Substrate processing method and substrate processing apparatus

Abstract

The present invention provides a substrate processing method and a substrate processing apparatus that enable the determination of the remaining film on the surface of each substrate in-line (during the substrate processing process). [Solution] The substrate processing method includes the steps of: supplying a chemical solution to the upper surface of a substrate on which a first film is formed and a second film is formed on the upper surface of the first film to etch the second film; supplying a charged liquid, which is a charged liquid, to the upper surface of the substrate and acquiring the amount of charge on the substrate during supply using an acquisition unit; and determining the remaining state of the second film on the surface of the substrate based on the acquired amount of charge and time-series data showing the change in the amount of charge on a sample substrate when a charged liquid is supplied to a sample substrate on which the second film does not exist on the upper surface of the first film.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing method and a substrate processing apparatus.

Background Art

[0002] Patent Document 1 discloses a substrate processing apparatus including an etching unit that etches a film provided on the surface of a substrate with a processing liquid.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure describes a substrate processing method and a substrate processing apparatus capable of grasping, for each individual substrate, the remaining state of a film on the surface of the substrate inline (during the substrate processing step).

Means for Solving the Problems

[0005] An example of the substrate processing method includes: a first step of supplying a chemical solution to the upper surface of a substrate on which a first film is formed on the upper surface of a substrate body and a second film is formed on the upper surface of the first film, and etching the second film; a second step of supplying a charged liquid, which is a charged solution, to the upper surface of the substrate after the first step; a third step of acquiring, by an acquisition unit, the amount of charge on the substrate during the second step; and a fourth step of determining the remaining state of the second film on the surface of the substrate based on the amount of charge acquired in the third step and time-series data indicating a change in the amount of charge on a sample substrate when the charged solution is supplied to the sample substrate on which no second film exists on the upper surface of the first film.

Effects of the Invention

[0006] According to the substrate processing method and substrate processing apparatus described herein, it becomes possible to ascertain the remaining film status on the surface of each substrate in-line (during the substrate processing process). [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic plan view showing an example of a substrate processing system and film deposition apparatus. [Figure 2] Figure 2 is a cross-sectional view showing an example of a substrate. [Figure 3] Figure 3 is a schematic diagram of an example of a liquid processing unit, showing a cross-sectional view of the unit when the substrate is in the lowered position. [Figure 4] Figure 4 is a perspective view showing the vicinity of the rotating plate and support plate in the liquid processing unit shown in Figure 3. [Figure 5] Figure 5 is a schematic diagram of an example of a liquid processing unit, showing a cross-sectional view of the unit when the substrate is in the raised position. [Figure 6] Figure 6 is a schematic diagram illustrating an example of how processing liquid is supplied from a supply tube to a substrate held in a holding section. [Figure 7] Figure 7(a) is a cross-sectional view along line VII-VII of Figure 6, showing an example of a supply tube, and Figure 7(b) is a cross-sectional view along line VII-VII of Figure 6, showing another example of a supply tube. [Figure 8] Figure 8(a) shows an example of a state in which a processing solution is supplied to a substrate in which a conductive film is formed on an insulating film, and Figure 8(b) shows an example of a state in which a processing solution is supplied to a substrate in which an insulating film is formed on a conductive film. [Figure 9] Figure 9 is a block diagram showing an example of the main components of a substrate processing system. [Figure 10] Figure 10 is a schematic diagram showing an example of the controller's hardware configuration. [Figure 11]Figure 11 shows examples of time-series data for a sample substrate that was successfully processed by etching and for a substrate that was not successfully processed by etching. [Figure 12] Figure 12 is a flowchart illustrating an example of substrate processing. [Figure 13] Figure 13 is a flowchart illustrating an example of the process for determining the remaining state of the conductive film. [Figure 14] Figure 14 shows an example of how the rate of misses changes over time. [Figure 15] Figure 15(a) shows an example of the relationship between current value and film thickness in a substrate where a conductive film is formed on an insulating film, and Figure 15(b) shows an example of the relationship between current value and film thickness in a substrate where an insulating film is formed on a conductive film. [Figure 16] Figure 16 schematically shows another example of how the processing liquid is supplied from the supply tube to the substrate held in the holding section. [Modes for carrying out the invention]

[0008] In the following descriptions, the same reference numeral will be used for identical elements or elements with the same function, and redundant explanations will be omitted. Furthermore, in this specification, when referring to the top, bottom, right, and left of a figure, the direction of the reference numeral in the figure will be used as the reference.

[0009] [Circuit board processing system] First, a substrate processing system 1 (substrate processing apparatus) configured to process a substrate W will be described with reference to Figures 1 and 2. The substrate processing system 1 comprises an input / output station 2, a processing station 3, and a controller Ctr (control unit). The input / output station 2 and the processing station 3 may be arranged in a single line horizontally, for example.

[0010] The substrate W may have a disc shape, or may have a plate shape other than circular such as a polygon. The substrate W may have a notch portion where a part is cut out. The notch portion may be, for example, a notch (grooves such as U-shaped or V-shaped grooves), or may be a linear portion (so-called orientation flat) that extends linearly. The substrate W may be, for example, a semiconductor substrate (silicon wafer), a glass substrate, a mask substrate, an FPD (Flat Panel Display) substrate, or other various substrates. The diameter of the substrate W may be, for example, about 200 mm to 450 mm.

[0011] As illustrated in FIG. 2, the substrate W may include a base W1, a film W2 (first film), and a film W3 (second film). The base W1 may be, for example, a silicon wafer, or may be one with at least one layer of film formed on the upper surface of the silicon wafer. The film W2 may be, for example, one of an insulating film and a conductive film. The film W3 may be, for example, the other of the insulating film and the conductive film.

[0012] Examples of the material constituting the insulating film include SiOx (silicon oxide), SiN (silicon nitride), Low-k (low dielectric constant) materials (e.g., SiOC, porous silica film, etc.). Examples of the material constituting the conductive film include TiN, TaN, Ta, Mo, Ru, Co, Cu, or a composite containing at least two or more of these.

[0013] In this specification, the upper surface Wa of the substrate W refers to the upper surface of the element located at the uppermost part among all the elements constituting the substrate W. That is, as illustrated in FIG. 2, when the substrate W is constituted by, for example, the base W1, the film W2, and the film W3, the upper surface Wa of the substrate W refers to the upper surface of the film W3. When the substrate W is constituted by, for example, the base W1 and the film W2, the upper surface Wa of the substrate W refers to the upper surface of the film W2. When the substrate W is constituted by, for example, the base W1, the upper surface Wa of the substrate W refers to the upper surface of the base W1.

[0014] Returning to Figure 1, the loading / unloading station 2 may be configured to receive the substrate W processed in the film deposition apparatus Q (film deposition section) and to send the substrate W processed in the substrate processing system 1 to the film deposition apparatus Q. The film deposition apparatus Q is configured to form a film on the upper surface Wa of the substrate W. Examples of film formation methods by the film deposition apparatus Q include ALD (atomic layer deposition), thermal oxidation, CVD (chemical vapor deposition), sputtering, and coating.

[0015] The loading / unloading station 2 includes a mounting section 4, a loading / unloading section 5, and a shelf unit 6. The mounting section 4 includes a plurality of mounting tables (not shown) arranged in the width direction (vertical direction in Figure 1). Each mounting table is configured to accommodate a carrier 7. The carrier 7 is configured to house at least one substrate W in a sealed state. The carrier 7 includes an opening / closing door (not shown) for loading and unloading the substrate W.

[0016] The loading / unloading section 5 is located adjacent to the loading / unloading section 4 in the direction in which the loading / unloading station 2 and processing station 3 are aligned (left-right direction in Figure 1). The loading / unloading section 5 includes an opening / closing door (not shown) provided for the loading / unloading section 4. When the carrier 7 is placed on the loading / unloading section 4, both the opening / closing door of the carrier 7 and the opening / closing door of the loading / unloading section 5 are opened, creating communication between the inside of the loading / unloading section 5 and the inside of the carrier 7.

[0017] The loading / unloading section 5 incorporates a transport arm A1 and a shelf unit 6. The transport arm A1 is configured to move horizontally in the width direction of the loading / unloading section 5, vertically in the vertical direction, and pivotally around the vertical axis. The transport arm A1 is configured to take the substrate W from the carrier 7 and pass it to the shelf unit 6, and to receive the substrate W from the shelf unit 6 and return it to the carrier 7. The shelf unit 6 is located near the processing station 3 and is configured to accommodate the substrate W.

