Patent ID: 12220732

DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention will now be described with reference to the drawings. Identical or corresponding structural elements are denoted by identical reference numerals and will not be described below repetitively.

Embodiments described below relate to a substrate cleaning method (and a substrate cleaning system) for cleaning a front surface (and back surface) of a substrate (particularly a semiconductor wafer), and more particularly to a substrate cleaning method performed in a substrate cleaning process of cleaning the surface of the substrate after polishing, such as CMP, of the substrate. This substrate cleaning method is also applied, e.g., to cleaning processes of manufacturing of flat panel, manufacturing of image sensor, such as CMOS or CCD, and manufacturing of magnetic film of MRAM.

Unless particularly described, “up” means a direction in which a cleaning tool is present starting from a substrate, and “under” means the opposite direction. With respect to the cleaning tool and components constituting the cleaning tool, “top surface” and “front surface” mean a surface on the side where the cleaning tool is in contact with the substrate. A central part of the substrate is a region including the center of the substrate. A periphery of the substrate is an annular region not including the center of the substrate, i.e., a region that surrounds the central part of the substrate. The periphery of the substrate is farther than the central part of the substrate viewed from the center of the substrate, and has a constant width along an outer-peripheral-end portion of the substrate W in the surface of the substrate W.

FIG.1is a plan view showing an entire structure of a substrate processing apparatus1(more specifically, a polishing apparatus) to which the above-described substrate cleaning method is applied. As shown inFIG.1, the substrate processing apparatus1includes a housing10and a load port12on which substrate cassettes for storing a large number of substrates, such as semiconductor wafers, is placed. The load port12is arranged adjacent to the housing10.

The substrate processing apparatus1includes a polishing section2and a cleaning section4arranged inside the housing10. The polishing section2includes a plurality of (four in this embodiment) polishing modules14A to14D. The cleaning section4includes a first cleaning module16and a second cleaning module18each configured to clean a polished substrate, and a drying module20configured to drying a cleaned substrate. The polishing modules14A to14D are arranged along a longitudinal direction of the substrate processing apparatus1. Similarly, the first cleaning module16, the second cleaning module18, and the drying module20are arranged along the longitudinal direction of the substrate processing apparatus1.

The substrate processing apparatus1includes a first transfer robot22arranged adjacent to the load port12and a transfer module24arranged adjacent to the polishing modules14A to14D. The first transfer robot22receives a substrate, to be polished, from the load port12and delivers the substrate to the transfer module24, and receives a dried substrate from the drying module20and returns the substrate to the load port12. The transfer module24transports the substrate received from the first transfer robot22and transfers the substrate between the polishing modules14A to14D.

The substrate processing apparatus1includes a second transfer robot26arranged between the first cleaning module16and the second cleaning module18, and a third transfer robot28arranged between the second cleaning module18and the drying module20. The second transfer robot26transfers the substrate between the transfer module24and the cleaning modules16and18. The third transfer robot28transfers the substrate between the modules18and20.

The substrate processing apparatus1includes a controller30arranged inside the housing10. The controller30is configured to control the operations of each device of the substrate processing apparatus1. In the present embodiment, the controller30is configured to specifically control an operation of a substrate cleaning system50, which will be described later.

FIG.2is a diagram showing the substrate cleaning system50. The substrate processing apparatus1includes the substrate cleaning system50. The substrate cleaning system50includes a heater51configured to heat pure water, a chemical-liquid diluting module (in other words, a chemical-liquid supply module)52configured to mix chemical liquid and the pure water heated by the heater51at a predetermined volume ratio, and the cleaning modules16and18each configured to clean the substrate. In the present embodiment, the substrate cleaning system50includes the first cleaning module16and the second cleaning module18, while in one embodiment, the substrate cleaning system50may include any one of the first cleaning module16and the second cleaning module18.

FIG.3is a diagram showing the first cleaning module16. As shown inFIG.3, the first cleaning module16includes a substrate holding device60configured to rotate the substrate W while holding the substrate W, cleaning members61and62each configured to contact the substrate W and scrub the substrate W, chemical-liquid supply nozzles65and66configured to supply the chemical liquid having a determined temperature to a front surface W1and a back surface W2of the substrate W, and pure-water supply nozzles67and68configured to supply the heated pure water to the front surface W1and the back surface W2of the substrate W.

The chemical-liquid supply nozzle65is a front-surface-side chemical-liquid supply nozzle configured to supply the diluted chemical liquid to the front surface W1of the substrate W. The chemical-liquid supply nozzle66is a back-surface-side chemical-liquid supply nozzle configured to supply the diluted chemical liquid to the back surface W2of the substrate W. Similarly, the pure-water supply nozzle67is a front-surface-side pure-water supply nozzle configured to supply the pure water to the front surface W1of the substrate W. The pure-water supply nozzle68is a back-surface-side pure-water supply nozzle configured to supply the pure water to the back surface W2of the substrate W. The chemical-liquid supply nozzle66and the pure-water supply nozzle68not only provide the cleaning action on the back surface W2of the substrate W but also prevent the temperature drop of the chemical liquid and the pure water on the front surface W1of the substrate W by the heat transfer action thereof.

Each of the cleaning members61and62is a sponge member having a cylindrical shape and having a longitudinal length longer than a diameter of the substrate W. A material of the sponge member may preferably be a material having high hydrophilicity, e.g., PU (polyurethane) or PVA (polyvinyl alcohol). The cleaning members61and62are arranged such that a direction of central axes thereof are parallel to the surface of the substrate W (i.e., the front surface W1and the back surface W2). Hereinafter, the cleaning member61may be referred to as an upper roll cleaning member61, and the cleaning member62may be referred to as a lower roll cleaning member62.

As shown inFIG.3, the substrate holding device60includes four rollers60ato60dconfigured to horizontally hold and rotate the substrate W with the surface W1of the substrate W facing upward. The rollers60ato60dare configured to be movable in directions closer to and away from each other by a not-shown drive mechanism (e.g., an air cylinder).

In the present embodiment, the substrate holding device60includes the rollers60ato60das its components, but the substrate holding device60is not limited to the rollers as long as it can hold a side surface of the substrate W. Instead of the rollers, the substrate holding device60may include, for example, a plurality of clamps (not shown). The clamps are configured to be movable between a position for holding the periphery of the substrate W and a position separated from the substrate W.

In one embodiment, the substrate holding device60may be configured to hold the substrate W in a vertical direction. In this case, the rollers60ato60d(or clamps) are arranged vertically.

The first cleaning module16includes a rotating mechanism69configured to rotate the upper roll cleaning member61and the lower roll cleaning member62. Each of the upper roll cleaning member61and the lower roll cleaning member62is supported by an elevating mechanism (not shown) and is movable in the vertical direction by the elevating mechanism. An example of the elevating mechanism includes a motor-driven mechanism using a ball screw or an air cylinder.

During loading and unloading of the substrate W, the upper roll cleaning member61and the lower roll cleaning member62are located away from each other. During cleaning of the substrate W, the upper roll cleaning member61and the lower roll cleaning member62move in directions closer to each other and come into contact with the front surface and the back surface of the substrate W. Thereafter, each of the upper roll cleaning member61and the lower roll cleaning member62is rotated by the rotating mechanism69to scrub the substrate W (scrub-cleaning).

FIG.4is a diagram showing the second cleaning module18. As shown inFIG.4, the second cleaning module18includes a substrate holding device60configured to rotate the substrate W while holding the substrate W, a cleaning member71configured to contact the substrate W and scrub the substrate W, chemical-liquid supply nozzles75and76configured to supply the chemical liquid having a determined temperature to the surface W1and the back surface W2of the substrate W, and pure-water supply nozzle77and78configured to supply the heated pure water to the front surface W1and the back surface W2of the substrate W.

The chemical-liquid supply nozzle75is a front-surface-side chemical-liquid supply nozzle configured to supply the diluted chemical liquid to the front surface W1of the substrate W. The chemical-liquid supply nozzle76is a back-surface-side chemical-liquid supply nozzle configured to supply the diluted chemical liquid to the back surface W2of the substrate W. Similarly, the pure-water supply nozzle77is a front-surface-side pure-water supply nozzle configured to supply the pure water to the front surface W1of the substrate W. The pure-water supply nozzle78is a back-surface-side pure-water supply nozzle configured to supply the pure water to the back surface W2of the substrate W.

