JP2006093497A - Substrate cleaning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate cleaning device which subjects a substrate to a prescribed cleaning treatment by supplying the droplets of processing liquid produced by mixing the processing liquid and gas together onto the substrate, and subjects the processing regions of the substrate to an optimal cleaning process corresponding to the regions so as to clean the substrate with high quality. <P>SOLUTION: The substrate center Wc which is slow in moving speed relative to a nozzle 5 is cleaned by reciprocating the nozzle 5 between the boundary position Ka and the rotational center Pa of the substrate W in a state wherein the processing liquid is discharged out from the externally mixed-type nozzle 5 which causes little damage to the substrate W. On the other hand, the substrate peripheral edge Ws which is high in moving speed relative to the nozzle is cleaned by reciprocating the nozzle 6 between the peripheral edge position Eb and boundary position Kb of the substrate W in a state wherein the droplets of the processing liquid discharged out from the internally mixed-type nozzle 6 excellent in detergency (removal rate). By this setup, optimal cleaning processes corresponding to the processing regions of the substrate W, the substrate center Wc and substrate peripheral edge Ws can be carried out, so that all the surface of the substrate W can be cleaned with high quality. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a substrate cleaning apparatus that performs a predetermined cleaning process on a substrate by supplying droplets of the processing solution generated by mixing the processing solution and gas to the substrate. Here, the substrate includes a semiconductor wafer, a glass substrate for photomask, a glass substrate for liquid crystal display, a glass substrate for plasma display, a substrate for optical disk, and the like.

  The manufacturing process of an electronic component such as a semiconductor device or a liquid crystal display device includes a step of repeatedly forming a fine pattern by repeatedly performing processes such as film formation and etching on the surface of the substrate. Here, in order to perform fine processing satisfactorily, it is necessary to keep the substrate surface clean, and the substrate is subjected to a cleaning process as necessary (see Patent Document 1). In the invention described in Patent Document 1, a treatment liquid suitable for a washing process, that is, a washing liquid and compressed air are supplied to a two-fluid nozzle, and the two-fluid nozzle mixes the air with the washing liquid to obtain a mixture (cleaning liquid liquid). Drops). Then, while rotating the substrate at a constant speed, the cleaning liquid is discharged over the entire surface of the substrate by reciprocating the nozzle so that the supply position of the cleaning liquid in the substrate surface passes between the center of the substrate and the edge of the substrate. Particles (fine foreign matter) adhering to the surface are removed and washed away.

Japanese Patent Laid-Open No. 2002-113429 (pages 4-5, FIG. 3)

  By the way, because the substrate is rotating, the relative speed with respect to the two-fluid nozzle is slow at the central portion of the substrate and becomes faster toward the edge. For this reason, there is a problem in that the cleaning time per unit area becomes long in the central portion where the relative speed is low, and the substrate is damaged. In order to solve such a problem, Japanese Patent Application Laid-Open No. H10-228667 proposes a technique for changing processing conditions in synchronization with the movement of the two-fluid nozzle while moving the two-fluid nozzle in the substrate surface. For example, the moving speed of the nozzle is variably controlled so that the moving speed of the two-fluid nozzle increases at the center. Further, the flow rate of the processing liquid or compressed air supplied to the two-fluid nozzle is controlled so as to decrease as the two-fluid nozzle moves toward the substrate center.

  However, it is difficult to accurately control various control elements (moving speed, flow rate, etc.) in real time in synchronization with the movement of the two-fluid nozzle, and the mixture (liquid droplets of the processing liquid) from the two-fluid nozzle is used as a substrate. It is difficult to give stable to In other words, it is difficult to make the cleaning characteristics of the two-fluid nozzle uniform for each surface region (processing region) of the substrate, which is one of the main factors that cause the quality of cleaning processing to deteriorate. For example, if the moving speed of the two-fluid nozzle becomes faster at the central portion than necessary, the cleaning power for the central region of the substrate decreases, and as a result, the removal rate of the particles at the central portion deteriorates. . In addition, when the center position of the substrate and the center position of the nozzle do not exactly match, the moving speed of the two-fluid nozzle is increased in a region deviated from the substrate center, and the cleaning power for both side regions of the substrate center is greatly different. . As a result, the cleaning result in the substrate surface varies (cleaning unevenness).

