JP2012204813A - Bubble detection method, resist application method, and resist application device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bubble detection method, a resist application method, and a resist application device with which it is possible to suppress elution of an impurity, such as a metal, into a photoresist and detect a flow amount of the photoresist and presence or absence of bubbles in the photoresist.SOLUTION: A flow amount sensor includes resin-made piping through which a fluid is caused to flow, a heating mechanism provided outside the resin-made piping and used to heat the fluid, and a temperature detection mechanism provided outside the resin-made piping and used to detect a temperature change resulting from the flow of the fluid. The flow amount sensor is provided for a photoresist supply piping through which a photoresist is caused to flow. Based on a signal from the flow amount sensor, a flow amount of the photoresist flowing through the photoresist supply piping is detected and presence or absence of bubbles in the photoresist is detected.

Description

  The present invention relates to a bubble detection method, a resist coating method, and a resist coating apparatus.

  2. Description of the Related Art Conventionally, in a semiconductor device manufacturing process, a resist coating apparatus that applies a photoresist to a substrate to be processed such as a semiconductor wafer in a photolithography process for forming a fine circuit pattern has been used. Such a resist coating apparatus includes a spin chuck for holding and rotating a semiconductor wafer, a photoresist supply mechanism for supplying a photoresist to the surface of the semiconductor wafer on the spin chuck, and a semiconductor wafer on the spin chuck. The thing which equipped the cup etc. which were arrange | positioned so that the circumference | surroundings of this may be enclosed is known (for example, refer patent document 1).

  In addition, as a flow rate sensor for measuring the flow rate of fluid such as liquid and gas flowing in the pipe, a heating mechanism is provided outside the pipe for heating the fluid inside the pipe, and the heated fluid passes through the pipe. 2. Description of the Related Art A flow sensor that includes a temperature measurement mechanism for measuring a temperature change caused by flowing and obtains a flow rate (mass flow rate) of a fluid flowing in a pipe from a measured temperature information is known (for example, Patent Literature) 2).

JP 7-320999 A JP-A-5-107093

  In the above resist coating apparatus, a certain amount of photoresist is supplied to the surface of the semiconductor wafer by a bellows pump or the like provided in the photoresist supply mechanism, and then the semiconductor wafer is rotated by a spin chuck, thereby removing the photoresist from the semiconductor. The entire surface of the wafer is diffused, and excess photoresist is scattered in the cup and removed from the surface of the semiconductor wafer.

  As described above, in a conventional resist coating apparatus, an amount of photoresist with a certain allowance is supplied to the surface of the semiconductor wafer, and excess photoresist is shaken off by the rotation of the spin chuck and removed. However, in recent years, the circuit pattern of a semiconductor device tends to be miniaturized, and an expensive photoresist capable of forming a fine circuit pattern is increasingly used.

  For this reason, it is required to reduce the amount of photoresist used. In this case, it is conceivable that the supply amount of the photoresist is controlled with high accuracy and the minimum necessary photoresist is supplied to the semiconductor wafer. However, the supply amount of the photoresist is about 0.5 ml, and it is difficult to accurately measure the flow rate of such a small amount of fluid. In addition, in order to prevent contaminants such as metals from entering the photoresist supply piping system, resin piping such as PFA (perfluoroalkoxy fluororesin) is used. Metal piping and glass piping are used. There is a problem that the used flow rate sensor cannot be used.

  Further, when bubbles are mixed in the photoresist and the bubbles are supplied to the semiconductor wafer, there is a problem that the resist application state becomes poor and the yield is lowered.

  The present invention has been made in response to the above-described conventional circumstances, and can suppress elution of impurities such as metals into the photoresist, and can detect the flow rate of the photoresist and the presence or absence of bubbles. An object of the present invention is to provide a bubble detection method, a resist coating method, and a resist coating apparatus.

