Substrate processing device and method for judging the degree of deterioration of conductive piping

Abstract

The present invention provides a substrate processing apparatus and a method for determining the degree of conductivity of a conductive piping that can easily and accurately detect conductivity degradation of the conductive piping. The substrate processing apparatus includes: a substrate holding portion; a nozzle portion; a conductive piping that supplies a processing liquid to the nozzle portion; a grounding wire connecting the conductive piping to a reference potential; a liquid receiving portion disposed around the substrate holding portion and receiving liquid released from the nozzle portion; and a degradation degree measuring portion for measuring the degree of conductivity degradation of the conductive piping. The degradation degree measuring portion includes: a measuring liquid supply portion that supplies a measuring liquid to the conductive piping and releases the measuring liquid from the nozzle portion; a potential difference applying portion that applies a potential difference between a liquid contact surface of the liquid receiving portion and a reference potential; and an ammeter that measures the value of a current flowing through a charge transfer path established between the liquid contact surface of the liquid receiving portion and the grounding wire via the measuring liquid when the measuring liquid is released from the nozzle portion to the liquid receiving portion.

Description

Technical Field

[0001] The present invention relates to a substrate processing apparatus and a method for determining the degree of deterioration of a conductive pipe. Background Art

[0002] The semiconductor device manufacturing process includes a liquid treatment step in which a substrate is treated by supplying a treatment liquid to the substrate through a nozzle. To prevent damage from the treatment liquid and prevent electrical charging due to friction of the treatment liquid flowing through the piping, conductive piping is typically used for supplying the treatment liquid to the nozzle. The piping consists of a fluororesin such as PFA with a conductive member such as carbon stripes attached (see, for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-278972 Summary of the Invention

[0006] Technical problem to be solved by the invention

[0007] The present invention provides a technology for easily and accurately detecting deterioration of the conductivity of a conductive pipe.

[0008] Technical solutions to technical problems

[0009] An embodiment of the substrate processing device of the present invention includes: a substrate holding portion for processing a substrate; a nozzle portion for releasing a processing liquid to a substrate held in the above-mentioned substrate holding portion; a conductive piping connected to the above-mentioned nozzle portion, which supplies the processing liquid to the above-mentioned nozzle portion; a grounding wire connecting the above-mentioned conductive piping to a reference potential; a liquid receiving portion arranged around the above-mentioned substrate holding portion, which receives the liquid released from the above-mentioned nozzle portion; and a degradation degree measuring portion, which is used to measure the degree of degradation of the conductivity of the above-mentioned conductive piping, the above-mentioned degradation degree measuring portion including: a measuring liquid supply portion, which supplies the measuring liquid to the above-mentioned conductive piping so that the above-mentioned measuring liquid is released from the above-mentioned nozzle portion; a potential difference applying portion for applying a potential difference between the liquid contact surface of the above-mentioned liquid receiving portion and the above-mentioned reference potential; and an ammeter, which measures the current value of the current flowing through the charge transfer path when the above-mentioned measuring liquid is released from the above-mentioned nozzle portion to the above-mentioned liquid receiving portion, wherein the above-mentioned charge transfer path is established between the liquid contact surface of the above-mentioned liquid receiving portion and the above-mentioned grounding wire via the above-mentioned measuring liquid.

[0010] Effects of the Invention

[0011] According to the present invention, deterioration of the conductivity of the conductive pipe can be easily detected with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a cross-sectional view of a substrate processing apparatus according to one embodiment.

[0013] Figure 2 This is a schematic diagram showing the configuration of a first embodiment of a degradation degree measuring unit included in a processing unit.

[0014] Figure 3 This is a cross-sectional view showing an example of the internal structure of the conductive pipe.

[0015] Figure 4 It is a cross-sectional view showing the structure near the electrode.

[0016] Figure 5 is a timing diagram showing the steps for measuring the degree of degradation.

[0017] Figure 6A This is a schematic diagram showing the steps for measuring the degree of degradation.

[0018] Figure 6B This is a schematic diagram showing the steps for measuring the degree of degradation.

[0019] Figure 6C This is a schematic diagram showing the steps for measuring the degree of degradation.

[0020] Figure 6D This is a schematic diagram showing the steps for measuring the degree of degradation.

[0021] Figure 6E This is a schematic diagram showing the steps for measuring the degree of degradation.

[0022] Figure 6F This is a schematic diagram showing the steps for measuring the degree of degradation.

[0023] Figure 7A This is a graph showing measurement conditions for explaining the degree of degradation.

[0024] Figure 7B This is a graph showing measurement conditions for explaining the degree of degradation.

