JP2005158913A - Ultrasonic nozzle and substrate treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic nozzle that reduces damage to a substrate and can supply a treatment liquid containing many bubbles by cavitation to the substrate, and to provide a substrate treatment apparatus using the nozzle. <P>SOLUTION: The ultrasonic nozzle 68 has a body 681 in a covered cylindrical shape having a drum 681a and a nozzle tip 681b in which a profile is nearly in a V shape at the lower section of the drum 681a. The body 681 has a filling space FS for filling a treatment liquid inside. A discharge port 683 for discharging the treatment liquid supplied into the filling space FS toward the substrate surface is provided at the nozzle tip 681b. Additionally, an ultrasonic vibrator 684 is fixed to the upper wall surface of the drum 681a opposite to the discharge port 683 in the inside of the body 681, and can give ultrasonic waves to the treatment liquid in the filling space FS. A flat member 70 is arranged in the filling space FS so that it is nearly in parallel with a discharge direction P of the treatment liquid. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention applies ultrasonic waves to the surface of various substrates (hereinafter simply referred to as “substrate”) such as semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, and substrates for optical disks. The present invention relates to an ultrasonic nozzle that discharges the processed liquid and a substrate processing apparatus using the nozzle.

  2. Description of the Related Art Conventionally, there is a substrate processing apparatus that supplies a processing liquid to a substrate surface and performs substrate processing such as cleaning processing in order to remove minute foreign matters such as particles attached to the substrate surface. Here, in addition to chemical cleaning with a processing liquid, cleaning (ultrasonic cleaning) is performed by applying a physical vibration to the processing liquid with an ultrasonic vibrator to enhance the cleaning effect of the substrate. . In this ultrasonic cleaning, it is known that bubbles are generated by cavitation (cavity phenomenon) in the processing liquid, and minute foreign matters are removed by the generated bubbles. In view of this, various substrate processing apparatuses have been proposed that discharge a processing liquid provided with ultrasonic waves onto the substrate surface (see Patent Document 1).

  In the apparatus described in Patent Document 1, the ultrasonic nozzle is configured so that the ultrasonic vibration is not directly applied to the semiconductor substrate or the primary reflected wave by the ultrasonic vibration is not directly irradiated. More specifically, by changing the arrangement position of the ultrasonic transducer inside the ultrasonic nozzle and the shape inside the ultrasonic nozzle, and by making it possible to arrange a shielding plate inside the ultrasonic nozzle, the semiconductor substrate Suppresses damage taken by.

JP 2001-85380 A (page 5, FIG. 11)

  By the way, in the ultrasonic cleaning, as described above, bubbles due to cavitation generated in the processing liquid by ultrasonic vibration are carried along with the processing liquid to the substrate as the object to be processed, and fine foreign matters such as particles adhering to the substrate surface. It is thought to remove. Therefore, increasing the oscillation output of the ultrasonic vibrator is an effective means to improve the processing performance, that is, the removal efficiency of particles, etc., but the vibration energy reaching the substrate increases, This destroys the fine pattern formed on the surface and loses the significance of disposing the shielding plate inside the ultrasonic nozzle.

  Further, in the apparatus described in Patent Document 1, since the shielding plate is disposed inside the ultrasonic nozzle, it is only necessary to prevent the ultrasonic vibration from reaching the substrate directly or the primary reflected wave due to the ultrasonic vibration. Rather, the shielding plate acts in a direction that inhibits cavitation bubbles from being carried to the substrate. For this reason, the desired removal efficiency is not always obtained. That is, in the apparatus described in Patent Document 1, it is practically difficult to improve the processing performance at the same time while reducing the damage to the fine pattern formed on the substrate.

  The present invention has been made in view of the above problems, and an ultrasonic nozzle capable of supplying a treatment liquid containing a large amount of bubbles due to cavitation to the substrate while reducing damage to the substrate, and a substrate using the nozzle An object is to provide a processing apparatus.

  As described above, in ultrasonic cleaning, it is considered that bubbles due to cavitation are closely related to substrate processing efficiency and substrate damage. Regarding the relationship, the present inventors have conducted various experiments using ultrasonic nozzles. The following findings were obtained. Hereinafter, the experimental contents and the knowledge contents will be described in detail with reference to FIGS. 6 and 7.

  The inventor of the present application evaluated the particle removal performance in a flowing water type ultrasonic nozzle by changing only the flow rate condition of the treatment liquid (that is, the oscillation condition of the ultrasonic vibrator is constant). FIG. 6 is a schematic diagram of a conventional ultrasonic nozzle used in the experiment. As shown in the figure, the processing liquid is filled into the nozzle body 102 from the supply port 101. Then, ultrasonic waves are applied by the ultrasonic vibrator 103 provided inside the nozzle body 102. In this way, by applying ultrasonic waves to the processing liquid, bubbles due to cavitation are generated in the processing liquid. Further, the generated bubbles are discharged together with the processing liquid from the discharge port 104 and are carried to the surface of the substrate W.