  One aspect of the bubble detection method of the present invention includes a resin pipe through which a fluid flows, a heating mechanism for heating the fluid provided outside the resin pipe, and an outside of the resin pipe. A flow rate sensor provided with a temperature detection mechanism for detecting a temperature change due to the flow of the fluid, and inserted in a photoresist supply pipe through which the photoresist is circulated, and a signal from the flow rate sensor Based on this, the flow rate of the photoresist flowing through the photoresist supply pipe is detected, and the presence or absence of bubbles in the photoresist is detected.

  One aspect of the resist coating method of the present invention includes a rotation holding mechanism that holds and rotates a substrate to be processed, and a photoresist supply pipe through which the photoresist is circulated, and is held by the rotation holding mechanism. A resist coating method for applying a photoresist to a substrate to be processed using a resist coating apparatus provided with a photoresist supply mechanism for supplying a photoresist to the surface of the substrate to be processed, wherein a fluid is circulated therein. A resin pipe, a heating mechanism provided outside the resin pipe for heating the fluid, and a temperature detection mechanism provided outside the resin pipe for detecting a temperature change caused by the flow of the fluid; And a flow rate sensor having a flow rate of the photoresist on the basis of a signal from the flow rate sensor. Wherein detecting the presence or absence of bubbles in the photoresist, and controlling the supply of the photoresist to the substrate to be processed on the basis of these detection results.

  One aspect of the resist coating apparatus of the present invention includes a rotation holding mechanism that holds and rotates a substrate to be processed, and a photoresist supply pipe through which the photoresist is circulated, and is held by the rotation holding mechanism. A photoresist supply mechanism for supplying a photoresist to the surface of the substrate to be processed; a resin pipe through which a fluid flows; a heating mechanism for heating the fluid provided outside the resin pipe; A temperature detection mechanism provided outside the resin pipe for detecting a temperature change due to the flow of the fluid, and based on a flow sensor inserted in the photoresist supply pipe and a signal from the flow sensor In addition, the flow rate of the photoresist is detected and the presence or absence of bubbles in the photoresist is detected. Based on the detection results, the photoresist on the substrate to be processed is detected. Characterized by comprising a control unit for controlling the supply of the resist.

  According to the present invention, a bubble detection method, a resist coating method, and a resist coating apparatus capable of suppressing the elution of impurities such as metals into the photoresist and detecting the flow rate of the photoresist and the presence or absence of bubbles. Can be provided.

The figure which shows typically the structure of the resist coating apparatus which concerns on one Embodiment of this invention. The figure which shows typically the manufacturing process of the flow sensor used for one Embodiment of this invention. The figure which shows typically the principal part structure of a flow sensor. The figure which shows typically the whole structure of a flow sensor. The graph which shows the difference in the measurement signal of the flow sensor by the presence or absence of a bubble. The figure which shows typically the principal part structure of another flow sensor. The graph which shows the temperature simulation result in the flow sensor of FIG. The graph which shows the temperature simulation result in the flow sensor of FIG. The figure which shows typically the structure of the flow sensor using a flexible substrate. The figure which shows typically the structure of the flow sensor using a hard board | substrate. The graph which shows the difference of (DELTA) T in the flow sensor of FIG.9 and FIG.10. The graph which shows the difference in the temperature of the to-be-measured fluid in the flow sensor of FIG.9 and FIG.10. The figure which shows the manufacturing process of another flow sensor typically. The figure which shows typically the principal part structure of another flow sensor.

  Hereinafter, details of the present invention will be described with reference to the drawings.

  FIG. 1 shows a configuration of a resist coating apparatus 100 according to an embodiment of the present invention. As shown in the figure, the resist coating apparatus 100 includes a spin chuck 101 as a rotation holding mechanism for holding and rotating a semiconductor wafer W as a substrate to be processed. A cup 102 is provided around the spin chuck 101 so as to surround the circumference of the spin chuck 101 and the semiconductor wafer W. Above the spin chuck 101, a resist supply nozzle 103 and a solvent supply nozzle 104 are provided. It is arranged. The resist supply nozzle 103 and the solvent supply nozzle 104 are connected to a nozzle drive mechanism 105 and are movable in the vertical and horizontal directions as indicated by arrows in the figure.

