Substrate cleaning apparatus, substrate cleaning method, and substrate polishing apparatus

Abstract

To suppress deposition of particles to a substrate during rinse processing according to a simple method.SOLUTION: A substrate cleaning device performing scrub cleaning by bringing a cleaner into slide contact with a surface of a substrate while rotating the substrate comprises a cleaning fluid supply section performing rinse processing of the substrate after the scrub cleaning by spraying a cleaning fluid to the surface of the substrate, and a temperature of the cleaning fluid during the rinse processing is set at 0°C to 20°C. The cleaning fluid supply section comprises a first cleaning fluid supply section supplying the cleaning fluid toward the vicinity of a center of the substrate and a second cleaning fluid supply section supplying the cleaning fluid in a sprayed state toward a region between the center and an edge of the substrate, and a first spray angle of the cleaning fluid by the first cleaning fluid supply section is smaller than a second spray angle of the cleaning fluid by the second cleaning fluid supply section. For a first period during the rinse processing, the substrate is rotated at a first speed and for a second period continued to the first period, the substrate is rotated at a second speed higher than the first speed.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an apparatus and method for cleaning a substrate after polishing. [Background technology]

[0002] One method for planarizing the surface of a substrate for semiconductor device fabrication is polishing using a chemical mechanical polishing (CMP) device. In CMP, the surface of the object to be polished, such as a substrate, is pressed against a polishing member, and a polishing solution is supplied between the polishing member and the object to be polished while the polishing member and the object to be polished are moved relative to each other, thereby polishing the surface of the object to a flat surface.

[0003] A polishing apparatus for polishing a substrate is equipped with a substrate cleaning apparatus for cleaning the substrate surface after polishing (see, for example, Patent Document 1). Substrate cleaning involves rotating the polished substrate and rotating a cleaning tool such as a roll sponge or pen sponge over the substrate while spraying a chemical solution onto the substrate. After the substrate has been cleaned with the cleaning solution, the cleaning tool is retracted from the substrate, and the substrate surface is rinsed by supplying the chemical solution or deionized water (DIW) to the substrate. This removes particles remaining on the substrate after the cleaning process (e.g., particles of the abrasive that were not completely removed during the cleaning process and particles from the polished substrate). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-35821 Summary of the Invention [Problem to be solved by the invention]

[0005] During substrate cleaning, the pH of the cleaning solution supplied to the substrate surface is adjusted to a basic level to prevent particles from adhering to the substrate. However, due to the viscosity of the cleaning solution on the substrate surface, the flow rate of the cleaning solution near the substrate surface is very low, making it difficult to remove particles suspended in the cleaning solution from the substrate surface even by rinsing. Furthermore, when a cleaning tool is removed from the substrate after a scrubbing process and a rinsing process is performed, cleaning solution containing particles may drip from the cleaning tool onto the substrate during the rinsing process. This can cause particles to remain on the substrate during the rinsing process, potentially degrading the quality of the substrate after polishing / cleaning.

[0006] The present invention has been made in consideration of the above, and aims to provide a substrate cleaning apparatus and method that can suppress adhesion of particles to a substrate during rinsing processing using a simple method, and a substrate polishing apparatus equipped with such a cleaning apparatus. [Means for solving the problem]

[0007] One aspect of the present invention is a substrate cleaning apparatus that scrubs a substrate by sliding a cleaning tool against the surface of the substrate while rotating the substrate, the apparatus comprising: a cleaning tool drive mechanism that retracts the cleaning tool from the surface of the substrate after the scrubbing; and a cleaning liquid supply unit that sprays a cleaning liquid onto the surface of the substrate to perform a rinsing process on the substrate after the scrubbing process, wherein the temperature of the cleaning liquid during the rinsing process is set to 0°C to 20°C. the cleaning liquid supply unit is configured to supply a cleaning liquid to the substrate during the scrub cleaning, and the temperature of the cleaning liquid supplied in the rinsing process is lower than the temperature of the cleaning liquid supplied in the scrub cleaning. It is characterized by:

[0008] One aspect of the present invention is a substrate cleaning apparatus that scrubs a substrate by rotating it and sliding a cleaning tool against the surface of the substrate, and includes a cleaning liquid supply unit that rinses the substrate after scrubbing by spraying cleaning liquid onto the surface of the substrate, the cleaning liquid supply unit including a first cleaning liquid supply unit that supplies cleaning liquid toward the center of the substrate, and a second cleaning liquid supply unit that supplies cleaning liquid in a spray form toward the area between the center and the edge of the substrate, wherein the spray angle of the cleaning liquid by the first cleaning liquid supply unit toward the surface of the substrate is defined as a first spray angle, and the spray angle of the cleaning liquid by the second cleaning liquid supply unit toward the surface of the substrate is defined as a second spray angle, and the first spray angle is smaller than the second spray angle.