  FIG. 7 is a graph showing experimental results using the ultrasonic nozzle. 7A shows the relationship between the flow rate of the processing liquid and the removal efficiency of Si particles, and FIG. 7B shows the relationship between the flow rate of the processing liquid and the sound pressure on the substrate W. Here, the sound pressure on the substrate W is a value measured in the same positional relationship as the evaluation of the particle removal efficiency, and represents the ultrasonic vibration energy that reaches the substrate W as it is.

  As is clear from FIG. 5A, the Si particle removal efficiency increases as the flow rate of the processing liquid increases. On the other hand, as shown in FIG. 5B, the sound pressure on the substrate W is substantially constant regardless of the increase in the flow rate of the processing liquid. This suggests that bubbles due to cavitation generated in the ultrasonic nozzle as the flow rate increases are quickly carried to the substrate surface. Moreover, since the ultrasonic vibration energy reaching the substrate W is constant regardless of the increase in the flow rate of the processing liquid, an additional cleaning effect by ultrasonic vibration (for example, physical vibration of the substrate due to ultrasonic waves). It is possible to consider that there is no need to consider.

  From this, the removal efficiency of particles and the amount of bubbles due to cavitation are inferred as follows. That is, the higher the flow rate of the processing liquid, the greater the amount of bubbles due to cavitation reaching the substrate surface, and the higher the removal efficiency of particles and the like. Conversely, if the flow rate of the treatment liquid is slow, the amount of bubbles due to cavitation reaching the substrate surface is reduced, so that the removal efficiency of particles and the like is lowered. Therefore, in order to increase the removal efficiency of particles, etc., how to efficiently generate bubbles due to cavitation in the processing liquid inside the ultrasonic nozzle (that is, how much the amount of bubbles due to cavitation generated in the processing liquid is determined. In addition, the important point is how efficiently the generated bubbles can reach the substrate surface. That is, it was found that the amount of bubbles and efficient supply of bubbles to the substrate are important in enhancing the removal efficiency of particles and the like.

  Therefore, the ultrasonic nozzle according to the present invention is configured as follows based on the above knowledge. The present invention is an ultrasonic nozzle that discharges a processing liquid to which ultrasonic vibration is applied to a substrate, and in order to achieve the above object, a filling space in which the processing liquid can be filled therein, and a substrate toward the substrate A main body capable of discharging the processing liquid in the filling space from the discharge port, and an ultrasonic vibrator for applying ultrasonic vibration to the processing liquid in the filling space And a plate-like member disposed substantially in parallel with the discharge direction of the processing liquid in the flow path of the processing liquid flowing toward the substrate.

  In the invention configured as described above, the plate-shaped member is disposed in the flow path of the processing liquid flowing toward the substrate, so that the plate-shaped member acts on the ultrasonic vibration wave from the ultrasonic vibrator to perform the processing. New cavitation is caused in the liquid. For this reason, the amount of bubbles due to cavitation can be increased. Further, since the plate-like member is arranged substantially in parallel with the discharge direction of the processing liquid, it is possible to efficiently supply bubbles due to cavitation generated in the processing liquid to the substrate without blocking the flow of the processing liquid. . As a result, the processing liquid containing a large amount of bubbles due to cavitation can be supplied to the substrate without increasing the oscillation output of the ultrasonic transducer.

  Here, in order to increase the amount of bubbles due to cavitation, for example, it is desirable to arrange a plate-like member in the vicinity of the ultrasonic transducer in the filling space. By arranging the plate-like member in this way, vibration waves from the ultrasonic vibrator are directly propagated to the plate-like member, and bubbles due to cavitation can be efficiently generated in the processing liquid. As a result, the amount of bubbles due to cavitation can be further increased.

  In addition, the main body has a barrel portion, a nozzle tip portion having a cross-sectional area substantially orthogonal to the discharge direction, and a nozzle tip portion provided with the discharge port at the tip thereof, the nozzle tip portion, The plate member may be disposed in the nozzle tip so as to include a communication part that communicates with the drum and guides the processing liquid in the drum to the nozzle tip. By arranging the plate-like member in this way, the amount of bubbles due to cavitation can be increased as described above, and the generated bubbles can be efficiently supplied to the substrate. Furthermore, since the plate-like member is disposed in the nozzle tip portion having a cross-sectional area that is substantially orthogonal to the discharge direction, the ultrasonic reflection caused by the reflection of the ultrasonic vibration on the plate-like member is the nozzle. Damped at the tip. For this reason, the element destruction of the ultrasonic transducer | vibrator by ultrasonic reflection can be prevented. Further, the plate-like member may be disposed outside the main body of the ultrasonic nozzle and in the vicinity of the discharge port. Even if the plate-like member is arranged in this manner, the ultrasonic reflected wave does not propagate directly to the ultrasonic transducer, and therefore the same effect as described above can be obtained.