  The resist supply nozzle 103 is connected to a photoresist supply source 107 via a resist supply pipe 106. The resist supply pipe 106 is made of a resin pipe made of PFA. The resist supply pipe 106 includes, in order from the upstream side (photoresist supply source 107 side), a pump 108, a filter 109, a bubble removing mechanism 110, a flow sensor 111, An on-off valve 112 and a suck back valve 113 are inserted. As will be described later, the flow sensor 111 includes a PFA resin pipe 10 (not shown in FIG. 1) that is the same as the resist supply pipe 106. On the other hand, the solvent supply nozzle 104 is connected to a solvent supply source 115 via a solvent supply pipe 114. An opening / closing valve 116 is inserted in the solvent supply pipe 114.

  The spin chuck 101, the nozzle drive mechanism 105, the pump 108, the bubble removal mechanism 110, the flow sensor 111, the opening / closing valve 112, the suck back valve 113, and the opening / closing valve 116 are connected to the control unit 120. The detection signal of the flow sensor 111 is sent to the control unit 120, and the spin chuck 101, the nozzle drive mechanism 105, the pump 108, the bubble removal mechanism 110, the opening / closing valve 112, the suck back valve 113, the opening / closing valve 116, etc. It is controlled by the control unit 120.

  In the resist coating apparatus having the above configuration, the semiconductor wafer W is placed on the spin chuck 101 and is held by suction on the spin chuck 101. Then, a predetermined amount of photoresist is supplied to the semiconductor wafer W from the resist supply nozzle 103, and the semiconductor wafer W is rotated by the spin chuck 101, whereby the photoresist is diffused over the entire surface of the semiconductor wafer W to be predetermined. A photoresist having a film thickness is applied. At this time, the control unit 120 supplies the photoresist to the semiconductor wafer W while accurately measuring the flow rate with the flow rate sensor 111. As a result, the minimum amount of photoresist can be supplied accurately.

  Prior to the application of the photoresist, if necessary, a solvent is supplied to the surface of the semiconductor wafer W from the solvent supply nozzle 104 so that the surface of the semiconductor wafer W is wetted with the solvent, and then the photoresist supply nozzle 103 applies the photo resist. Supply resist.

  Further, the control unit 120 detects the presence or absence of bubbles in the photoresist by the flow sensor 111, and controls the supply state of the photoresist based on the detection result. That is, for example, when the mixing of bubbles into the photoresist is detected, the supply of the photoresist to the semiconductor wafer W from the resist supply nozzle 103 is stopped. Then, the photoresist is discharged until the bubbles are discharged from the resist supply nozzle 103. As a result, it is possible to prevent bubbles from being supplied to the semiconductor wafer W and the coating state of the photoresist film on the semiconductor wafer W from becoming defective.

  Next, the configuration of the flow sensor 111 will be described. FIG. 2 is a diagram for explaining a manufacturing process of the flow sensor used in the embodiment of the present invention. As shown in FIG. 2A, this flow sensor uses a resin pipe 10 in which a photoresist as a fluid is circulated. In this embodiment, the resin pipe 10 is made of PFA (perfluoroalkoxy fluororesin), and has an inner diameter (diameter) of, for example, 3 mm, an outer diameter (diameter) of, for example, 4 mm, and a tube wall thickness of, for example, 500 μm. Has been.

  When manufacturing this flow sensor, first, as shown in FIG. 2 (b), a thin-walled portion 10a that is thinned by cutting the tube wall from the outside is provided in the middle portion in the longitudinal direction of the resin pipe 10. The thickness of the tube wall in the thin portion 10a is preferably about 100 μm, for example. That is, it is preferable that a tube wall having a thickness of 500 μm is cut by about 400 μm so that the remaining tube wall thickness is about 100 μm.