The cleaning member71is a sponge member that has a pencil shape and contacts the surface W1of the substrate W while rotating around a central axis of the cleaning member71to scrub the substrate W. Hereinafter, the cleaning member71may be referred to as a pencil cleaning member71. The substrate holding device60includes four rollers60ato60d(or clamps) configured to hold and rotate the substrate W horizontally with the front surface W1of the substrate W facing upward.

The second cleaning module18includes an oscillating mechanism79configured to oscillate the pencil cleaning member71. The pencil cleaning member71is supported by an elevating mechanism (not shown), and is movable in the vertical direction by the elevating mechanism. An example of the elevating mechanism includes a motor-driven mechanism using a ball screw or an air cylinder.

The oscillating mechanism79is configured to oscillate the pencil cleaning member71in the radial direction of the substrate W. When the pencil cleaning member71is oscillating, the direction of the central axis of the pencil cleaning member71is perpendicular to the front surface W1(or the back surface W2) of the substrate W.

In one embodiment, the oscillating mechanism79oscillates the pencil cleaning member71from the center of the substrate W to the periphery of the substrate W (one-way oscillation) while placing a lower surface of the rotating pencil cleaning member71in contact with the front surface W1of the rotating substrate W with a predetermined pressing force. In another embodiment, the oscillating mechanism79oscillates the pencil cleaning member71from the periphery of the substrate W via the center of the substrate W to the periphery of the substrate W (reciprocating oscillation) while placing the lower surface of the rotating pencil cleaning member71in contact with the front surface W1of the rotating substrate W with a predetermined pressing force. In this manner, the pencil cleaning member71scrubs the substrate W (scrub-cleaning).

As described above, when the roll cleaning member61and the lower roll cleaning member62are scrubbing the substrate W, the first cleaning module16supplies the chemical liquid onto the front surface W1and the back surface W2of the substrate W by the chemical-liquid supply nozzles65and66. The chemical liquid is, for example, an alkaline cleaning liquid. Specifically, an aqueous solution containing any one of ammonia, a primary amine, a secondary amine, a tertiary amine, and a quaternary ammonium compound as a component is suitable. Similarly, when the pencil cleaning member71is scrubbing the substrate W, the second cleaning module18supplies the chemical liquid (e.g., an alkaline cleaning liquid) onto the front surface W1and the back surface W2of the substrate W by the chemical-liquid supply nozzles75and76. Hereinafter, the chemical-liquid supply devices of supplying the chemical liquid onto the substrate W will be described with reference toFIG.2.

As shown inFIG.2, the substrate cleaning system50includes a chemical-liquid supply line80coupled to the chemical-liquid supply nozzles65and66and the chemical-liquid supply nozzles75and76, a pure-water supply line81coupled to the pure-water supply nozzles67and68and the pure-water supply nozzles77and78, and a pure-water return line83configured to circulate the pure water from the pure-water supply line81to the heater51.

The heater51is coupled to the pure-water supply line81. The chemical-liquid supply line80is coupled to the pure-water supply line81, and is arranged downstream of the heater51in the flow direction of the pure water flowing through the pure-water supply line81. The chemical-liquid supply line80is coupled to the pure-water supply line81by a coupling member82. Therefore, the heater51is arranged upstream of the coupling member82in the flow direction of the pure water.

The heater51heats the pure water flowing through the pure-water supply line81to a predetermined temperature. More specifically, a flow-rate sensor84and a temperature sensor85are disposed adjacent to the heater51at positions downstream of the heater51. The controller30(seeFIG.1) is electrically connected to the flow-rate sensor84and the temperature sensor85. The controller30is configured to control the operation of the heater51such that the pure water flowing through the pure-water supply line81has a predetermined temperature and the pure water flows through the pure-water supply line81at a predetermined flow rate, based on a temperature data transmitted from the temperature sensor85.

In the embodiment shown inFIG.1, the heater51includes therein a heating element54configured to heat the pure water flowing through the pure-water supply line81and a flow-rate regulator55configured to regulate the flow rate of the pure water flowing through the pure-water supply line81. The heating element54includes, for example, an infrared irradiation-type heater. Specifically, types of the heating element54include a halogen heater, a carbon heater, a ceramic heater, a quartz-tube heater, etc. The heater may be a known heating device, such as electric heating (resistance, arc, induction, dielectric (microwave), infrared ray, laser, heat pump), light, hot air, burner, etc., as long as the heater can satisfy a required installation environment, a start-up time, and a temperature condition, and can maintain the temperature. The heater may use hot water supplied from a factory where the heater is installed.

In the embodiment shown inFIG.1, the heater51heats the pure water flowing through the pure-water supply line81and regulates the flow rate of the pure water. In one embodiment, the heater51may be disposed downstream of the chemical-liquid diluting module52. In this case, the heater51heats the diluted chemical liquid and regulates the flow rate of the diluted chemical liquid. In another embodiment, the heater51may be disposed in a chemical-liquid coupling line52b(described later). In this case, the heater51heats raw chemical-liquid and regulates the flow rate of the raw chemical-liquid. In this manner, the heater51is configured to heat at least one of the pure water, the diluted chemical liquid, and the raw chemical-liquid, and regulate the flow rate of at least one of the pure water, the diluted chemical liquid, and the raw chemical-liquid. In the embodiment shown inFIG.1, the single heater51is provided, but the number of heaters51is not limited to this embodiment. A plurality of heaters51may be provided.

In one embodiment, the flow-rate regulator55may be provided as a separate component independently of the heater51. In this case, the flow-rate regulator55may be disposed in any of the chemical-liquid supply line80, the pure-water supply line81, and the chemical-liquid coupling line52b. The number of flow-rate regulators55is also not limited to this embodiment. A plurality of flow-rate regulators55may be provided.

In one embodiment, the heater51may be a heating device having the flow-rate sensor84and the temperature sensor85incorporated therein. In another embodiment, the substrate cleaning system50may further include flow sensors (not shown) and temperature sensors (not shown) disposed adjacent to the chemical-liquid supply nozzles65,66,75, and76and the pure-water supply nozzles67,68,77, and78. The number of temperature sensors may correspond to the number of pure-water supply nozzles and the number of chemical-liquid supply nozzles.

The pure water heated to a predetermined temperature by the heater51flows through the pure-water supply line81. Thereafter, the heated pure water branches off from the pure-water supply line81into the pure-water supply line81and the chemical-liquid supply line80.

The chemical-liquid diluting module52is coupled to the chemical-liquid supply line80. More specifically, the chemical-liquid diluting module52includes a chemical-liquid supply source52aand the chemical-liquid coupling line52bconfigured to couple the chemical-liquid supply source52ato the chemical-liquid supply line80.

The chemical-liquid diluting module52supplies the raw chemical-liquid having a normal temperature from the chemical-liquid supply source52athrough the chemical-liquid coupling line52binto the chemical-liquid supply line80to add the raw chemical-liquid to the heated pure water flowing through the chemical-liquid supply line80. In this manner, the chemical-liquid diluting module52mixes the raw chemical-liquid having a normal temperature and the heated pure water at a predetermined volume ratio to dilute the raw chemical-liquid with the heated pure water. Therefore, the temperature of the pure water supplied from the pure-water supply nozzles67,68,77, and78is higher than the temperature of the diluted chemical liquid supplied from the chemical-liquid supply nozzles65,66,75, and76.

The temperature of the diluted chemical liquid mixed by the chemical-liquid diluting module52is determined to be a temperature higher than a normal temperature and lower than glass transition points of the cleaning members61and62(and/or the cleaning member71). The reason for this is as follows. The temperature of the diluted chemical liquid is preferably higher than a normal temperature and lower than 100° C., which is the boiling point of water, in order to improve the cleaning effect on the substrate W, in other words, from the viewpoint of promoting the chemical action.