[0009] One aspect of the present invention is a substrate cleaning apparatus that scrubs a substrate by sliding a cleaning tool against the surface of the substrate while rotating the substrate, and is characterized in that it includes a cleaning liquid supply unit that rinses the substrate after scrubbing by spraying a cleaning liquid onto the surface of the substrate, and a substrate rotation mechanism that rotates the substrate at a predetermined speed, wherein the substrate rotation mechanism is configured to rotate the substrate at a first speed during a first period during the rinsing process, and to rotate the substrate at a second speed faster than the first speed during a second period following the first period. [Effects of the Invention]

[0010] According to the present invention, it is possible to suppress the adhesion of particles to a substrate during a rinsing process by a simple method. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a plan view showing a schematic configuration of a substrate processing apparatus including a substrate cleaning apparatus according to an embodiment of the present invention. [Figure 2] FIG. 1 is a perspective view showing a configuration of a substrate cleaning apparatus. [Figure 3] FIG. 3 is a plan view showing the configuration of the substrate cleaning apparatus of FIG. [Figure 4] FIG. 2 is a functional block diagram of the substrate cleaning apparatus. [Figure 5]10 is a graph showing an example of the relationship between the distance from the surface of a rotating substrate and the flow rate of a cleaning liquid on the substrate. [Figure 6] 10A and 10B are explanatory views showing how particles on a substrate are removed or re-adhered. [Figure 7] 1 is a graph showing the relationship between the liquid temperature on the substrate and the mass transfer coefficient. [Figure 8] 10 is a graph showing the relationship between the liquid temperature on the substrate and the ratio of the number of remaining particles. [Figure 9] FIG. 1 is an explanatory diagram showing an example of the positional relationship between a pin-type nozzle and a spray-type nozzle. [Figure 10] FIG. 1 is an explanatory diagram showing the positional relationship between a pin-type nozzle and a spray-type nozzle and the ratio of the number of residual particles. [Figure 11] 10 is a graph showing the relationship between the radial position of the substrate and the thickness of the liquid film on the substrate. [Figure 12] FIG. 10 is a diagram illustrating the rotation speed of the substrate and the simulation conditions for the rinse process. [Figure 13] 10 is an explanatory diagram showing how the cleaning liquid flows from the edge portion of the substrate to the surface. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] (First embodiment) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the drawings. Fig. 1 shows a schematic configuration of a substrate processing apparatus including a substrate cleaning apparatus according to this embodiment. The substrate processing apparatus 10 has a housing 12 and a load port 14. The load port 14 is equipped with, for example, an open cassette for accommodating a large number of substrates W.

[0013] The housing 12 accommodates a plurality of polishing units 16a to 16d for polishing (planarizing) the substrate W, a first cleaning unit 18 and a second cleaning unit 20 for cleaning the polished substrate W, and a drying unit 22 for drying the cleaned substrate W. In the example of Fig. 1, the polishing units 16a to 16d are arranged along the longitudinal direction of the substrate processing apparatus 10, and the cleaning units 18, 20 and the drying unit 22 are arranged in parallel to the polishing units 16a to 16d.

[0014] A first transport robot 24 is disposed between the load port 14 and the polishing unit 16a and drying unit 22. The first transport robot 24 receives the unpolished substrate W from the load port 14 and delivers it to the transport unit 24, and also receives the dried substrate W taken out from the drying unit 22 from the transport unit 24. In addition, a transport unit 26 is disposed between the polishing units 16a to 16d and the cleaning units 18 and 20 and drying unit 22.

[0015] A second transport robot 28 is disposed between the first cleaning unit 18 and the second cleaning unit 20 to transfer the substrate W therebetween. In addition, a third transport unit 30 is disposed between the second cleaning unit 20 and the drying unit 22 to transfer the substrate W therebetween.

[0016] A control unit 32 that controls the operation of each device in the substrate processing apparatus 10 is disposed inside the housing 12. The control unit 32 is, for example, a general-purpose computer device, and includes a CPU, a memory that stores a control program, an input unit, a display unit, etc. The control unit 32 also includes an input unit 34 that accepts external input. Here, the external input may include mechanical operations by a user, as well as wired or wireless input of signals from an external device.