[0025] Figure 7C This is a graph showing measurement conditions for explaining the degree of degradation.

[0026] Figure 8 This is a schematic diagram showing the configuration of a second embodiment of a degradation degree measuring unit included in a processing unit.

[0027] Description of Reference Numerals

[0028] W substrate

[0029] 20 substrate holding portion

[0030] 100 Nozzle

[0031] 102 Conductive piping

[0032] 150, 152 liquid receiving part

[0033] 116, 118 Measuring liquid supply unit

[0034] 124 Ammeter

[0035] 170 Amperemeter (with built-in resistance meter)

[0036] 130, 160 potential difference applying unit

[0037] 170 Potential difference applying section (with built-in resistance meter). DETAILED DESCRIPTION

[0038] An embodiment of a substrate processing apparatus will be described with reference to the accompanying drawings.

[0039] Figure 1 1 is a diagram showing a schematic configuration of a substrate processing system according to the present embodiment. Hereinafter, to clarify positional relationships, the X-axis, Y-axis, and Z-axis are defined as being orthogonal to each other, with the positive direction of the Z-axis being the vertically upward direction.

[0040] like Figure 1 As shown, the substrate processing system 1 includes a feeding station 2 and a processing station 3. The feeding station 2 and the processing station 3 are arranged adjacent to each other.

[0041] The loading and unloading station 2 includes a carrier placement unit 11 and a transport unit 12. The carrier placement unit 11 places a plurality of carriers C for storing a plurality of substrates, in this embodiment, semiconductor wafers (hereinafter referred to as wafers W) in a horizontal state.

[0042] The transport unit 12 is disposed adjacent to the carrier placement unit 11 and includes a substrate transport device 13 and a delivery unit 14 therein. The substrate transport device 13 includes a wafer holding mechanism for holding a wafer W. The substrate transport device 13 is movable in the horizontal and vertical directions and rotatable about a vertical axis, and uses the wafer holding mechanism to transport wafers W between the carrier C and the delivery unit 14.

[0043] The processing station 3 is disposed adjacent to the conveying portion 12. The processing station 3 includes a conveying portion 15 and a plurality of processing units 16. The plurality of processing units 16 are disposed side by side on both sides of the conveying portion 15.

[0044] The transport unit 15 is internally provided with a substrate transport device 17. The substrate transport device 17 includes a wafer holding mechanism for holding the wafer W. The substrate transport device 17 is movable in the horizontal and vertical directions and rotatable about a vertical axis, and uses the wafer holding mechanism to transport the wafer W between the interface 14 and the processing unit 16.

[0045] The processing unit 16 performs predetermined substrate processing on the wafer W transported by the substrate transport device 17 .

[0046] The substrate processing system 1 also includes a control device 4. The control device 4 is, for example, a computer and includes a control unit 18 and a storage unit 19. The storage unit 19 stores programs for controlling various processes performed in the substrate processing system 1. The control unit 18 controls the operation of the substrate processing system 1 by reading and executing the programs stored in the storage unit 19.

[0047] Alternatively, the program may be stored in a computer-readable storage medium and installed from the storage medium into the storage unit 19 of the control device 4. Examples of computer-readable storage media include a hard disk (HD), a floppy disk (FD), a compact disk (CD), a magneto-optical disk (MO), and a memory card.

[0048] In the substrate processing system 1 configured as described above, the substrate transport device 13 of the transport station 2 first removes a wafer W from the carrier C placed on the carrier placement portion 11 and places the removed wafer W on the delivery portion 14. The wafer W placed on the delivery portion 14 is then removed from the delivery portion 14 by the substrate transport device 17 of the processing station 3 and transported to the processing unit 16.

[0049] After the wafer W is carried into the processing unit 16 and processed in the processing unit 16, it is carried out from the processing unit 16 by the substrate transport device 17 and placed on the delivery unit 14. Then, the substrate transport device 13 returns the processed wafer W placed on the delivery unit 14 to the carrier C of the carrier placement unit 11.

[0050] Below, refer to Figure 2 , the structure of the processing unit 16 is described.

[0051] The processing unit 16 includes a spin chuck 20 as a substrate holding unit. The spin chuck 20 includes a substrate holding body 22 that holds a substrate W, such as a semiconductor wafer, in a horizontal position, and a rotation drive unit 24 that rotates the substrate holding body 22 about a vertical axis. The substrate holding body 22 can be either a vacuum chuck or a mechanical chuck. A processing liquid is supplied to the substrate W from at least one nozzle unit 100. The substrate holding body 22 is surrounded by a liquid receiving cup 26. The liquid receiving cup 26 recovers the processing liquid that has been supplied to the substrate W from the nozzle unit 100 and then separated from the substrate W.