  The same problem as described above can occur even when there is a region (damage emphasis region) that does not want to be damaged locally on the substrate, as well as the center and edge portions of the rotating substrate. Here, let us consider a case where the two-fluid nozzle and the substrate are moved relative to each other to clean the damage emphasis area and the other areas. As described above, it is difficult to accurately control various control elements in synchronization with the relative movement of the two-fluid nozzle with respect to the substrate, and it is also difficult to optimize the cleaning characteristics of the two-fluid nozzle for each region. For this reason, damage more than necessary may be caused in the damage emphasis area. Conversely, in areas other than damage-critical areas, the focus is on better cleaning than damage, but it is very important to optimize the cleaning characteristics of the two-fluid nozzle in real time corresponding to these areas. Have difficulty. For this reason, the cleaning characteristic of the two-fluid nozzle with respect to each part of the region is deteriorated, and a desired cleaning process may not be executed. As described above, in the conventional apparatus, it is difficult to optimize the cleaning characteristics of the two-fluid nozzle corresponding to each processing region, and optimal cleaning may not be performed for each region.

  The present invention has been made in view of the above problems, and in a substrate cleaning apparatus for performing a predetermined cleaning process by supplying droplets of a processing liquid generated by mixing a processing liquid and a gas to the substrate, the processing on the substrate is performed. The purpose is to clean the substrate with high quality by performing the optimal cleaning corresponding to the area.

  The present invention provides a substrate cleaning apparatus that performs a predetermined cleaning process on a substrate by supplying droplets of the processing solution generated by mixing the processing solution and gas to the substrate. In order to achieve this, the processing liquid is discharged from the liquid discharge port, and the processing liquid and the gas are mixed in the air by blowing the gas to the processing liquid discharged from the liquid discharge port, so that a droplet of the processing liquid is formed. An external mixing type nozzle that generates and supplies the droplets toward the substrate; and a mixing chamber inside. The processing solution and gas are mixed in the mixing chamber to generate droplets of the processing solution, An internal mixing nozzle for supplying droplets toward the substrate, a driving means for moving each of the external mixing nozzle and the internal mixing nozzle relative to the substrate, and adjusting the relative position of each nozzle with respect to the substrate Control means for controlling the supply position of droplets from the nozzle It is characterized in that was.

  According to such a configuration, the processing liquid and the gas are mixed in the air to generate the processing liquid droplets, and the processing liquid and the gas are mixed in the mixing chamber to mix the processing liquid and the gas. And an internal mixing type nozzle for generating the same. Although the configuration and characteristics of each nozzle will be described in detail later, these two nozzles have approximately the following cleaning characteristics structurally. That is, the internal mixing type nozzle has a higher cleaning power (particle removal rate) than the external mixing type nozzle, but the damage to the substrate is large. On the other hand, the external mixing type nozzle is inferior in cleaning power to the internal mixing type nozzle, but the damage to the substrate is extremely small. Each of these nozzles is moved relative to the substrate to control the supply position of droplets ejected from each nozzle. For this reason, by discharging droplets from two nozzles having different cleaning characteristics for each processing region on the substrate, optimum cleaning corresponding to each processing region can be performed, and the substrate is cleaned with high quality. be able to. For example, when cleaning a non-damaged area (damage emphasis area) and other areas (removal rate emphasis area) as a processing area on the substrate, external mixing that damages the substrate with less damage is given to the substrate. While cleaning with a mold nozzle, the substrate with a good removal rate can be cleaned without damaging the substrate by cleaning with an internal mixing type nozzle that excels in the removal rate in the area where the removal rate is important. it can.

  Here, the supply position of the liquid droplets from the external mixing nozzle and the supply position of the liquid droplets from the internal mixing nozzle may be different from each other, or may be partially overlapped. In other words, the cleaning area may be divided for each nozzle, and a nozzle suitable for each processing area may be arranged for cleaning, or a processing area where damage can be tolerated even if droplets are supplied from both nozzles. If there is, the droplets may be supplied from both nozzles and cleaned in order to improve the removal rate. In this way, by using each nozzle properly or in combination, the cleaning process can be performed in such a manner that importance is attached to damage or removal rate.