[0017] The control unit 32 controls the operation of each device of the substrate processing apparatus 10 by activating a control program stored in a storage section (memory) 36. The control program for controlling the operation of the substrate processing apparatus 10 may be pre-installed in a computer constituting the control unit 32, or may be stored in a storage medium such as a DVD, a BD, or an SSD, or may be installed in the control unit 32 via the Internet.

[0018] The cleaning units 18 and 20 of this embodiment clean the substrate W by rotating a cleaning tool (described later) and bringing it into contact with the surface of the substrate W, and after the cleaning process, a cleaning liquid is supplied to perform a rinsing process. The cleaning units 18 and 20 may also use a two-fluid jet cleaning device, which cleans the surface of the substrate W with a two-fluid jet, in combination with the cleaning tool.

[0019] For example, the drying unit 22 dries the substrate W by ejecting IPA vapor from a nozzle (not shown) toward the rotating substrate W. Alternatively, the substrate W may be rotated at high speed to dry the substrate W by centrifugal force.

[0020] 2 and 3 show a schematic configuration of a substrate cleaning apparatus 40 according to this embodiment, and Fig. 4 is a functional block diagram of the substrate cleaning apparatus. Substrate cleaning apparatus 40 (corresponding to substrate cleaning units 18 and 20 in Fig. 1) includes a substrate roller drive mechanism 42 that drives substrate rollers 50 that rotate the substrate W, a sponge drive mechanism 44 that drives roll sponges 52 and 53 for brushing the substrate, a deionized water supply unit 46 that supplies deionized water (DIW) as a cleaning liquid, and a chemical liquid supply unit 48 that supplies a chemical liquid as a cleaning liquid.

[0021] The cleaning liquid may be, for example, a rinse liquid such as deionized water (DIW), an alkaline solution (ammonia water, ammonia hydrogen peroxide (SC1)), a chemical liquid such as a surfactant or a chelating agent, or a mixture of these chemical liquids, depending on the type of film on the target substrate surface. In this embodiment, a chemical liquid and deionized water (DIW) are used as the cleaning liquid.

[0022] The substrate cleaning apparatus 40 includes four substrate rollers 50 arranged on approximately the same horizontal plane, a pair of approximately cylindrical roll sponges 52 and 53, deionized water (DIW) supply nozzles 54 and 55, and chemical liquid supply nozzles 56 and 57. The two substrate cleaning apparatuses 40 are separated from each other by a partition wall (not shown) or the like to prevent the cleaning liquid (chemical liquid, deionized water) sprayed during the substrate cleaning process from leaking to the outside. The partition wall may be provided with a shutter mechanism for moving the substrate W into and out of the substrate cleaning apparatus 40.

[0023] A combination of the pure water supply nozzle 54 and the chemical liquid supply nozzle 56 that supply cleaning liquid near the center of the substrate W is referred to as a first cleaning liquid supply unit 61. A combination of the pure water supply nozzle 55 and the chemical liquid supply nozzle 57 that supply cleaning liquid to the region between the center and the edge of the substrate W is referred to as a second cleaning liquid supply unit 62.

[0024] Each of the substrate rollers 50 has a two-stage structure consisting of a shoulder portion (support portion) 50A and a small-diameter holding portion 50B provided on the shoulder portion 50A. The shoulder portion 50A supports the bottom surface of the substrate W, while the holding portion 50B holds the side (edge ​​portion) of the substrate W. The substrate rollers 50 can be moved toward and away from each other by an air cylinder (not shown) provided in the substrate roller drive mechanism 42. When the substrate rollers 50 approach each other, the holding portion 50B can hold the substrate W approximately horizontally. At least one of the substrate rollers 50 is configured to be rotationally driven by the substrate roller drive mechanism 42, thereby rotating the substrate W in a horizontal plane. The rotational speed of the substrate rollers 50 (i.e., the rotational speed of the substrate W) can be appropriately adjusted by the control unit 32.

[0025] The roll sponges 52 and 53 extend in a horizontal plane and come into contact with and clean the substrate W held by the substrate roller 50. The roll sponges 52 and 53 are rotated around their longitudinal axes by the sponge drive mechanism 44. The roll sponges 52 and 53 are attached to guide rails 58 that guide their vertical movement, and can be moved vertically along the guide rails 58 by the sponge drive mechanism 44, thereby enabling them to move between a position in contact with the substrate W and a position retracted from the substrate W.