[0052] The nozzle unit 100 can be moved between a processing position above the substrate W held on the spin chuck 20 and a retracted position directly above the dummy dispensing end 150 provided on the outside of the liquid receiving cup 26 by a nozzle moving mechanism (not shown). The nozzle moving mechanism (not shown) includes, for example, a rotating arm that holds the nozzle unit 100 (and the conductive pipe 102 described later). Figure 2 The upper left side of FIG schematically shows the nozzle portion 100 in the processing position. Figure 2 The center portion of FIG. 1 schematically shows the nozzle unit 100 in the retracted position.

[0053] The nozzle unit 100 can be formed by the front end portion of the conductive pipe 102 . In this case, the opening at the front end of the conductive pipe 102 serves as a discharge port of the nozzle unit 100 .

[0054] Alternatively, the nozzle unit 100 may be a separate component from the conductive pipe 102 attached to the distal end of the conductive pipe 102. In this case, the nozzle unit 100 may be made of a fluorine-based resin (e.g., PFA, PTFA, etc.) having high chemical resistance.

[0055] Figure 3 An example of the structure of the conductive pipe 102 is shown. Figure 3 In this example, conductive tubing 102 includes a non-conductive tubing body 102A made of a fluororesin and four conductive H-shaped strips 102B attached to tubing body 102A. Strips 102B can be made of, for example, a fluororesin such as PFA doped with conductive particles such as carbon black. Conductive tubing 102 can have other structures. For example, the entire tubing 102 can be made of a fluororesin doped with conductive particles.

[0056] The following description will be given of a case where the nozzle unit 100 is constituted by the distal end portion of the conductive pipe 102 .

[0057] The upstream end of the conductive pipe 102 is connected to a non-conductive pipe 106 made of an insulating material (e.g., fluorine-based resin) via a pipe joint 104 made of an insulating material (e.g., fluorine-based resin). At least one non-conductive processing liquid supply pipe 110P branches out from a branch point 108 on the non-conductive pipe 106. The upstream end of the processing liquid supply pipe 110P is connected to a processing liquid supply source 112P. A flow control mechanism 114P including an on-off valve, a flow meter, a flow control valve, etc. is provided on the processing liquid supply pipe 112P. When liquid treatment is performed on the substrate W, the processing liquid (e.g., a chemical solution such as SPM) is supplied from the processing liquid supply source 112P to the nozzle unit 100 via the processing liquid supply pipe 110P.

[0058] The upstream end of non-conductive piping 106 is connected to a measuring liquid supply source 116. An on-off valve 118, such as an air-operated valve, is provided between branch point 108 and measuring liquid supply source 116. The resistivity of the measuring liquid is preferably as high as possible, and DIW (deionized water, also known as pure water) is a suitable example of a measuring liquid. Components 116 and 118 constitute a measuring liquid supply unit.

[0059] In addition, if the processing liquid discharged from the nozzle unit 100 has a sufficiently high resistivity, the processing liquid can also be used as a measuring liquid. In this case, the processing liquid supply unit (110P, 112P, 114P) can also be used as a measuring liquid supply unit.

[0060] One end of a ground line 120 is electrically connected to the conductive pipe 102 at a position spaced apart from the nozzle 100 on the upstream side (e.g., near the pipe joint 104). The other end of the ground line 120 is electrically connected to a reference potential point (reference potential) (FG). Figure 3 In the illustrated configuration, the outer portion 102C of the outer circumference of the conductive pipe 102, which is exposed to the H-shaped cross-section strip 102B, is connected to a ground wire 120. The reference potential point is, for example, the metal frame (frame) of the substrate processing system 1 (not shown), also known as the frame ground (FG). The metal frame is preferably connected to the ground. The ground wire 120 is used to install components associated with the degradation degree measurement unit described later.

[0061] When liquid processing is performed on substrates W within processing unit 16, static electricity is generated by friction between the inner surface of tube body 102A of conductive tubing 102 and the processing liquid passing through conductive tubing 102. The static electricity (charge) moves from inner portion 102D, which contacts the processing liquid in strip 102B, to outer portion 102C, where it flows through ground wire 120 to the frame ground, thereby discharging the processing liquid. This prevents electrostatic damage to devices formed on substrates W or ignition of the flammable processing liquid.

