is reduced. Yes.

  The pressure receiving element 20 is an electrostatic capacitance type pressure detection element, and is configured by disposing a first electrode 21 and a second electrode 22 to face each other and further arranging a third electrode 23 for correction. The first electrode 21 is a flat plate electrode that is embedded and held in the lower surface of the housing 201 and is disposed in contact with the upper end of the push rod 19 at the lower portion of the pressure receiving element 20. On the other hand, the second electrode 22 is a flat plate electrode formed on the lower surface of the pedestal 24 mounted on the housing 202 at the upper part of the pressure receiving element 20, and is disposed in parallel and opposed to the first electrode 21. Note that the housing 201 and the housing 202 are mounted in the inner concave portion of the upper support member 11, and the pedestal 24 is a plate-like member mounted on the lower surface side of the housing 202.

  When the diaphragm 13 is deformed, the deformation is transmitted to the first electrode 21 via the push rod 19, and the position of the first electrode 21 is changed. As a result, the distance between the first electrode 21 and the second electrode 22 changes, and the capacitance between both electrodes changes. The third electrode 23 is for correcting the capacitance between the first electrode 21 and the second electrode 22, and is formed and disposed on the lower surface of the pedestal 24 like the second electrode 22. ing.

  The circuit unit 28 is installed inside the upper support member 11 and above the pressure receiving element 20. The first electrode 21, the second electrode 22, and the third electrode 23 are electrically connected to the circuit unit 28 through wiring. The capacitance between the first electrode 21 and the second electrode 22 is output as a voltage to the displacement amplifier 31 by the circuit unit 28. At this time, the circuit unit 28 performs correction by a signal from the third electrode 23. The electrical signal output from the circuit unit 28 is amplified by the displacement amount amplifier 31 and digitized to be converted into a value indicating the deformation amount of the diaphragm 13 and output to the calculation unit 32. The calculation unit 32 converts the value indicating the deformation amount of the diaphragm 13 output from the displacement amount amplifier 31 into a pressure value by a predetermined calculation and outputs the pressure value to the outside. The calculation unit 32 stores a relational expression or correlation table between the displacement amount and the pressure in a memory (not shown) in advance, and the deformation amount of the diaphragm 13 is converted into a pressure value based on the relational expression or the correlation table. Convert.

  A vent hole 15 is formed between the upper support member 11 and the lower support member 12. The vent 15 is an opening that communicates the upper space of the diaphragm 13 with the external space. Although the diaphragm 13 is formed of a fluororesin excellent in permeation resistance, it has been found that hydrofluoric acid and hydrochloric acid permeate in a minute amount as described above, and O that seals the holding portion of the diaphragm 13. Even through the ring, a slightly corrosive gas may leak above the diaphragm 13. The vent hole 15 is a passage for discharging the corrosive gas leaked above the diaphragm 13 to the outside. Thereby, it is prevented that the pressure receiving element 20 is deteriorated by the corrosive gas slightly leaked, and the reliability of the pressure sensor 1 can be improved and the life can be extended. If a plurality of vent holes 15 are provided, the gas discharge efficiency can be increased.

  In the pressure sensor 1 of the first embodiment, the deformation of the diaphragm 13 is transmitted to the pressure receiving element 20 via the push rod 19. In such a case, it is necessary to increase the sensitivity of the detection mechanism constituted by the pressure receiving element 20, the circuit unit 28, the displacement amount amplifier 31, and the calculation unit 32, so that the dissolved gas is precipitated and re-dissolved in hydrofluoric acid. As described above, the influence of noise due to the minute pressure fluctuation caused is also increased.

  Therefore, in the pressure sensor 1 of the first embodiment, gas is stored in the secondary pressure receiving chamber 42 that is in contact with the diaphragm 13. The pressure of hydrofluoric acid flowing through the flow pipe 2 is first received by the liquid (hydrofluoric acid) in the primary pressure receiving chamber 41, and after that pressure is transmitted to the communication path 45, it finally becomes the gas in the secondary pressure receiving chamber 42. It is transmitted and presses the diaphragm 13. In other words, the pressure of hydrofluoric acid flowing through the flow path pipe 2 is transmitted to the diaphragm 13 through the gas staying in the secondary pressure receiving chamber 42. When the diaphragm 13 is deformed by being pressed through the gas, a detection mechanism constituted by the pressure receiving element 20, the circuit unit 28, the displacement amount amplifier 31 and the calculation unit 32 detects the deformation amount of the diaphragm 13 and pressurizes it. Convert to value and output to the outside.

  The hydrofluoric acid in the primary pressure receiving chamber 41 is a liquid (incompressible fluid), whereas the gas filling the secondary pressure receiving chamber 42 is a compressive fluid and flows through such a compressive fluid. Since the pressure of hydrofluoric acid flowing through the pipe 2 is transmitted to the diaphragm 13, even if a minute pressure fluctuation caused by deposition and re-dissolution of dissolved gas occurs in the hydrofluoric acid in the primary pressure receiving chamber 41, Such pressure fluctuations are absorbed and relaxed by the gas in the secondary pressure receiving chamber 42. As a result, the influence of noise due to minute pressure fluctuations can be suppressed, and pressure measurement can be performed with high accuracy.