[0018] The processing station 3 includes a transport unit 8 and a plurality of liquid processing units U. The transport unit 8 extends horizontally, for example, in the direction in which the loading / unloading station 2 and the processing station 3 are aligned (left-right direction in Figure 1). The transport unit 8 incorporates a transport arm A2. The transport arm A2 is configured to move horizontally in the longitudinal direction of the transport unit 8, move up and down in the vertical direction, and rotate around the vertical axis. The transport arm A2 is configured to take the substrate W from the shelf unit 6 and pass it to the liquid processing unit U, and to receive the substrate W from the liquid processing unit U and return it to the shelf unit 6.

[0019] Multiple liquid processing units U are arranged in a line along the longitudinal direction of the conveying unit 8 (left-right direction in Figure 1) on each side of the conveying unit 8. The configuration of the liquid processing units U will be described later.

[0020] The controller Ctr is configured to partially or entirely control the substrate processing system 1, as will be described in more detail later.

[0021] [Liquid Processing Unit] The configuration of the liquid processing unit U will be explained with reference to Figures 3 to 8. As illustrated in Figure 3, the liquid processing unit U includes a rotating holding unit 10, a lifting unit 20, a cup unit 30, a chemical liquid supply unit 40 (first supply unit), and a cleaning liquid supply unit 50 (second supply unit).

[0022] The rotating and holding unit 10 includes a rotating plate 11, a support plate 12, a holding unit 13, and a regulating unit 14.

[0023] The rotating plate 11 is, for example, a disc with a larger diameter than the substrate W. The rotating plate 11 includes a collection groove 11a provided on the upper surface of the rotating plate 11 so as to extend in the circumferential direction of the rotating plate 11, a discharge hole 11b extending in the radial direction of the rotating plate 11 from the bottom surface of the collection groove 11a toward the outer circumferential surface of the rotating plate 11, and a plurality of through holes 11c.

[0024] The collection groove 11a is configured to collect the processing liquid (in this document, the chemical solution L1 and the cleaning solution L2 described later are sometimes collectively referred to as "processing liquid") that has entered between the rotating plate 11 and the support plate 12. The discharge hole 11b is inclined downward as it extends radially outward and is configured to discharge the processing liquid collected in the collection groove 11a to the outside using the centrifugal force of the rotating plate 11. Multiple through holes 11c penetrate the rotating plate 11 along the vertical direction. The multiple through holes 11c may be arranged at approximately equal intervals so that they form a circular shape when viewed from above. As illustrated in Figure 4, if there are three multiple through holes 11c, they may be arranged at approximately 120° intervals.

[0025] The rotating plate 11 is connected at its lower central portion to the upper end of a rotating shaft 15 that extends vertically. The rotating shaft 15 is connected to a drive unit 16. The drive unit 16 operates based on an operation signal from the controller Ctr and is configured to rotate the rotating shaft 15. As the drive unit 16 rotates the rotating shaft 15, the rotating plate 11 rotates together with the rotating shaft 15 in a substantially horizontal position around the rotating shaft 15. The drive unit 16 may be, for example, a rotary motor.

[0026] A conductive part 11d made of a conductive material is provided on a portion of the upper surface of the rotating plate 11. The conductive part 11d is grounded via a conductor.

[0027] The support plate 12 is, for example, a disc approximately the same size as the substrate W. The support plate 12 includes a protrusion 12a that projects downward. The protrusion 12a is configured to fit into a recess 11e provided on the upper surface of the rotating plate 11. When the support plate 12 is placed on the rotating plate 11, the protrusion 12a of the support plate 12 and the recess 11e of the rotating plate 11 fit together, and the lower surface of the support plate 12 comes into contact with the upper surface of the rotating plate 11. In this state, the support plate 12 rotates together with the rotating plate 11.

[0028] As illustrated in Figures 3 and 4, the support plate 12 includes a plurality of projections 12b that protrude upward from the upper surface of the support plate 12. The plurality of projections 12b are configured to support the substrate W in a substantially horizontal position at a height above the upper surface of the support plate 12 by contacting the lower surface Wb of the substrate W with their tips. The plurality of projections 12b may be arranged at substantially equal intervals near the outer circumference of the support plate 12 so as to form a circular shape when viewed from above.

[0029] A conductive portion 12c made of a conductive material is provided on a part of the lower surface of the support plate 12. The conductive portion 12c is positioned so as to overlap with the conductive portion 11d of the rotating plate 11 and the pressed portion 18a (described later) of the movable member 18 when viewed from above or below.

[0030] Multiple push-up sections 17 are provided on the lower surfaces of the rotating plate 11 and the support plate 12. Each push-up section 17 includes a cylindrical member 17a, a push-up pin 17b, and a spring member 17c.

[0031] The cylindrical member 17a is attached to the lower surface of the rotating plate 11. The cylindrical member 17a communicates with the through hole 11c of the rotating plate 11 and extends along the vertical direction. The push-up pin 17b is inserted inside the cylindrical member 17a and is movable up and down inside the cylindrical member 17a. The upper end of the push-up pin 17b is connected to the protrusion 12a of the support plate 12. The lower end of the push-up pin 17b is provided with a flange member 17d which is approximately the same size as the inner diameter of the cylindrical member 17a. The spring member 17c is, for example, a compression coil spring. The spring member 17c is positioned between the lower surface of the rotating plate 11 and the flange member 17d of the push-up pin 17b so as to surround the push-up pin 17b.

[0032] The holding portion 13 is configured to hold the substrate W together with the restricting portion 14 by pressing the outer peripheral edge Wc of the substrate W against the restricting portion 14. The holding portion 13 includes a movable member 18 and a spring member 19.

[0033] The movable member 18 is conductive. The movable member 18 may be formed of a conductive resin in which conductive particles such as carbon filler or carbon black are dispersed. The resin may be, for example, perfluoroalkoxy alkane (PFA) or polyether ether ketone (PEEK).

[0034] The movable member 18 is substantially L-shaped and includes a pressed portion 18a and an upright portion 18b. The pressed portion 18a extends horizontally from the outer edge of the support plate 12 toward the center, so as to be located within the groove 11f formed in the rotating plate 11.

[0035] The upright portion 18b extends upward continuously from the outer end of the pressed portion 18a, outside the outer peripheral edge of the support plate 12. The tip portion 18c of the upright portion 18b protrudes radially inward from the rotating plate 11. A groove (not shown) may be formed on the inner circumferential surface of the tip portion 18c at a position facing the outer peripheral edge Wc of the substrate W. By fitting the outer peripheral edge Wc of the substrate W into this groove, the outer peripheral edge Wc of the substrate W can be held while being pressed towards the restricting portion 14.

[0036] The movable member 18 is supported so as to be rotatable around the rotation axis 18d near the lower end of the upright portion 18b. When viewed from above, the rotation axis 18d extends along the tangential direction of the outer edge of the support plate 12.

[0037] The spring member 19 is, for example, a torsion spring wound around the rotating shaft 18d. One end of the spring member 19 is connected to the side surface of the movable member 18. The spring member 19 biases the upright portion 18b in a direction that causes it to tilt radially outward from the rotating plate 11. Therefore, when the support plate 12 moves to the raised position (details will be described later), as illustrated in Figure 5, the inner end of the pressed portion 18a springs up and pops out of the groove 11f, and the upper end of the upright portion 18b moves radially outward from the rotating plate 11.

[0038] The restricting portion 14 is fixed in a predetermined position (for example, a position facing the movable member 18 with the substrate W in between) as illustrated in Figures 3 and 4. When the support plate 12 is placed on the rotating plate 11, that is, when the support plate 12 moves to the lowered position (details will be described later), the restricting portion 14 is configured to restrict the outer edge Wc of the substrate W and to hold the substrate W in cooperation with the movable member 18, as illustrated in Figure 3.

[0039] As illustrated in Figure 4, multiple regulating sections 14 are provided at predetermined positions along the circumferential direction of the support plate 12. The regulating sections 14 may be provided one at each position facing the movable member 18, or two or more at each position.

[0040] The lifting unit 20 includes a supply pipe 21, a plurality of shafts 22, and a drive unit 23, as illustrated in Figure 3.

[0041] The supply pipe 21 is a hollow tubular member extending vertically. The supply pipe 21 is inserted inside the rotating shaft 15. The tip of the supply pipe 21 penetrates the rotating plate 11 and the support plate 12 and is located above the upper surface of the support plate 12. A nozzle 21a is provided at the tip of the supply pipe 21.