However, when the substrate W is scrub-cleaned while the heated chemical liquid is supplied, it is necessary to consider a heat resistance of the cleaning member (reference numeral omitted). As described above, the cleaning member is constituted by a sponge member. A material of the sponge member is generally a thermoplastic resin. Therefore, a glass transition point is in a temperature range lower than a melting point.

The glass transition point is a temperature at which a resin is in a state between a hard glass-like state and a soft rubber-like state. A modulus of elasticity is significantly lowered at a higher temperature than this glass transition point. Specifically, a rigidity of the sponge member is reduced, and as a result, the scrubbing action of the sponge member is lowered. Therefore, it is desirable that the temperature of the chemical liquid during the scrub-cleaning be higher than a normal temperature and lower than the glass transition point of the sponge member. For example, when the sponge member is a polyvinyl alcohol (PVA) resin, its glass transition point is about 60° C.

In the present embodiment, the cleaning members61and62(and/or cleaning member71) scrub the substrate W while the heated chemical liquid having a determined temperature higher than a normal temperature and lower than the glass transition point of the cleaning members61and62(and/or the cleaning member71) is supplied onto the substrate W.

The glass transition point may vary depending on a type of cleaning member used. Thus, the controller30may store a glass transition point corresponding to a cleaning member in a memory30afor each type of the cleaning member. The controller30includes a processer30bconfigured to perform arithmetic operations based on the data stored in the memory30a. The memory30ais a component of the controller30. The controller30controls the temperature of the heated chemical liquid based on the cleaning member used and the glass transition point stored in the memory30a.

According to the above-described embodiments, the scrubbing action is not lowered due to the deterioration of the mechanical property of the sponge member, and the chemical action (e.g., a decrease in surface tension, a decrease in kinematic viscosity, dissolution of organic substance) is promoted by the heating of the chemical liquid. As a result, the substrate cleaning system50can achieve a high cleaning effect on the substrate W. When the substrate W is rinsed without the scrub-cleaning, the temperature of the heated chemical liquid may be higher than the glass transition point.

As shown inFIG.2, a filter86configured to capture foreign matter mixed in the pure water flowing through the pure-water supply line81is disposed upstream of the coupling member82. When the pure water heated by the heater51flows through the pure-water supply line81, foreign matter adhering to an inner wall of the pure-water supply line81may be peeled off by the heated pure water. In such a case, the peeled foreign-matter flows through the pure-water supply line81(and the chemical-liquid supply line80) and is supplied onto the substrate W. In the present embodiment, since the substrate cleaning system50includes the filter86arranged next to the heater51, the filter86can prevent the foreign matter from being supplied onto the substrate W.

In order to more reliably prevent the foreign matter from being supplied onto the substrate W, the substrate cleaning system50may include a filter87arranged adjacent to the pure-water supply nozzle67and a filter88arranged adjacent to the pure-water supply nozzle77. Although not shown, the substrate cleaning system50may include filters arranged adjacent to the pure-water supply nozzles68and78.

Similarly, the substrate cleaning system50may include a filter90arranged adjacent to the chemical-liquid supply nozzle65and a filter91arranged adjacent to the chemical-liquid supply nozzle75. Although not shown, the substrate cleaning system50may include filters arranged adjacent to the chemical-liquid supply nozzles66and76.

An on-off valve120is disposed upstream of the filter87, an on-off valve121is disposed upstream of the filter88, an on-off valve122is disposed upstream of the filter90, and an on-off valve123is disposed upstream of the filter91. Each of these on-off valves120,121,122, and123is electrically connected to the controller30. Therefore, the controller30supplies the pure water and/or the chemical liquid onto the substrate W by operating each of the on-off valves120,121,122, and123.

More specifically, the chemical-liquid supply line80includes a first chemical-liquid branch line80A to which the filter87and the on-off valve120are attached, and a second chemical-liquid branch line80B to which the filter91and the on-off valve123are attached. Similarly, the pure-water supply line81includes a first pure-water branch line81A to which the filter90and the on-off valve122are attached, and a second pure-water branch line81B to which the filter88and the on-off valve121are attached.

As shown inFIG.2, the pure-water return line83is coupled to the pure-water supply line81and the heater51. The pure-water return line83is provided as a heat retaining device for preventing the temperature drop of the pure water present in the pure-water supply line81during a standby of the cleaning section4. By providing the pure-water return line83, the temperature of the pure water present in the pure-water supply line81can be maintained at a constant temperature. Therefore, the pure water is returned to the heater51through the pure-water supply line81and the pure-water return line83during the standby of the cleaning section4, such as during the processing of the substrate W in the polishing section2. As a result, the pure water flowing through the pure-water supply line81is maintained at a constant temperature.

The pure-water return line83includes a first return branch line83A coupled to the first pure-water branch line81A and provided with an on-off valve124, and a second return branch line83B coupled to the second pure-water branch line81B and provided with an on-off valve125.

Each of the on-off valves124and125is electrically connected to the controller30. During the standby of the cleaning section4, the controller30opens the on-off valves124and125and closes the on-off valves120,121,122, and123. With such operations, the pure water circulates through the pure-water supply line81, the pure-water return line83, and the heater51. As a result, the circulating pure water is maintained at a constant temperature. During the operation of the cleaning section4, the controller30closes the on-off valves124and125and opens the on-off valves120,121,122, and123.

FIG.5is a diagram showing another embodiment of the substrate cleaning system50. In the present embodiment, identical or corresponding members are denoted by identical reference numerals as those in the above-described embodiment and will not be described below repetitively.

As shown inFIG.5, the substrate cleaning system50may include a heat insulating member100covering the chemical-liquid supply line80and the pure-water supply line81. The heat insulating member100can minimize the temperature drop of the heated chemical liquid flowing through the chemical-liquid supply line80and the temperature drop of the heated pure water flowing through the pure-water supply line81. As a result, each of the heated pure water and the heated chemical liquid reaches each of the first cleaning module16and the second cleaning module18, while the heated pure water and the heated chemical liquid maintain their temperatures. In this way, by providing the heat insulating member100, the thermal efficiency of the heater51can be increased.

As described above, by supplying the heated chemical liquid onto the substrate W, the chemical action of the chemical liquid is promoted, and the cleaning effect on the substrate W can be increased. In order to uniformly supply the heated chemical liquid to the entire substrate W, the heated chemical liquid is supplied onto the center of the rotating substrate W. Ther centrifugal force due to the rotating substrate W acts on the heated chemical liquid supplied onto the center of the substrate W, and the heated chemical liquid spreads from the center of the substrate W toward the periphery of the substrate W in the radially outward directions of the substrate W.

In the present embodiment, the supply position of the heated chemical liquid is fixed, while in one embodiment, the chemical-liquid supply nozzle65(and/or the chemical-liquid supply nozzle66) may supply the heated chemical liquid onto the substrate W while the chemical-liquid supply nozzle65(and/or the chemical-liquid supply nozzle66) oscillate between the center of the substrate W and the periphery of the substrate W.

Therefore, the temperature of the heated chemical liquid on the periphery of the substrate W may be lower than the temperature of the heated chemical liquid on the center of the substrate W. As a result, the cleaning effect on the periphery of the substrate W may be lower than the cleaning effect on the center of the substrate W. Thus, the first cleaning module16(and the second cleaning module18) may have a configuration which maintains the heated chemical liquid on the periphery of the substrate W at the same temperature as the temperature of the heated chemical liquid on the center of the substrate W.

FIG.6is a diagram showing a heater101disposed adjacent to the periphery of the substrate W. In the embodiment shown inFIG.6, the heater101is provided in the first cleaning module16, but the heater101may be provided in the second cleaning module18. As shown inFIG.6, the cleaning module16may include the heater101arranged adjacent to the periphery of the substrate W.

The heater101is a heating device configured to heat the heated chemical liquid (and the heated pure water) present on the periphery of the substrate W. The heater101can maintain the heated chemical liquid (and the heated pure water) on the periphery of the substrate W at the same temperature as the temperature of the heated chemical liquid (heated pure water) on the center of the substrate W. Therefore, the cleaning effect on the periphery of the substrate W can be improved.