  FIG. 3 is a diagram for illustrating a noise suppression effect by the pressure sensor 1. FIG. 3 (a) shows the result of measuring the pressure of a 50% HF solution flowing in the pipe by a conventional pressure sensor, and FIG. 3 (b) shows the pressure measurement under the same conditions by the pressure sensor 1 according to the present invention. The result of having performed is shown. As apparent from FIGS. 3A and 3B, the minute pressure fluctuation (noise) recognized in the conventional pressure sensor is eliminated in the pressure sensor 1 according to the present invention, and the measurement is performed for 1 minute. The standard deviation σ of the conventional pressure sensor was 1.39 kPa, whereas the pressure sensor 1 according to the present invention was significantly reduced to 0.43 kPa.

However, since the pressure sensor 1 transmits the pressure of hydrofluoric acid flowing through the flow pipe 2 to the diaphragm 13 through the gas in the secondary pressure receiving chamber 42, the liquid is increased if the capacity of the secondary pressure receiving chamber 42 is excessively increased. There is a possibility that the responsiveness when the pressure fluctuates is lowered. For this reason, the capacity of the secondary pressure receiving chamber 42 is desirably 1 cm ³ or less, and the height in the vertical direction is desirably 1 mm or less.

  In the pressure sensor 1, due to the measurement principle, pressure measurement becomes impossible when the gas in the secondary pressure receiving chamber 42 flows into the flow path pipe 2 together with the liquid flow as bubbles. For this reason, it is necessary to reduce the diameter of the communication path 45 as much as possible to prevent the gas from flowing out from the secondary pressure receiving chamber 42 to the primary pressure receiving chamber 41. The diameter of the communication path 45 is set equal to the diameter of the secondary pressure receiving chamber 42. Less than half. Note that hydrofluoric acid may flow into a part of the communication path 45 as long as gas leakage from the secondary pressure receiving chamber 42 can be prevented.

<2. Second Embodiment>
Next, a second embodiment of the present invention will be described. FIG. 4 is a longitudinal sectional view showing the configuration of the pressure sensor 1a of the second embodiment. In the figure, the same reference numerals are given to the same elements as those in FIG. 1 of the first embodiment. The pressure sensor 1a of the second embodiment is greatly different from the pressure sensor 1 of the first embodiment in that the pressure receiving element 20 is in direct contact with the upper surface of the diaphragm 13a.

  In the second embodiment, the diaphragm 13a is stretched by the upper support member 11 holding the peripheral edge of the diaphragm 13a via an O-ring. A portion where the upper support member 11 holds the diaphragm 13a is sealed by an O-ring.

The diaphragm 13a of the second embodiment is made of glassy carbon (for example, glassy carbon or amorphous carbon). Glassy carbon is hard and amorphous carbon that is black and glassy in appearance and has a glossy shell shape with a broken surface, and has a very homogeneous and dense structure. In addition to the properties of general carbon materials such as conductivity, chemical stability, heat resistance, and high purity, glassy carbon has excellent characteristics that the material surface does not powder and fall off Since it has, it can be used also as a member which contacts liquid directly. Furthermore, the glassy carbon has excellent corrosion resistance against acids such as hydrochloric acid and hydrofluoric acid, and gas impermeability is 10 ⁻⁹ to 10 ⁻¹² cm ² / sec. Therefore, it is suitable as a diaphragm of the pressure sensor according to the present invention. The diaphragm 13a of the second embodiment is obtained by forming glassy carbon having such characteristics into a film shape.

  The inner side of the lower support member 12 is partitioned up and down by a partition member 12a as in the first embodiment, and a primary pressure receiving chamber 41 and a secondary pressure receiving chamber 42 are formed. The lower primary pressure receiving chamber 41 is a space disposed so as to face the pipe of the flow path pipe 2, and hydrofluoric acid flowing through the flow path pipe 2 flows into the primary pressure receiving chamber 41. On the other hand, the upper secondary pressure receiving chamber 42 is a space that directly contacts the lower surface of the diaphragm 13a and is filled with gas. The primary pressure receiving chamber 41 and the secondary pressure receiving chamber 42 are connected in communication by a communication path 45 that is a through hole formed in the partition member 12a. Also in the second embodiment, the secondary pressure receiving chamber 42 and the communication path 45 are both cylindrical, and the diameter of the communication path 45 is less than half the diameter of the secondary pressure receiving chamber 42.