[0042] The supply pipe 21 may include a flow path formed inside. This flow path extends along the direction of extension of the supply pipe 21. This flow path is connected to a liquid source and / or gas source (not shown). The liquid stored in the liquid source (e.g., chemical solution, cleaning solution, etc.) is supplied through the flow path from the nozzle 21a to the lower surface Wb of the substrate W. The inert gas stored in the gas source (e.g., nitrogen, etc.) is supplied through the flow path from the nozzle 21a to the lower surface Wb of the substrate W. As illustrated in Figure 3, the supply pipe 21 may include a plurality of flow paths. In this case, the liquid from the liquid source may be supplied to the lower surface Wb of the substrate W through one of the plurality of flow paths, and the inert gas from the gas source may be supplied to the lower surface Wb of the substrate W through another of the plurality of flow paths.

[0043] Each of the multiple shafts 22 is connected to the supply pipe 21 via a connecting member 22a. The multiple shafts 22 extend vertically upward toward the support plate 12. The multiple shafts 22 may be arranged at approximately equal intervals so that they form a circular shape when viewed from above. For example, if there are three multiple shafts 22, they may be arranged at approximately 120° intervals.

[0044] The drive unit 23 is connected to the supply pipe 21. The drive unit 23 operates based on an operation signal from the controller Ctr and is configured to raise and lower the supply pipe 21. The drive unit 23 may be a power source such as a linear actuator. As the drive unit 23 raises and lowers the supply pipe 21, the supply pipe 21 and the multiple shafts 22 connected to the supply pipe 21 move up and down between a lowered position (see Figure 3) and an raised position (see Figure 5).

[0045] As illustrated in Figure 3, in the lowered position, the tip of the supply pipe 21 (nozzle 21a) is located below the tips of the multiple protrusions 12b. In the lowered position, the tips of the multiple shafts 22 are located below the push-up portion 17. In the lowered position, the restoring force of the spring acts in the direction that extends the spring member 17c, so that the support plate 12 is pulled downward via the push-up pin 17b. As a result, the convex portion 12a of the support plate 12 and the concave portion 11e of the rotating plate 11 fit together, and the lower surface of the support plate 12 comes into contact with the upper surface of the rotating plate 11. Therefore, the pressed portion 18a of the movable member 18 is pushed downward by the lower surface (conductive portion 12c) of the support plate 12 and pushed into the groove 11f formed in the rotating plate 11. Then, the upright portion 18b becomes upright, extending vertically, and the tip portion 18c of the upright portion 18b comes into contact with the outer edge Wc of the substrate W, which is supported on the multiple protrusions 12b. As a result, the movable member 18 presses the outer edge Wc of the substrate W against the restricting portion 14, and holds the substrate W together with the restricting portion 14.

[0046] In the lowered position, the conductive part 11d and the conductive part 12c come into contact, and the conductive part 12c comes into contact with the pressed part 18a. As a result, the conductive parts 11d, 12c and the movable member 18 are electrically connected to earth.

[0047] On the other hand, as illustrated in Figure 5, as the supply pipe 21 rises from the lowered position to the raised position, the multiple shafts 22 rise together with the supply pipe 21 via the connecting member 22a. When the multiple shafts 22 reach the push-up section 17, the push-up pins 17b located at positions corresponding to the multiple shafts 22 are pushed up by the shafts 22. As a result, the spring member 17c is compressed, the support plate 12 floats up relative to the rotating plate 11, and the multiple protrusions 12b come into contact with the lower surface of the substrate W. At the same time, the biasing force of the spring member 19 causes the upright section 18b to tilt radially outward from the rotating plate 11. Therefore, the holding of the outer edge Wc of the substrate W by the regulating section 14 and the movable member 18 is released, and the substrate W is supported by the multiple protrusions 12b. As the supply pipe 21 rises further to the raised position, the substrate W floats up to a height above the cup section 30. In this case, it becomes possible to transfer the substrate W between the external transport arm and the main unit without interfering with other equipment.

[0048] In the raised position, the support plate 12 floats above the rotating plate 11, causing the conductive part 11d and the conductive part 12c to separate. As a result, the conductive part 12c and the movable member 18 are electrically disconnected from the ground.

[0049] The cup section 30 functions as a liquid collection container that receives the processing liquid supplied to the upper surface Wa and lower surface Wb of the substrate W and shaken off from the substrate W. The cup section 30 includes an inner cup 31, an intermediate cup 32, and an outer cup 33.

[0050] The inner cup 31 has an annular shape overall and is provided to surround the substrate W from the outside while it is being held by the regulating portion 14 and the movable member 18. The inner cup 31 is connected to the rotating plate 11 by a connecting member (not shown) with its lower edge separated from the upper surface of the rotating plate 11. As a result, the inner cup 31 rotates in conjunction with the rotation of the rotating plate 11. As a result, the processing liquid supplied to the lower surface Wb of the substrate W and shaken off the substrate W is discharged into the outer cup 33 through the gap between the lower edge of the inner cup 31 and the rotating plate 11.

[0051] The middle cup 32 has an annular shape overall and is positioned to surround the inner cup 31 from the outside. The middle cup 32 is connected to the rotating plate 11 by a connecting member (not shown) such that its lower edge is separated from the upper surface of the rotating plate 11. As a result, the middle cup 32 rotates in conjunction with the rotation of the rotating plate 11. This causes the processing liquid supplied to the upper surface Wa of the substrate W and then shaken off the substrate W to be discharged into the outer cup 33 through the gap between the lower edge of the middle cup 32 and the rotating plate 11.

[0052] The outer cup 33 has an annular shape overall and is positioned to surround the inner cup 32 from the outside, extending from the lower part of the rotating plate 11 to the side of the inner cup 32. A drain pipe 33a is provided in the bottom wall of the outer cup 33. The processed liquid discharged from the inner cup 31 and the inner cup 32 is received by the outer cup 33 and discharged to the outside of the liquid processing unit U through the drain pipe 33a.

[0053] The chemical supply unit 40 includes a liquid source 41, a pump 42, a valve 43, piping 44, a drive unit 45, and a supply tube 100A. The liquid source 41 is the source of the chemical solution L1.

[0054] The chemical solution L1 may include, for example, an alkaline or acidic chemical solution (etching solution) for removing the film on the upper surface Wa of the substrate W. The alkaline chemical solution may include, for example, SC-1 solution (a mixture of ammonia, hydrogen peroxide, and pure water). The acidic chemical solution may include, for example, SC-2 solution (a mixture of hydrochloric acid, hydrogen peroxide, and pure water), SPM (a mixture of sulfuric acid and hydrogen peroxide), HF / HNO3 solution (a mixture of hydrofluoric acid and nitric acid). The film on the upper surface Wa of the substrate W may be a conductive film such as titanium nitride, tungsten, or cobalt.

[0055] Pump 42 operates based on an operating signal from controller Ctr and is configured to supply the chemical solution L1 drawn from liquid source 41 to supply tube 100A via piping 44 and valve 43. Valve 43 operates based on an operating signal from controller Ctr and is configured to transition between an open state that allows fluid flow in piping 44 and a closed state that prevents fluid flow in piping 44. Piping 44 connects, in order from upstream, the liquid source 41, pump 42, valve 43, and supply tube 100A.

[0056] The drive unit 45 is connected to the supply tube 100A via an arm 46. The drive unit 45 is configured to operate based on an operating signal from the controller Ctr and to drive the arm 46. As a result, the supply tube 100A moves horizontally or vertically above the substrate W as the arm 46 moves. The supply tube 100A may pivot between, for example, a discharge position where the discharge port faces the center of the substrate W and a retracted position where the discharge port is retracted radially outward from the outer edge Wc of the substrate W.

[0057] The supply tube 100A is positioned above the substrate W such that its discharge port faces the upper surface Wa of the substrate W. The supply tube 100A is configured to discharge the chemical solution L1 sent from the pump 42 from its discharge port toward the upper surface Wa of the substrate W. The detailed configuration of the supply tube 100A will be described later.

[0058] The cleaning fluid supply unit 50 includes a liquid source 51, a pump 52, a valve 53, piping 54, a drive unit 55, and a supply tube 100B. The liquid source 51 is the source of the cleaning fluid L2 (charged fluid).

[0059] The cleaning solution L2 is a liquid used to remove (wash away) the chemical solution L1 supplied to the upper surface Wa of the substrate W, as well as the film-dissolving components caused by the chemical solution L1, from the substrate W. The cleaning solution L2 may contain, for example, pure water (DIW: deionized water), ozonated water, carbonated water (CO2 water), ammonia water, etc.

[0060] Pump 52 operates based on an operating signal from controller Ctr and is configured to send cleaning fluid L2 drawn from liquid source 51 to supply tube 100B via piping 54 and valve 53. Valve 53 operates based on an operating signal from controller Ctr and is configured to transition between an open state that allows fluid flow in piping 54 and a closed state that prevents fluid flow in piping 54. Piping 54 connects, in order from upstream, the liquid source 51, pump 52, valve 53, and supply tube 100B.