FIG.7is a diagram showing a liquid-splash prevention cup102disposed adjacent to the periphery of the substrate W. As shown inFIG.7, the first cleaning module16may include a heater105arranged inside the liquid-splash prevention cup102. The liquid-splash prevention cup102is a member configured to receive the liquid splashed from the substrate W to prevent the splash of the liquid.

The heater105is attached to an inner circumferential surface of the liquid-splash prevention cup102and surrounds the substrate W. The heater105mounted to the liquid-splash prevention cup102can maintain the heated chemical liquid (and heated pure water) on the periphery of the substrate W at the same temperature as the temperature of the heated chemical liquid (heated pure water) on the center of the substrate W. Therefore, the cleaning effect on the periphery of the substrate W can be improved.

FIG.8is a diagram showing another embodiment of the chemical-liquid supply nozzle65(and the pure-water supply nozzle67). As shown inFIG.8, the chemical-liquid supply nozzle65(and the pure-water supply nozzle67) may be a radial nozzle configured to supply the heated diluted chemical liquid to a region from the center to the periphery of the substrate W held by the substrate holding device60. The radial nozzle is preferably a nozzle which is such that a cross section of a spray pattern on the surface of the substrate W has substantially a circular area, an elliptical area, or a flat area. Examples of the radial nozzle include a fan-shaped nozzle or a conical nozzle.

The chemical-liquid supply nozzle65, which is a radial nozzle, can supply the chemical liquid uniformly over a region from the center of the substrate W to the periphery of the substrate W. Therefore, the chemical-liquid supply nozzle65can maintain the heated chemical liquid (and heated pure water) on the periphery of the substrate W at the same temperature as the temperature of the heated chemical liquid (heated pure water) on the center of the substrate W. As a result, the temperature of the surface, to be cleaned, of the substrate W can be maintained at the same temperature.

In one embodiment, the chemical-liquid supply nozzle66(and the pure-water supply nozzle68) may be a radial nozzle. Further, the chemical-liquid supply nozzles75and76and the pure-water supply nozzles77and78provided in the second cleaning module18may also be radial nozzles.

FIG.9is a diagram showing still another embodiment of the chemical-liquid supply nozzle65(and the pure-water supply nozzle67). As shown inFIG.9, the chemical-liquid supply nozzle65(and the pure-water supply nozzle67) may include a first chemical-liquid supply nozzle65A (and a first pure-water supply nozzle67A) configured to supply the diluted chemical liquid to the center of the substrate W held by the substrate holding device60, and a second chemical-liquid supply nozzle65B (and a second pure-water supply nozzle67B) configured to supply the diluted chemical liquid to the periphery of the substrate W held by the substrate holding device60.

In one embodiment, the embodiment shown inFIG.8and the embodiment shown inFIG.9may be combined. In this case, each of the first chemical-liquid supply nozzle65A (and the first pure-water supply nozzle67A) and the second chemical-liquid supply nozzle65B (and the second pure-water supply nozzle67B) is a radial nozzle.

FIG.10is a diagram showing an embodiment of a series of cleaning and drying sequences performed by the substrate cleaning system50and the drying module20. In the embodiment shown inFIG.10, cleaning and drying sequences performed by the first cleaning module16and the drying module20will be described. In one embodiment, the cleaning sequences may be performed by the second cleaning module18and the drying module20.

In one embodiment, the cleaning and drying sequences may be performed by a single module (i.e., the cleaning and drying module) which may be the cleaning module16or the cleaning module18. Such a configuration can omit the transfer robot28(seeFIG.1), and can therefore improve the throughput of the substrate processing apparatus1.

In one embodiment, the cleaning and drying module may have a configuration including an exhaust port arranged below the substrate W transferred therein. With such a configuration, the cleaning and drying module can form a downward flow in the cleaning and drying chamber to quickly discharge vapor (mist) of the heated pure water and the heated chemical liquid. As a result, the cleaning and drying module can prevent the vapor from reattaching to the substrate W.

As shown in step S101ofFIG.10, first, the heated chemical liquid is supplied onto the substrate W to rinse the substrate W, and then, while the heated chemical liquid is continuously supplied, the substrate W is scrubbed by the cleaning members61and62(see step S102). Subsequently, the cleaning members61and62are separated from the substrate W, and the substrate W is rinsed again (see step S103). After the end of the step S103, the supplying of the heated chemical liquid is stopped, and the supplying of the heated pure water is started to rinse the substrate W (see step S104).

In the present embodiment, the heated pure water is supplied to rinse the substrate W to thereby remove the heated chemical liquid quickly from the substrate W. As a result, the rinse-cleaning time can be shortened. The temperature of the heated pure water supplied in the step S104is higher than the temperature of the heated chemical liquid supplied in the step S101. After the rinse-cleaning of the substrate W with the heated pure water is terminated, the substrate W is transferred to the drying module20and the substrate W is dried (see step S105).

FIG.11is a diagram showing a cleaning process of the front surface W1and the back surface W2of the substrate W performed by the first cleaning module16. As shown inFIG.11, the cleaning of the substrate W is performed as follows. First, the substrate W waiting in the transfer module24(seeFIG.1) is transferred to the first cleaning module16. In one embodiment, the heated pure water may be supplied to the substrate W waiting in the transfer module24. In this case, the transfer module24includes a heated pure water supply nozzle (not shown) configured to supply the heated pure water to the waiting substrate W.

The substrate holding device60holds the substrate W that has been transferred to the first cleaning module16, and in this state, the rotation of the substrate W is started (see step S201). Then, the heated chemical liquid is started to be supplied to both surfaces of the substrate W (i.e., the front surface W1and the back surface W2) through the chemical-liquid supply nozzles65and66(see step S202). In order to evenly clean the entire substrate W after the starting of the scrub-cleaning, it is desirable to preheat the substrate W such that a temperature difference is unlikely to occur in the central region and the peripheral region of the substrate W. From such a viewpoint, it is desirable to supply the chemical liquid to the front surface W1of the substrate W and the chemical liquid to the back surface W2of the substrate W simultaneously.

After the supplying of the heated chemical liquid is started, the cleaning members61and62are moved from predetermined standby positions to predetermined processing positions, until the cleaning members61and62are brought into contact with both surfaces of the substrate W (see step S203). The scrubbing of the substrate W with the cleaning members61and62is then started (see step S204), whereby the scrub-cleaning of the substrate W is performed.

After the scrub-cleaning of the substrate W is terminated, the cleaning members61and62are separated from the substrate W (see step S205), and the cleaning members61and62are moved to the standby positions (see step S206). Thereafter, the supplying of the heated chemical liquid is stopped (see step S207). The supplying of the heated pure water is then started (see step S208), so that the substrate W is rinsed. The step S206, the step S207, and the step S208may be performed sequentially or simultaneously. When these steps are performed simultaneously, the substrate cleaning system50can achieve a time shortening of the series of cleaning sequences.

After the rinse-cleaning of the substrate W is terminated, the supplying of the heated pure water is stopped (see step S209), and the rotation of the substrate W is stopped (see step S210). The substrate W is then transferred to the drying module20. The drying module20may include a nozzle configured to emit IPA vapor and a nozzle configured to emit inert gas which are arranged adjacent to a distal end of an arm which can oscillates above the substrate W. The arm oscillates above the substrate W, while the IPA vapor is supplied onto the rotating substrate W and the inert gas is supplied onto the substrate W to dry the substrate W. In this manner, the substrate W is dried in the drying module20. The dried substrate W is then returned to the load port12.

FIG.12is a diagram showing a cleaning effect achieved by the configuration of the cleaning module according to the above-described embodiment.FIG.12shows a comparison result of the number of defects (the number of contaminated particles) on a surface of a silicon oxide film when the cleaning sequences shown inFIG.10are performed on the substrate W having the silicon oxide film with particles, such as the slurry, remaining thereon immediately after the polishing process.