[0062] The conductive particles near the surface of the inner portion 102D of the strip 102B (the surface in contact with the treatment liquid) gradually fall off due to the flow of treatment liquid inside the conductive piping 102. The portion near the surface of the inner portion 102D where the conductive particles have fallen off is a resin material with multiple pores. The conductivity of this portion is very low. As the volume of the portion where the conductive particles have fallen off increases, the resistance between the surface of the inner portion 102D of the strip 102B and the outer portion 102C increases, and the static elimination performance deteriorates. The processing unit 16 of this embodiment is provided with a degradation degree measuring unit for detecting the degree of degradation of the conductivity of the conductive piping 102, especially the strip 102B.

[0063] Next, a first embodiment of the degradation degree measuring unit will be described.

[0064] A liquid discharge pipe 152 is connected to the dummy dispensing end 150. The dummy dispensing end 150 and the liquid discharge pipe 152 are collectively referred to as the "liquid receiving portion." The dummy dispensing end 150 and the liquid discharge pipe 152 are formed from a dielectric material. Examples of dielectric materials include fluororesins such as PFA and PTFE. The structure and materials of the dummy dispensing end 150 and the liquid discharge pipe 152 can be the same as those used in conventional substrate processing units.

[0065] An electrode 160 made of a conductive material is provided on the outer surface of the portion near the dummy dispensing end 150 of the discharge pipe 152. The electrode 160 is connected to the voltage applying unit 130 (at Figure 2 Voltage is applied to the portion surrounded by the mid-dotted line).

[0066] The structure of the voltage application unit 130 will now be described. The voltage application unit 130 includes a high-voltage DC power supply 132. The high-voltage DC power supply 132 can apply a desired potential (e.g., several kV) to the electrode 160 relative to the frame ground (FG). The positive electrode of the high-voltage DC power supply 132 is electrically connected to the electrode 160 via a first conductive line (first conductive path) 134, while the negative electrode is electrically connected to the frame ground (reference potential point) via a ground line 136. The positive and negative electrodes of the high-voltage DC power supply 132 can be connected to opposite ends.

[0067] A first switch 138 is provided on the first conductive line 134. A branch point 140 provided on the first conductive line 134 is electrically connected to a frame ground (reference potential point) via a ground line (second conductive path) 142.

[0068] A second switch 144 and a resistor 146 (preferably a variable resistor) are provided on the ground line 142. To measure the potential of the electrode 160, a potentiometer 148 is directly connected to the electrode 160 or to any position of the first conductive line 134 between the electrode 160 and the first switch 138. Figure 2 , the potentiometer 148 is described as a contact type potentiometer, but a non-contact type surface potentiometer may be used as the potentiometer 148. The potentiometer 148 may also be used to confirm whether or not there is leakage in the voltage applying unit 130.

[0069] The first switch 138 and the second switch 144 are preferably normally closed contacts (also referred to as "B contacts"). This allows for reliable de-energization of the electrode 160 in the event of a malfunction in the power supply system of the substrate processing system 1, which is preferable from the perspective of maintaining operator safety. Furthermore, since a high voltage of several kV is applied to the first switch 138 and the second switch 144, it is preferable to use a high-voltage-resistant switch, such as a reed switch (reed relay).

[0070] The degradation degree measuring unit further includes a resistor 122 (preferably a variable resistor) and an ammeter 124. Resistor 122 and ammeter 124 are provided on the aforementioned ground line 120. Ammeter 124 is preferably one capable of detecting microampere-level currents. Resistor 122 can have a resistance of, for example, approximately 100 MΩ.

[0071] The degradation degree measurement unit also includes a controller 180. Controller 180 is capable of controlling at least the operation of voltage application unit 130 and the operation of on-off valve 118. Controller 180 receives detection signals from potentiometer 148 and ammeter 124. Controller 180 functions as a calculation unit capable of determining the resistance value of conductive tubing 102 based on the detection results of ammeter 124. This calculation unit may also determine the soundness (conductivity) of belt-shaped member 102B of conductive tubing 102 based on the resistance value.

[0072] Figure 4 This figure shows an example of the structure surrounding electrode 160. An arc-shaped electrode 160 is provided on the outside of the portion of the drainage piping 152 near the dummy dispensing end 150. A shielded wire serving as the first conductive wire 132 is connected to the electrode 160. The drainage piping 152 is preferably as thin as possible without causing insulation breakdown, thereby improving resistance measurement accuracy. Electrode 160 can be formed from a conductive material such as metal or conductive rubber. To prevent electrical leakage, insulating material 162 is provided outside the electrode 160.