  Further, the plate-like member may be constituted by a vibration plate that can vibrate substantially perpendicular to the discharge direction of the processing liquid. In this case, the ultrasonic vibration wave acts on the vibration plate, so that the vibration plate vibrates substantially perpendicularly to the discharge direction of the processing liquid. Thereby, bubbles due to cavitation can be generated more effectively in the processing liquid, and the amount of bubbles due to cavitation can be increased. Moreover, when the diaphragm vibrates, the ultrasonic vibration energy from the ultrasonic vibrator is consumed, and the vibration energy reaching the substrate can be attenuated. As a result, the fine pattern formed on the substrate can be prevented from being destroyed. Here, when an ultrasonic nozzle in which a plurality of openings are provided as discharge ports in the main body is used, the ultrasonic energy can be further attenuated by being scattered at the discharge port and reaching the substrate. Examples of the discharge port provided with such a plurality of openings include a mesh shape or a slit shape.

In addition, as a treatment liquid used in the present invention, from the viewpoint of efficiently generating cavitation in the treatment liquid, 5 ppm or more of nitrogen is dissolved in the pure water for treatment, preferably in a range from 10 ppm or more to a saturated solution concentration. (Maximum about 20 ppm at room temperature and normal pressure) should be set. Alternatively, it is preferable to perform the treatment by dissolving 50 ppm or more of the chemical in pure water. For example, ammonia (NH ₄ OH): hydrogen peroxide solution (H ₂ O ₂ ): water (H ₂ O) may be used at 1: 1: 200 as the SC1 (Standard Clean 1) solution.

In order to further enhance the cleaning effect using ultrasonic waves, chemical treatment using a chemical solution having an etching action may be performed before ultrasonic treatment using the above-described treatment liquid. Alternatively, ultrasonic treatment may be performed using a chemical solution having an etching action instead of the above treatment solution. Here, when a chemical solution having an etching action is used as the processing solution, the main body and the plate-like member of the ultrasonic nozzle must be formed of a material having chemical resistance against the chemical solution. Note that chemicals having an etching action include SC1 (NH ₄ OH / H ₂ O ₂ / H ₂ O), dilute hydrofluoric acid, HF / HCl, and the like. Thereby, the adhesive force between the substrate and minute foreign matters such as particles can be weakened, and the removal of particles and the like can be facilitated.

  Thus, since the high particle removal performance can be obtained by using the chemical solution having an etching action in combination, the oscillation output of the ultrasonic vibrator can be reduced. In other words, it is possible to obtain a result equivalent to the particle removal efficiency when a chemical solution having an etching action is not used together with a lower oscillation output. Therefore, the fine pattern formed on the substrate can be prevented from being destroyed.

  Further, a substrate processing apparatus according to the present invention includes the ultrasonic nozzle according to any one of claims 1 to 7, thereby reducing damage to the substrate and containing a large amount of bubbles due to cavitation in the substrate. Can be supplied. Thereby, the removal efficiency of particles and the like can be increased while preventing the fine pattern formed on the substrate from being destroyed.

  As described above, according to the present invention, since the plate-like member is arranged in the ultrasonic nozzle, the amount of bubbles due to cavitation generated in the processing liquid can be increased without increasing the oscillation output of the ultrasonic vibrator. Can do. In addition, since the plate-like member is disposed substantially parallel to the discharge direction of the processing liquid, the generated bubbles can be efficiently discharged onto the substrate surface. Therefore, it is possible to supply a treatment liquid containing a large amount of bubbles due to cavitation to the substrate while reducing damage to a fine pattern formed on the substrate.

<Overall configuration of substrate processing apparatus>
FIG. 1 is a diagram showing an embodiment of a substrate processing apparatus according to the present invention. This substrate processing apparatus is a single wafer processing apparatus that performs a cleaning process on a substrate W that is a semiconductor wafer (more specifically, a silicon wafer). The substrate processing apparatus mainly includes an ultrasonic for a spin base 10 that rotates while holding the substrate W, and an alkaline processing liquid that supplies an alkaline processing liquid to which ultrasonic vibration is applied to the substrate W held on the spin base 10. Nozzle 68, ultrasonic nozzle 78 for acidic treatment liquid that supplies acidic treatment liquid to substrate W held on spin base 10, and pure water nozzle that supplies pure water to substrate W held on spin base 36, a receiving member 26 that constitutes a drainage tank or the like that discards or collects used processing liquid (alkaline processing liquid, acidic processing liquid, pure water, etc.), and the like, and a substrate that is held on the spin base 10 and rotates. A splash guard 50 for receiving the processing liquid shaken off from W and a control unit 90 for controlling the operation of the entire apparatus are provided.

  The spin base 10 is a disk-shaped member having an opening at the center, and a plurality of chuck pins 14 for gripping the peripheral edge of the circular substrate W are erected on the upper surface thereof. Three or more (for example, six) chuck pins 14 may be provided in order to securely hold the circular substrate W, and equiangular intervals (for example, 60 ° intervals) along the peripheral edge of the spin base 10. Is arranged in. Each of the chuck pins 14 includes a substrate support portion 14a that supports the peripheral portion of the substrate W from below, and a substrate holding portion 14b that holds the substrate W by pressing the outer peripheral end surface of the substrate W supported by the substrate support portion 14a. It has. Each chuck pin 14 is configured to be switchable between a pressing state in which the substrate holding portion 14 b presses the outer peripheral end surface of the substrate W and an open state in which the substrate holding portion 14 b is separated from the outer peripheral end surface of the substrate W.