  In addition, a rotation means for rotating the substrate is provided, and the control means adjusts the relative position of the external mixing nozzle to the substrate so as to supply droplets from the external mixing nozzle to the central portion of the substrate including the rotation center of the substrate. On the other hand, the relative position of the internal mixing type nozzle with respect to the substrate may be adjusted so that the droplets from the internal mixing type nozzle are supplied to the edge portion radially outward from the central portion of the substrate. When the substrate is rotated in this way, as described in the section “Problems to be Solved by the Invention”, the progress of processing differs between the central portion and the edge portion of the substrate. In other words, if the most suitable cleaning level is set at the center of the substrate, the substrate edge of the substrate having a high relative speed cannot be sufficiently cleaned, and conversely, the most suitable at the substrate edge. If the degree of cleaning is set, the cleaning effect at the center of the substrate becomes high, and the substrate is damaged. Therefore, the central part of the substrate that needs to be considered for damage to the substrate is cleaned by supplying droplets from an externally mixed nozzle that has relatively little damage to the substrate, and the substrate edge is relatively fast and resistant to damage. The edge is cleaned by supplying droplets from an internal mixing nozzle having a high removal rate. Thereby, it is possible to perform optimum cleaning corresponding to each processing region of the central portion of the substrate and the edge portion of the substrate, and the cleaning processing is made uniform over the entire surface of the substrate. As a result, the entire surface of the substrate can be cleaned with a good removal rate without damaging the substrate.

  Here, the central portion of the substrate is cleaned by moving the external mixing nozzle between the rotation center of the substrate and the boundary position between the central portion of the substrate and the substrate edge while discharging droplets. The part can be cleaned by moving the internal mixing type nozzle between the edge of the substrate and the boundary position while discharging droplets. In this case, the external mixing type nozzle and the internal mixing type nozzle may be moved individually, or may be moved by a common moving mechanism. In the former case, the external mixing type nozzle is moved between the rotation center and the boundary position of the substrate by the first nozzle moving mechanism, while the inner mixing type nozzle is moved by the second nozzle movement mechanism by the second nozzle moving mechanism. And move between them. In the latter case, for example, the internal mixed nozzle may be moved by a first nozzle moving mechanism that moves the external mixed nozzle. Further, when the external mixing type nozzle and the internal mixing type nozzle are moved by separate moving mechanisms, either the external mixing type nozzle or the internal mixing type nozzle may be fixedly disposed on the substrate during cleaning. Good.

  When the cleaning process using droplets from the external mixing type nozzle is not executed, the first nozzle moving mechanism can position the external mixing type nozzle at the retracted position on the side of the substrate. The external mixing nozzle is moved from the retracted position to the center of the substrate when the external mixing nozzle is moved to the retracted position after the substrate is cleaned by the droplets from In this case, even when the discharge of droplets, that is, the supply of the processing liquid and the gas to the nozzle is stopped, the processing liquid may fall to the edge of the substrate due to liquid leakage from the nozzle and become a contamination source. . Therefore, while the external mixing type nozzle moves on the edge of the substrate, by supplying droplets from the internal mixing type nozzle to the edge of the substrate, the processing liquid due to the liquid leakage from the external mixing type nozzle is washed away, and the substrate Contamination of the edge portion can be prevented.

In addition, when the processing conditions using droplets from the external mixing type nozzle and the internal mixing type nozzle can be changed, optimum processing according to the type of the substrate or the processing region on the substrate can be performed. The processing conditions include (i) the positional relationship between the nozzle and the substrate, (ii) the angle of the droplet from the nozzle with respect to the substrate, (iii) the particle size and velocity of the droplet. For example, in order to change the processing conditions by the droplets discharged from the external mixing type nozzle,
-An interval adjustment mechanism that adjusts the interval between the external mixing nozzle and the substrate to change the processing conditions may be further provided.
An angle adjustment mechanism that adjusts the angle of the droplets discharged from the external mixing type nozzle with respect to the substrate to change the processing conditions may be further provided.
A flow rate adjusting mechanism that adjusts the flow rate of at least one of the processing liquid and gas supplied to the external mixing type nozzle to change the processing conditions may be further provided. Of course, the processing conditions for the liquid droplets ejected from the internal mixing nozzle may be changed.

  Furthermore, by providing a plurality of external mixing type nozzles and / or internal mixing type nozzles and changing the processing conditions of each nozzle to be different from each other, it is more flexible and finer according to the processing area on the substrate. This makes it possible to perform the optimum cleaning for each processing region. In this case, the substrate may be divided into several processing areas, and cleaning may be performed by arranging one nozzle suitable for cleaning in each processing area, or a plurality of nozzles for one processing area. You may make it perform washing | cleaning by. Thereby, the substrate can be effectively cleaned with higher cleaning power (removal rate) without damaging the substrate.