  In the second embodiment, the pressure receiving element 20 is in contact with the upper surface side of the diaphragm 13a, that is, the surface of the diaphragm 13a opposite to the secondary pressure receiving chamber 42. Specifically, the first electrode 21 of the pressure receiving element 20 is formed on the upper surface of the diaphragm 13a. For this reason, when the diaphragm 13a is deformed by being pressed, the deformation directly changes the position of the first electrode 21. On the other hand, the second electrode 22 and the third electrode 23 are formed on the lower surface of the pedestal 24 fixedly held by the casing 203, and the first electrode 21 and the second electrode 22 are arranged in parallel and facing each other in a non-contact manner. Has been. The housing 203 is disposed in the housing 204 that forms the outer frame of the pressure receiving element 20.

  A vent 16 is formed in a part of the side wall of the upper support member 11 to communicate the upper space of the diaphragm 13a and the outer space. Therefore, the corrosive gas slightly leaking through the O-ring that seals the holding portion of the diaphragm 13a is discharged to the outside through the vent 16 from the gap between the housing 204 and the upper support member 11. And the deterioration of the pressure receiving element 20 can be prevented. If a plurality of vent holes 16 are provided, the gas discharge efficiency can be increased. The remaining configuration (the circuit unit 28, the displacement amount amplifier 31, the calculation unit 32, and the like) is the same as that in the first embodiment, and a description thereof will be omitted.

  Also in the pressure sensor 1a of the second embodiment, gas is stored in the secondary pressure receiving chamber 42 in contact with the diaphragm 13a. The pressure of hydrofluoric acid flowing through the flow pipe 2 is first received by the liquid (hydrofluoric acid) in the primary pressure receiving chamber 41, and after that pressure is transmitted to the communication path 45, it finally becomes the gas in the secondary pressure receiving chamber 42. Then, the diaphragm 13a is pressed. That is, the pressure of hydrofluoric acid flowing through the flow path pipe 2 is transmitted to the diaphragm 13 a through the gas staying in the secondary pressure receiving chamber 42. When the diaphragm 13a is deformed by being pressed through the gas, a detection mechanism constituted by the pressure receiving element 20, the circuit unit 28, the displacement amount amplifier 31 and the calculation unit 32 detects the deformation amount of the diaphragm 13a and applies pressure. Convert to value and output to the outside.

  As in the first embodiment, the gas filling the secondary pressure receiving chamber 42 is a compressive fluid, and the pressure of hydrofluoric acid flowing through the flow pipe 2 is transmitted to the diaphragm 13a via such a compressive fluid. Therefore, even if a minute pressure fluctuation caused by deposition and re-dissolution of dissolved gas occurs in the hydrofluoric acid in the primary pressure receiving chamber 41, the minute pressure fluctuation is absorbed and relaxed by the gas in the secondary pressure receiving chamber 42. Will be. As a result, the influence of noise due to minute pressure fluctuations can be suppressed, and pressure measurement can be performed with high accuracy.

  Moreover, since the pressure sensor 1a of 2nd Embodiment makes the 1st electrode 21 of the pressure receiving element 20 contact | abut directly on the upper surface of the diaphragm 13a, the deformation amount which the pressure receiving element 20 receives from the diaphragm 13a is 1st Embodiment. The sensitivity of the detection mechanism may be lower than that of the first embodiment. For this reason, the influence of noise can be suppressed more effectively.

  However, since the pressure receiving element 20 is located immediately above the diaphragm 13a, leakage of corrosive gas through the diaphragm 13a must be strictly prevented. In the pressure sensor 1a of the second embodiment, since the diaphragm 13a is formed of glassy carbon having a very low gas permeability, the corrosive gas passes through the diaphragm 13a from the pressure receiving chamber side and reaches the pressure receiving element 20. Can be surely prevented.

  In the second embodiment, the diaphragm 13a is formed of glassy carbon. However, the diaphragm 13a is not limited to this, and any material having a gas permeability as low as that may be used. For example, instead of vitreous carbon, silicon carbide (SiC) or graphite having a silicon carbide film formed on the surface of the secondary pressure receiving chamber 42 in contact with the gas may be applied. Silicon carbide also has high corrosion resistance and extremely low gas permeability. The silicon carbide film is formed by CVD (Chemical Vapor Deposition), sputtering, or the like. Silicon carbide is a so-called ceramic, and its deformability is lower than that of resin. However, if it is formed into a thin film, it is elastically deformed and can be used as the diaphragm 13a.

<3. Third Embodiment>
Next, a third embodiment of the present invention will be described. FIG. 5 is a longitudinal sectional view showing the configuration of the pressure sensor 1b of the third embodiment. In the figure, the same reference numerals are given to the same elements as those in FIG. 4 of the second embodiment. The pressure sensor 1b of the third embodiment is different from the pressure sensor 1a of the second embodiment in that the primary pressure receiving chamber is integrated with the flow path pipe 2.