  Then, as shown in FIG. 3, a heater 11 as a heating mechanism, an upstream temperature sensor 12a and a downstream temperature sensor 12b as temperature detection mechanisms are arranged in the thin portion 10a of the resin pipe 10. The upstream temperature sensor 12a is disposed on the upstream side of the heater 11 with respect to the flow direction (indicated by an arrow in FIG. 3) of the fluid to be measured that circulates inside the resin pipe 10. The side temperature sensor 12 b is disposed on the downstream side of the heater 11.

  As shown in FIG. 4, the heater 11 is electrically connected to the power supply circuit 8, and power is supplied from the power supply circuit 8 to the heater 11. Further, the measurement signal from the upstream temperature sensor 12a and the measurement signal from the downstream temperature sensor 12b are separately input to the flow rate calculation module 7 and the two heat capacity measurement circuits 9, respectively. The flow rate calculation module 7 is connected to the power supply circuit 8 and the two heat capacity measurement circuits 9 by signal lines, and the power supply circuit 8 and the two heat capacity measurement circuits 9 are also connected by signal lines.

  The flow rate calculation module 7 includes a temperature difference detection circuit 4, a flow rate calculation circuit 5, and a physical property data change circuit 6. The temperature difference detection circuit 4 detects these temperature differences ΔT from the measurement signals of the upstream temperature sensor 12a and the downstream temperature sensor 12b. The flow rate calculation circuit 5 includes a temperature difference ΔT detected by the temperature difference detection circuit 4, a coefficient ks (or ka) as physical property data from the physical property data changing circuit 6, and electric power supplied from the power supply circuit 8 to the heater 11. The flow rate (mass flow rate) of the fluid to be measured is calculated from the heating amount W of the fluid to be measured based on the amount.

That is, the flow rate calculation circuit 5 uses the following equation (1) for the coefficient ks as the physical property data of the fluid S determined by the specific heat Cp of the fluid S for calibration, the heat capacity Cs of the fluid S, and the like, and the temperature difference ΔT from the temperature difference detection circuit 4. ) To calculate the mass flow rate F.
W = ks · Cp · F · ΔT (1)

For an arbitrary fluid A to be measured, using the heat capacity Ca of the fluid A to be measured measured by the heat capacity measuring circuit 9, the physical property data changing circuit 6 needs to measure the flow required for calculating the flow rate based on the following equation (2). The coefficient ka of the fluid A is obtained.
ka = Ca / Cs (2)

  The heat capacity measuring circuit 9 is configured to measure the fluid A to be measured based on the measurement amount of the fluid to be measured W based on the measurement signals from the upstream temperature sensor 12a and the downstream temperature sensor 12b and the amount of power supplied from the power supply circuit 8 to the heater 11. , And the calculated heat capacity Ca of the fluid A to be measured is output to the physical property data changing circuit 6 of the flow rate calculation module 7. Here, in the case of measuring the flow rate of only the fluid to be measured whose heat capacity is known, the heat capacity measuring circuit 9 is omitted, and the above-mentioned coefficient as the physical property data such as the heat capacity of each measured fluid is given to the physical property data changing circuit 6. The flow rate of the fluid to be measured may be calculated by using the coefficient as the physical property data stored in the physical property data changing circuit 6 by storing the fluid and specifying the fluid to be measured.

  The flow sensor having the above configuration uses a resin pipe 10 made of PFA (perfluoroalkoxy fluororesin). The resin pipe 10 made of PFA is the same as the resin pipe used for the resist supply pipe 106 of the resist coating apparatus 100 in material, inner diameter, and outer diameter. By using such a resin pipe 10, it is possible to suppress the elution of impurities such as metals in the photoresist.

  Further, since the heater 11, the upstream temperature sensor 12a, and the downstream temperature sensor 12b are disposed in the thin portion 10a of the resin pipe 10, the photoresist flowing through the resin pipe 10 can be efficiently and quickly removed. And can detect a temperature change due to the flow of the photoresist with high sensitivity. Thereby, the flow rate of the photoresist can be measured with high accuracy.