[0073] Below, refer to Figure 5 、 Figure 6A 、 Figure 6B 、 Figure 6C 、 Figure 6D 、 Figure 6E 、 Figure 6F , the operation of the degradation degree measuring unit is described. The resistance measurement operation based on the degradation degree measuring unit is performed under the control of the controller 180. The controller 180 can be Figure 1 The controller 180 is a part of the control device 4. The storage unit of the controller 180 stores a recipe defining the steps of the resistance measurement operation. The controller 180 causes the processing unit 16 (or the substrate processing system 1) to execute the resistance measurement operation described below according to the recipe.

[0074] Figure 5 It is a timing diagram for explaining the operation of the degradation degree measuring unit. The horizontal axis represents the passage of time. "SW1" represents the state of the first switch 138, "SW2" represents the state of the second switch 144, and the filled portion represents that the switch is in the closed state. "HV" represents the state of the high-voltage DC power supply 132, and the filled portion represents the output voltage of the high-voltage DC power supply 132. "AOV" represents the state of the on-off valve 118, and the filled portion represents that the on-off valve 118 is open to release the measuring liquid from the nozzle portion 100. "V" represents the potential of the electrode 160. "μA" represents the detection current detected by the ammeter 124. The definitions of "SW1", "SW2", "HV", "AOV", "V", and "μA" are as follows: Figures 6A to 6F The same is true in Chinese.

[0075] Figure 6A The state at time t0 is the initial state. The high voltage DC power supply 132 (HV) is OFF, the first switch 138 (SW1) and the second switch 144 (SW2) are closed, and the potential of the electrode 160 is 0V (step 1).

[0076] Next, at time t1, while the first switch 138 is maintained in the closed state, the second switch 144 is turned off (step 2).

[0077] Next, at time t2, the high voltage DC power supply 132 is turned on, and a predetermined voltage is applied to the electrode 160 to positively charge the electrode 160 (step 3). Figure 6B In other words, the electric field generated by the positively charged electrode 160 causes dielectric polarization in the liquid receiving portion (in the illustrated example, the discharge pipe 152), causing the liquid contact surface of the discharge pipe 152 (the surface with which the liquid discharged from the nozzle 100 contacts) to become positively charged. At this point, the electrode 160 can be confirmed to be at the desired potential using the potentiometer 148. Alternatively, the voltage monitor of the high-voltage DC power supply 132 can be used to confirm that the electrode 160 is at the desired potential.

[0078] The detection voltage detected by potentiometer 148 is transmitted to controller 180, which executes the next step after the detection voltage reaches the target value. If the detection voltage does not reach the target value after a predetermined period of time, controller 180 determines that an abnormality has occurred in voltage application unit 130 (e.g., leakage or failure of high-voltage DC power supply 132) and issues an alarm via a user interface (e.g., a display, not shown).

[0079] Furthermore, since the first switch 138 and the second switch 144 have a limited contact life, it is preferable to count the number of times the switches are opened and closed using the controller 180 or a higher-level controller. When the count reaches a predetermined number, the user interface can be used to prompt the operator to replace the switches 138 and 144.

[0080] At time t3 after the detection voltage reaches the target value, the first switch 138 is turned off, and the electrode 160 is kept charged and floated (step 4). At this time, the potential of the electrode 160 is continuously measured by the potentiometer 148.

[0081] After confirming that the potential of electrode 160 remains at the target value, at time t4, on-off valve 118 is opened, and the measuring liquid is released to dummy dispensing tip 150 via conductive tubing 102 and nozzle 100. At this time, the measuring liquid is released to form a liquid column extending continuously from the release port of nozzle 100 to the point where the measuring liquid lands on dummy dispensing tip 150. In other words, the measuring liquid is released without forming a plurality of discontinuous droplets.

[0082] As described above, by releasing the measuring liquid from the nozzle unit 100 , a path (hereinafter also referred to as a “charge transfer path”) through which electrons can transfer, including the following section, can be established.

[0083] The first section from the frame ground (FG) through the ground wire 120 to the connection point of the ground wire 120 to the conductive pipe 102 (specifically, the connection point of the ground wire 120 to the outer portion 102C of the conductive pipe 102)

[0084] - A second section (the second section is electrically connected to the first section via the conductive strip 102B) extending from the contact interface between the measuring liquid flowing through the conductive tube 102 and the inner portion 102D of the conductive strip 102B, through the flowing measuring liquid, to the dummy dispensing end 150 or the portion of the drain tube 152 where the measuring liquid flows near the electrode 160.

[0085] At the moment the charge transfer path is established (this moment is the moment the measuring liquid begins to pass near electrode 160), electrons migrate from the frame ground (FG) to the measuring liquid near electrode 160 due to electrostatic induction. In other words, current momentarily flows through ground wire 120 toward the frame ground (FG). This current A is measured by ammeter 124 (step 5). Figure 6C Indicates this status.