  According to this invention, depending on the processing region on the substrate, droplets are supplied to the substrate from the external mixing nozzle or the internal mixing nozzle, or droplets are supplied to the substrate from both nozzles to perform a predetermined cleaning process. It is configured to run. As a result, it is possible to perform cleaning with optimum cleaning characteristics corresponding to the processing region on the substrate, and it is possible to perform high-quality cleaning processing on the substrate.

<First Embodiment>
FIG. 1 is a schematic view showing a first embodiment of a substrate cleaning apparatus according to the present invention. FIG. 2 is a plan view of the substrate cleaning apparatus of FIG. The substrate cleaning apparatus 1 is for cleaning the surface of a substrate W such as a semiconductor wafer. The substrate cleaning apparatus 1 is a spin chuck 10 that rotates while holding the substrate W substantially horizontally, a processing solution, nitrogen gas (“ 2), the two liquid nozzles 5 and 6 for discharging the liquid droplets toward the substrate W held by the spin chuck 10, and the spin chuck 10. And a cup 30 arranged so as to surround the. The treatment liquid used is not particularly limited as long as it is a cleaning liquid used for substrate cleaning such as pure water, acid, alkali, and ozone water in which ozone is dissolved in pure water.

  The spin chuck 10 includes a rotating shaft 11 disposed along the vertical direction and a disk-shaped spin base 12 attached to the upper end of the rotating shaft 11. A plurality of chuck pins 13 are erected on the edge of the upper surface of the spin base 12 at an appropriate interval in the circumferential direction of the spin base 12. The chuck pins 13 support the lower surface edge of the substrate W and abut on the end surface (circumferential surface) of the substrate W, so that the substrate W can be held in a state of being separated upward from the spin base 12. It has become.

  Further, the rotation shaft 11 of the spin chuck 10 is connected to a motor (not shown) of a rotation drive mechanism 14 corresponding to the “rotation means” of the present invention, and rotates according to motor drive by a controller 20 that controls the entire apparatus. It rotates as the drive mechanism 14 operates. As a result, the substrate W held by the chuck pins 13 above the spin base 12 rotates around the rotation center Pa together with the spin base 12. Thus, in this embodiment, the rotation center Pa corresponds to the “rotation center of the substrate” of the present invention.

  The two two-fluid nozzles 5 and 6 are respectively arranged at positions above the spin base 12 in order to supply droplets of the processing liquid to the surface of the substrate W thus rotationally driven. These two-fluid nozzles 5 and 6 are fixed to the tips of arms 51 and 61 for moving the respective two-fluid nozzles. A first nozzle moving mechanism 52 and a second nozzle moving mechanism 62 are connected to the base end portions of the arms 51 and 61, respectively. Then, the first nozzle moving mechanism 52 is actuated in response to a control command from the controller 20 to swing the arm 51 around the rotation center Pb, while the second nozzle moving mechanism 62 is actuated to actuate the arm 61. Is driven to swing around the rotation center Pc. The configuration and operation of the two-fluid nozzles 5 and 6 will be described in detail later.

  In this embodiment, as shown in FIG. 2, the nozzle 5 is configured to be disposed above the substrate central portion Wc including the rotation center Pa of the substrate W, while the nozzle 6 is configured to be closer to the substrate W than the substrate central portion Wc. It is comprised so that arrangement | positioning is possible in the board | substrate edge part Ws of the radial direction outer side. Specifically, when the first nozzle moving mechanism 52 is actuated to swing the arm 51, the nozzle 5 moves along the movement trajectory Ta in the figure, that is, the substrate rotation center Pa, the substrate center Wc, and the substrate edge Ws. It is possible to move between the boundary position Ka. On the other hand, when the second nozzle moving mechanism 62 is actuated to swing the arm 61, the nozzle 6 moves in the movement trajectory Tb, that is, the substrate edge position Eb, the substrate center Wc, and the substrate edge Ws. It is possible to move between the boundary position Kb. Further, the nozzles 5 and 6 can be retreated to retreat positions Sa and Sb (dashed line positions) on the side of the substrate W, respectively, except during cleaning.