  The third embodiment is the same as the second embodiment in that the diaphragm 13a is formed of graphite having a silicon carbide film formed on the surface of the glass-like carbon, silicon carbide, or secondary pressure receiving chamber 42 in contact with the gas. . Further, the pressure receiving element 20 is directly brought into contact with the upper surface of the diaphragm 13a.

  In the third embodiment, only the secondary pressure receiving chamber 42 is formed inside the lower support member 12. The secondary pressure receiving chamber 42 is a space that directly contacts the lower surface of the diaphragm 13a, and is filled with gas. The pipe of the flow path pipe 2 and the secondary pressure receiving chamber 42 are directly connected to each other by a communication path 45 that is a through hole formed in the partition member 12a. The secondary pressure receiving chamber 42 and the communication path 45 are both cylindrical, and the diameter of the communication path 45 is the same as that described above in that it is less than half the diameter of the secondary pressure receiving chamber 42.

  Such a configuration should be a configuration in which the primary pressure receiving chamber into which the hydrofluoric acid flows is integrated with the flow path pipe 2, in other words, the primary pressure receiving chamber is replaced by the flow path pipe 2. It is. The remaining configuration of the third embodiment is the same as that of the second embodiment.

  Also in the pressure sensor 1b of the third embodiment, gas is stored in the secondary pressure receiving chamber 42 in contact with the diaphragm 13a. The pressure of hydrofluoric acid flowing through the flow path pipe 2 is directly received by the gas in the secondary pressure receiving chamber 42 via the communication path 45, and the gas presses the diaphragm 13a. That is, as in the first and second embodiments, the pressure of hydrofluoric acid flowing through the flow path pipe 2 is transmitted to the diaphragm 13a through the gas staying inside the secondary pressure receiving chamber 42. When the diaphragm 13a is deformed by being pressed through the gas, a detection mechanism constituted by the pressure receiving element 20, the circuit unit 28, the displacement amount amplifier 31 and the calculation unit 32 detects the deformation amount of the diaphragm 13a and applies pressure. Convert to value and output to the outside.

  Even in this case, since the pressure of hydrofluoric acid flowing through the flow pipe 2 via the compressive fluid is transmitted to the diaphragm 13a, minute pressure fluctuations due to precipitation and re-dissolution of dissolved gas in the hydrofluoric acid are caused. Even if it occurs, the minute pressure fluctuation is absorbed and relaxed by the gas in the secondary pressure receiving chamber 42. As a result, the influence of noise due to minute pressure fluctuations can be suppressed, and pressure measurement can be performed with high accuracy.

  In particular, if the primary pressure receiving chamber is configured integrally with the flow path pipe 2 as in the third embodiment, there is no liquid (hydrofluoric acid) retention portion, and therefore a change in the concentration of hydrofluoric acid occurs and accompanying it. It is difficult for pressure fluctuation to occur, and the influence of noise can be suppressed more effectively.

<4. Fourth Embodiment>
Next, a substrate processing apparatus 5 to which the pressure sensor 1 shown in FIG. 1 is applied will be described as a fourth embodiment of the present invention. FIG. 6 is a diagram showing a schematic configuration of the substrate processing apparatus 5. The substrate processing apparatus 5 is a so-called batch-type substrate processing apparatus that immerses a plurality of semiconductor wafers W as a substrate in a processing solution in which a chemical solution such as hydrofluoric acid is mixed with another solution and performs an etching process collectively. The substrate processing apparatus 5 will be described as applying the pressure sensor 1 of the first embodiment, but the same applies to the pressure sensors 1b and 1c of the second and third embodiments.

  The substrate processing apparatus 5 stores a processing liquid in which pure water is mixed with hydrofluoric acid having a predetermined concentration and soaks the semiconductor wafer W, a pipe 9 that guides the processing liquid to the processing tank 60, and a pipe 9. A pipe 92 on the upstream side of the inserted mixing valve 57, a pure water supply source 58 to which the base end portion of the pipe 92 is connected, and a flow rate controller 50 inserted in the pipe 91 branched from the mixing valve 57. Prepare. The processing tank 60 stores the processing liquid discharged from a tubular nozzle (not shown) disposed at the inner bottom portion of the processing tank 60 and stands up a plurality of semiconductor wafers W in a standing posture (a posture where the wafer surface is along the vertical direction). Etching is carried out by holding in a bath in a state of being arranged in parallel with each other and immersing in a processing solution. Note that the treatment liquid overflowing from the upper end of the treatment tank 60 is collected by the collection tank 61.

  A proximal end portion of a pipe 91 branched from the pipe 9 that guides the processing liquid to the processing tank 60 is connected to a chemical liquid supply source 83. The chemical solution supply source 83 has a pressure-resistant structure capable of pressurizing the inside, and is connected to the pressurizing unit 81 via the regulator 82. By supplying nitrogen gas from the pressurizing unit 81 to the chemical liquid supply source 83, the internal pressure of the chemical liquid supply source 83 is increased, and hydrofluoric acid as a processing liquid is sent from the chemical liquid supply source 83 to the pipe 91. At this time, the regulator 82 adjusts the supply gas pressure from the pressurizing unit 81, thereby adjusting the delivery pressure of hydrofluoric acid to the pipe 91.