A temperature of heated chemical liquid in comparative example 1 was 22° C. In the comparative example 1, the chemical liquid having a normal temperature was used. A temperature of a heated chemical liquid in this embodiment was 55° C. In this embodiment, the chemical liquid having a temperature higher than a normal temperature and lower than a temperature of a glass transition point of a cleaning member (reference numeral omitted) was used. A temperature of heated chemical liquid in comparative example 2 was 63° C. In the comparative example 2, a chemical liquid having a temperature higher than a temperature of a glass transition point of a cleaning member was used.

As can be seen fromFIG.12, when the heated chemical liquid in the present embodiment was used, the number of contaminated particles present on the substrate W was much lower than the number of contaminated particles in the comparative example 1 and the number of contaminated particles in the comparative example 2. According to the embodiment discussed above, the substrate cleaning system50can achieve an optimum cleaning effect.

In the above-described embodiment, the roll cleaning member and the pencil cleaning member have been described as examples of the cleaning member, but the cleaning member may be a member other than the roll cleaning member and the pencil cleaning member. In one embodiment, the cleaning member may be a buffing pad.

FIG.13is a diagram showing another embodiment of the substrate cleaning system50. Operations of the present embodiment, which will not be particularly described, are the same as those of the above-described embodiment described with reference toFIG.2, and duplicated descriptions will be omitted.

The substrate cleaning system50includes heater51configured to heat pure water to produce heated pure water, chemical-liquid diluting module52configured to mix a chemical liquid and the heated pure water to produce a heated chemical liquid, and cleaning module16configured to clean the substrate. In one embodiment, the substrate cleaning system50may include second cleaning module18(seeFIG.4) instead of the first cleaning module16, or may include both the first cleaning module16and the second cleaning module18.

The substrate cleaning system50further includes chemical-liquid supply line80to which chemical-liquid supply nozzles65and66are coupled, pure-water supply line81and normal-temperature pure-water supply line81-2to which pure-water supply nozzles67and68are coupled, and pure-water return line83configured to circulate the pure water from the water supply line81to the heater51. The pure-water supply line81is coupled to the heater51. The chemical-liquid supply line80is coupled to the pure-water supply line81by coupling member82, which is located downstream of the heater51in a flow direction of the pure water. In one embodiment, as in the embodiment described with reference toFIG.2, the substrate cleaning system50may not include the normal-temperature pure-water supply line81-2. Alternatively, the normal-temperature pure-water supply line81-2may be applied to the embodiment described with reference toFIG.2.

The first cleaning module16includes internal pipes63aand64acoupled to cleaning members61and62, respectively. The internal pipes63aand64aare arranged inside the cleaning members61and62, respectively, and extend in the longitudinal direction (axial direction) of the cleaning members61and62.

The substrate cleaning system50further includes heated-fluid delivery lines111A and111B coupled to the pure-water supply line81and the internal pipes63aand64a. Ends of the heated-fluid delivery lines111A and111B are coupled to the pure-water supply line81, and the other ends of the heated-fluid delivery lines111A and111B are coupled to the internal pipes63aand64a, respectively, via rotary connectors (not shown). The heated pure water flowing through the pure-water supply line81flows through the heated-fluid delivery lines111A and111B into the internal pipes63aand64a, and is further supplied directly to insides of the cleaning members61and62through a multiple apertures of the internal pipes63aand64a. The heated pure water permeates throughout the entire cleaning members61and62, and the heated pure water is supplied onto the front surface W1and the back surface W2of the substrate W which are in contact with the cleaning members61and62. The details of the configuration of the first cleaning module16of this embodiment will be described later.

The heater51includes therein heating element54configured to heat the pure water flowing through the pure-water supply line81and flow-rate regulator55configured to regulate a flow rate of the pure water flowing through the pure-water supply line81. The heating element54is, for example, an infrared lamp heater. The flow-rate regulator55is, for example, a diaphragm pump. The heater51heats the pure water flowing through the pure-water supply line81to a predetermined temperature. The pure water heated to the predetermined temperature by the heater51flows through the pure-water supply line81. The heated pure water then branches off from the pure-water supply line81and flows through the chemical-liquid supply line80and the heated-fluid delivery lines111A and111B.

The chemical-liquid diluting module52is coupled to the chemical-liquid supply line80. The chemical-liquid diluting module52includes chemical-liquid supply source52a, chemical-liquid coupling line52bconfigured to couple the chemical-liquid supply source52ato the chemical-liquid supply line80. The chemical-liquid diluting module52produces a heated chemical liquid by mixing raw chemical-liquid having a normal temperature and the heated pure water at a predetermined volume ratio to dilute the raw chemical-liquid.

The chemical-liquid supply line80is coupled to the chemical-liquid supply nozzles65and66at positions downstream of the chemical-liquid diluting module52in a flow direction of the heated chemical liquid. On-off valves120A and120B are attached to the chemical-liquid supply line80. The on-off valve120A is located between the chemical-liquid diluting module52and the chemical-liquid supply nozzle65, and the on-off valve120B is located between the chemical-liquid diluting module52and the chemical-liquid supply nozzle66.

The heated-fluid delivery lines111A and111B are coupled to the pure-water supply line81at positions downstream of the heater51in the flow direction of the pure water. The normal-temperature pure-water supply line81-2is coupled to the pure-water supply line81at a position upstream of the heater51in the flow direction of the pure water. On-off valves122A and122B are attached to the pure-water supply line81. The on-off valve122A is located between the heater51and the pure-water supply nozzle67, and the on-off valve122B is located between the heater51and the pure-water supply nozzle68. On-off valves122C and122D are attached to the normal-temperature pure-water supply line81-2. On-off valves126A and126B are attached to the heated-fluid delivery lines111A and111B, respectively. The on-off valves126A and126B are located between the cleaning members61and62and the pure-water supply line81. An on-off valve124is attached to the pure-water return line83. An on-off valve127is attached to the pure-water supply line81at a position upstream of the heater51in the flow direction of the pure water.

Each of the on-off valves120A,120B,122A,122B,122C,122D,124,126A,126B, and127is electrically connected to the controller30(seeFIG.1). Opening and closing operations of the on-off valves120A,120B,122A,122B,122C,122D,124,126A,126B, and127can be performed based on control signals emitted from the controller30. During standby of the cleaning, the controller30opens the on-off valves124and127, and closes the on-off valves120A,120B,122A,122B,122C,122D,126A, and126B. With such operations, the pure water circulates through the pure-water supply line81, the pure-water return line83, and the heater51. As a result, the heated pure water is maintained at a constant temperature.

The controller30operates the on-off valves120A,120B,122A,122B,122C, and122D so as to allow the pure water and/or the heated chemical liquid to be supplied onto the substrate W. When the on-off valves122A and122B are opened and the on-off valves122C and122D are closed, the heated pure water is supplied to the pure-water supply nozzles67and68. When the on-off valves122C and122D are opened and the on-off valves122A and122B are closed, the pure water having a normal temperature is supplied to the pure-water supply nozzles67and68. In this way, the heated pure water or the pure water having a normal temperature is selectively supplied from the pure-water supply nozzles67and68onto the substrate W. When the controller30opens the on-off valves126A and126B, the heated pure water flows through the heated-fluid delivery lines111A and111B and flows into the internal pipes63aand64a, and the heated pure water is supplied to the front surface W1and the back surface W2of the substrate W through the cleaning members61and62.

FIG.14is a diagram showing still another embodiment of the substrate cleaning system50. Operations of the present embodiment, which will not be particularly described, are the same as those of the above-described embodiments described with reference toFIGS.2and13, and duplicated descriptions will be omitted. In the embodiment described with reference toFIG.13, the heated pure water is supplied as the heated fluid to the cleaning members61and62, while in the embodiment shown inFIG.14, the heated chemical liquid as the heated fluid is supplied to the cleaning members61and62.

As shown inFIG.14, heated-fluid delivery lines111A and111B coupled to the internal pipes63aand64aare coupled to the chemical-liquid supply line80. When the controller30opens the on-off valves126A and126B, the heated chemical liquid flows through the heated-fluid delivery lines111A and111B and flows into the internal pipes63aand64a. The heated chemical liquid is further directly supplied to the interiors of the cleaning members61and62through a multiple apertures of the internal pipes63aand64a. The heated chemical liquid permeates throughout the entire cleaning members61and62, and the heated chemical liquid is supplied onto the front surface W1and the back surface W2of the substrate W which are in contact with the cleaning members61and62.