  As shown in FIG. 1, each of the nozzles 5 and 6 is connected to a processing liquid supply source via processing liquid pipes 24 and 26, and receives supply of processing liquid from the processing liquid supply source. These processing liquid pipes 24 and 26 are respectively provided with valves 24V and 26V whose opening degree can be adjusted, and in accordance with a command from the controller 20, the processing liquid supplied to the two-fluid nozzles 5 and 6 is supplied. The flow path can be opened and closed and the flow rate of the processing liquid can be adjusted. Each of the two fluid nozzles 5 and 6 is supplied with high-pressure nitrogen gas from a nitrogen gas supply source via nitrogen gas pipes 25 and 27. These nitrogen gas pipes 25 and 27 are respectively provided with valves 25V and 27V whose opening degree can be adjusted, and in accordance with a command from the controller 20, the nitrogen gas supplied to the two-fluid nozzles 5 and 6 is supplied. The flow path can be opened and closed and the flow rate of nitrogen gas can be adjusted. In the nitrogen gas pipes 25 and 27, pressure gauges 25P and 27P are respectively provided downstream of the valves 25V and 27V (between the valve 25V and the two-fluid nozzle 5 and between the valve 27V and the two-fluid nozzle 6). The pressure of nitrogen gas introduced into each of the two-fluid nozzles 5 and 6 can be measured.

  Thus, while the controller 20 controls the valves 24V and 25V, the flow rates of the processing liquid and nitrogen gas supplied to the nozzle 5 can be adjusted, while the nozzles 6 can be controlled by controlling the valves 26V and 27V. The flow rate of the supplied processing liquid and nitrogen gas can be adjusted. For this reason, each of the two-fluid nozzles 5 and 6 is supplied with the processing liquid and nitrogen gas whose flow rates are adjusted, respectively, generates a droplet of the processing liquid, and can discharge the liquid droplet toward the substrate W. Yes.

  Next, the configuration and operation of the two-fluid nozzle employed in the substrate cleaning apparatus of FIG. 1 will be described. In this embodiment, the nozzle 5 for cleaning the substrate center Wc is a so-called external mixing type nozzle (hereinafter referred to as “external mixing nozzle”), while the nozzle 6 for cleaning the substrate edge Ws is a so-called internal. It is a mixing type nozzle (hereinafter referred to as “internal mixing type nozzle”).

  FIG. 3 is a diagram showing the configuration of the external mixing nozzle. The external mixing type nozzle 5 collides gas (nitrogen gas) with the processing liquid in the air to generate droplets of the processing liquid. In the external mixing type nozzle 5, a liquid discharge nozzle 54 having a liquid discharge port 541 inside the body portion 53 is inserted. The liquid discharge port 541 is disposed on the upper surface portion 532 of the umbrella portion 531 of the nozzle 5. For this reason, when the processing liquid is supplied from the processing liquid supply source via the pipe 24, the processing liquid is discharged toward the substrate W from the liquid discharge port 541.

  The gas discharge nozzle 55 defines a ring-shaped gas passage surrounding the liquid discharge nozzle 54. The tip of the gas discharge nozzle 55 is tapered and the nozzle opening faces the surface of the substrate W. For this reason, when nitrogen gas is supplied from the nitrogen gas supply source via the pipe 25, the nitrogen gas is discharged toward the substrate W from the gas discharge port 551 of the gas discharge nozzle 55. The nitrogen gas discharge locus intersects with the treatment liquid discharge locus from the liquid discharge port 541. That is, the liquid (treatment liquid) flow from the liquid discharge port 541 collides with the gas (nitrogen gas) flow at the collision site G in the mixing region. The gas flow is discharged so as to converge at the collision site G. This mixed region is a space at the lower end of the trunk portion 53. For this reason, the treatment liquid is quickly formed into droplets by the gas that collides with the treatment liquid in the immediate vicinity of the discharge direction of the treatment liquid from the liquid discharge port 541. In this way, cleaning droplets are generated.