  The flow rate controller 50 inserted in the middle of the route of the pipe 91 adjusts the flow rate of hydrofluoric acid mixed with the pure water by the mixing valve 57 through the pipe 91 and adjusts the mixing ratio of hydrofluoric acid with respect to the pure water. By doing so, a treatment liquid having a predetermined concentration is obtained. The flow rate controller 50 includes two pressure sensors 1, 1, a pressure loss material 55, a flow rate calculation unit 51, a flow rate control unit 52, and a flow rate adjustment valve 53.

  The two pressure sensors 1, 1 are as described in the first embodiment, one is arranged at the upstream side position of the pipe 91 (side near the chemical liquid supply source 83), and the other is the downstream side of the pipe 91. Placed in position. In the pipe 91, a pressure loss material 55 is disposed between the two pressure sensors 1 and 1. In the fourth embodiment, an orifice is used as the pressure loss material 55. When the flow is throttled in the middle of the pipe 91 by the orifice (pressure loss material 55), the pressure of hydrofluoric acid is lowered downstream from the pressure loss material 55. Since the degree of the pressure drop is related to the fluid density and flow velocity of hydrofluoric acid, if the differential pressure between the hydraulic pressure upstream and the hydraulic pressure downstream of the pressure loss material 55 is measured, the hydrofluoric acid flowing through the pipe 91 is measured. The flow rate can be measured.

  In the fourth embodiment, the pressure value on the upstream side and the pressure value on the downstream side of the pressure loss material 55 measured by the two pressure sensors 1 and 1 are respectively transmitted to the flow rate calculation unit 51. The flow rate calculation unit 51 calculates the differential pressure between the upstream side and the downstream side from these two pressure values, and calculates the flow rate flowing through the pipe 91 based on the obtained differential pressure. That is, a differential pressure type flow meter is configured by the two pressure sensors 1, 1, the pressure loss material 55, and the flow rate calculation unit 51 among the elements constituting the flow rate controller 50. Note that a calibration curve as shown in FIG. 7 for obtaining a flow rate from a differential pressure created in advance is stored as a table in the memory or the like of the flow rate calculation unit 51, and the flow rate calculation unit 51 uses a pipe 91 from the calibration curve table. And the flow rate of hydrofluoric acid reaching the mixing valve 57 is calculated.

  FIG. 7 is a diagram illustrating an example of the created calibration curve. As described in the first embodiment, as a result of measuring the pressure of the 50% HF solution flowing in the pipe for 1 minute, the standard deviation σ is 1.39 kPa in the conventional pressure sensor, but the present invention is concerned. In the pressure sensor 1, it was 0.43 kPa. This is because, in a differential pressure type flow meter using two pressure sensors, when a conventional pressure sensor is used, an error of 2.78 kPa occurs in the differential pressure, whereas the pressure sensor 1 according to the present invention is applied. This means that the error in the differential pressure is 0.86 kPa. When the error of these differential pressures is converted into the flow rate from the calibration curve of FIG. 7, the flow rate of hydrofluoric acid flowing through the pipe 91 is about 100 ml / min. In the case of a pressure difference type flow meter using a conventional pressure sensor, it is 2.84 ml / min. In contrast, in the differential pressure type flow meter to which the pressure sensor 1 according to the present invention is applied, 0.88 ml / min. It will be suppressed by the fluctuation width. Accordingly, the measurement error is 1.42% in the differential pressure type flow meter using the conventional pressure sensor, whereas the measurement error is 0.44% in the differential pressure type flow meter to which the pressure sensor 1 according to the present invention is applied. Thus, the accuracy of flow rate measurement is greatly improved.

  Returning to FIG. 6, the flow rate adjustment valve 53 is provided on the downstream side of the differential pressure type flow meter of the pipe 91, that is, on the side closer to the processing tank 60 than the two pressure sensors 1, 1. The flow rate control unit 52 controls the flow rate adjustment valve 53 based on the flow rate of hydrofluoric acid flowing through the pipe 91 calculated by the flow rate calculation unit 51. That is, a flow rate of hydrofluoric acid appropriate for the process for obtaining a treatment liquid having a predetermined concentration is set in advance in the flow rate control unit 52, and the flow rate control unit 52 is configured to flow through the pipe 91 calculated by the flow rate calculation unit 51. The flow rate adjustment valve 53 is feedback controlled so that the acid flow rate becomes the set value.