[0026] The pure water supply nozzles 54, 55 are positioned diagonally above the substrate W and supply pure water to the upper surface of the substrate W. The chemical solution supply nozzles 56, 57 are positioned diagonally above the substrate W and supply chemical solutions to the upper surface of the substrate W. The pure water supply nozzles 54, 55 and the chemical solution supply nozzles 56, 57 are supported by a support member 60 extending approximately parallel to the longitudinal direction of the roll sponges 52, 53. The pure water supply nozzles 54, 55 are connected to the pure water supply unit 46 via separate pure water supply pipes 64, 65, respectively, and pure water is supplied to each nozzle individually. The chemical solution supply nozzles 56, 57 are connected to the chemical solution supply unit 48 via separate chemical solution supply pipes 66, 67, respectively, and chemical solutions are supplied to each nozzle individually.

[0027] The pure water supply unit 46 and the chemical liquid supply unit 48 are provided with a flow rate adjustment function and a temperature adjustment mechanism, and their operations are controlled by the control unit 32. This allows the flow rate and temperature of the pure water and chemical liquid supplied to the pure water supply nozzles 54, 55 and the chemical liquid supply nozzles 56, 57 to be appropriately adjusted.

[0028] The cleaning and rinsing process for the substrate W by the substrate cleaning apparatus 40 is performed as follows: When the substrate W is loaded, the substrate rollers 50 are spaced apart from each other. The upper roll sponge 52 is held in a position elevated from the transport position for the substrate W, and the lower roll sponge 53 is held in a position lowered from the transport position for the substrate W.

[0029] The substrate W transported by a transport unit (not shown) is first placed on the shoulder 50A of the substrate roller 50. Thereafter, the roller drive mechanism 42 is driven to move the substrate rollers 50 in a direction in which they approach each other (toward the substrate W), and the substrate W is held substantially horizontally by the holder 50B.

[0030] Next, when the sponge driving mechanism 44 is driven, the upper roll sponge 52 descends to contact the upper surface of the substrate W, and the lower roll sponge 53 ascends to contact the lower surface of the substrate W. As a result, an area including the center of the substrate W is sandwiched between the roll sponges 52 and 53, as shown in Fig. 2. Note that the positions at which the roll sponges 52 and 53 contact the substrate W are not limited to the positions shown in Fig. 2, and they may be configured to contact positions off the center of the substrate W.

[0031] Thereafter, the pure water supply unit 46 and the chemical solution supply unit 48 are driven, and pure water and chemical solutions, the flow rates and temperatures of which have been adjusted, are supplied to the substrate W from the pure water supply nozzles 54, 55 and the chemical solution supply nozzles 56, 57. Then, the roller drive mechanism 42 and the sponge drive mechanism 44 are driven, and the substrate W is rotated in a horizontal plane at a set speed by the substrate roller 50, while the roll sponges 52, 53 rotate about their axes and come into contact with the upper and lower surfaces of the substrate W, respectively, thereby scrubbing the upper and lower surfaces of the substrate W. Note that the scrubbing process may involve only supplying the chemical solution from the chemical solution supply nozzles 56, 57.

[0032] After the scrubbing, the roll sponges 52, 53 are retracted from the top and bottom surfaces of the substrate W, and the substrate W is rinsed by supplying pure water and a chemical solution from the pure water supply nozzles 54, 55 and the chemical solution supply nozzles 56, 57 to the substrate W. Details of the rinse process will be described later. After the rinse process, the substrate W is transported out of the substrate cleaning apparatus 40 by a transport unit (not shown).

[0033] 3, it is assumed that the substrate W is rotating clockwise as viewed from above, and that the roll sponge 52 above the substrate W is rotating clockwise as viewed from the side. In the example of FIG. 3, chemical liquid supply nozzles 56 and 57 are disposed above the pure water supply nozzles 54 and 55, and supply cleaning liquid (chemical liquid, pure water) to the vicinity of the areas where the roll sponges 52 and 53 contact the substrate W. The supply direction of the cleaning liquid from the pure water supply nozzles 54 and 55 and the chemical liquid supply nozzles 56 and 57 is approximately perpendicular to the longitudinal direction of the roll sponges 52 and 53.

[0034] Alternatively, the pure water supply nozzles 54, 55 may be installed above the chemical solution supply nozzles 56, 57. The position where the chemical solution is supplied to the substrate W by the chemical solution supply nozzles 56, 57 and the position where the pure water is supplied to the substrate W by the pure water supply nozzles 54, 55 may be the same or different. For example, by positioning the position where the chemical solution is sprayed onto the substrate W by the chemical solution supply nozzles 56, 57 closer to the roll sponges 52, 53, scrubbing can be performed more effectively.