[0086] The above-mentioned current A is a pulsed current that flows for a very short time. To reliably detect such a current, it is preferable that the ammeter 124 itself or the controller 180 that receives the detection value of the ammeter 124 has a peak hold function. Hereinafter, the peak value of the current A is referred to as the peak current AP.

[0087] Furthermore, current A (peak current AP) varies with the potential of electrode 160. Therefore, it is preferable to continue monitoring the potential of electrode 160 using potentiometer 148 for a certain period before and after the release of the measuring liquid in step 5. By determining the relationship between the potential of electrode 160 and the detection value of ammeter 124 in advance through experiments and correcting the detection value of ammeter 124 based on this relationship, more accurate resistance measurement can be achieved.

[0088] Then, at time t5, the high voltage DC power supply 132 is switched to the off state (step 6). Figure 6D In this case, the distribution of charges near the electrode 160 is stable, and no current flows through the ground line 120 .

[0089] Next, at time t6, while the measuring liquid continues to be released from nozzle 100, second switch 144 is closed to electrically connect electrode 160 to the frame ground. This causes the potential of electrode 160 to drop sharply to 0V. Subsequently, due to electrostatic induction, electrons migrate away from electrode 160 along the aforementioned charge transfer path and move to the frame ground via ground wire 120. This instantaneously causes a current to flow from the frame ground (FG) through ground wire 120 to conductive strip 102B. This current B is measured by ammeter 124 (step 7). Figure 6E The current B is also a pulsed current that flows for a very short time. The peak value of the current B is referred to as the peak current BP.

[0090] By providing resistor 146 on ground line 142, the surge current flowing into ammeter 124 at the moment second switch 144 is closed can be minimized, thereby improving the measurement accuracy of ammeter 124. Furthermore, other electronic devices connected to the frame ground can be protected from the effects of surge current. The resistance value of resistor 146 can be, for example, several tens of MΩ.

[0091] Next, at time t7, while the measuring liquid continues to be discharged from the nozzle unit 100, the first switch 138 is turned on (step 8). Figure 6F This shows the state at this time. This can minimize the charge on the simulated distribution end 150. This helps improve the measurement accuracy in the next measurement cycle.

[0092] Next, at time t8, the on-off valve 118 is closed, and the discharge of the measuring liquid from the nozzle unit 100 is stopped (step 9). Thus, one measurement cycle is completed.

[0093] The measurement cycle of steps 1 to 9 described above is repeated multiple times.

[0094] Controller 180 calculates the sum of the absolute values ​​of peak value AP and peak value BP (|AP| + |BP|) in each measurement cycle and averages (|AP| + |BP|) across all cycles. Based on this average, the degree of degradation of conductive tape 102B of conductive pipe 102 can be determined.

[0095] By performing the above measurement on the conductive pipe 102 that has deteriorated to approximately the permissible limit, the permissible limit value of the average value can be determined. Therefore, the necessity of replacing the conductive pipe 102 can be determined based on the comparison between the average value and the permissible limit value.

[0096] In addition, the degree of deterioration of the conductive tape 102B may be determined based on the measurement value of one cycle instead of the average value of the measurement values ​​of a plurality of cycles.

[0097] Alternatively, the value obtained by dividing the applied voltage to the electrode 160 by the detected current value of the ammeter 124 (for example, the above-mentioned sum (|AP| + |BP|)) may be used as the resistance value (apparent resistance value), and the degree of degradation of the conductive belt 102B may be determined based on this resistance value. However, if the applied voltage to the electrode 160 can be maintained constant, the degree of degradation of the conductive belt 102B can be determined based solely on the detected current value of the ammeter 124. Therefore, the detected current value of the ammeter 124 itself may be used as a criterion for determining the degree of degradation of the conductive belt 102B.

[0098] Next, the considerations for setting the resistance value of resistor 122 provided on ground line 120 will be described. In the aforementioned charge transfer path, conductive strip 102B and resistor 122 are connected in series. Therefore, if the resistance value of resistor 122 is significantly greater than that of conductive strip 102B, even if the resistance value of conductive strip 102B, which serves as an indicator of the degree of deterioration of conductive strip 102B, slightly changes, the current value measured by ammeter 124 will barely change. The change in the resistance value of conductive strip 102B due to deterioration of conductive strip 102B is approximately 400 MΩ (this value is an example), so setting the resistance value of resistor 122 much greater than 400 MΩ should be avoided.