  In this way, the flow rate of hydrofluoric acid flowing through the pipe 91 can be adjusted with high accuracy by the flow rate controller 50 to which the pressure sensor 1 according to the present invention is applied, and a very small amount of hydrofluoric acid is mixed with pure water. Mixing is possible with a valve 57. As a result, a treatment liquid having a predetermined concentration is supplied to the treatment tank 60, and the etching treatment can be performed on the plurality of semiconductor wafers W at an appropriate rate by the treatment liquid. Moreover, the uniformity of the process between the semiconductor wafers W in the same processed batch and between different batches is improved.

  In the substrate processing apparatus 5 of the fourth embodiment, the flow rate controller 50 is provided in the pipe 91, but the differential pressure type flow rate configured by the two pressure sensors 1, 1, the pressure loss material 55 and the flow rate calculation unit 51 in the pipe 91. Only a total may be inserted. If it does in this way, it will become possible to monitor the flow volume of hydrofluoric acid as processing liquid which flows through piping 91 with high accuracy by the differential pressure type flow meter to which pressure sensor 1 concerning the present invention is applied. Moreover, you may make it insert the pressure sensor 1 itself which concerns on this invention in the piping 91 independently. In this way, it is possible to perform accurate liquid pressure measurement while suppressing the influence of noise caused by minute pressure fluctuations generated in hydrofluoric acid as the processing liquid flowing through the pipe 91. Further, a plurality of chemical liquid pipes may be connected to the mixing valve 57, and the flow rate controller 50 may be provided in each chemical liquid pipe.

<5. Fifth Embodiment>
Next, a substrate processing apparatus 6 to which the pressure sensor 1 shown in FIG. 1 is applied will be described as a fifth embodiment of the present invention. FIG. 8 is a diagram showing a schematic configuration of the substrate processing apparatus 6. The substrate processing apparatus 6 is a so-called single-wafer type substrate processing apparatus that supplies a processing liquid obtained by mixing a chemical liquid such as hydrofluoric acid with another liquid to one semiconductor wafer W as a substrate to perform an etching process. The substrate processing apparatus 6 will be described as applying the pressure sensor 1 of the first embodiment, but the same applies to the pressure sensors 1b and 1c of the second and third embodiments.

  The substrate processing apparatus 6 includes a chuck 72 that holds the semiconductor wafer W in a horizontal posture (a posture in which the wafer surface is along the horizontal direction), a rotation motor 73 that rotates the chuck 72 around an axis along the vertical direction, and a chuck. 72, a discharge nozzle 71 that discharges a treatment liquid in which pure water is mixed with hydrofluoric acid having a predetermined concentration to the semiconductor wafer W held by 72, a pipe 9 that guides the treatment liquid to the discharge nozzle 71, and a mixing inserted in the pipe 9 A pipe 92 on the upstream side of the valve 57, a pure water supply source 58 to which the base end portion of the pipe 92 is connected, and a flow rate controller 50 inserted in the pipe 91 branched from the mixing valve 57. In the substrate processing apparatus 6, the processing liquid is discharged from the discharge nozzle 71 onto the main surface of the semiconductor wafer W while the semiconductor wafer W held by vacuum chucking on the chuck 72 is rotated in a horizontal plane by the rotation motor 73. The processing liquid deposited on the rotating semiconductor wafer W spreads over the entire main surface by centrifugal force, and the etching process proceeds. Further, the processing liquid splashed from the peripheral edge of the semiconductor wafer W due to the centrifugal force is received and collected by the cup 74 disposed so as to surround the periphery of the chuck 72 and discharged from the discharge port 75. Note that the chuck 72 is not limited to the one that vacuum-sucks the back surface of the semiconductor wafer W, and may be one that grips the edge of the semiconductor wafer W.

  Since the mechanism for supplying the treatment liquid of a predetermined concentration to the discharge nozzle 71 is the same as that in the fifth embodiment, the same reference numerals as those in FIG. 6 are given. That is, hydrofluoric acid sent from the chemical solution supply source 83 to the pipe 91 is adjusted in flow rate by the flow rate controller 50, mixed with pure water in the mixing valve 57, and sent to the discharge nozzle 71. In this way, the flow rate of hydrofluoric acid flowing through the pipe 91 can be adjusted with high accuracy by the flow rate controller 50 to which the pressure sensor 1 according to the present invention is applied, and a mixed treatment liquid having an appropriate concentration can be obtained. it can. As a result, the semiconductor wafer W can be etched at an appropriate rate by the mixed processing liquid having an appropriate concentration discharged from the discharge nozzle 71. In addition, the uniformity of processing between the processed semiconductor wafers W is improved.

  Similarly to the fourth embodiment, in the substrate processing apparatus 6 of the fifth embodiment, only the differential pressure type flow meter constituted by two pressure sensors 1, 1, the pressure loss material 55 and the flow rate calculation unit 51 is provided in the pipe 91. You may make it insert. If it does in this way, it will become possible to monitor the flow volume of hydrofluoric acid as processing liquid which flows through piping 91 with high accuracy by the differential pressure type flow meter to which pressure sensor 1 concerning the present invention is applied. Moreover, you may make it insert the pressure sensor 1 itself which concerns on this invention in the piping 91 independently. In this way, it is possible to perform accurate fluid pressure measurement while suppressing the influence of noise caused by minute pressure fluctuations generated in the hydrofluoric acid flowing through the pipe 91. Further, a plurality of chemical liquid pipes may be connected to the mixing valve 57, and the flow rate controller 50 may be provided in each chemical liquid pipe.