  Therefore, it is not necessary to supply a large amount of photoresist more than the necessary minimum amount in anticipation of a margin, and the consumption of the photoresist can be reduced. Since the photoresist is expensive, the manufacturing cost can be reduced.

  Further, when bubbles are mixed in the photoresist, the detected temperature change is different from the case where there are no bubbles, and therefore the presence or absence of bubbles can also be detected.

  The graph of FIG. 5 shows the difference in time change of the temperature difference ΔT when the bubble is present in the photoresist and when there is no bubble, with the temperature difference ΔT (° C.) on the vertical axis and the time (s) on the horizontal axis. is there. As shown in the figure, when bubbles exist in the photoresist, the rise in temperature difference ΔT when the photoresist is flowed is stagnant. Thereby, the presence of bubbles in the photoresist can be detected. As described above, when it is detected that bubbles are present in the photoresist, the control unit 120 controls the supply state of the photoresist to be changed from the normal state. That is, for example, when the mixing of bubbles into the photoresist is detected, the supply of the photoresist to the semiconductor wafer W from the resist supply nozzle 103 is stopped. Then, the photoresist is discharged until the bubbles are discharged from the resist supply nozzle 103. As a result, it is possible to prevent bubbles from being supplied to the semiconductor wafer W and the coating state of the photoresist film on the semiconductor wafer W from becoming defective.

  In the above example, the case where the flow sensor provided with the thin portion 10a is used in the resin pipe 10 has been described. However, as shown in FIG. A flow rate sensor in which a heater 11, an upstream temperature sensor 12a, and a downstream temperature sensor 12b are disposed outside a resin pipe 20 having an outer diameter of 4 mm and a tube wall thickness of 500 μm and no thin wall portion may be used. Good. However, in this case, the detection accuracy is lowered as compared with the case where the flow sensor provided with the thin portion 10a is used.

  When the flow rate sensor configured as shown in FIG. 6 is used, the temperature detection signals measured by the upstream temperature sensor 12a and the downstream temperature sensor 12b and the thickness of the resin pipe 10 as shown in FIG. Simulate temperature detection signals measured by the upstream temperature sensor 12a and the downstream temperature sensor 12b when the heater 11, the upstream temperature sensor 12a, and the downstream temperature sensor 12b are disposed in the thin wall portion 10a of 100 μm. The comparison results are shown in the graphs of FIGS.

  In the graphs of FIGS. 7 and 8, the vertical axis represents temperature and the horizontal axis represents time. The simulation is performed using an upstream temperature sensor 12a at a position of 0.3 mm upstream of the heater 11 and a downstream temperature sensor 12b at a position of 0.3 mm downstream, and using physical properties of cyclohexanone as a fluid to be measured. It was. In addition, when the flow rate of the fluid to be measured is zero and the heater 11 is heated for 0 to 18 seconds, and then the fluid to be measured is flowed at a flow rate of 0.25 ml / s for 18 to 20 seconds. A simulation was performed. The graph of FIG. 7 is the case of the configuration shown in FIG. 6, and the graph of FIG. 8 is the case of the configuration shown in FIG.

  As shown in the graphs of FIGS. 7 and 8, the temperature increase width is larger in the case of the configuration of FIG. This is because the thermal conductivity of PFA is 0.25 W / m · K, whereas the thermal conductivity of cyclohexanone is as low as 0.12 W / m · K, and the tube wall is thicker, the heater 11 This is because there is much heat that reaches the upstream temperature sensor 12a and the downstream temperature sensor 12b through the pipe wall.