[0061] The drive unit 55 is connected to the supply tube 100B via an arm 56. The drive unit 55 is configured to operate based on an operating signal from the controller Ctr and to drive the arm 56. As a result, the supply tube 100B moves horizontally or vertically above the substrate W as the arm 56 moves. The supply tube 100B may also pivot between, for example, a position where the discharge port faces the center of the substrate W and a position where the discharge port is retracted radially outward from the outer edge Wc of the substrate W.

[0062] The supply tube 100B is positioned above the substrate W such that its discharge port faces the upper surface Wa of the substrate W. The supply tube 100B is configured to discharge the cleaning fluid L2 sent from the pump 52 from its discharge port toward the upper surface Wa of the substrate W. The detailed configuration of the supply tube 100B will be described later.

[0063] Here, the configuration of supply tubes 100A and 100B will be explained with reference to Figures 6 and 7. In this document, supply tubes 100A and 100B will sometimes be collectively referred to as "supply tube 100".

[0064] The supply tube 100 includes a resin tube body 110 and a plurality of conductive parts 120, as illustrated in Figures 5 and 6(a). The tube body 110 may be made of, for example, a heat-meltable fluororesin. The plurality of conductive parts 120 may be made of, for example, a heat-meltable fluororesin composition containing a conductive substance.

[0065] In the examples shown in Figures 6 and 7(a), the multiple conductive parts 120 are provided on the outer circumferential surface of the tube body 110 so as to extend along the longitudinal direction of the tube body 110, with the tube body 110 spaced apart from each other in the radial direction of the tube body 110. As illustrated in Figure 7(a), if there are four multiple conductive parts 120, the multiple conductive parts 120 may be arranged at approximately 90° intervals in the radial direction of the tube body 110.

[0066] As illustrated in Figure 6, a sensor SE (acquisition unit) is connected to the supply tube 100. Specifically, the sensor SE may be connected to at least one of the multiple conductive parts 120. The sensor SE may also be an ammeter configured to measure the current generated when the processing liquid flows through the supply tube 100. That is, when the processing liquid flows through the supply tube 100, the processing liquid becomes charged due to the frictional force between the processing liquid and the supply tube 100. Here, a virtual capacitance is generated between the processing liquid and each of the multiple conductive parts 120, so the current when the processing liquid is supplied to the substrate W is measured by the sensor SE.

[0067] As illustrated in Figure 8(a), we consider a case where a charged processing liquid is supplied to a substrate W, which has an insulating film W2 and a conductive film W3, and is held by a restricting part 14 and a movable member 18. When the processing liquid flows over the surface of film W3 and reaches the movable member 18, the charge in the processing liquid moves to the ground through the conductive film (film W3), the movable member 18, the conductive part 12c, and the conductive part 11d. As a result, the charge in the processing liquid is discharged. That is, in the configuration illustrated in Figure 8(a), at the start of supplying the charged processing liquid, the sensor SE detects a current value of a predetermined magnitude due to the movement of the processing liquid (movement of charge) within the supply tube 100, but after discharge, the current value detected by the sensor SE approaches 0.

[0068] On the other hand, consider the case where a charged processing liquid is supplied to a substrate W, which is held by the restricting part 14 and the movable member 18, as illustrated in Figure 8(b), where the substrate W is a conductive film W2 and an insulating film W3. When the processing liquid flows over the surface of the film W3 and reaches the movable member 18, the charge in the processing liquid accumulates on the surface of the insulating film (film W3) because it is insulated from the ground by the insulating film, and the substrate W becomes charged. Therefore, the charge in the processing liquid is not discharged. In other words, in the configuration illustrated in Figure 8(b), while the charged processing liquid is being supplied, the sensor SE continuously detects a current value of a predetermined magnitude due to the movement of the processing liquid (movement of charge) within the supply tube 100.

[0069] As described above, the current value measured by the sensor SE corresponds to the amount of charge on the substrate W. In other words, the sensor SE is configured to acquire the amount of charge on the substrate W.

[0070] The multiple conductive parts 120 may include an outer conductor 121, an inner conductor 122, and a connecting conductor 123, as illustrated in Figure 7(b). The outer conductors 121 are provided on the outer circumferential surface of the tube body 110 so as to extend along the longitudinal direction of the tube body 110, spaced apart from each other in the radial direction of the tube body 110. As illustrated in Figure 7(b), if there are four of the multiple outer conductors 121, the multiple outer conductors 121 may be arranged at approximately 90° intervals in the radial direction of the tube body 110.

[0071] The inner conductors 122 are provided on the inner circumferential surface of the tube body 110 so as to extend along the longitudinal direction of the tube body 110, with each conductor spaced apart from the others in the radial direction of the tube body 110. The inner conductors 122 are positioned to face the outer conductors 121. As illustrated in Figure 7(b), if there are four inner conductors 122, the inner conductors 122 may be arranged at approximately 90° intervals in the radial direction of the tube body 110.

[0072] The connecting conductor 123 extends along the thickness direction of the tube body 110 to integrally connect the pair of opposing outer conductors 121 and inner conductor 122. Thus, the outer conductor 121, inner conductor 122, and connecting conductor 123 are electrically connected to each other.

[0073] [controller] As shown in Figure 9, the controller Ctr has a reading unit M1, a storage unit M2, a processing unit M3, and an instruction unit M4 as functional modules. These functional modules are merely a convenient division of the controller Ctr's functions into multiple modules, and do not necessarily mean that the hardware constituting the controller Ctr is divided into such modules. Each functional module is not limited to being implemented by program execution, but may also be implemented by a dedicated electrical circuit (e.g., a logic circuit) or an integrated circuit (ASIC: Application Specific Integrated Circuit) that integrates these.

[0074] The reading unit M1 is configured to read a program from a computer-readable recording medium RM (device). The recording medium RM stores a program for operating each part of the substrate processing system 1 (drive units 16, 23, 45, 55, pumps 42, 52, valves 43, 53, etc.). The recording medium RM may be, for example, a semiconductor memory, an optical recording disk, a magnetic recording disk, or a magneto-optical recording disk. The recording medium RM may be built into the substrate processing system 1 or may be a separate unit from the substrate processing system 1.

[0075] The memory unit M2 is configured to store various types of data. For example, the memory unit M2 may store programs read from the recording medium RM by the reading unit M1, setting data input from the operator via an external input device (not shown), etc. The memory unit M2 may also store data of current values ​​measured by the sensor SE. The memory unit M2 may also store time-series data (details will be described later) showing changes in the amount of charge on the sample substrate.

[0076] The processing unit M3 is configured to process various types of data. For example, the processing unit M3 may be configured to generate operation signals for operating each part of the substrate processing system 1 based on various types of data stored in the storage unit M2.

[0077] The instruction unit M4 is configured to transmit the operation signals generated in the processing unit M3 to each part of the substrate processing system 1.

[0078] The hardware of the controller Ctr may consist of, for example, one or more control computers. The controller Ctr may include, for example, the circuit C1 shown in Figure 10 as a hardware configuration. Circuit C1 may consist of electrical circuit elements. Circuit C1 may include, for example, a processor C2, a memory C3 (storage unit), a storage C4 (storage unit), a driver C5, and an input / output port C6. The processor C2 executes a program in cooperation with at least one of the memory C3 and the storage C4, and performs input and output of signals via the input / output port C6, thereby configuring each of the above-mentioned functional modules. The memory C3 and the storage C4 function as storage units M2. The driver C5 is a circuit that drives each part of the board processing system 1. The input / output port C6 performs input and output of signals between the driver C5 and each part of the board processing system 1.

[0079] The substrate processing system 1 may have one controller Ctr, or it may have a controller group (control unit) composed of multiple controllers Ctr. In the latter case, each of the above functional modules may be implemented by one controller Ctr, or by a combination of two or more controllers Ctr. If the controller Ctr is composed of multiple computers (circuit C1), each of the above functional modules may be implemented by one computer (circuit C1), or by a combination of two or more computers (circuit C1). The controller Ctr may include multiple processors C2. In this case, each of the above functional modules may be implemented by one processor C2, or by a combination of two or more processors C2.

[0080] [Preparation] Next, we will explain the preparations made before processing the substrate W. In the following explanation, we will use as an example the process of etching a substrate W, as illustrated in Figure 8(a), in which film W2 is an insulating film and film W3 is a conductive film, to leave film W3 as a thin film.