  In such an external mixing type nozzle 5, gas (nitrogen gas) is discharged so as to surround the liquid flow of the discharged processing liquid, and the processing liquid and the nitrogen gas collide and are mixed. Then, the generated cleaning droplets clean a limited range of the surface of the substrate W in a uniformly distributed state. Further, as described above, the entire surface of the substrate central portion Wc is cleaned with the mixture of nitrogen gas and the processing liquid by swinging the nozzle 5 on the substrate W along the movement locus Ta around the rotation center Pb. Is done. In this embodiment, the liquid discharge port 541 and the gas discharge port 551 do not need to be flush with each other on the upper surface portion 532 of the nozzle 5, and either of them may protrude.

  FIG. 4 is a diagram showing the configuration of the internal mixing type nozzle. The internal mixing type nozzle 6 mixes a processing liquid and a gas (nitrogen gas) in a mixing chamber provided therein to generate a droplet of the processing liquid. The internal mixing type nozzle 6 includes a nozzle main body 63 having an opening 64 at the tip thereof, and a processing liquid and nitrogen gas are mixed inside the nozzle main body 63 to generate cleaning droplets. Discharge toward Specifically, the nozzle body 63 has a cylindrical mixing portion 631 that forms a mixing chamber 65 in which the processing liquid and nitrogen gas are mixed, and a tapered shape in which one end is connected to the mixing portion 631 and narrows toward the other end. A tapered portion 632 and a direct current portion 633 that is a straight cylindrical tube for accelerating the cleaning droplet are connected to each other.

  The mixing unit 631 has a structure in which the outside of the gas introduction pipe 66 connected to the nitrogen gas pipe 27 is surrounded by the treatment liquid supply pipe 67 connected to the treatment liquid pipe 26, that is, inside the treatment liquid supply pipe 67. It is composed of a double tube structure into which is inserted. The mixing part 631 and the gas introduction pipe 66 are each substantially cylindrical, and the central axes thereof coincide with each other, and the end of the gas introduction pipe 66 is accommodated in the mixing part 631. Further, the mixing unit 631, the gas introduction pipe 66, and the processing liquid supply pipe 67 are fixed by a housing 68. The shapes of the gas introduction pipe 66 and the processing liquid supply pipe 67 may be, for example, a curved pipe or a rectangular tube, and are not particularly limited. In order to suppress the particles to be generated, it is preferable that each tube is formed of a straight cylindrical tube, and in particular, the gas introduction tube 66 is formed of a straight cylindrical tube.

  In such an internal mixing type nozzle 6, when pressurized gas (nitrogen gas) is introduced from the gas introduction pipe 66 and the treatment liquid is supplied from the treatment liquid supply pipe 67, the nitrogen gas is mixed in the mixing chamber 65. Are mixed with the treatment liquid, and droplets of the treatment liquid are generated. The generated cleaning droplets pass through the taper portion 632 and the direct current portion 633, thereby accelerating the moving speed and being discharged from the opening 64 at the tip of the direct current portion 633. Then, as described above, the entire surface of the substrate edge Ws is made of a mixture of nitrogen gas and processing liquid by swinging the nozzle 6 on the substrate W along the movement trajectory Tb around the rotation center Pc. Washed.

  When the above-mentioned external mixing type nozzle 5 and the internal mixing type nozzle 6 are compared, there are the following differences due to the nozzle structures. That is, in the external mixing type nozzle 5, since the discharged liquid (processing liquid) and gas (nitrogen gas) are mixed in the air, the processing liquid is dispersed in the form of mist droplets in the substrate W. Will be reached. On the other hand, in the internal mixing type nozzle 6, the droplet of the processing liquid generated inside the nozzle is accelerated to a predetermined speed, and the generated droplet of the processing liquid travels straight in a state where the attenuation of the speed is small and the substrate. W will be reached. For this reason, the internal mixing type nozzle 6 performs the cleaning process with droplets having a particle size range in which droplets having a relatively large particle size existed, and the cleaning power (particle removal rate) compared to the external mixing type nozzle 5. However, the damage to the substrate W increases. On the other hand, the external mixing type nozzle 5 performs the cleaning process with droplets having a relatively small particle diameter, and although the cleaning power is inferior to the internal mixing type nozzle 6, the damage to the substrate W is overwhelmingly small. It has the characteristic of becoming.

  Next, the operation of the substrate cleaning apparatus configured as described above will be described with reference to FIGS. FIG. 5 is a view showing a cleaning range of the substrate cleaning apparatus of FIG. FIG. 6 is a diagram showing characteristics of the cleaning process executed by the substrate cleaning apparatus of FIG. FIG. 7 is a timing chart showing the operation of the substrate cleaning apparatus of FIG. In this substrate cleaning apparatus, when the unprocessed substrate W is transported onto the chuck pins 13 by the transport means (not shown) and is held by the chuck pins 13, the controller 20 The cleaning process is executed by controlling each part of the apparatus.