[0035] The first cleaning liquid supply unit 61 is a so-called pen-type sprayer, and supplies cleaning liquid toward the center of the substrate W, approximately perpendicular to the longitudinal direction of the roll sponge 52, at a relatively small angle in the width direction. When the cleaning liquid from the first cleaning liquid supply unit 61 passes between the roll sponge 52 and the substrate W, the contact area between the substrate W and the roll sponge 52 is cleaned. The cleaning liquid then penetrates to the back of the roll sponge 52. Because the centrifugal force is not very strong near the center of the substrate W, the cleaning liquid is returned to the roll sponge 52 as the substrate W rotates (see arrow F1 in FIG. 3). As a result, the back side of the top surface of the substrate W is also cleaned by the roll sponge 52.

[0036] The second cleaning liquid supply unit 62 supplies the cleaning liquid in a spray form at a larger width angle than the first cleaning liquid supply unit 61, toward a position slightly away from the center of the substrate W, approximately perpendicular to the longitudinal direction of the roll sponge 52, and in the same direction as the rotation direction of the substrate W. Because the cleaning liquid is supplied in a spray form, the force of the cleaning liquid can be suppressed, and the load on the substrate W can be reduced.

[0037] When the cleaning liquid from the second cleaning liquid supply unit 62 passes between the roll sponge 52 and the substrate W, it cleans the contact area between the substrate W and the roll sponge 52 in a portion slightly outside the center of the substrate W. Here, in the area where the cleaning liquid is supplied from the second cleaning liquid supply unit 102, the rotation direction of the substrate W, the rotation direction of the roll sponge 52, and the supply direction of the cleaning liquid from the cleaning liquid supply unit 62 are all the same. Therefore, the relative speeds between them become smaller, the time that the cleaning liquid is in contact with the substrate W and the roll sponge 52 becomes longer, and the cleaning power is improved.

[0038] The cleaning liquid from the second cleaning liquid supply unit 62 penetrates deep into the roll sponge 52. The supply direction of the cleaning liquid is perpendicular to the roll sponge 52, and the rotation direction of the substrate W coincides with the supply direction of the cleaning liquid, so the cleaning liquid is not pushed back into the substrate W by the rotation of the substrate W, but is blown to the outside of the substrate W by centrifugal force (see arrow F2 in FIG. 3). This makes it possible to prevent the cleaning liquid from remaining on the substrate W after being used for long-term cleaning.

[0039] 3, it is desirable that the supply direction from the first cleaning liquid supply unit 61 and the supply direction from the second cleaning liquid supply unit 62 coincide with each other on the upper surface of the substrate W. If the supply directions of the cleaning liquids are reversed, when the cleaning liquid from the first cleaning liquid supply unit 61 and the cleaning liquid from the second cleaning liquid supply unit 62 collide with each other, convection occurs, causing the cleaning liquid to fly up, and the cleaning liquid containing dust and the like in the air may land on the substrate W and contaminate the substrate W.

[0040] 5 shows an example (calculated value) of the relationship between the liquid flow rate (liquid flow rate) and the distance from the surface of the substrate W, where the substrate rotation speed is 100 rpm and the liquid (pure water) supply rate is 1 L / min. It can be seen that the flow of liquid near the substrate W (area at a short distance from the surface) is very small due to the influence of friction between the substrate W and the liquid and the viscosity of the liquid.

[0041] 6 is an explanatory diagram showing the flow of particles when the particles adhere to the liquid film of the cleaning liquid on the substrate W. When the particles 70 remain in the upper layer of the liquid film 72, the flow of the liquid in the upper layer is fast (the liquid flow velocity is high), and therefore the particles are easily removed to the outside of the substrate W by the rinsing process that involves rotation of the substrate W. On the other hand, when the particles reach the lower layer of the liquid film, the flow of the liquid in the lower layer is slow (the liquid flow velocity is low), and therefore the particles are difficult to remove to the outside of the substrate W.

[0042] Therefore, particles remaining on the surface of the substrate after the cleaning process and cleaning liquid (with particles attached) dripping onto the substrate from the roll sponge (cleaning tool) may remain in the liquid film on the substrate W during the rinsing process and adhere to the surface of the substrate W after the rinsing process, which may result in a deterioration in the quality of the substrate after the polishing / cleaning process.

[0043] Here, the amount of particles adhering in the spin rinse process depends on the mass transfer coefficient k (a coefficient that determines the amount of particle movement in the vertical direction on the substrate surface). The higher the mass transfer coefficient k, the easier it is for the material to move in the vertical direction. In other words, particles adhering to the liquid film on the substrate W tend to move toward the surface of the substrate W (in the vertical direction).