[0081] First, N (where N is a natural number of 2 or more) sample substrates W that have been properly processed by etching, i.e., substrates W in which film W3 remains as a thin film on film W2, are prepared. Next, with each sample substrate held by the restricting unit 14 and the movable member 18, a cleaning solution L2 (for example, pure water) is supplied to the upper surface of each sample substrate through the supply tube 100B for a predetermined time. Then, the change in the current value (change in the amount of charge on the sample substrate) during the supply of this cleaning solution L2 is acquired by the sensor SE, and each time-series data is stored in the storage unit M2 as the change in the current value over time.

[0082] Figure 11 shows an example of time-series data DT1 for one sample substrate. According to the time-series data DT1, as mentioned above, at the start of supplying the charged cleaning solution L2, the sensor SE detects a current value of approximately -0.9 μA due to the movement of the cleaning solution L2 (charge movement) within the supply tube 100. Subsequently, after the charge in the cleaning solution L2 is discharged, the current value detected by the sensor SE gradually approaches 0. In the time-series data DT1, the current value approaches approximately -0.3 μA.

[0083] [Substrate Processing Method] Next, the processing of the substrate W with the processing liquid will be explained with reference to Figure 12. First, the controller Ctr instructs the drive unit 23 to raise the supply pipe 21. As a result, the supply pipe 21 and the multiple shafts 22 connected to the supply pipe 21 rise to the raised position (see Figure 5). Next, the transport arm A2 places the substrate W onto the multiple protrusions 12b.

[0084] Next, the controller Ctr instructs the drive unit 23 to lower the supply pipe 21. The supply pipe 21 and the multiple shafts 22 connected to the supply pipe 21 are lowered to the lowered position (see Figure 3). This allows the substrate W to be transported into the liquid processing unit U (see step S1 in Figure 12).

[0085] As the supply pipe 21 is lowered, the lower surface of the support plate 12 comes into contact with the upper surface of the rotating plate 11, and the pressed portion 18a of the movable member 18 is pushed downward by the lower surface (conductive portion 12c) of the support plate 12. As a result, the tip 18c of the upright portion 18b comes into contact with the outer edge Wc of the substrate W, which is supported on a plurality of protrusions 12b. Consequently, the movable member 18 holds the substrate W together with the regulating portion 14. Furthermore, when the supply pipe 21 is in the lowered position, the conductive portion 11d and the conductive portion 12c come into contact, and the conductive portion 12c comes into contact with the pressed portion 18a. Therefore, the conductive portions 11d, 12c and the movable member 18 are electrically connected to earth.

[0086] Next, the controller Ctr instructs the drive unit 16 to rotate the rotation shaft 15. As a result, the substrate W, which is mounted on the multiple protrusions 12b, rotates together with the rotating plate 11, the support plate 12, and the rotation shaft 15, around the rotation shaft 15 in a substantially horizontal position.

[0087] Next, the controller Ctr instructs the drive unit 45 to move the supply tube 100A from the retracted position to the discharge position. Then, the controller Ctr instructs the pump 42 and valve 43 to supply the chemical solution L1 from the liquid source 41 to the upper surface Wa of the substrate W from the discharge port of the supply tube 100A (see step S2 in Figure 12). As a result, the chemical solution L1 spreads from the center of the substrate W toward the outer edge Wc, covering the entire upper surface Wa of the substrate W, and comes into contact with the movable member 18. Therefore, the upper surface Wa (film W3) of the substrate W is etched by the chemical solution L1.

[0088] If the etching process is completed successfully, film W3 will be etched away, resulting in a thin film. On the other hand, if the etching process is not completed successfully, film W3 will be completely removed, leaving film W2 exposed.

[0089] After a predetermined time has elapsed since the start of supplying the chemical solution L1 to the substrate W, the controller Ctr instructs the pump 42 and valve 43 to stop supplying the chemical solution L1. The controller Ctr instructs the drive unit 45 to move the supply tube 100A from the discharge position to the retracted position.

[0090] Next, the controller Ctr instructs the drive unit 55 to move the supply tube 100B from the retracted position to the discharge position. Then, the controller Ctr instructs the pump 52 and valve 53 to supply the cleaning liquid L2 (for example, pure water) from the liquid source 51 to the upper surface Wa of the substrate W from the discharge port of the supply tube 100B (see step S3 in Figure 12). As a result, the cleaning liquid L2 spreads from the center of the substrate W toward the outer edge Wc, covering the entire upper surface Wa of the substrate W and coming into contact with the movable member 18. Therefore, the upper surface Wa of the substrate W is treated by the cleaning liquid L2.

[0091] At this time, if the etching process is completed successfully, the charged cleaning solution L2 is supplied to the conductive film W3. Therefore, as shown in the time-series data DT1 illustrated in Figure 11, the sensor SE detects a current value of a predetermined magnitude at the beginning of the supply of the cleaning solution L2, and then the current value detected by the sensor SE gradually approaches 0. On the other hand, if the etching process is not completed successfully, the charged cleaning solution L2 is supplied to the insulating film W3. Therefore, as shown in the time-series data DT2 and DT3 illustrated in Figure 11, the sensor SE continuously detects a current value of a predetermined magnitude. The controller Ctr then determines the remaining state of the film W3 (conductive film) while the cleaning solution L2 is being supplied to the substrate W (see step S3 in Figure 12). Details of this determination will be described later.

[0092] After a predetermined time has elapsed since the start of supplying cleaning solution L2 to the substrate W, the controller Ctr instructs the pump 52 and valve 53 to stop supplying cleaning solution L2. The controller Ctr instructs the drive unit 55 to move the supply tube 100B from the discharge position to the retracted position.

[0093] Next, the rotation of the substrate W is continued for a predetermined time. This causes the cleaning solution L2 adhering to the substrate W to be shaken off by the rotation of the substrate W, and the surface of the substrate W is dried (see step S4 in Figure 12).

[0094] Next, the controller Ctr instructs the drive unit 23 to raise the supply pipe 21. As a result, the supply pipe 21 and the multiple shafts 22 connected to the supply pipe 21 rise to the raised position (see Figure 5). Next, the transport arm A2 removes the substrate W, which is supported by the multiple protrusions 12b, from the liquid processing unit U (see step S5 in Figure 12). With this, the processing of the substrate W is completed.

[0095] [Determination of the remaining conductive film] The remaining state of film W3 (conductive film) is determined based on time-series data obtained during the preparation phase (e.g., time-series data DT1) and the current value (charge amount of substrate W) acquired by sensor SE on the substrate W currently being processed. The specific method for determining the remaining state of film W3 (conductive film) is described below with reference to Figures 11, 13, and 14.

[0096] First, the controller Ctr calculates the z-score (see step S11 in Figure 13). The z-score is an index that shows the relative position within a population of a normal distribution, and is a score transformed so that the mean is 0 and the standard deviation is 1. As illustrated in Figure 11, the z-score z(t) at time t from the start of supply of cleaning solution L2 is calculated by the parameters μ(t), σ(t), and s(t), respectively. μ(t): Average value of current at time t in time-series data of N sample substrates. σ(t): Standard deviation of the current value at time t in the time series data of N sample substrates. s(t): Current value obtained by sensor SE at time t on substrate W during processing with cleaning solution L2. If defined as such, it can be expressed by Equation 1.

number

[0097] Here, the standard deviation σ(t) is given by the parameter x i (t) x i (t): Current value at time t on the i-th sample board (where i is a natural number from 1 to N) out of N sample boards. In this case, it can be expressed by Equation 2.

number

[0098] Next, the controller Ctr calculates the p-value (see step S12 in Figure 13). The p-value is the probability that the observed statistic (z-score) or a greater absolute value is obtained, assuming the null hypothesis is true. The p-value p(t) corresponding to the z-score z(t) at time t can be determined, for example, based on a standard normal distribution table.

[0099] Next, the controller Ctr calculates the deviation rate (see step S13 in Figure 13). The deviation rate is the probability that the current value s(t) deviates from the range of current values ​​at time t (normal range) in the time-series data of N sample substrates. In other words, the closer the deviation rate is to 0, the higher the probability that the film W3 on substrate W remains, and the closer the deviation rate is to 1, the higher the probability that the film W3 on substrate W has been completely removed. In other words, the deviation rate can be said to be an index value that indicates the degree of deviation from the normal value (normal range).

[0100] The outlier Por(t) at time t may also be calculated using Equation 3. Por(t) = 1 - p(t) ... (3)

[0101] Furthermore, to address the issue of multiple testing, instead of Equation 3, the outlier Por(t) adjusted for significance levels may be calculated using a multiple comparison method. Examples of multiple comparison methods include the Bonferroni method, Holm method, Tukey method, Scheffé method, Dunnett method, Tukey-Kramer method, and Williams method. As an example, when using the Bonferroni method, the outlier Por(t) may be calculated using Equation 4.

number

[0102] Figure 14 shows an example of the time change in the deactivation rate when the time-series data DT2, as illustrated in Figure 11, is acquired by the sensor SE on a substrate W during processing with cleaning solution L2. The deactivation rate was calculated based on Equation 4.