  In this cleaning process, the rotation of the substrate W is started. Subsequently, the nozzles 5 and 6 are moved from the retracted position to the droplet supply position on the substrate W by operating the first nozzle moving mechanism 52 and the second nozzle moving mechanism 62, respectively. Specifically, the external mixing nozzle 5 is moved to the supply start position (boundary position Ka) on the substrate center Wc, and is further swung toward the supply end position (substrate rotation center Pa). On the other hand, the internal mixing type nozzle 6 is moved to the supply start position (edge position Eb) on the substrate edge Ws, and is further swung toward the supply end position (boundary position Kb). In conjunction with these nozzle swings, the valves 24V and 25V are opened to supply the processing liquid and nitrogen gas to the nozzle 5 at a predetermined flow rate, while the valves 26V and 27V are opened to supply the processing liquid and nitrogen to the nozzle 6. Gas is supplied at a predetermined flow rate. As a result, droplets of the processing liquid are generated by the nozzles 5 and 6, and the droplets are discharged toward the rotating substrate W.

  Further, the first nozzle moving mechanism swings the arm 51 around the rotation center Pb while the liquid droplets are being discharged from the external mixing type nozzle 5, so that the nozzle 5 moves from the movement locus Ta (from the boundary position Ka to the substrate position Ka). Accordingly, the droplets discharged from the nozzle 5 are supplied to the substrate center Wc as shown in FIG. 5A, and the cleaning process is performed. On the other hand, the arm 61 is swung around the rotation center Pc by the second nozzle moving mechanism while the droplets are discharged from the internal mixing type nozzle 6, so that the nozzle 6 moves along the movement locus Tb (edge position Eb). Therefore, the droplets discharged from the nozzle 6 are supplied to the substrate edge Ws as shown in FIG. 4B, and the cleaning process is performed. Note that the hatched portions in FIGS. 5A and 5B indicate the cleaning process portion.

Here, since the moving speeds of the nozzles 5 and 6 are constant, the relative speed with respect to the nozzles is slow at the center of the substrate W, and becomes faster toward the edge. For this reason, the cleaning time per unit area becomes longer in the substrate central portion Wc having a low relative speed, and the cleaning process in the substrate central portion Wc proceeds more than the edge portion Ws. That is, as shown by the curve C ₆ in Fig. 6 _(cleaning characteristics of the internal mixing type nozzle 6), the particle removal rate from the substrate W by the liquid droplets from the nozzle 6 is high at the center, towards the edges It is decreasing according to. Therefore, when the cleaning process using an internal mixing type nozzle 6 having a cleaning characteristic curve C _6, the cleaning effect at the substrate center portion Wc is increased, the allowable damage level L (level one-dot chain line in FIG. ). On the contrary, when the cleaning process is performed using the external mixing type nozzle 5, the substrate edge Ws having a high relative speed is removed as shown by a curve C ₅ (cleaning characteristics of the external mixing type nozzle 5) in FIG. The rate becomes too low to perform sufficient cleaning.

  On the other hand, in this embodiment, the substrate central portion Wc that needs to be considered for damage to the substrate W is cleaned by supplying droplets from the external mixing nozzle 5, and the relative speed is high and damage is not easily generated. The substrate edge Ws is cleaned by supplying droplets from the internal mixing nozzle 6 having a high removal rate (cleaning characteristics indicated by a solid line in FIG. 6). Thereby, it is possible to perform optimum cleaning corresponding to each processing region of the substrate center portion Wc and the substrate edge portion Ws, and the cleaning processing is made uniform over the entire surface of the substrate. As a result, the entire surface of the substrate can be cleaned with a good removal rate without damaging the substrate W.