  When the substrate W is delivered to the spin base 10, the plurality of chuck pins 14 are released, and when performing various processes on the substrate W, the plurality of chuck pins 14 are pressed. By setting the pressed state, the plurality of chuck pins 14 can grip the peripheral edge of the substrate W and hold the substrate W in a substantially horizontal posture at a predetermined interval from the spin base 10. The substrate W is held with its front surface (electronic circuit pattern formation surface) WS1 facing the upper surface and the rear surface WS2 facing the lower surface.

  On the lower surface side of the center portion of the spin base 10, a rotating shaft 11 is suspended. The rotating shaft 11 is a hollow cylindrical member, and a back surface (WS2) treatment liquid nozzle 15 is inserted in a hollow portion inside thereof. In the vicinity of the lower end of the rotating shaft 11, an electric motor 20 is linked and connected via a belt drive mechanism 21. That is, the belt 21 c is wound between a driven pulley 21 a fixed to the outer periphery of the rotating shaft 11 and a main pulley 21 b connected to the rotating shaft of the electric motor 20. By driving the electric motor 20, the driving force is transmitted to the rotating shaft 11 via the belt driving mechanism 21, and the substrate W held on the chuck pins 14 together with the rotating shaft 11 and the spin base 10 is vertically aligned in the horizontal plane. It can be rotated about a rotation axis J along the direction. The rotating shaft 11, the belt driving mechanism 21, the electric motor 20, etc. are accommodated in a covered cylindrical casing 25 provided on the base member 24.

  The back surface treatment liquid nozzle 15 passes through the rotating shaft 11, and its tip portion 15 a is located immediately below the center portion of the substrate W held on the spin base 10, and an alkaline treatment is performed near the center portion of the back surface WS 2 of the substrate W. A liquid (here, diluted ammonia water), an acidic treatment liquid (here, diluted hydrochloric acid), and pure water can be selectively switched and discharged and supplied. A gap between the inner wall of the hollow portion of the rotating shaft 11 and the outer wall of the back surface treatment liquid nozzle 15 serves as a gas supply path 19. The tip 19a of the gas supply path 19 has an annular opening, and an inert gas (here, nitrogen gas) can be supplied toward the center of the back surface WS2 of the substrate W.

  An ultrasonic nozzle 68 for alkaline processing liquid is disposed above the substrate W held on the spin base 10 so that dilute ammonia water can be supplied to the surface WS1 of the substrate W. . The ultrasonic nozzle 68 for the alkaline processing liquid is connected to the nozzle moving mechanism 65 via a link member 66 bent in a convex shape. The nozzle moving mechanism 65 includes an electric motor 65a having a rotation axis along the vertical direction. A link member 66 and an ultrasonic nozzle 68 for alkaline processing liquid connected to the link member 66 are provided around the rotation axis. Can be rotated. Thereby, the ultrasonic nozzle 68 for the alkaline processing liquid has a facing position facing the surface WS1 of the substrate W held by the spin base 10, and a retracted position retracted from the facing position to the outside of the splash guard 50 laterally. It is possible to move between the two by rotational movement. Also at the facing position, the ultrasonic nozzle 68 for the alkaline processing liquid can face each part from the center part to the peripheral part of the surface WS1 of the substrate W held by the spin base 10. Further, the nozzle moving mechanism 65 is connected to a nozzle lifting mechanism 69 and is configured to be able to lift and lower the ultrasonic nozzle 68 for alkaline processing liquid together with the nozzle moving mechanism 65. Thereby, the splash guard 50 can be avoided and the ultrasonic nozzle 68 for alkaline processing liquid can be moved between the retracted position and the facing position.

  In addition, an ultrasonic nozzle 78 for acidic treatment liquid is disposed on the upper portion of the substrate W held on the spin base 10 so that dilute hydrochloric acid can be supplied to the surface WS1 of the substrate W. . The configuration around the ultrasonic nozzle 78 for the acidic processing liquid is the same as the configuration around the ultrasonic nozzle 68 for the alkaline processing liquid, and a description thereof will be omitted. The configuration and operation of the two types of ultrasonic nozzles 68 and 78 will be described in detail later.

  Above the substrate W held on the spin base 10, there are a disk-shaped atmosphere blocking plate 30, an annular rotating shaft 35 suspended from the center of the upper surface of the atmosphere blocking plate 30, and an inside of the rotating shaft 35. The inserted pure water nozzle 36 is disposed so as to be movable up and down as a unit.

  An opening substantially equal to the inner diameter of the rotating shaft 35 is provided at the center of the atmosphere blocking plate 30, and a pure water nozzle 36 is inserted into a hollow portion inside the rotating shaft 35. The pure water nozzle 36 penetrates the rotating shaft 35, and its tip end portion 36 a is located immediately above the center portion of the substrate W held on the spin base 10 and is pure toward the center portion of the surface WS 1 of the substrate W. Water can be supplied. A gap between the inner wall of the hollow portion of the rotating shaft 35 and the inner wall of the opening at the center of the atmosphere blocking plate 30 and the outer wall of the pure water nozzle 36 is a gas supply path 45. A tip 45a of the gas supply path 45 has an annular opening, and nitrogen gas can be supplied toward the center of the surface WS1 of the substrate W.