[0103] Next, the controller Ctr determines whether the delamination rate is above a predetermined threshold Th (see step S14 in Figure 13). As illustrated in Figure 14, this threshold may be around 0.6. If it is determined that the delamination rate is below the threshold Th during the discharge period of the cleaning solution L2 to the substrate W (NO in step S14 in Figure 13), it is presumed that the film W3 on the substrate W remains and the etching process has been performed successfully. This completes the process of determining the remaining state of the film W3 (conductive film).

[0104] On the other hand, if the delamination rate is determined to be above a threshold Th during the discharge period of the cleaning solution L2 to the substrate W (YES in step S14 of Figure 13), it is presumed that the film W3 on the substrate W was completely removed and the etching process was not performed correctly. Therefore, if the controller Ctr determines that the delamination rate is above a threshold Th, it will issue an alarm from an alarm unit (not shown) indicating that the etching process was not performed correctly (see step S15 of Figure 13). The alarm from the alarm unit may be displayed as text on a display, or it may be issued as an alarm sound or alarm announcement from a speaker.

[0105] Next, the controller Ctr performs reprocessing on the substrate W (see step S16 in Figure 13). Specifically, the controller Ctr controls the liquid treatment unit U to perform etching on the substrate W. This further etches the film W2 from the substrate W, from which film W3 has been completely removed, and completely removes film W2 from the substrate W. Next, the controller Ctr uses the transport arm A2 to remove the substrate W from the liquid treatment unit U, and the transport arms A1 and A2 to transport it to the mounting section 4 and place it in the carrier 7. The substrate W placed in the carrier 7 is sent to the film deposition apparatus Q, where films W2 and W3 are formed again on the upper surface of the substrate W1. The substrate W, with films W2 and W3 thus reformed, is again placed in the carrier 7 of the mounting section 4, transported to the liquid treatment unit U by the transport arms A1 and A2, and then the processes in steps S1 to S5 are performed so that film W3 remains as a thin film. After the reprocessing of the substrate W described above, the process of determining the remaining state of film W3 (conductive film) is completed.

[0106] [Effect] In the above example, the remaining state of the film W3 is determined based on the current value (amount of charge on the substrate W) when the charged cleaning solution L2 is supplied to the upper surface Wa of the substrate W, and time-series data DT1, which shows the change in the current value (amount of charge) on a sample substrate, acquired in advance. Therefore, by applying the current value (amount of charge) of the substrate W currently being processed to the time-series data DT1, the remaining state of the film W3 on that substrate W can be determined. Thus, it is possible to grasp the remaining state of the film W3 in-line (during the processing of the substrate W) for each individual substrate W.

[0107] Based on the above example, it is determined that film W3 remains on the upper surface of film W2 when the fall rate is greater than or equal to the threshold Th. Therefore, it is possible to accurately determine the presence or absence of film W3 using the fall rate.

[0108] As shown in the above example, if it is determined that no film W3 remains, an alarm is issued according to the remaining state of film W3. Therefore, it is possible to inform workers and others that film W3 has not been properly processed.

[0109] As shown in the above example, if it is determined that film W3 is no longer present, new films W2 and W3 are formed on the substrate W1 of the substrate W. Therefore, the substrate W, which would normally be discarded as defective, can be reused, making it possible to utilize the substrate W1 without waste.

[0110] [Differentiation] The disclosures herein should be considered in all respects to be illustrative and not restrictive. Various omissions, substitutions, and modifications may be made to the above examples without departing from the claims and the gist thereof.

[0111] (1) The controller Ctr may determine whether the measurement units provided in various parts of the substrate processing system 1 are abnormal based on whether the failure rate is greater than or equal to a threshold Th. Examples of such measurement units include sensors that measure the temperature of the processing liquid, sensors that measure the discharge amount (flow rate) of the processing liquid, and sensors that measure the temperature inside the liquid processing unit U. One example of how to determine whether a measurement unit is abnormal is to divide the values ​​of each measurement unit into two groups: the values ​​when the failure rate is less than the threshold Th, and the values ​​when the failure rate is greater than or equal to the threshold Th, perform a statistical test, and determine whether there is a statistically significant difference between the normal values ​​and the abnormal values. Another example of how to determine whether a measurement unit is abnormal is to generate a learning model by machine learning using the values ​​of each measurement unit when the failure rate is less than the threshold Th and the values ​​when the failure rate is greater than or equal to the threshold Th, and input the data measured at each measurement unit into the learning model. For example, machine learning may be performed using supervised learning, unsupervised learning, or reinforcement learning. If the controller Ctr determines that there is an abnormality in any of the measurement units, it may issue an alarm from a notification unit (not shown).

[0112] (2) If the deformability rate is determined to be above a threshold Th, the controller Ctr may change the supply conditions (recipe) of the chemical solution L1 to the subsequent substrate W when etching the subsequent substrate W. Examples of such supply conditions include the discharge amount (flow rate) of the chemical solution L1 and the discharge time of the chemical solution L1. Alternatively, the optimal supply conditions (recipe) of the chemical solution L1 to the substrate W for manufacturing the product may be determined by repeatedly etching a sample substrate in advance and changing the supply conditions (recipe) of the chemical solution L1 when it is determined that the deformability rate is above a threshold Th.

[0113] (3) If it is determined that the failure rate is above the threshold Th, the processing of subsequent substrates W may be stopped along with the alarm in step S15, or without the alarm being issued. If an alarm is issued, there is a possibility that the film W3 will not be processed properly on subsequent substrates W, so by stopping the processing of subsequent substrates W, it is possible to reduce processing costs.

[0114] (4) The above describes an example of a process in which a substrate W in which film W2 is an insulating film and film W3 is a conductive film is etched to leave film W3 as a thin film. However, this technology may also be applied to a process in which a substrate W in which film W2 is an insulating film and film W3 is a conductive film is etched to completely remove film W3. This technology may also be applied to a process in which a substrate W in which film W2 is a conductive film and film W3 is an insulating film is etched to leave film W3 as a thin film. This technology may also be applied to a process in which a substrate W in which film W2 is a conductive film and film W3 is an insulating film is etched to completely remove film W3.

[0115] (5) The storage unit M2 may store data that corresponds the type of substrate W (for example, whether the film W3 is a conductive film or an insulating film) and the timing at which the substrate is loaded into the liquid processing unit U. The controller Ctr may obtain information on the type of substrate W from the storage unit M2 at the timing when the substrate W is loaded into the liquid processing unit U, set processing conditions corresponding to the type of substrate W, and execute the etching process on the substrate W. In this case, the film W3 is etched according to the processing conditions that are automatically set according to the type of film W3. Therefore, it becomes possible to process the substrate W efficiently.

[0116] (6) In the process of etching the substrate W to completely remove the film W3, if it is determined that the delamination rate is above a threshold Th (meaning that film W3 remains), the controller Ctr may control the chemical supply unit 40 to supply chemical L1 to the substrate W. This causes the substrate W to be etched again and the film W3 to be completely removed. As a result, the substrate W, which would normally be discarded as defective, can be used as a product. In addition, since the presence of film W3 is detected in-line (during the processing of the substrate W), the etching process can be completed in an appropriate time. As a result, waste of chemical L1 can be suppressed, and damage to the substrate W due to excessive supply of chemical L1 to the substrate W can be suppressed.

[0117] (7) The inventors have found that when the film thickness of the film W3 is less than or equal to a predetermined size, there is a correlation between the film thickness and the current value (amount of charge) obtained by the sensor SE when the cleaning solution L2 is supplied to the substrate W. The predetermined size may be, for example, about 4 nm.

[0118] For example, when film W2 is an insulating film and film W3 is a conductive film, a correlation was found in Figure 15(a) where, when the film thickness of film W3 is below a predetermined size, the film thickness increases as the current value increases. In Figure 15(a), the solid circle and the dashed circle indicate that the substrate W is of different types, with films W2 and W3 made of different materials.

[0119] On the other hand, for example, when film W2 is a conductive film and film W3 is an insulating film, a correlation was found in which, as illustrated in Figure 15(b), the film thickness of film W3 decreases as the current value increases, provided that the film thickness is below a predetermined size. In Figure 15(b), the solid circle and the dashed circle indicate that the substrate W is of different types, with films W2 and W3 made of different materials.