[0099] On the other hand, when the resistance value of the resistor 122 is too low (including the case where the resistor 122 does not exist), other problems may occur. Figure 7A This is illustrated in the diagram below. Figure 7A In the graph, the horizontal axis represents the resistance (R) from the surface of the inner portion 102D of the conductive tape 102B to the connection point of the ground wire 120 to the frame ground. The vertical axis represents the current (I) measured by the ammeter 124 in step 5 above.

[0100] According to Ohm's law, the current value measured by the ammeter 124 is inversely proportional to the sum of the resistance value of the resistor 122 and the resistance value of the conductive tape 102B (specifically, the resistance value between the inner portion 102D and the outer portion 102C). Therefore, in the case where the resistor 122 does not exist or the resistance 122 is too low (for example, Figure 7A In the region P of the conductive tape 102B, the measured value of the ammeter 124 changes excessively due to a slight change in the resistance value of the conductive tape 102B. In this case, the measured value of the ammeter 124 changes significantly due to slight changes in the measurement conditions (for example, changes in the degree of ionization of the measurement liquid), and the obtained resistance data becomes unstable.

[0101] The resistance value of the resistor 122 is preferably determined so that the measured value of the ammeter 124 changes stably with respect to the change in the resistance value of the conductive tape 102B, and the change in the measured value of the ammeter 124 becomes sufficiently large (but not too large) with respect to the change in the resistance value of the conductive tape 102B (for example, Figure 7A When the resistance value change of the conductive tape 102B due to degradation of the conductive tape 102B is approximately 400 MΩ as described above, the resistance value of the resistor 122 is preferably approximately 100 MΩ (this value is an example).

[0102] Figure 7B1 is a graph showing the test results obtained by measuring the resistance value of the resistor 122 and the measured value of the ammeter 124 by measuring the applied voltage applied to the electrode 160 when using an undamaged conductive pipe 102, using DIW as the measuring liquid, and using a variable resistor as the resistor 122. The resistance value of the variable resistor can be regarded as a resistance value that is substantially equivalent to the sum of the resistance values ​​of the conductive strip 102B and the resistor 122 connected in series. That is, by changing the resistance value of the variable resistor, the resistance (damage) change of the conductive strip 102B can be simulated. It can be seen that the higher the applied voltage applied to the electrode 160, the greater the slope of the resistance value-current value line graph. This means that changes in the damage of the conductive strip 102B can be detected with higher sensitivity.

[0103] Figure 7C It means using Figure 7B The same test equipment as the test described in the experiment is used to measure the relationship between the resistance value of the resistor 122 and the measured value of the ammeter 124 at each flow rate of DIW released from the nozzle portion 100 to the simulated distribution end 150. It can be seen that the greater the DIW flow rate, the greater the slope of the resistance value-current value line graph, and the more sensitive it is to detect damage to the conductive strip 102B. The greater the DIW flow rate, the larger the surface area of ​​the measuring liquid (DIW) present in the simulated distribution end 150 and the drainage pipe 152, and therefore the larger the induced current. This means that the flow rate of the measuring liquid needs to be maintained at the same value in each measurement.

[0104] Figure 8 This figure shows a second embodiment of the degradation degree measuring unit. In this second embodiment, the dummy dispensing tip 150 and the drain pipe 152 (specifically, at least the portion connected to the first terminal 171 described later) are formed of a conductive material. The degradation degree measuring unit includes an ohmmeter 170. The ohmmeter 170 has a first terminal 171 electrically connected to the drain pipe 152 and a second terminal 172 electrically connected to the ground wire 120. The second terminal 172 can be connected to the outer portion 102C of the strip 102B of the conductive pipe 102.

[0105] In the second embodiment, the resistance between the first terminal 171 and the second terminal is measured by the resistance meter 170 while the measuring liquid is continuously released from the nozzle 100 , and the degree of deterioration of the conductive pipe 102 can be determined based on the resistance value.

[0106] As described above, the resistance meter includes a voltage applying unit that applies voltage to the resistance measurement section and a current measuring unit (ammeter) that measures the current flowing through the resistance measurement section, and is capable of measuring the resistance of the resistance measurement section based on the relationship between voltage and current.

[0107] The degradation degree measuring unit of the second embodiment has a simple structure, so a single resistance meter 170 can be used to measure the degradation degrees of multiple conductive pipes 102. In this case, terminals that can reliably and stably electrically connect the first terminal 171 and the second terminal of the resistance meter 170 are provided at the dummy distribution end 150 (or the drain pipe 152) and the ground wire 120.