  The rotary shaft 35 is rotatably supported by the support arm 40 via a bearing, and is connected to an electric motor 42 attached to the support arm 40 via a belt drive mechanism 41. That is, the belt 41 c is wound between a driven pulley 41 a fixed to the outer periphery of the rotating shaft 35 and a main pulley 41 b connected to the rotating shaft of the electric motor 42. By driving the electric motor 42, the driving force is transmitted to the rotating shaft 35 via the belt driving mechanism 41, and the rotating shaft 35 and the atmosphere shielding plate 30 are centered on the rotating shaft J along the vertical direction in the horizontal plane. Can be rotated as The atmosphere shielding plate 30 rotates at substantially the same rotational speed as the substrate W. The belt drive mechanism 41 is accommodated in the support arm 40.

  Further, the support arm 40 is connected to an arm lifting mechanism 49 and can be lifted and lowered. As the arm elevating mechanism, various known mechanisms such as a feed screw mechanism using a ball screw and a mechanism using an air cylinder can be adopted. The arm elevating mechanism 49 can elevate and lower the rotating shaft 35 and the atmosphere shielding plate 30 connected to the support arm by raising and lowering the support arm, and the atmosphere shielding plate 30 is supported on the surface of the substrate W held on the spin base. It can be moved between a position close to WS1 and a position retracted away above the substrate W. In FIG. 1, the atmosphere shielding plate 30 is in the retracted position.

A receiving member 26 is fixedly attached around the casing 25 on the base member 24. Cylindrical partition members 27 a and 27 b are erected on the receiving member 26. A first drain tank 28 is formed with the casing 25 and the partition member 27a as side walls, and a second drain tank 29 is formed with the partition member 27a and the partition member 27b as side walls. A V-groove is formed at the bottom of the first drainage tank 28, and a discharge port 28a connected to the waste drain 28b is provided at a part of the center of the V-groove. Used pure water and gas can be discharged from the discharge port 28a of the first drainage tank 28 to the waste drain 28b, and can be discarded according to a predetermined procedure after gas-liquid separation. On the other hand, a V-groove is formed at the bottom of the second drainage tank 29, and a discharge port 29a connected to the recovery drain 29b is provided at a part of the center of the V-groove. The used chemical solution can be discharged from the discharge port 29a of the second drainage tank 29 to the recovery drain 29b and recovered in a recovery tank (not shown).

  A cylindrical splash guard 50 is arranged so as to surround the periphery of the spin base 10 and the substrate W held thereon. At the upper part of the inner surface of the splash guard 50, a groove-shaped first guide portion 51 is formed that is inwardly opened in a cross-sectional shape. Further, at the lower part of the splash guard 50, a second guide part 52 having an arc shape with a quarter cross section opened inward and downward, and an annular groove 53 are formed inside the second guide part 52. . The splash guard 50 is connected to the guard lifting mechanism 55 via the link member 56, and can be raised and lowered by the guard lifting mechanism 55. As the guard lifting mechanism 55, various known mechanisms such as a feed screw mechanism using a ball screw and a mechanism using an air cylinder can be adopted.

  When the guard elevating mechanism 55 lowers the splash guard 50, the partition member 27a is loosely fitted in the groove 53, and the first guide portion 51 is positioned around the spin base 10 and the substrate W held thereon. This state is a state at the time of rinsing and spin drying. The pure water scattered from the rotating substrate W or the like is received by the first guide portion 51 and poured into the first drainage tank 28 along the inclination, and the discharge port It becomes a state which can be discharged | emitted from 28a to the waste drain 28b.

  On the other hand, when the guard elevating mechanism 55 raises the splash guard 50, the partition member 27a is separated from the groove 53, and the second guide portion 52 is positioned around the spin base 10 and the substrate W held thereon. (State of FIG. 1). This state is a state at the time of the cleaning process using the alkaline processing liquid or the acidic processing liquid. The alkaline processing liquid or the acidic processing liquid scattered from the rotating substrate W is received by the second guide portion 52, and the second processing unit 52 follows the curved surface. 2 It will be in the state which can be poured into the drainage tank 29 and discharged | emitted from the discharge port 29a to the collection | recovery drain 29b.

<First Embodiment of Ultrasonic Nozzle>
Next, the configuration and operation of the ultrasonic nozzle will be described in detail with reference to FIG. Since the basic configuration of the ultrasonic nozzle 68 for the alkaline processing liquid and the ultrasonic nozzle 78 for the acidic processing liquid are the same, only the ultrasonic nozzle 68 for the alkaline processing liquid will be described here.