[0044] The mass transfer coefficient k is defined as follows: k=0.332×Sc 1 / 3 ×Re x 1 / 2 ×(D / x) Sc=μ / D, Re x =ux / ν Here, D[m 2 / s] is the diffusion coefficient, x is the radial position of the substrate W, μ is the viscosity coefficient, u is the velocity of the substance, and ν is the dynamic viscosity coefficient.

[0045] Figure 7 is a graph showing the temperature dependence of the mass transfer coefficient k, where (a) is the absolute value (calculated value) of the mass transfer coefficient k, and (b) shows the ratio of the mass transfer coefficient at each temperature when the mass transfer coefficient k at 20°C is used as the reference. The graph shows the calculation results for a substrate W rotation speed of 100 rpm, a radial position r of the substrate W of 100 mm, and a liquid supply rate of 1 L / min. The graph in Figure 7 shows that the higher the liquid temperature, the higher the mass transfer coefficient k (i.e., the more easily particles in the liquid film will reattach to the substrate W).

[0046] 8 is a graph showing the ratio of the number of particles remaining on the substrate W after the rinse process when the temperature of the cleaning liquid (pure water) supplied in the rinse process is changed, and it can be seen that the lower the liquid temperature, the more the number of particles remaining decreases. Note that the temperature of the cleaning liquid supplied in the rinse process is preferably 0°C to 20°C, and particularly preferably 0°C to 15°C, when the rotation speed of the substrate W is 300 rpm or less. It is also preferable to set the temperature of the cleaning liquid in the rinse process lower than the liquid temperature in the scrub cleaning process.

[0047] Therefore, by lowering the temperature of the pure water supplied to the substrate W in the rinsing process after the cleaning process, particles remaining in the liquid film after the cleaning process and particles contained in the cleaning liquid dropped from the roll sponge onto the liquid film on the substrate W can be efficiently discharged outside the substrate W by the rinsing process. This eliminates the need to rotate the substrate W at high speed or to perform a rinsing process that takes time to remove particles from the liquid film on the substrate W, and makes it possible to shorten the time required for the rinsing process (improve throughput).

[0048] (Second embodiment) FIG. 9 shows an overview of a substrate cleaning apparatus according to the second embodiment. Except for the positional relationship between the first cleaning liquid supply unit 61 and the second cleaning liquid supply unit 62, the configuration is the same as that of the first embodiment described above, and therefore detailed description thereof will be omitted.

[0049] 9, the angle at which the cleaning liquid is supplied by the nozzle constituting the first cleaning liquid supply unit 61, which is made up of a pin-type nozzle (the angle θ1 between the central axis of the nozzle and the substrate W), is configured to be smaller than the angle at which the cleaning liquid is supplied by the nozzle constituting the second cleaning liquid supply unit 62. By making the supply angle of the cleaning liquid smaller, the horizontal component of the speed of the cleaning liquid reaching the substrate W increases, and the cleaning liquid is more likely to be discharged outside the substrate W without being turned around by the rotation of the substrate W. This allows particles in the liquid film on the substrate W to be efficiently discharged outside.

[0050] 10 is a graph showing the change in the residual particle number ratio when the location of the first cleaning liquid supply unit 61 is changed, where (a) shows the location of the first cleaning liquid supply unit 61 and the conditions of the rinse process, and (b) shows the residual particle number ratio under each condition. In FIG. 10(a), condition (1) is when the first cleaning liquid supply unit 61 is placed in the same position as in the first embodiment, and the cleaning liquid is supplied toward the center of the substrate W at approximately the same height (approximately the same spray angle) as the second cleaning liquid supply unit. In the same figure, the particle liquid dropping position indicates the position where the particle liquid was dropped to conduct an experiment simulating the discharge of cleaning liquid falling from a roll sponge.

[0051] Condition (2) is a case where the supply angle of the cleaning liquid by the first cleaning liquid supply unit 61 formed of a pin-type nozzle is set smaller than that of the second cleaning liquid supply unit 62 (see FIG. 9), and the cleaning liquid from the first cleaning liquid supply unit 61 is more likely to be discharged outside the substrate W without being turned around by the rotation of the substrate W. In this embodiment, the supply angle θ1 of the cleaning liquid by the first cleaning liquid supply unit 61 is set to 15°, and the supply angle θ2 of the cleaning liquid by the second cleaning liquid supply unit 62 is set to 30°.