[0108] According to the above embodiment, conductivity degradation of the conductive piping can be easily and accurately detected. Therefore, the conductive piping can be replaced when needed. This prevents the costly replacement of relatively expensive conductive piping when it is not needed. Furthermore, it prevents the occurrence of adverse effects caused by the use of degraded conductive piping.

[0109] Furthermore, the above-described method is also applicable to a case where the nozzle portion 100 is a separate component from the conductive pipe 102 attached to the distal end of the conductive pipe 102 .

[0110] The embodiments disclosed herein are illustrative in all respects and should not be considered restrictive. The embodiments described above may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.

Claims

1. A substrate processing device, characterized in that: include: a substrate holding portion for processing a substrate; a nozzle portion for releasing a processing liquid toward the substrate held by the substrate holding portion; a conductive pipe connected to the nozzle portion and supplying a treatment liquid to the nozzle portion; a grounding wire connecting the conductive pipe to a reference potential; a liquid receiving portion provided around the substrate holding portion and receiving the liquid discharged from the nozzle portion; and a degradation degree measuring unit for measuring the degree of degradation of the electrical conductivity of the conductive pipe, The degradation degree measuring unit includes: a measuring liquid supply unit configured to supply the measuring liquid to the conductive pipe so as to release the measuring liquid from the nozzle unit; a potential difference applying unit for applying a potential difference between a liquid contact surface of the liquid receiving unit and the reference potential; and an ammeter that measures a current value of a current flowing through a charge transfer path established between a liquid contact surface of the liquid receiving portion and the ground line via the measuring liquid when the measuring liquid is released from the nozzle portion to the liquid receiving portion.

2. The substrate processing device according to claim 1, wherein: The liquid receiving portion is made of a dielectric material, The potential difference applying unit includes: an electrode disposed proximate to the liquid receiving portion; and a voltage applying unit for applying a voltage to the electrode; The ammeter is arranged on the ground line, When the measuring liquid discharged from the nozzle portion to the liquid receiving portion passes through the liquid receiving portion, an induced current flowing through the ground wire is measured by the ammeter.

3. The substrate processing device according to claim 2, wherein: A resistor is provided on the ground line.

4. The substrate processing device according to claim 2, wherein: The potential difference applying unit further includes a switching device capable of realizing at least a state in which the electrode is electrically connected to the voltage applying unit and not electrically connected to a reference potential, and a state in which the electrode is not electrically connected to the voltage applying unit and is electrically connected to a reference potential.

5. The substrate processing device according to claim 4, wherein: The switching device comprises: a first conductive path connecting the voltage applying unit to the electrode; a first switch disposed on the first conductive circuit; a second conductive path connecting the electrode to a reference potential; and A second switch is provided on the second conductive circuit.

6. The substrate processing device according to claim 5, wherein: The first switch and the second switch are B-contact switches.

7. The substrate processing device according to any one of claims 2 to 6, characterized in that: Also included is a potentiometer for measuring the potential of the electrode.

8. The substrate processing device according to claim 5, wherein: A resistor is provided in the second conductive line.

9. The substrate processing device according to claim 1, wherein: The liquid receiving portion is made of a conductive material, The DC power supply as the potential difference applying unit and the ammeter constitute a resistance meter. A first terminal of the resistance meter is electrically connected to the ground line, and a second terminal of the resistance meter is connected to the liquid receiving portion made of a conductive material.

10. The substrate processing device according to claim 1, wherein: The nozzle portion is formed by a front end portion of the conductive pipe, or is formed by a component attached to the conductive pipe that is separate from the conductive pipe.

11. A method for determining the degree of degradation, characterized in that: Determining the degree of deterioration of the conductivity of the conductive piping in a substrate processing apparatus, The substrate processing device comprises: a substrate holding portion for processing a substrate; a nozzle portion for releasing a processing liquid toward the substrate held by the substrate holding portion; a conductive pipe connected to the nozzle portion and supplying a treatment liquid to the nozzle portion; a ground wire connecting the conductive pipe to a reference potential; and a liquid receiving portion provided around the substrate holding portion and receiving the liquid discharged from the nozzle portion; The method for determining the degree of degradation includes: applying a potential difference between a liquid contact surface of the liquid receiving portion and the reference potential; supplying a measuring liquid to the conductive pipe so as to release the measuring liquid from the nozzle portion to the liquid receiving portion; and A step of measuring a current value of a current flowing through a charge transfer path established between a liquid contact surface of the liquid receiving portion and the ground line via the measuring liquid when the measuring liquid is released from the nozzle portion to the liquid receiving portion.

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