FIG.15is a diagram showing still another embodiment of the substrate cleaning system50. Operations of the present embodiment, which will not be particularly described, are the same as those of the above-described embodiment described with reference toFIG.14, and duplicated descriptions will be omitted. In the embodiment shown inFIG.15, the heated chemical liquid is produced by directly heating the chemical liquid with the heater51. The chemical liquid is supplied from the chemical-liquid supply source52ato the chemical-liquid supply line80to which the chemical-liquid supply nozzles65and66are coupled. The heater51is coupled to the chemical-liquid supply line80and heats the chemical liquid flowing through the chemical-liquid supply line80to a predetermined temperature. The heated chemical liquid that has been heated to the predetermined temperature by the heater51flows through the chemical-liquid supply line80. The heated chemical liquid then branches off from the chemical-liquid supply line80and flows through the heated-fluid delivery lines111A and111B.

The pure water is flowing through the pure-water supply line81, and the pure-water supply nozzles67and68are coupled to the pure-water supply line81. In the present embodiment, the pure water having a normal temperature is supplied from the pure-water supply nozzles67and68, while the pure-water supply line81may be provided with a heater that produces heated pure water, which may be supplied from the pure-water supply nozzles67and68. Alternatively, as with the embodiment described with reference toFIG.13, the heated pure water or the pure water having a normal temperature may be selectively supplied from the pure-water supply nozzles67and68. Further, the above-described configuration that the heated chemical liquid is produced by directly heating the chemical liquid by the heater51may be applied to the embodiment described with reference toFIG.2.

FIG.16is a diagram showing still another embodiment of the substrate cleaning system50. Operations of the present embodiment, which will not be particularly described, are the same as those of the above-described embodiments described with reference toFIGS.2and14, and duplicated descriptions will be omitted. In the embodiment shown inFIG.16, the internal pipes63aand64aare coupled to both the pure-water supply line81and the chemical-liquid supply line80via the heated-fluid delivery lines111A and111B. A first switching valve129is disposed between the heated-fluid delivery lines111A and111B and the pure-water supply line81, and a second switching valve130is disposed between the heated-fluid delivery lines111A and111B and the chemical-liquid supply line80. The first switching valve129and the second switching valve130are electrically connected to the controller30(seeFIG.1), and opening and closing operations of the first switching valve129and the second switching valve130are controlled by the controller30.

When the first switching valve129is opened and the second switching valve130is closed, the pure-water supply line81communicates with the internal pipes63aand64athrough the first switching valve129and the heated-fluid delivery lines111A and111B. Therefore, the heated pure water flows from the pure-water supply line81through the first switching valve129and the heated-fluid delivery lines111A and111B to the internal pipes63aand64a. When the second switching valve130is opened and the first switching valve129is closed, the chemical-liquid supply line80communicates with the internal pipes63aand64athrough the second switching valve130and the heated-fluid delivery lines111A and111B. Therefore, the heated chemical liquid flows from the chemical-liquid supply line80through the second switching valve130and the heated-fluid delivery lines111A and111B to the internal pipes63aand64a. In this way, the internal pipes63aand64acoupled to the heated-fluid delivery lines111A and111B selectively communicate with the pure-water supply line81or the chemical-liquid supply line80.

FIG.17is a perspective view showing an embodiment of the first cleaning module16shown inFIGS.13to16, andFIG.18is a cross-sectional view showing a part of the first cleaning module16shown inFIG.17. Operations of the present embodiment, which will not be particularly described, are the same as those of the above-described embodiment described with reference toFIG.3, and duplicated descriptions will be omitted. As shown inFIG.17, the first cleaning module16includes rollers60ato60dconfigured to hold and rotate the substrate W, cleaning members61and62configured to scrub the substrate W, rotating mechanism69configured to rotate the cleaning members61and62, the chemical-liquid supply nozzles65and66configured to supply the heated chemical liquid to the front surface W1and the back surface W2of the substrate W, and the pure-water supply nozzle67and68configured to supply the heated pure water to the front surface W1and the back surface W2of the substrate W.

The rollers60ato60dis movable in directions closer to and away from each other by a not-shown drive mechanism (e.g., an air cylinder). The rollers60ato60dhave a two-steps structure constituted by holding portions60a-1to60d-1and shoulder portions (supporting portions)60a-2to60d-2. The diameter of the shoulder portions60a-2to60d-2is larger than the diameter of the holding portions60a-1to60d-1, and the holding portions60a-1to60d-1are located on the shoulder portions60a-2to60d-2, respectively.

When the substrate W is to be held, the substrate W is first placed on the shoulder portions60a-2to60d-2. Next, the rollers60ato60dare moved in directions closer to each other until the periphery of the substrate W is held by the holding portions60a-1to60d-1. At least one of the rollers60ato60dis configured to be rotated by a not-shown rotating mechanism (e.g., a spindle), whereby the substrate W rotates while being held by the rollers60ato60d.

As shown inFIG.18, upper surfaces of the shoulder portions60a-2to60d-2have tapered shapes inclined downward toward the outside thereof. During holding of the substrate W with the holding portions60a-1to60d-1, the substrate W is kept in non-contact with the shoulder portions60a-2to60d-2.

Returning back toFIG.17, the chemical-liquid supply nozzle65is a front-surface-side chemical-liquid supply nozzle configured to supply the diluted chemical liquid to the front surface W1of the substrate W. The chemical-liquid supply nozzle66is a back-surface-side chemical-liquid supply nozzle configured to supply the diluted chemical liquid to the back surface W2of the substrate W. Similarly, the pure-water supply nozzle67is a front-surface-side pure-water supply nozzle configured to supply the pure water to the front surface W1of the substrate W. The pure-water supply nozzle68is a back-surface-side pure-water supply nozzle configured to supply the pure water to the back surface W2of the substrate W.

Each of the cleaning members61and62is a sponge member having a cylindrical shape and having a longitudinal length longer than the diameter of the substrate W. Each of the cleaning members61and62is arranged such that the direction of the central axis thereof is parallel to the surface of the substrate W (i.e., the front surface W1and the back surface W2). Hereinafter, the cleaning member61may be referred to as an upper roll cleaning member61, and the cleaning member62may be referred to as a lower roll cleaning member62.

During loading and unloading of the substrate W, the upper roll cleaning member61and the lower roll cleaning member62are located away from each other. During cleaning of the substrate W, the upper roll cleaning member61and the lower roll cleaning member62move in directions closer to each other and come into contact with the front surface W1and the back surface W2of the substrate W. Each of the upper roll cleaning member61and the lower roll cleaning member62is rotated by the rotating mechanism69to scrub the entire surface of the rotating substrate W (scrub-cleaning).

The rotating mechanism69includes an upper-cleaning-member rotating mechanism69A, a lower-cleaning-member rotating mechanism69B, a guide rail69C, and an elevating mechanism69D. The upper-cleaning-member rotating mechanism69A is attached to a guide rail69C configured to define a vertical movement of the upper-cleaning-member rotating mechanism69A, and is supported by the elevating mechanism69D. The upper roll cleaning member61is movable in the vertical direction by the elevating mechanism69D. The elevating mechanism69D is, for example, a motor-driven mechanism using a ball screw or an air cylinder. Similarly, the lower-cleaning-member rotating mechanism69B is also supported by a guide rail and an elevating mechanism (not shown), and the lower roll cleaning member62is movable in the vertical direction.

As shown inFIG.18, the first cleaning module16includes shafts63and64arranged inside the cleaning members61and62, respectively. The shaft63is a rotation shaft of the cleaning member61, and the shaft64is a rotation shaft of the cleaning member62. The shaft63includes the internal pipe63ahaving multiple apertures63b, and the shaft64includes the internal pipe64ahaving multiple apertures64b. The heated fluid constituted by the heated pure water or the heated chemical liquid is supplied to the internal pipes63aand64afrom the heated-fluid delivery lines111A and111B (seeFIGS.13to16).