  FIG. 2A shows a perspective view of the ultrasonic nozzle according to the first embodiment of the present invention, and FIG. 2B shows a longitudinal sectional view of the ultrasonic nozzle. The ultrasonic nozzle 68 includes a cylindrical main body 681 having a barrel portion 681a and a nozzle tip portion 681b whose longitudinal section is substantially V-shaped at the lower portion of the barrel portion 681a. The main body 681 has a filling space FS in which the processing liquid can be filled. The nozzle tip portion 681b is provided with a discharge port 683 for discharging the processing liquid supplied in the filling space FS toward the surface WS1 of the substrate W. In addition, the opening area of the discharge port 683 is smaller than the area of the cross section of the body portion 681a (cross section substantially orthogonal to the discharge direction of the processing liquid). For this reason, the area of the cross section of the nozzle tip 681b gradually decreases from the upper part (the cross section of the body part 681a) to the lower part (the opening surface of the discharge port 683). A supply port 682 for supplying a processing liquid to the filling space FS is provided on a side surface of the body portion 681a, and is connected to a supply source (not shown) of an alkaline processing liquid via a pipe 37. Therefore, when the processing liquid is supplied to the filling space FS via the pipe 37, the processing liquid flows from the filling space FS to the substrate W via the discharge port 683 and in a flow path substantially parallel to the discharge direction P. .

  In addition, an ultrasonic vibrator 684 is fixed inside the main body 681 on the upper wall surface of the body portion 681a so as to face the discharge port 683. A cable 67 is electrically connected to the ultrasonic transducer 684, and the cable 67 is electrically connected to an ultrasonic oscillator (not shown). The ultrasonic vibrator 684 can oscillate ultrasonic waves toward the processing liquid in the filling space FS, and can apply ultrasonic waves to the processing liquid. A thin plate of quartz or high-purity SiC (silicon carbide) is attached to the surface of the ultrasonic vibrator 684. The main body 681 is made of PTFE (polytetrafluoroethylene) or quartz from the viewpoint of chemical resistance, but the body portion 681a is made of PTFE and the nozzle tip portion 681b (or only the peripheral portion of the discharge port 683). You may comprise combining as quartz.

  A plate-like member 70 is disposed in the filling space FS so as to be substantially parallel to the discharge direction P of the processing liquid. The plate-like member 70 is provided in order to increase the amount of bubbles due to cavitation generated in the processing liquid by causing cavitation in the processing liquid by acting with the vibration wave from the ultrasonic vibrator 684. . The plate-like member 70 is disposed inside the main body 681 by, for example, a fixing rod having a minute diameter so as not to hinder the flow of the processing liquid. Further, when the plate-like member 70 is constituted by a diaphragm (described later), it is necessary to dispose it so as not to disturb the vibration of the diaphragm. Note that the plate-like member 70 is also preferably formed of a material having chemical resistance like the main body 681.

  As shown in FIG. 2B, the treatment liquid supplied into the filling space FS from the supply port 682 is given ultrasonic waves by the ultrasonic vibrator 684. Thereby, cavitation is caused in the processing liquid, and bubbles are generated by cavitation. Here, since the plate-like member 70 is disposed in the filling space FS, the plate-like member 70 acts on the vibration wave from the ultrasonic transducer 684 to cause further cavitation to induce the generation of bubbles. . Therefore, the amount of bubbles due to cavitation generated in the ultrasonic nozzle 68 can be increased. Further, by arranging the plate-like member 70 in the vicinity of the ultrasonic vibrator 684, vibration energy is directly propagated to the plate-like member 70, and bubbles can be generated more efficiently by cavitation.

  In addition, since the plate-like member 70 is disposed substantially parallel to the processing liquid discharge direction P, the processing liquid is efficiently discharged from the discharge port 683 without blocking the flow of the processing liquid. In other words, it is possible to quickly supply the surface WS1 of the substrate W without substantially eliminating bubbles due to cavitation generated in the processing liquid. Therefore, the processing liquid containing a large amount of bubbles due to cavitation can be supplied to the surface WS1 of the substrate W.

  As described above, according to the first embodiment, cavitation generated in the processing liquid without increasing the oscillation output of the ultrasonic vibrator 684 by disposing the plate-like member 70 in the ultrasonic nozzle 68. The amount of bubbles due to can be increased. In addition, since the plate-like member 70 is disposed substantially parallel to the processing liquid discharge direction P, the generated bubbles can be promptly sent to the substrate surface with almost no disappearance. Therefore, it is possible to supply a treatment liquid containing a large amount of bubbles due to cavitation to the substrate surface. Thereby, it is possible to increase the removal efficiency of minute foreign matters such as particles while reducing damage to the substrate W.

  Further, the plate-like member 70 may be constituted by a diaphragm that can vibrate substantially perpendicularly to the treatment liquid discharge direction P. In this case, the vibration wave from the ultrasonic vibrator 684 acts on the vibration plate, so that the vibration plate vibrates substantially perpendicularly to the discharge direction P of the processing liquid. Thereby, bubbles due to cavitation can be generated more efficiently in the processing liquid, and the amount of bubbles due to cavitation can be increased. In addition, the vibration energy from the ultrasonic vibrator 684 is consumed by the vibration of the diaphragm, and the vibration energy reaching the substrate W can be attenuated. As a result, the damage to the substrate W can be further reduced, and the fine pattern formed on the substrate W can be prevented from being destroyed.