  An important characteristic of the thermal flow sensor is that the temperature difference detected by the upstream temperature sensor 12a and the downstream temperature sensor 12b is large in the time 18 to 20 seconds when the fluid to be measured flows. This temperature difference is clearly larger in the case of FIG. Therefore, the flow rate of the photoresist can be measured with high accuracy in the case of the configuration in which the thin portion 10a shown in FIG. 3 is provided as compared to the configuration in which the thin portion 10a is not provided as shown in FIG. . Further, when the photoresist continues to flow, the time until the measured temperature at the upstream temperature sensor 12a and the downstream temperature sensor 12b reaches a constant temperature is also shortened.

  Further, as shown in FIG. 9, the heater 11, the upstream temperature sensor 12a, and the downstream temperature sensor 12b (not shown in FIG. 9) are formed on the flexible substrate 50, and the flexible substrate 50 is formed on the thin portion 10a. It is preferable that the heater 11, the upstream temperature sensor 12a, the downstream temperature sensor 12b, and the thin portion 10a are in contact with each other in a line contact state by being disposed so as to be wound around.

  Thus, for example, as shown in FIG. 10, the heater 11, the upstream temperature sensor 12a, and the downstream temperature sensor 12b (not shown in FIG. 10) are formed on the rigid substrate 51, and the heater 11, upstream The heat of the heater 11 can be efficiently transferred to the fluid to be measured in the resin pipe 10 as compared with the case where the side temperature sensor 12a and the downstream temperature sensor 12b are in contact with each other in the point contact state. it can. Further, the upstream temperature sensor 12a and the downstream temperature sensor 12b can efficiently detect the temperature, and as a result, the flow rate can be measured with high accuracy.

  In the graph of FIG. 11, the temperature difference on the vertical axis and the time on the horizontal axis, the upstream temperature sensor 12a and the temperature sensor 12a when the fluid to be measured flows according to the configuration shown in FIG. 9 and the configuration shown in FIG. The result of having investigated the difference in the temperature difference detected with the downstream temperature sensor 12b by simulation is shown. In FIG. 11, the curve A shows the case of the line contact configuration shown in FIG. 9, and the curve B shows the case of the point contact configuration shown in FIG. The upstream temperature sensor 12a and the downstream temperature sensor 12b are installed at a position 0.3 mm away from the heater 11 upstream and downstream, heating by the heater is 37 ° C. or less, and the flow rate setting by the pump is 0.25 ml / s. It is.

  As shown in the graph of FIG. 11, the temperature difference that can be detected is clearly larger in the case of the line contact configuration of the curve A than in the case of the point contact configuration of the curve B. Thus, if the configuration is a line contact using the flexible substrate 50, the flow rate of the fluid to be measured is measured more efficiently and accurately than in the case of the point contact configuration using the hard substrate 51. be able to.

  The graph of FIG. 12 is a result of examining, by simulation, the difference in temperature rise of the fluid to be measured that occurs between the case of the configuration shown in FIG. 9 and the case of the configuration shown in FIG. Is shown. In FIG. 12, curve A shows the case of the line contact configuration shown in FIG. 9, and curve B shows the case of the point contact configuration shown in FIG.

  As shown in FIG. 12, the configuration using the flexible substrate 50 as shown in FIG. 9 is more efficient than the case where the hard substrate 51 is used as shown in FIG. The heat of the heater 11 can be transmitted to the fluid to be measured, and the fluid to be measured can be heated to a higher temperature in a short time. Therefore, if the configuration is a line contact using the flexible substrate 50, the flow rate of the fluid to be measured can be measured more efficiently and accurately than the point contact configuration using the hard substrate 51. Can do.