[0120] Therefore, an approximation line may be calculated in advance in the region where there is a correlation between the film thickness of film W3 and the current value, and the memory unit M2 may store data (film thickness model) that associates the type of substrate W (for example, whether film W3 is a conductive film or an insulating film) with the said approximation line. The controller Ctr may calculate the film thickness of film W3 on the substrate W currently being processed based on the current value (charge amount) acquired by the sensor SE during the supply of cleaning solution L2 to the substrate W and the film thickness model stored in the memory unit M2. In this case, the film thickness of film W3 can be determined in-line for each substrate W (during the substrate processing process), and the film thickness of film W3 can be calculated with greater accuracy using the film thickness model. The controller Ctr may also change the supply conditions (recipe) of the chemical solution L1 based on the film thickness of film W3 calculated using the film thickness model.

[0121] (8) Incidentally, during the pretreatment process of the substrate W, the substrate W may become charged. When a polar processing solution is supplied to such a charged substrate W, the processing solution acts as a conductor and charges move on the substrate W. As a result, an electric current flows on the substrate W, and a discharge from the substrate W called arcing (surface discharge) occurs. Consequently, devices (e.g., patterns) formed on the upper surface of the substrate W may be damaged by dielectric breakdown.

[0122] In the example above, the current when the processing solution is supplied to the substrate W is measured by the sensor SE. Therefore, the sudden change in current when arcing occurs can also be detected by the sensor SE. Consequently, it becomes possible to easily identify the substrate W in which arcing has occurred.

[0123] (9) The sensor SE does not have to be attached to the supply tube 100. As illustrated in Figure 16, the sensor SE may be configured to measure the potential generated on the movable member 18. In this case, the sensor SE may be a non-contact surface potential meter configured to measure the potential generated on the movable member 18 in a non-contact manner.

[0124] (10) In the above example, the deviation rate Por(t), which is the probability that the current value s(t) falls outside the range of current values ​​at time t in the time-series data of N sample substrates that were processed normally, was compared with a threshold Th. Based on the result of this comparison, it was determined whether or not the etching process was performed normally on the substrate W currently being processed, that is, whether or not an abnormality occurred in the etching process. However, the determination of whether or not an abnormality occurred in the etching process may be performed by other methods that do not use the deviation rate. For example, a learning model may be generated by machine learning using the time-series data of multiple sample substrates that were processed normally and the time-series data of multiple sample substrates that were not processed normally. Then, by inputting the current value (charge amount of substrate W) obtained by the sensor SE on the substrate W currently being processed into the learning model, it may be determined whether or not an abnormality occurred in the etching process on the substrate W currently being processed.

[0125] When using machine learning to make the above determination, a distance index may be used as an indicator value that shows the degree of deviation from the normal value (normal range). Specifically, the controller Ctr may use a learning model to feature the current value (charge amount of substrate W) obtained by the sensor SE on the substrate W currently being processed, and calculate the distance between this feature and the feature in multiple sample substrates that have been processed normally as a distance index. Examples of such distances include the Euclidean distance, Mahalanobis distance, and cosine distance.

[0126] [Other examples] Example 1. An example of a substrate processing method includes a first step of supplying a chemical solution to the upper surface of a substrate on which a first film is formed on the upper surface of the substrate and a second film is formed on the upper surface of the first film to etch the second film; a second step of supplying a charged liquid, which is a charged liquid, to the upper surface of the substrate after the first step; a third step of acquiring the amount of charge on the substrate by an acquisition unit during the second step; and a fourth step of determining the remaining state of the second film on the surface of the substrate based on the amount of charge acquired in the third step and time-series data showing the change in the amount of charge on the sample substrate when a charged liquid is supplied to a sample substrate on which the second film does not exist on the upper surface of the first film.

[0127] Incidentally, in a substrate on which two different types of films are formed, there are processes such as completely removing the second film located above the first film by etching, or leaving the second film as a thin film. In the former case, it is necessary to determine the etching conditions so that there is no residual second film, or that the substrate is not damaged by the second film being completely removed and the first film being further etched. In the latter case, it is necessary to determine the etching conditions so that subsequent processing on a defective substrate with the second film completely removed does not lead to increased processing costs, or that the durability of subsequent equipment is affected by the defective substrate being processed by the equipment. For this reason, it is necessary to know how much of the second film located above the substrate has been removed after etching, that is, the remaining state of the second film. However, conventionally, in order to determine this remaining state, substrates after etching were randomly sampled and the thickness of the second film was measured. Therefore, it was difficult to measure the thickness of the second film for all substrates after etching during the processing (in-line).

[0128] Therefore, the inventors conducted diligent research and discovered that when the second film located above is etched away and reaches close to the first film, the electrical properties change. Specifically, they found that when a charging solution is applied to the substrate, the amount of charge on the substrate changes according to the thickness of the second film. Based on this, in Example 1, the remaining state of the second film on the surface of the substrate is determined based on the amount of charge on the substrate when the charging solution is supplied to the upper surface of the substrate and time-series data showing the change in the amount of charge on a sample substrate, which was acquired in advance. Therefore, by applying the amount of charge of the substrate currently being processed to the time-series data, the remaining state of the second film on that substrate can be determined. Thus, it is possible to grasp the remaining state of the film on the surface of the substrate in-line (during the substrate processing process) for each individual substrate.

[0129] Example 2. In the method of Example 1, the fourth step may include calculating an index value indicating the degree of deviation of the charge amount from a normal value based on the charge amount and time-series data showing the change obtained in the third step, and determining that the second film remains on the upper surface of the first film when the index value is above a predetermined threshold. In this case, it becomes possible to accurately determine the presence or absence of a film on the surface of the substrate using the index value.

[0130] Example 3. In the method of Example 2, the index value may be calculated based on the difference between the amount of charge obtained in the third step and the average value of the amount of charge in the time series data at the time the amount of charge was obtained.

[0131] Example 4. In the method of Example 3, the index value may be calculated based on the p-value corresponding to the z-score obtained by dividing the difference by the standard deviation of the charge amount in the time series data at the time when the charge amount was acquired in the third step.

[0132] Example 5. Any of the methods in Examples 1 to 4 may further include a fifth step before the first step, in which processing conditions for the second film in the first step are set based on the type of second film stored in the memory unit. In this case, the second film is etched according to the processing conditions that are automatically set according to the type of second film. This makes it possible to process the substrate efficiently.

[0133] Example 6. Any of the methods in Examples 1 to 5 may further include a sixth step in which an alarm is issued according to the remaining state of the second film determined in the fourth step. In this case, it becomes possible to inform workers or others that the second film has not been properly processed.

[0134] Example 7. In the method of Example 6, the sixth step may include stopping the processing of subsequent substrates along with sounding an alarm. If an alarm is sounded, there is a possibility that the second film may not be properly processed on subsequent substrates, so stopping the processing of subsequent substrates can reduce processing costs.

[0135] Example 8. If any of the methods in Examples 1 to 7 is determined to have no remaining second film in the fourth step, it may further include a seventh step in which the first and second films are newly formed on the substrate of the substrate on which the determination was made in the fourth step. In a process that leaves the second film as a thin film, if it is determined in the fourth step that the second film has no remaining, the substrate becomes defective and is discarded. However, according to Example 8, by newly forming the first and second films on the substrate, it becomes possible to utilize the substrate without waste.

[0136] Example 9. Any of the methods in Examples 1 to 8 may further include an eighth step in which, if it is determined in the fourth step that the second film remains, a chemical solution is supplied to the upper surface of the substrate to re-etch the remaining second film. In a process that completely removes the second film by etching, substrates with the remaining second film are considered defective and discarded. However, according to Example 9, the second film is etched again, and the second film is completely removed, so the substrate can be used as a product.

[0137] Example 10. Any of the methods in Examples 1 to 9 may further include a ninth step of calculating the thickness of the second film based on the amount of charge obtained in the third step. In this case, the thickness of the second film can be determined in-line (during the substrate processing step) for each individual substrate.

[0138] Example 11. In the method of Example 10, the ninth step may include calculating the thickness of the second film based on a film thickness model representing the relationship between the amount of charge on the substrate when the charging liquid is supplied to the upper surface of the substrate and the thickness of the second film on the substrate, and the amount of charge obtained in the third step. In this case, it becomes possible to calculate the thickness of the remaining second film with greater accuracy.

[0139] Example 12. In any of the methods in Examples 1 to 11, the first film may be either an insulating film or a conductive film, and the second film may be the other of an insulating film or a conductive film.

[0140] Example 13. In any of the methods in Examples 1 to 12, the charging solution may be pure water.