<Second Embodiment of Ultrasonic Nozzle>
Next, the configuration and operation of the ultrasonic nozzle according to the second embodiment of the present invention will be described in detail with reference to FIG. FIG. 3A shows a longitudinal sectional view of the ultrasonic nozzle according to the second embodiment of the present invention, and FIGS. 3B and 3C show the shape of the discharge port when the ultrasonic nozzle is viewed from below. The second embodiment is different from the first embodiment in that the ultrasonic nozzle 68 has a communication portion 681c that allows the body portion 681a and the nozzle tip portion 681b to communicate with each other, and a plate is provided inside the nozzle tip portion 681b. This is the point that the shaped member 70 is disposed. Accordingly, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The description will focus on the different components.

  As shown in FIG. 3A, the nozzle tip portion 681b has a cylindrical shape in which the flow path is extended from the lower portion of the communication portion 681c in the treatment liquid discharge direction P. A discharge port 683 is provided at the tip of the nozzle tip portion 681b, and the opening area of the discharge port 683 is larger than the area of the cross section of the body portion 681a (cross section substantially perpendicular to the treatment liquid discharge direction P). It is getting smaller. For this reason, the area of the cross section of the communication portion 681c gradually decreases from the upper portion (the cross section of the body portion 681a) to the lower portion (the cross section of the nozzle tip portion 681b, that is, the opening surface of the discharge port 683). In the ultrasonic nozzle 68 configured as described above, the processing liquid in the body portion 681a is guided to the communication portion 681c and discharged from the discharge port 683 of the nozzle tip portion 681b.

  The plate-like member 70 is disposed substantially parallel to the treatment liquid ejection direction P inside the nozzle tip portion 681b. The plate-like member 70 may be arranged by cutting a groove about the thickness of the plate-like member 70 on the inner wall of the nozzle tip portion 681b and fitting the plate-like member 70 into the groove. It may be formed integrally with 681b. As shown in FIG. 3B, the plate-like member 70 has a cross-shaped cross section, and the processing liquid is surrounded by the inner wall of the nozzle tip portion 681 b and the plate-like member 70 ( It is discharged from the discharge port 683). In addition, the cross-shaped plate-shaped member may be configured by combining two simple flat plates, or may be integrally molded. Further, the plate-like member 70 disposed inside the nozzle tip portion 681b is not limited to the above-described cross shape (a shape in which two flat plates are combined), and is configured by a single flat plate as shown in FIG. May be.

  According to the second embodiment, the same effect as in the first embodiment can be obtained. That is, the plate-like member 70 acts on the vibration wave from the ultrasonic vibrator 684 to cause further cavitation in the processing liquid flowing down the nozzle tip portion 681b to induce the generation of bubbles. Therefore, the amount of bubbles due to cavitation can be increased without increasing the oscillation output of the ultrasonic vibrator 684. In addition, since the plate-like member 70 is disposed substantially parallel to the treatment liquid discharge direction P, the flow of the treatment liquid along the flow path is not blocked, and the cavitation generated in the ultrasonic nozzle 68 is prevented. The bubbles due to are quickly discharged from the discharge port 683 and supplied to the surface WS1 of the substrate W. Therefore, it is possible to supply a treatment liquid containing a large amount of bubbles due to cavitation to the substrate surface.

  Further, in the second embodiment, since the plate-like member 70 is arranged at the nozzle tip portion, the ultrasonic reflection caused by the vibration wave from the ultrasonic vibrator 684 being reflected on the plate-like member 70 is caused by the nozzle tip. It will be attenuated in the part 681b. That is, since the reflected wave from the plate-like member 70 does not directly propagate to the ultrasonic transducer 684, element destruction of the ultrasonic transducer 684 due to ultrasonic reflection can be prevented.

  In the second embodiment as well, the plate-like member 70 may be constituted by a diaphragm that can vibrate substantially perpendicularly to the discharge direction P of the processing liquid. With this configuration, bubbles due to cavitation can be efficiently generated in the processing liquid, and vibration energy reaching the substrate W can be attenuated. As a result, the fine pattern formed on the substrate W can be prevented from being destroyed.

<Third Embodiment of Ultrasonic Nozzle>
Next, the configuration and operation of the ultrasonic nozzle 68 according to the third embodiment of the present invention will be described in detail with reference to FIG. FIG. 4A shows a front view of an ultrasonic nozzle according to the third embodiment of the present invention, and FIG. 4B shows a side view of the ultrasonic nozzle. The third embodiment of the ultrasonic nozzle is different from the first embodiment in that the plate-like member 70 is disposed outside the main body 681 of the ultrasonic nozzle 68 and in the vicinity of the discharge port 683. . Accordingly, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The description will focus on the different components.

  According to the third embodiment, the plate-like member 70 is attached to the outside of the main body 681 in the vicinity of the discharge port 683 so as to be substantially parallel to the discharge direction P of the processing liquid flowing toward the substrate W. Therefore, the processing liquid is discharged from the discharge port 683 along the plate member 70 in parallel. Here, the plate-like member 70 acts on the vibration wave from the ultrasonic vibrator 684 to cause further cavitation in the processing liquid discharged from the discharge port 683 to induce the generation of bubbles. Therefore, the amount of bubbles due to cavitation can be increased without increasing the oscillation output of the ultrasonic vibrator 684. In addition, since the plate-like member 70 is disposed substantially parallel to the processing liquid discharge direction P, the flow of the processing liquid is not blocked, and bubbles caused by cavitation discharged from the ultrasonic nozzle 68 are promptly introduced into the substrate W. To the surface WS1. Therefore, it is possible to supply a treatment liquid containing a large amount of bubbles due to cavitation to the substrate surface.