  Moreover, in the above-described flow rate sensor, the mechanical strength in the thin portion 10a is reduced. For this reason, it is preferable to use a flow sensor having the configuration shown in FIG. In this flow rate sensor, a heater 11 as a heating mechanism, an upstream temperature sensor 12a and a downstream temperature sensor 12b as temperature detection mechanisms are provided on a thin portion 10a of a resin pipe 10 as shown in FIG. Arrange. The upstream temperature sensor 12 a is disposed upstream of the heater 11 with respect to the flow direction of the fluid to be measured flowing through the resin pipe 10, and the downstream temperature sensor 12 b is downstream of the heater 11. Arranged on the side. These heater 11, upstream temperature sensor 12a, and downstream temperature sensor 12b are disposed on, for example, a flexible substrate 13 having flexibility, and the flexible substrate 13 is wound around the thin portion 10a. It can be arranged. FIG. 14 schematically shows the positional relationship among the thin portion 10a, the heater 11, the upstream temperature sensor 12a, and the downstream temperature sensor 12b in a longitudinal section. In addition, the arrow shown in FIG. 14 has shown the flow direction of the to-be-measured fluid which distribute | circulates the inside of the resin piping 10. As shown in FIG.

  As described above, the heat-shrinkable tube 14 serving as a tubular reinforcing member is provided for the resin pipe 10 in which the heater 11, the upstream temperature sensor 12a, and the downstream temperature sensor 12b are disposed in the thin wall portion 10a. To the state shown in FIG. At this stage, the heat-shrinkable tube 14 has an inner diameter larger than the outer diameter of the resin pipe 10. As a result, the heat-shrinkable tube 14 is covered on the outside of the resin pipe 10, and the heat-shrinkable tube 14 can be moved along the tube axis direction of the resin pipe 10 in this state. At this time, the heat-shrinkable tube 14 is preliminarily cut to connect cables such as a power supply line to the heater 11 and signal lines of the upstream temperature sensor 12a and the downstream temperature sensor 12b from the cut. A part of the flexible substrate 13 on which the electrode pads are formed is taken out of the heat-shrinkable tube 14.

  Next, as shown in FIG. 13 (c), the heat-shrinkable tube 14 is heated and shrunk to bring the heat-shrinkable tube 14 into close contact with the outside of the thin portion 10a. Thereby, a tubular reinforcing member made of the heat-shrinkable tube 14 that covers the outer side of the thin portion 10a can be disposed. Then, cables such as a power supply line to the heater 11 and signal lines of the upstream temperature sensor 12a and the downstream temperature sensor 12b are connected to the electrode pads of the flexible substrate 13 taken out of the heat shrinkable tube 14 in advance. In addition, as shown in FIG.13 (c), the thickness of the tube wall of the heat-shrinkable tube 14 is 100 micrometers of the tube wall thickness of the thin part 10a in the state which contracted the heat-shrinkable tube 14. It is preferable that the thickness of the tube wall of the heat-shrinkable tube 14 is equal to the thickness of 500 μm of the other partial tube wall of the resin pipe 10. That is, in this case, it is preferable that the thickness of the heat-shrinkable tube 14 is about 400 μm in the contracted state.

  The thin wall portion 10a is in a state where the physical strength is low because the wall of the thin wall portion 10a is thinner than the other portions of the resin pipe 10. For this reason, when attaching and detaching the flow sensor to / from the piping, there is a high possibility that stress is applied and damage is caused, but by arranging a tubular reinforcing member made of the heat-shrinkable tube 14 in the thin wall portion 10a, The possibility of such damages is reduced, and sufficient robustness can be ensured. As the heat-shrinkable tube 14, for example, a tube made of PFA (perfluoroalkoxy fluororesin) similar to the resin pipe 10 can be used. However, it is not limited to those made of PFA, and heat shrinkable tubes of other materials may be used.

  As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications are possible.

  DESCRIPTION OF SYMBOLS 10 ... Resin (PFA) piping, 10a ... Thin part, 11 ... Heater, 12a ... Upstream temperature sensor, 12b ... Downstream temperature sensor.