<6. Modification>
While the embodiments of the present invention have been described above, the present invention can be modified in various ways other than those described above without departing from the spirit of the present invention. For example, in each of the above-described embodiments, the fluid to be measured is a mixed treatment liquid in which hydrofluoric acid and pure water are mixed. However, the present invention is not limited to this, and other types of chemical liquids may be used. . In particular, the pressure sensor according to the present invention is used to measure the pressure of a treatment liquid containing a chemical solution rich in reactivity (corrosive) such as hydrofluoric acid, hydrochloric acid, nitric acid, sulfuric acid, hydrogen peroxide water or ammonia water (and a mixture thereof). If 1 is used, the influence of the noise resulting from the minute pressure fluctuation generated in the liquid can be suppressed and accurate liquid pressure measurement can be performed. Further, if the flow rate of these processing liquids is measured by a differential pressure type flow meter to which the pressure sensor 1 according to the present invention is applied, the flow rate can be measured with high accuracy, and the flow rate adjustment can be performed with the pressure sensor 1 according to the present invention. With the applied flow controller 50, the flow rate can be adjusted with high accuracy, and the etching rate of the silicon oxide film, the formation of an ultrathin oxide film with a dilute solution, the resist peeling, the cleaning process, etc. can be managed with high accuracy. It becomes possible.

  In the fourth and fifth embodiments, an orifice is used as the pressure loss material 55. However, a capillary (capillary tube) may be used as the pressure loss material 55 instead. It is preferable to use an orifice as the pressure loss material 55 when the flow rate of the processing liquid flowing through the pipe 91 is large, and to use a capillary when the flow rate is relatively small. By such proper use, the measurable flow rate can be widened.

  The gas stored in the secondary pressure receiving chamber 42 is not limited to air, and may be nitrogen gas, for example.

  Moreover, the diaphragm 13 of the first embodiment is formed of graphite having a silicon carbide coating formed on the surface in contact with the gas in the glassy carbon, silicon carbide or the secondary pressure receiving chamber 42 as in the second embodiment. Anyway. Corrosive gas can be more reliably prevented from reaching the pressure receiving element 20 through the diaphragm 13 from the pressure receiving chamber side.

  Further, gas replacement in the upper space of the diaphragms 13 and 13a may be performed by a forced ventilation mechanism in addition to natural ventilation through the vent holes 15 and 16.

  In the fourth and fifth embodiments, the substrate to be processed may be a glass substrate for a liquid crystal display device.

It is a longitudinal cross-sectional view which shows the structure of the pressure sensor which concerns on this invention. It is sectional drawing which cut | disconnected the pressure sensor in the AA position of FIG. It is a figure for showing the noise suppression effect by the pressure sensor concerning the present invention. It is a longitudinal cross-sectional view which shows the structure of the pressure sensor of 2nd Embodiment. It is a longitudinal cross-sectional view which shows the structure of the pressure sensor of 3rd Embodiment. It is a figure which shows schematic structure of the batch type substrate processing apparatus to which the pressure sensor which concerns on this invention is applied. It is a figure which shows an example of the calibration curve of a differential pressure type flow meter. It is a figure which shows schematic structure of the single wafer type substrate processing apparatus to which the pressure sensor which concerns on this invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1a Pressure sensor 2 Flow path piping 5,6 Substrate processing apparatus 9,91,92 Piping 11 Upper support member 12 Lower support member 13,13a Diaphragm 15,16 Vent 19 Push rod 20 Pressure sensing element 21 First electrode 22 First electrode 22 2 electrode 23 3rd electrode 28 circuit part 31 displacement amount amplifier 32 calculating part 41 primary pressure receiving chamber 42 secondary pressure receiving chamber 45 communication path 50 flow rate controller 51 flow rate calculating part 52 flow rate control part 53 flow rate adjusting valve 55 pressure loss material 60 processing tank 71 Discharge nozzle 72 Chuck 73 Rotation motor

Claims (17)