[0052] In condition (3), the angle at which the cleaning liquid is supplied by the first cleaning liquid supply unit 61, which is composed of a pin-type nozzle, is set to the same angle as in condition (2), and the cleaning liquid is supplied by the first cleaning liquid supply unit 61 toward the particle liquid droplet dropping position. In addition, in conditions (1) to (3), the rinsing time with the chemical liquid is set to 10 seconds, followed by the rinsing time with pure water is set to 10 seconds, and the time for dropping the cleaning liquid is set to 5 seconds. Conditions (1) to (3) are also the same as those for conditions (1) to (3), with regard to the rotation speed of the substrate W, the flow rate and temperature of the cleaning liquid, and the radius of the substrate W.

[0053] 10(b) shows the ratio of the number of remaining particles under each condition, and it can be seen that, compared to condition (1), by reducing the supply angle of the cleaning liquid from the cleaning liquid supply unit of the pin-type nozzle, the particles on the substrate W are forcibly expelled by the cleaning liquid, thereby increasing the particle removal effect by the cleaning liquid. Note that the supply angle θ1 of the cleaning liquid from the first cleaning liquid supply unit 61 is preferably in the range of 0° to 30°, and particularly preferably 5° to 10°.

[0054] (Third embodiment) In the third embodiment, the rotation speed of the substrate W is changed during the rinsing process to enhance the particle removal effect of the cleaning liquid. Figure 11 shows an example of the film thickness of the cleaning liquid relative to the radial position on the substrate, and the supply rate of the cleaning liquid is set to 1 L / min. The conditions are the same except that the rotation speed of the substrate W is set to 50 rpm and 150 rpm.

[0055] 11, the thickness of the cleaning liquid is thick near the center of the substrate W, which corresponds to the area where the cleaning liquid is supplied, and decreases toward the periphery of the substrate W. It can also be seen that the lower the rotation speed of the substrate W, the smaller the centrifugal force acting on the cleaning liquid, resulting in a larger cleaning liquid film thickness. By increasing the thickness of the cleaning liquid film, it is possible to prevent particles adhering to the surface of the substrate W during the rinsing process from migrating to the surface of the substrate W, thereby improving the particle removal effect.

[0056] FIG. 12 shows an example of a rinse process when the rotation speed of the substrate W is changed. (a) shows the conditions for the rotation speed of the substrate W, and (b) shows the results of the residual particle number ratio. Under condition (1), the rotation speed (150 rpm) is the same from the start of the rinse to its end (20 seconds later). Under condition (2), the rotation speed is low (50 rpm) for 5 seconds from the start of the rinse, and then the same speed (150 rpm) as under condition (1) for the next 15 seconds. Under conditions (1) and (2), the rinse time with the chemical solution is 10 seconds, followed by a rinse time with pure water for 10 seconds, and the drip time of the cleaning solution is 5 seconds. Conditions (1) and (2), such as the flow rate and temperature of the cleaning solution and the radius of the substrate W, are the same.

[0057] 12(b) shows the ratio of the number of remaining particles under each condition. Compared to condition (1), lowering the rotation speed of the substrate W increases the thickness of the cleaning liquid on the substrate W, making it easier for particles to move to the periphery of the substrate W without adhering to the substrate W. Then, by increasing the rotation speed of the substrate W, centrifugal force makes it easier for particles to be expelled to the outside of the substrate W. This shows that the cleaning liquid is more effective at removing particles.

[0058] In this embodiment, the rotation speed of the substrate W as the low speed is 50 rpm, but it is not limited to this and may be any speed lower than the normal speed (150 rpm in this embodiment, but preferably 100 rpm or higher), for example, 30 rpm to 150 rpm is preferable. Furthermore, the time for which the low speed is maintained is not limited to 5 seconds and can be adjusted taking into consideration the throughput of the rinsing process and the flow rate of the cleaning liquid.

[0059] In this embodiment, the rotation speed of the substrate W is changed in two stages, but the present invention is not limited to this, and the rotation speed may be switched in three stages (in the order of 50 rpm, 100 rpm, and 150 rpm), or in four or more stages.

[0060] (Fourth embodiment) During and after substrate cleaning (as well as during and after rinsing), liquid adhering to the substrate W may move. This is because liquid droplets are attracted to and move in the direction of higher solid surface energy, and because the surface of the substrate W is hydrophilic and has high solid surface energy, liquid droplets tend to move to the surface. For this reason, during substrate cleaning, the cleaning liquid may move from the edge of the back surface of the substrate toward the edge of the front surface of the substrate. Furthermore, after substrate cleaning, the cleaning liquid adhering to the side of the substrate may move around to the front surface of the substrate W. This may cause particles from the cleaning liquid to adhere to the surface of the substrate W.