Claims (15)

Resin piping through which fluid is circulated;
A heating mechanism that is provided outside the resin pipe and heats the fluid;
A temperature detection mechanism that is provided outside the resin pipe and detects a temperature change caused by the flow of the fluid;
And a flow rate sensor comprising: a photo-resist supply pipe in which a photo-resist is circulated, and detecting a flow rate of the photo-resist flowing through the photo-resist supply pipe based on a signal from the flow-rate sensor. And detecting the presence or absence of bubbles in the photoresist. The bubble detection method according to claim 1,
A bubble detection method comprising detecting the presence or absence of bubbles in the photoresist based on a change with time of a temperature difference ΔT between when the bubbles are present and when there is no bubbles. The bubble detection method according to claim 1 or 2,
A bubble detection method comprising: providing a thin part with a thin pipe wall in a part of the resin pipe, and arranging the heating mechanism and the temperature detection mechanism in the thin part. It is a bubble detection method of any one of Claims 1-3,
The bubble detection method, wherein the resin pipe is made of PFA (perfluoroalkoxy fluororesin). It is a bubble detection method of any one of Claims 1-4,
The thin-walled portion is formed by cutting the outside of the resin pipe. It is a bubble detection method of any one of Claims 1-5,
The temperature detection mechanism includes an upstream temperature detection mechanism disposed upstream from the heating mechanism with respect to the flow of the fluid to be measured, and a downstream temperature detection mechanism disposed downstream. A bubble detection method characterized by comprising: The bubble detection method according to any one of claims 1 to 6,
The bubble detection method, wherein the heating mechanism and the temperature detection mechanism are formed on a flexible substrate, and the flexible substrate is disposed around the thin portion so that at least a part thereof is wound. . A rotation holding mechanism for holding and rotating the substrate to be processed;
A photoresist supply mechanism for supplying a photoresist to the surface of the substrate to be processed held by the rotation holding mechanism;
A resist coating method for applying a photoresist to the substrate to be processed using a resist coating apparatus comprising:
Resin piping through which fluid is circulated, a heating mechanism provided outside the resin piping for heating the fluid, and temperature changes caused by the flow of the fluid provided outside the resin piping A flow rate sensor having a temperature detection mechanism for inserting into the photoresist supply pipe,
Based on the signal from the flow sensor, the flow rate of the photoresist is detected and the presence or absence of bubbles in the photoresist is detected, and the supply of the photoresist to the substrate to be processed is performed based on the detection results. A resist coating method characterized by controlling. The resist coating method according to claim 8, wherein:
A resist coating method, wherein presence or absence of bubbles in the photoresist is detected based on a change over time in a temperature difference ΔT between when the bubbles are present and when bubbles are absent. A resist coating method according to claim 8 or 9, wherein
A resist coating method, wherein supply of the photoresist is stopped when air bubbles are detected in the photoresist. A resist coating method according to any one of claims 8 to 10,
A resist coating method comprising: providing a thin part with a thin pipe wall in a part of the resin pipe, and disposing the heating mechanism and the temperature detection mechanism in the thin part. A rotation holding mechanism for holding and rotating the substrate to be processed;
A photoresist supply mechanism for supplying a photoresist to the surface of the substrate to be processed held by the rotation holding mechanism;
Resin piping through which fluid is circulated, a heating mechanism provided outside the resin piping for heating the fluid, and temperature changes caused by the flow of the fluid provided outside the resin piping A flow rate sensor inserted into the photoresist supply pipe, and a temperature detection mechanism for
Based on the signal from the flow sensor, the flow rate of the photoresist is detected and the presence or absence of bubbles in the photoresist is detected, and the supply of the photoresist to the substrate to be processed is performed based on the detection results. And a control unit for controlling the resist coating apparatus. The resist coating apparatus according to claim 12,
A resist coating apparatus, wherein presence or absence of bubbles in the photoresist is detected based on a change over time of a temperature difference ΔT between when the bubbles are present and when there are bubbles. The resist coating apparatus according to claim 12 or 13,
A resist coating apparatus that stops supply of the photoresist when it is detected that air bubbles are mixed into the photoresist. The resist coating apparatus according to any one of claims 12 to 14,
A resist coating apparatus, wherein a thin wall portion having a thin pipe wall is provided in a part of the resin pipe, and the heating mechanism and the temperature detection mechanism are arranged in the thin wall portion.

Images