The multiple apertures63band64bare arranged in entire outer peripheral surfaces of the internal pipes63aand64a, and communicate with interiors of the internal pipes63aand64a, respectively. The internal pipes63aand64aare longer than the diameter of the substrate W, and the multiple apertures63band64bare arranged across the substrate W. The apertures63band64bface the cleaning members61and62. More specifically, the apertures63band64bface inner surfaces of the cleaning members61and62. Therefore, the heated fluid constituted by the heated pure water or the heated chemical liquid supplied through the heated-fluid delivery lines111A and111B flows into the internal pipes63aand64aand is then directly supplied to the interiors of the cleaning members61and62from the apertures63band64b. The heated fluid permeates throughout the entire cleaning members61and62, further exudes to the outsides of the cleaning members61and62to be supplied to the entire front surface W1and back surface W2of the substrate W.

According to the present embodiment, the cleaning members61and62, to which the heated fluid is directly supplied, are in contact with not only the central portion but also the periphery of the substrate W. Therefore, the first cleaning module16can perform the scrub-cleaning of the substrate W at a desired temperature without lowering the liquid temperature at the periphery of the substrate W due to a cooling action associated with the rotational movement of the substrate W. As a result, a uniformity of the liquid temperature over the entire surface of the substrate W during the cleaning process can be improved, and a stable removal effect for particulate contamination, molecular contamination, and metal element contamination can be achieved.

FIG.19is a perspective view showing another embodiment of the second cleaning module18, andFIG.20is a cross-sectional view showing a part of the second cleaning module18shown inFIG.19. Operations of the present embodiment, which will not be particularly described, are the same as those of the above-described embodiments described with reference toFIGS.4and13, and duplicated descriptions will be omitted. Further, for simplification of the drawings, the illustration of each valve shown inFIG.13is omitted.

As shown inFIG.19, the second cleaning module18includes substrate holding device74configured to hold and rotate the substrate W, cleaning member71configured to scrub the substrate W, arm73coupled to the cleaning member71, moving mechanism79configured to move the cleaning member71, chemical-liquid supply nozzle75configured to supply the heated chemical liquid to the front surface W1of the substrate W, and pure-water supply nozzle77configured to supply the heated pure water to the front surface W1of the substrate W. Although not shown inFIG.19, the second cleaning module18may include nozzles configured to supply the heated chemical liquid and the heated pure water to the back surface W2of the substrate W.

The substrate holding device74includes chucks95ato95dconfigured to hold the periphery of the substrate W, and a motor96coupled to the chucks95ato95d. The chucks95ato95dare, for example, spring-type clamp mechanisms. The chucks95ato95dhold the substrate W, and the substrate W is rotated about its axis by driving the motor96.

The cleaning member71is a sponge member having a pencil shape and being configured to contact the front surface W1of the substrate W while rotating around the central axis of the cleaning member71to scrub the substrate W. Hereinafter, the cleaning member71may be referred to as a pencil cleaning member71. An upper part of the pencil cleaning member71is coupled to an internal pipe72, and the internal pipe72is coupled to a heated-fluid delivery line111. The heated-fluid delivery line111is coupled to the pure-water supply line81. In one embodiment, the heated-fluid delivery line111may be coupled to the chemical-liquid supply line80as described in the embodiments shown inFIGS.14and15, or the heated-fluid delivery line111may be coupled to both the pure-water supply line81and the chemical-liquid supply line80as described in the embodiment shown inFIG.16.

The arm73is arranged above the substrate W and is coupled to the moving mechanism79. The moving mechanism79includes a pivot shaft79A and a cleaning-member moving mechanism79B. One end of the arm73is coupled to the pivot shaft79A, and the other end of the arm73is coupled to the pencil cleaning member71. The direction of the central axis of the pencil cleaning member71is perpendicular to the front surface W1(or the back surface W2) of the substrate W.

The pivot shaft79A is coupled to the cleaning-member moving mechanism79B configured to cause the arm73to pivot. The cleaning-member moving mechanism79B is configured to cause the arm73to pivot in a plane parallel to the substrate W by rotating the pivot shaft79A with a predetermined angle. The cleaning member71moves in the radial direction of the substrate W by the pivot movement of the arm73. The pivot shaft79A is movable in the vertical direction by an elevating mechanism (not shown), so that the cleaning member71is pressed against the front surface W1of the substrate W at a predetermined pressure to scrub the substrate W (scrub cleaning). An example of the elevating mechanism includes a motor-driven mechanism using a ball screw or an air cylinder. In one embodiment, the moving mechanism79may perform the same operations as those of the oscillating mechanism described with reference toFIG.4.

As shown inFIG.20, the pencil cleaning member71is fixed to a lower end of a supporting shaft73A extending in the direction perpendicular to the substrate W, i.e., in the vertical direction. The supporting shaft73A has a hollow structure and is coupled to a cleaning-member rotating mechanism73B mounted inside the arm73. The pencil cleaning member71is rotated about the supporting shaft73A by the cleaning-member rotating mechanism73B and moves in the radial direction of the substrate W by the rotation of the arm73to thereby scrub the front surface W1of the rotating substrate W.

The pencil cleaning member71is coupled to the internal pipe72extending through the inside of the supporting shaft73A. One end of the internal pipe72is coupled to the heated-fluid delivery line111, and the other end of the internal pipe72is coupled to the upper part of the pencil cleaning member71. The internal pipe72has an aperture72afacing the upper part of the pencil cleaning member71. The heated pure water as the heated fluid is directly supplied to the pencil cleaning member71through the aperture72aof the internal pipe72.

The heated pure water permeates throughout the entire pencil cleaning member71, and exudes to the outside of the pencil cleaning member71to be supplied to the front surface W1of the substrate W. In one embodiment, the heated-fluid delivery line111may be coupled to the chemical-liquid supply line80(seeFIG.19) and the heated chemical liquid may be supplied directly to the pencil cleaning member71through the internal pipe72.

According to the present embodiment, the pencil cleaning member71, to which the heated pure water or the heated chemical liquid is directly supplied, contacts not only the central portion but also the periphery of the substrate W. Therefore, the pencil cleaning member71can perform the scrub cleaning while maintaining a desired temperature without lowering the liquid temperature near the periphery of the substrate W due to a cooling action associated with the rotational movement of the substrate W. As a result, the second cleaning module18can improve a uniformity of the liquid temperature over the entire surface of the substrate W during the cleaning process, and a stable removal effect for particulate contamination, molecular contamination, and metal element contamination can be achieved.

FIG.21is a flowchart showing an embodiment of a cleaning sequence of the substrate W performed by the first cleaning module16shown inFIG.13. In a standby state of the first cleaning module16in which the processing of the substrate W is not performed, the heater51is operated in advance and the temperature of the heated pure water in the pure-water supply line81is maintained at 60° C. In the chemical-liquid supply line80, the temperature of the heated chemical liquid is maintained at 54° C. by the chemical-liquid diluting module52, which produces the heated chemical liquid by mixing the raw chemical-liquid having a normal temperature and the heated pure water at a predetermined volume ratio to dilute the raw chemical-liquid with the heated pure water.

First, the on-off valves120A and120B coupled to the chemical-liquid supply nozzles65and66and the on-off valves122A and122B coupled to the pure-water supply nozzles67and68are closed, and the on-off valves126A and126B coupled to the internal pipes63aand64aare opened (see step S301). Since the heated pure water is supplied to the cleaning members61and62through the internal pipes63aand64aand exudes to the outside of the cleaning members61and62, the cleaning members61and62are clean and heated. During the cleaning process of the substrate, the on-off valves126A and126B are opened at all times (i.e., the heated pure water is supplied continuously to the cleaning members61and62).

The substrate W is transferred to the first cleaning module16, and the periphery of the substrate W is placed on the shoulder portions60a-2to60d-2. The holding portions60a-1to60d-1hold the substrate W by moving the rollers60ato60din the directions closer to the center of the substrate W. When the rollers60ato60drotate, the rotation of the substrate W is started (see step S302).