  Further, in the third embodiment, the plate-like member 70 is disposed outside the main body 681 of the ultrasonic nozzle 68, so that the vibration wave from the ultrasonic vibrator 684 is reflected on the plate-like member 70 and is generated. The sound wave reflection does not propagate directly to the ultrasonic transducer 684. Thereby, element destruction by the ultrasonic vibrator 684 can be prevented.

  Also in the third embodiment, the plate-like member 70 may be constituted by a diaphragm that can vibrate substantially perpendicularly to the discharge direction P of the processing liquid. With this configuration, bubbles due to cavitation can be efficiently generated in the processing liquid, and vibration energy reaching the substrate W can be attenuated. As a result, the fine pattern formed on the substrate W can be prevented from being destroyed.

<Others>
The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in each of the above-described embodiments, the discharge port 683 has one opening, but the discharge port 683 may have a shape having a plurality of openings through which the processing liquid passes. If the mesh shape shown in FIG. 5A or the slit shape shown in FIG. 5B is adopted as the shape of the discharge port 683, vibration energy that is scattered at the opening and reaches the substrate W is obtained. Can be attenuated. Thereby, the damage which the board | substrate W receives can be reduced further.

  Further, the number, shape, size, and the like of the plate-like members 70 arranged in the above embodiment are arbitrary as long as the effects of the present invention are exhibited. That is, it is only necessary that the amount of bubbles due to cavitation is increased by causing cavitation in the processing liquid, and the generated bubbles can be efficiently reached without blocking the flow of the processing liquid. .

  Substrate processing in which a processing liquid to which ultrasonic waves are applied is discharged onto the surface of an object to be processed such as a semiconductor wafer, a glass substrate for a photomask, a glass substrate for liquid crystal display, a glass substrate for plasma display, a substrate for optical disk, etc. The present invention can be applied to an apparatus, particularly a substrate cleaning apparatus.

It is a figure which shows one Embodiment of the substrate processing apparatus concerning this invention. It is the perspective view and longitudinal cross-section of the ultrasonic nozzle which concern on 1st Embodiment of this invention. It is a figure which shows the longitudinal cross-sectional view of the ultrasonic nozzle which concerns on 2nd Embodiment of this invention, and the shape of a discharge outlet. It is the front view and side view of an ultrasonic nozzle which concern on 3rd Embodiment of this invention. It is a figure which shows the shape of the discharge outlet concerning a modification. It is a schematic diagram of the conventional ultrasonic nozzle. It is a graph which shows the experimental result using an ultrasonic nozzle.

Explanation of symbols

68 ... Ultrasonic nozzle for alkaline processing liquid 681 ... Main body 681a ... Body portion 681b ... Nozzle tip portion 681c ... Communication portion 683 ... Discharge port 684 ... Ultrasonic vibrator 70 ... Plate member 78 ... Ultrasonic wave for acidic processing liquid Nozzle FS ... Filling space P ... Discharge direction

Claims (8)

In the ultrasonic nozzle that discharges the processing liquid to which the ultrasonic vibration is applied to the substrate,
A main body having a filling space capable of filling the processing liquid therein and a discharge port opened toward the substrate, and capable of discharging the processing liquid in the filling space from the discharge port;
An ultrasonic transducer for applying ultrasonic waves to the treatment liquid in the filling space;
An ultrasonic nozzle, comprising: a plate-like member disposed substantially parallel to a discharge direction of the processing liquid in a flow path of the processing liquid flowing toward the substrate.   The ultrasonic nozzle according to claim 1, wherein the plate-like member is disposed in the vicinity of the ultrasonic transducer in the filling space. The main body has a body portion, a nozzle tip portion having a cross-sectional area substantially perpendicular to the discharge direction and smaller than the body portion, and the discharge port provided at the tip thereof, and the nozzle tip portion and the body portion. And a communication part that guides the processing liquid in the body part to the nozzle tip part,
The ultrasonic nozzle according to claim 1, wherein the plate-like member is disposed in the nozzle tip.   The ultrasonic nozzle according to claim 1, wherein the plate-like member is disposed outside the main body and in the vicinity of the discharge port.   The ultrasonic nozzle according to claim 1, wherein the plate-like member is a vibration plate that can vibrate substantially perpendicularly to the ejection direction.   The ultrasonic nozzle according to claim 1, wherein a plurality of openings are provided in the main body as the discharge ports. The ultrasonic nozzle according to claim 1, wherein a chemical liquid having an etching action is discharged onto the substrate as the processing liquid.
The ultrasonic nozzle in which the main body and the plate-like member are formed of a material having chemical resistance against the chemical solution.   A substrate processing apparatus for performing a predetermined process by supplying a processing liquid from the ultrasonic nozzle according to claim 1 to a substrate.

Images