A pressure sensor for measuring the pressure of a fluid flowing through a flow pipe,
A pressure receiving chamber attached to the flow path pipe and retaining gas inside the flow path pipe;
A diaphragm that is deformed by the pressure of the fluid flowing through the flow path pipe, which is transmitted through the gas staying inside the pressure receiving chamber;
A detector that detects the amount of deformation of the diaphragm and converts it into a pressure value;
A pressure sensor comprising: The pressure sensor according to claim 1,
The pressure receiving chamber is
A primary pressure receiving chamber disposed so as to face the pipe of the flow path pipe and into which a fluid flowing through the flow path pipe is introduced;
A secondary pressure receiving chamber disposed in contact with the diaphragm and filled with gas;
A communication path for connecting the primary pressure receiving chamber and the secondary pressure receiving chamber in communication;
A pressure sensor comprising: The pressure sensor according to claim 1,
The pressure receiving chamber is
A secondary pressure receiving chamber disposed in contact with the diaphragm and filled with gas;
A communication path for communicating and connecting the inside of the flow path pipe and the secondary pressure receiving chamber;
A pressure sensor comprising: The pressure sensor according to claim 2 or claim 3,
The secondary pressure receiving chamber and the communication path are cylindrical.
The pressure sensor according to claim 1, wherein a diameter of the communication path is not more than half of a diameter of the secondary pressure receiving chamber. The pressure sensor according to any one of claims 1 to 4,
The diaphragm is formed of glassy carbon, silicon carbide, or graphite having a silicon carbide film formed on a surface of the pressure receiving chamber in contact with the gas. The pressure sensor according to claim 5, wherein
The detection unit includes a capacitive detection element,
One electrode of the detection element is in contact with a surface of the diaphragm opposite to the pressure receiving chamber. The pressure sensor according to any one of claims 1 to 6,
The pressure sensor, wherein the fluid contains hydrofluoric acid, hydrochloric acid, nitric acid, sulfuric acid, hydrogen peroxide water or ammonia water. A differential pressure type flow meter that measures the flow rate of fluid flowing through a pipe,
The pressure sensor according to any one of claims 1 to 7, provided at an upstream position and a downstream position of the pipe;
A pressure loss material disposed between the upstream position and the downstream position of the pipe;
A flow rate calculating means for calculating a flow rate of the fluid flowing through the pipe based on a differential pressure between pressure values measured by pressure sensors at the upstream position and the downstream position;
A differential pressure type flow meter comprising: The differential pressure type flow meter according to claim 8,
The differential pressure type flow meter, wherein the pressure loss material is an orifice. The differential pressure type flow meter according to claim 8,
The differential pressure type flow meter, wherein the pressure loss material is a capillary. A flow controller for adjusting a flow rate of a fluid flowing through a pipe;
The differential pressure type flow meter according to any one of claims 8 to 10, provided in the pipe,
A flow rate adjusting valve provided in the pipe downstream of the differential pressure type flow meter;
Flow rate control means for controlling the flow rate adjustment valve based on the flow rate of the fluid obtained by the differential pressure type flow meter;
A flow controller comprising: A substrate processing apparatus for performing processing by immersing a substrate in a processing solution,
A treatment tank for storing the treatment liquid and immersing the substrate;
Piping for guiding the treatment liquid to the treatment tank;
The pressure sensor according to any one of claims 1 to 7, provided in the pipe,
A substrate processing apparatus comprising: A substrate processing apparatus for performing processing by immersing a substrate in a processing solution,
A treatment tank for storing the treatment liquid and immersing the substrate;
Piping for guiding the treatment liquid to the treatment tank;
The differential pressure type flow meter according to any one of claims 8 to 10, provided in the pipe,
A substrate processing apparatus comprising: A substrate processing apparatus for performing processing by immersing a substrate in a processing solution,
A treatment tank for storing the treatment liquid and immersing the substrate;
Piping for guiding the treatment liquid to the treatment tank;
The flow controller according to claim 11 provided in the pipe,
A substrate processing apparatus comprising: A substrate processing apparatus for supplying a processing liquid to a substrate to perform processing,
A substrate holder for holding the substrate in a horizontal position;
Rotating means for rotating the substrate holder around an axis along the vertical direction;
A discharge nozzle that discharges the processing liquid onto the substrate held by the substrate holding unit;
A pipe for guiding the treatment liquid to the discharge nozzle;
The pressure sensor according to any one of claims 1 to 7, provided in the pipe,
A substrate processing apparatus comprising: A substrate processing apparatus for supplying a processing liquid to a substrate to perform processing,
A substrate holder for holding the substrate in a horizontal position;
Rotating means for rotating the substrate holder around an axis along the vertical direction;
A discharge nozzle that discharges the processing liquid onto the substrate held by the substrate holding unit;
A pipe for guiding the treatment liquid to the discharge nozzle;
The differential pressure type flow meter according to any one of claims 8 to 10, provided in the pipe,
A substrate processing apparatus comprising: A substrate processing apparatus for supplying a processing liquid to a substrate to perform processing,
A substrate holder for holding the substrate in a horizontal position;
Rotating means for rotating the substrate holder around an axis along the vertical direction;
A discharge nozzle that discharges the processing liquid onto the substrate held by the substrate holding unit;
A pipe for guiding the treatment liquid to the discharge nozzle;
The flow controller according to claim 11 provided in the pipe,
A substrate processing apparatus comprising:

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