The on-off valves122A and122B are opened to start the supplying of the heated pure water from the pure-water supply nozzles67and68onto both surfaces of the substrate W (i.e., the front surface W1and the back surface W2) (see step S303). The on-off valve122A is closed to stop the supplying of the heated pure water from the pure-water supply nozzle67onto the front surface W1of the substrate W (see step S304). The on-off valves120A and120B are opened to start the supplying of the heated chemical liquid from the chemical-liquid supply nozzles65and66onto both surfaces of the substrate W (see step S305). Since the substrate W transferred to the first cleaning module16has a normal temperature, the surface temperature of the substrate W is raised in advance by supplying the heated pure water in the step S303. This operation can prevent the temperature drop of the chemical liquid when the heated chemical liquid is supplied in the step S305.

The cleaning members61and62are moved from predetermined standby positions to predetermined processing positions by the elevating mechanism69D and the elevating mechanism (not shown). While the cleaning members61and62are rotated by the rotating mechanisms69A and69B, the cleaning members61and62are pressed against both surfaces of the substrate W to start the scrub-cleaning of the substrate W (see step S306). At this time, since the heated pure water is supplied through the cleaning members61and62onto the front surface W1and the back surface W2of the substrate W in contact with the cleaning members61and62, the first cleaning module16can scrub-clean the substrate W while maintaining the liquid temperature on the periphery of the substrate W.

After a predetermined time has elapsed, the cleaning members61and62are separated from the front surface W1and the back surface W2of the substrate W by the elevating mechanism69D and the elevating mechanism (not shown) to terminate the scrub-cleaning (see step S307). The on-off valves120A and120B are then closed to stop the supplying of the heated chemical liquid from the chemical-liquid supply nozzles65and66onto both surfaces of the substrate W (see step S308). The on-off valve122A is opened to restart the supplying of the heated pure water from the pure-water supply nozzle67onto the front surface W1of the substrate W (see step S309). Subsequently, the on-off valves122A and122B are closed to stop the supplying of the heated pure water from the pure-water supply nozzles67and68onto both surfaces of the substrate W (see step S310). In the step309, instead of the on-off valve122A, the on-off valve122C may be opened to supply the pure water having a normal temperature from the pure-water supply nozzle67onto the front surface W1of the substrate W.

The rotations of the rollers60ato60dare stopped, so that the rotation of the substrate W is stopped (see step S311). The rollers60ato60dare moved in the directions away from the center of the substrate W, so that the holding portions60a-1to60d-1are separated from the substrate W, and the periphery of the substrate W is placed on the shoulder portions60a-2to60d-2again. The cleaned substrate W is then removed from the first cleaning module16by the transfer robot (not shown). The on-off valves126A and126B are maintained opened, so that the cleaning members61and62are kept clean and heated at all times.

In the above embodiment, the heated pure water as the heated fluid is supplied to the cleaning members61and62, while in one embodiment, the heated chemical liquid as the heated fluid may be supplied to the cleaning members61and62as in the embodiments described with reference toFIGS.14and15. In another embodiment, the heated chemical liquid as the heated fluid is supplied to the cleaning members61and62during the scrubbing of the substrate W, and the heated pure water as the heated fluid may be supplied to the cleaning members61and62after the scrubbing of the substrate W. For example, in the step of supplying the chemical liquid from the chemical-liquid supply nozzles65and66onto both surfaces of the substrate W (see the steps S305to S308), the heated chemical liquid may be supplied to the cleaning members61and62, and in the other steps, the heated pure water may be supplied to the cleaning members61and62.

Although a description is omitted, the second cleaning module18described with reference toFIG.19also scrubs the substrate W according to a cleaning sequence basically the same as the cleaning sequence shown inFIG.21.

FIG.22is a diagram showing an effect of liquid temperature uniformity on the front surface W1of the substrate W according to an embodiment of the substrate cleaning system. Specifically,FIG.22is a diagram showing a measurement result of the liquid temperature in the central part and the periphery of the front surface W1of the substrate W during performing the cleaning sequence shown inFIG.21. The measuring method is, for example, measuring of radiant heat using a thermography camera.

Comparative example 1 shows a measurement result when the on-off valves120A and120B were opened to supply the heated chemical liquid from the chemical-liquid supply nozzles65and66, the on-off valve122B was opened to supply the heated pure water from the pure-water supply nozzle68, and the on-off valves122A,126A, and126B were closed. Specifically, the heated fluid was not supplied to the cleaning members61and62.

Comparative example 2 shows a measurement result when the on-off valves120A and120B were opened to supply the heated chemical liquid from the chemical-liquid supply nozzles65and66, the on-off valve122B was opened to supply the heated pure water from the pure-water supply nozzle68, the on-off valve122A was closed, and the unheated pure water was supplied from the internal pipes63aand64a. Specifically, the pure water having a normal temperature was supplied to the cleaning members61and62.

Embodiment example shows a measurement result when the on-off valves120A and120B were opened to supply the heated chemical liquid from the chemical-liquid supply nozzles65and66, the on-off valve122B was opened to supply the heated pure water from the pure-water supply nozzle68, the on-off valve122A was closed, and the heated pure water was supplied from the internal pipes63aand64a. Specifically, the heated pure water was supplied to the cleaning members61and62.

As can be seen fromFIG.22, when the heated pure water was supplied from the cleaning members61and62in the present embodiment, the decrease in the liquid temperature from the temperature of the heated pure water of 60° C. on the front surface W1of the substrate W was suppressed. In addition, the temperature difference between the central portion and the periphery of the substrate W was also suppressed to be small. Therefore, according to the present embodiment, the first cleaning module16can not only raise the temperature of the substrate W, but also improve a uniformity of the liquid temperature over the entire surface of the substrate W, and a stable removal effect for contamination of the substrate W can be achieved.

The previous description of embodiments is provided to enable a person skilled in the art to make and use the present invention. Moreover, various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles and specific examples defined herein may be applied to other embodiments. Therefore, the present invention is not intended to be limited to the embodiments described herein but is to be accorded the widest scope as defined by limitation of the claims.

INDUSTRIAL APPLICABILITY

The present invention is applicable to a substrate cleaning system and a substrate cleaning method for cleaning a substrate.

REFERENCE SIGNS LIST

1substrate processing apparatus2polishing section4cleaning section10housing12load port14A˜14D polishing module16first cleaning module18second cleaning module20drying module22first transfer robot24transfer module26second transfer robot28third transfer robot30controller30amemory30bprocesser50substrate cleaning system51heater52chemical-liquid diluting module52achemical-liquid supply source52bchemical-liquid coupling line54heating element55flow-rate regulator60substrate holding device60a˜60droller60a-1˜60d-1holding portion60a-2˜60d-2shoulder portion (supporting portion)61,62cleaning member (roll cleaning member)63,64shaft63a,64ainternal pipe63b,64baperture65,66chemical-liquid supply nozzle65A first chemical-liquid supply nozzle65B second chemical-liquid supply nozzle67,68pure-water supply nozzle67A first pure-water supply nozzle67B second pure-water supply nozzle69rotating mechanism69A upper-cleaning-member rotating mechanism69B lower-cleaning-member rotating mechanism69C guide rail69D elevating mechanism71cleaning member (pencil cleaning member)72internal pipe73arm73A supporting shaft73B cleaning-member rotating mechanism74substrate holding device75,76chemical-liquid supply nozzle77,78pure-water supply nozzle79oscillating mechanism (moving mechanism)79A pivot shaft79B cleaning-member moving mechanism80chemical-liquid supply line80A first chemical-liquid branch line80B second chemical-liquid branch line81pure-water supply line81A first pure-water branch line81B second pure-water branch line81-2normal-temperature pure-water supply line82coupling member83pure-water return line83A first return branch line83B second return branch line84flow-rate sensor85temperature sensor86,87,88,90,91filter95a˜95dchuck96motor100heat insulating member101heater102liquid-splash prevention cup105heater111,111A,111B heated-fluid delivery line120,120A,120B,121,122,122A,122B,122C,122D,123,124,125,126A,126B,127on-off valve129first switching valve130second switching valveW substrateW1front surfaceW2back surface