[0061] For this reason, in this embodiment, the side surfaces and rear surface of the substrate W are subjected to hydrophilic treatment during or before the substrate cleaning treatment, thereby preventing the cleaning liquid adhering to the side surfaces and rear surface from seeping around onto the front surface of the substrate W. As a method for the hydrophilic treatment, it is preferable to spray a mixture of sulfuric acid and hydrogen peroxide, a hydrogen fluoride-based chemical solution, or an alcohol liquid such as isopropyl alcohol onto the side surfaces and rear surface of the substrate W, or to subject the side surfaces and rear surface of the substrate W to ozone treatment or plasma treatment.

[0062] In each of the above embodiments, the effect of particle removal by the cleaning liquid is enhanced by adjusting the temperature of the cleaning liquid, the arrangement of the cleaning liquid supply unit of the pin-type nozzle, and the rotation speed of the substrate W. A combination of these methods may be used, thereby further enhancing the effect of particle removal by the cleaning liquid.

[0063] The above-described embodiments have been described for the purpose of enabling a person having ordinary skill in the art to practice the present invention. Various modifications of the above-described embodiments would naturally be possible for a person skilled in the art, and the technical concept of the present invention may also be applied to other embodiments. The present invention is not limited to the described embodiments, but is to be interpreted in the broadest scope in accordance with the technical concept defined by the claims. [Explanation of symbols]

[0064] 10. Substrate processing equipment 32 Control Unit 40 Substrate cleaning equipment 42 Substrate roller drive mechanism 44 Sponge drive mechanism 46 Pure water supply unit 48 Chemical supply unit 50 Substrate roller 52,53 Roll sponge 54,55 Pure water supply nozzle 56,57 Chemical supply nozzle 61 First cleaning liquid supply unit 62 Second cleaning liquid supply unit W substrate

Claims

1. A substrate cleaning apparatus that scrubs a substrate by rotating the substrate and bringing a cleaning tool into sliding contact with the surface of the substrate, a cleaning tool drive mechanism that retracts the cleaning tool from the surface of the substrate after the scrubbing; a cleaning liquid supply unit that performs a rinsing process on the substrate after scrubbing by spraying a cleaning liquid onto the surface of the substrate, wherein the temperature of the cleaning liquid during the rinsing process is set to 0°C to 15°C; the cleaning liquid supply unit is configured to supply a cleaning liquid to the substrate during the scrub cleaning, and in order to suppress movement of residual particles to the substrate surface, a temperature of the cleaning liquid supplied in the rinsing process is set lower than a temperature of the cleaning liquid supplied in the scrub cleaning.

2. the cleaning liquid supply unit includes a first cleaning liquid supply unit that supplies the cleaning liquid toward the vicinity of the center of the substrate, and a second cleaning liquid supply unit that supplies the cleaning liquid in a spray form toward a region between the center and the edge of the substrate; 2. The substrate cleaning apparatus of claim 1, wherein when a spray angle of the cleaning liquid by the first cleaning liquid supply unit toward the surface of the substrate is defined as a first spray angle and a spray angle of the cleaning liquid by the second cleaning liquid supply unit toward the surface of the substrate is defined as a second spray angle, the first spray angle is smaller than the second spray angle.

3. 3. The substrate cleaning apparatus according to claim 2, wherein the first spray angle is within a range of 5 degrees to 10 degrees.

4. a substrate rotation mechanism that rotates the substrate at a predetermined speed; 4. The substrate cleaning apparatus of claim 1, wherein the substrate rotation mechanism is configured to rotate the substrate at a first speed during a first period of the rinsing process, and to rotate the substrate at a second speed faster than the first speed during a second period following the first period.

5. 5. The substrate cleaning apparatus of claim 4, wherein the first speed is in the range of 30 rpm to 150 rpm.

6. a step of scrubbing the surface of the substrate by sliding a cleaning tool against the surface of the substrate while rotating the substrate; retracting the cleaning tool from the surface of the substrate after the scrubbing; and performing a rinsing process on the substrate after scrubbing by spraying a cleaning liquid onto the surface of the substrate, wherein the temperature of the cleaning liquid during the rinsing process is set to 0°C to 15°C; a cleaning liquid is supplied to the substrate during the scrub cleaning, and a temperature of the cleaning liquid supplied in the rinsing process is set lower than a temperature of the cleaning liquid supplied in the scrub cleaning in order to suppress migration of remaining particles to the substrate surface.

7. 6. A substrate processing apparatus comprising: a polishing section for polishing the substrate; and a cleaning apparatus according to claim 1, wherein the substrate is cleaned after the polishing.

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