[0141] Example 14. An example of a substrate processing apparatus comprises a rotating holding unit configured to rotate a substrate having a first film formed on its upper surface and a second film formed on the upper surface of the first film, a first supply unit configured to supply a chemical solution to the upper surface of the substrate held by the rotating holding unit, a second supply unit configured to supply a charged liquid, which is a charged liquid, to the upper surface of the substrate held by the rotating holding unit, an acquisition unit configured to acquire the amount of charge on the substrate, a storage unit configured to store time-series data showing the change in the amount of charge on a sample substrate when a charged liquid is supplied to a sample substrate in which the second film does not exist on the upper surface of the first film, and a control unit. The control unit is configured to perform a first process of controlling a first supply unit to supply a chemical solution to the upper surface of the substrate and etching the second film; a second process of controlling a second supply unit after the first process to supply a charging solution to the upper surface of the substrate; a third process of acquiring the amount of charge on the substrate by an acquisition unit during the second process; and a fourth process of determining the remaining state of the second film on the surface of the substrate based on the amount of charge acquired in the third process and time-series data showing the change in the amount of charge on the sample substrate stored in the storage unit. In this case, the same effects and advantages as in Example 1 can be obtained.

[0142] Example 15. In the apparatus of Example 14, the fourth process may include calculating an index value indicating the degree of deviation of the charge amount from a normal value based on the charge amount and time-series data showing the change obtained in the third process, and determining that the second film remains on the upper surface of the first film when the index value is above a predetermined threshold. In this case, the same effects as the method of Example 2 can be obtained.

[0143] Example 16. In the apparatus of Example 14 or Example 15, the control unit may be configured to perform a fifth process before the first process, which sets the processing conditions for the second film in the first process based on the type of second film stored in the memory unit. In this case, the same effects as the method of Example 5 can be obtained.

[0144] Example 17. Any of the devices in Examples 14 to 16 may further include a notification unit configured to issue an alarm, and the control unit may further perform a sixth process to cause the notification unit to issue an alarm according to the remaining state of the second film determined in the fourth process. In this case, the same effects and advantages as the method in Example 6 can be obtained.

[0145] Example 18. Any apparatus of Examples 14 to 17 may further include a film-forming unit configured to form a first film and a second film on a substrate, and the control unit may be configured to control the film-forming unit to perform a seventh process in which, if it is determined in the fourth process that the second film is not present, the first film and the second film are newly formed on the substrate of the substrate where the determination was made in the fourth process. In this case, the same effects and advantages as the method of Example 8 can be obtained.

[0146] Example 19. In any of the apparatuses in Examples 14 to 18, the control unit may be configured to perform an eighth process in which, if it is determined that the second film remains in the fourth process, it controls the first supply unit to supply the chemical solution to the upper surface of the substrate, thereby etching the remaining second film again. In this case, the same effects as the method in Example 9 can be obtained.

[0147] Example 20. In any of the apparatuses of Examples 14 to 19, the control unit may be configured to further perform a ninth process in which the thickness of the second film is calculated based on the amount of charge obtained in the third process. In this case, the same effects as the method of Example 10 can be obtained. [Explanation of Symbols]

[0148] 1...Substrate processing system (substrate processing apparatus), 10...Rotation holding unit, 40...Chemical solution supply unit (first supply unit), 50...Cleaning solution supply unit (second supply unit), C3...Memory (storage unit), C4...Storage (storage unit), Ctr...Controller (control unit), L1...Chemical solution, L2...Cleaning solution (charging solution), M2...Storage unit, Q...Film deposition apparatus (film deposition unit), SE...Sensor (acquisition unit), U...Liquid processing unit, W...Substrate, W1...Substrate, W2...Film (first film), W3...Film (second film), Wa...Top surface.

Claims

1. A first step involves supplying a chemical solution to the upper surface of a substrate on which a first film is formed and a second film is formed on the upper surface of the first film, thereby etching the second film. A second step is to supply a charged liquid, which is a charged liquid, to the upper surface of the substrate after the first step, During the second step, a third step is to acquire the amount of charge on the substrate using an acquisition unit, A substrate processing method comprising: a fourth step of determining the remaining state of the second film on the surface of the substrate based on the amount of charge obtained in the third step and time-series data showing the change in the amount of charge on the sample substrate when the charging solution is supplied to a sample substrate in which the second film is not present on the upper surface of the first film.

2. The fourth step described above is: Based on the amount of charge obtained in the third step and the time-series data, an index value indicating the degree of deviation of the amount of charge from the normal value is calculated. The method according to claim 1, further comprising determining that the second film remains on the upper surface of the first film when the index value is equal to or greater than a predetermined threshold.

3. The method according to claim 2, wherein the index value is calculated based on the difference between the amount of charge obtained in the third step and the average value of the amount of charge in the time series data at the time the amount of charge was obtained.

4. The method according to claim 3, wherein the index value is calculated based on the p value corresponding to the z score obtained by dividing the difference by the standard deviation of the charge amount in the time series data at the time when the charge amount was acquired in the third step.

5. The method according to claim 1, further comprising a fifth step of setting the processing conditions for the second film in the first step based on the type of the second film stored in the memory unit, before the first step.

6. The method according to claim 1, further comprising a sixth step of issuing an alarm according to the remaining state of the second film determined in the fourth step.

7. The method according to claim 6, wherein the sixth step includes stopping the subsequent processing of the substrate along with issuing an alarm.

8. The method according to claim 1, further comprising a seventh step of newly forming the first film and the second film on the substrate of the substrate on which the determination was made in the fourth step, if it is determined in the fourth step that the second film is not present.

9. The method according to claim 1, further comprising an eighth step of supplying the chemical solution to the upper surface of the substrate to re-etch the remaining second film if it is determined in the fourth step that the second film remains.

10. The method according to claim 1, further comprising a ninth step of calculating the thickness of the second film based on the amount of charge obtained in the third step.

11. The method according to claim 10, wherein the ninth step includes calculating the thickness of the second film based on the amount of charge on the substrate when the charging liquid is supplied to the upper surface of the substrate, a film thickness model representing the relationship between the amount of charge on the substrate and the thickness of the second film on the substrate, and the amount of charge obtained in the third step.

12. The first film is either an insulating film or a conductive film. The method according to any one of claims 1 to 11, wherein the second film is the other of an insulating film and a conductive film.

13. The method according to any one of claims 1 to 11, wherein the charging liquid is pure water.

14. A rotating holding unit configured to rotate a substrate having a first film formed on its upper surface and a second film formed on the upper surface of the first film, A first supply unit configured to supply a liquid chemical to the upper surface of the substrate held by the rotating holding unit, A second supply unit is configured to supply a charged liquid, which is a charged liquid, to the upper surface of the substrate held by the rotating holding unit, An acquisition unit configured to acquire the amount of charge on the substrate, A storage unit configured to store time-series data showing the change in the amount of charge on a sample substrate when the charging solution is supplied to a sample substrate in which the second film is not present on the upper surface of the first film, It includes a control unit, The control unit, The first process involves controlling the first supply unit to supply a chemical solution to the upper surface of the substrate and etching the second film, After the first process, a second process is performed in which the second supply unit is controlled to supply the charged liquid to the upper surface of the substrate, During the second process, a third process is performed in which the amount of charge on the substrate is acquired by the acquisition unit, A substrate processing apparatus configured to perform a fourth process, which determines the remaining state of the second film on the surface of the substrate based on the amount of charge obtained in the third process and the time-series data.

15. The fourth process is, Based on the amount of charge obtained in the third process and the time-series data shown above, an index value indicating the degree of deviation of the amount of charge from the normal value is calculated. The apparatus according to claim 14, further comprising determining that the second film remains on the upper surface of the first film when the index value is equal to or greater than a predetermined threshold.

16. The apparatus according to claim 14, wherein the control unit is configured to further perform a fifth process, before the first process, to set the processing conditions for the second membrane in the first process based on the type of second membrane stored in the storage unit.

17. It further includes a notification unit configured to issue an alarm, The apparatus according to claim 14, wherein the control unit is configured to further perform a sixth process that causes the notification unit to issue an alarm according to the remaining state of the second film determined in the fourth process.

18. The substrate further comprises a film-forming section configured to form the first film and the second film on the substrate, The apparatus according to claim 14, wherein the control unit is configured to control the film-forming unit to further perform a seventh process in which the first film and the second film are newly formed on the substrate of the substrate determined in the fourth process, if it is determined that the second film is not present in the fourth process.

19. The apparatus according to claim 14, wherein the control unit is configured to, if it is determined that the second film remains in the fourth process, control the first supply unit to supply the chemical solution to the upper surface of the substrate, thereby further performing an eighth process to re-etch the remaining second film.

20. The apparatus according to any one of claims 14 to 19, wherein the control unit is configured to further perform a ninth process for calculating the thickness of the second film based on the amount of charge obtained in the third process.

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