  When the cleaning process for the substrate W is completed as described above, the valves 24V and 25V are closed, and the supply of the processing liquid and nitrogen gas to the nozzle 5 (droplet discharge from the nozzle 5) is stopped. Here, at the same time when the droplet discharge from the nozzle 5 is stopped, the valves 26V and 27V may be closed to stop the droplet discharge from the nozzle 6, but it is preferable to stop at the following timing. This is because when the external mixing nozzle 5 is moved to the retracted position Sa after the cleaning process of the substrate center Wc, the supply of the processing liquid and nitrogen gas to the nozzle 5 is stopped. The processing liquid may fall on the substrate edge Ws due to liquid leakage and become a contamination source. Therefore, as shown in FIG. 7, while the external mixing nozzle 5 moves from the boundary position Ka to the substrate edge, that is, while the external mixing nozzle 5 moves on the substrate edge Ws, the internal mixing nozzle 6 By continuing to supply droplets to the substrate edge Ws, the processing liquid due to liquid leakage from the external mixing nozzle 5 can be washed away, and contamination of the substrate edge Ws can be prevented. Then, at the same time as or after the external mixing nozzle 5 passes through the substrate edge toward the retreat position Sa, the droplet discharge from the internal mixing nozzle 6 is stopped.

  Thereafter, the rotational speed of the substrate W is increased, centrifugal force is applied to the droplets remaining on the substrate W to remove the droplets from the substrate W, and drying is performed (spin drying). When the series of processing is completed, the processed substrate W is carried out of the substrate cleaning apparatus by the transport means.

  As described above, in this embodiment, the substrate center Wc having a slow relative speed with respect to the nozzle is cleaned with the external mixed nozzle 5 with little damage to the substrate W, while the substrate edge having a fast relative speed with respect to the nozzle. The portion Ws is configured to be cleaned by the internal mixing type nozzle 6 having excellent cleaning power (removal rate). That is, the substrate central portion Wc that needs to be considered for damage is cleaned by the external mixing nozzle 5, while the substrate edge Ws that is unlikely to be damaged is cleaned by the internal mixing nozzle 6. Thereby, it is possible to perform optimum cleaning corresponding to each processing region of the substrate center portion Wc and the substrate edge portion Ws, and the cleaning processing is made uniform over the entire surface of the substrate. As a result, the entire surface of the substrate can be cleaned with a good removal rate without damaging the substrate W.

  Further, since the uniform cleaning process can be performed without changing the processing conditions while the nozzles 5 and 6 are moving, the processing conditions are set during the nozzle movement as in the invention described in Patent Document 1. Compared to the case of changing, the mixture (droplets of the processing liquid) from the nozzles 5 and 6 can be stably applied to the substrate W, which is advantageous in further improving the stability of the cleaning process. Furthermore, since the control method becomes simple, an increase in manufacturing cost can be effectively suppressed.

Second Embodiment
By the way, in the said embodiment, although it comprised so that a separate process area | region may be wash | cleaned by one external mixing type nozzle 5 and one internal mixing type nozzle 6, respectively, an external mixing type nozzle and / or an internal There may be a plurality of mixed nozzles. Further, the cleaning is not limited to the case where one nozzle is disposed for each processing region, and cleaning may be performed with a plurality of nozzles for one processing region. That is, the cleaning process may be performed so that the supply positions of the droplets from the nozzles partially overlap.

FIG. 8 is a plan view showing a second embodiment of the substrate cleaning apparatus according to the present invention. The second embodiment is greatly different from the first embodiment in that a nozzle 7 for cleaning the processing region Wc ₁ (shaded portion) on the radially outer side (edge side) in the central portion Wc of the substrate is additionally provided. Other configurations and operations are the same as those of the first embodiment. Therefore, the following description will focus on the differences.

The nozzle 7 employs, for example, an external mixing method, and can have the same configuration as that shown in FIG. The external mixing nozzle 7 is fixed to the distal end of the arm 71, and a third nozzle moving mechanism 72 is connected to the base end of the arm 71. Then, the third nozzle moving mechanism 72 is actuated in response to a control command from the controller 20 to drive the arm 71 to swing around the rotation center Pd. For this reason, by operating the third nozzle moving mechanism 72 to swing the arm 71, the side W of the substrate W is moved from the side retraction position (not shown) to the processing position Fc radially outside in the substrate central portion Wc. Positioning is possible. Accordingly, the processing region Wc ₁ is cleaned with the droplets from the external mixing nozzle 5 and is cleaned with the droplets from the external mixing nozzle 7. In this embodiment, for example, a mechanism (interval adjustment mechanism) that moves and positions the arm 71 in the vertical direction in the nozzle moving mechanism 72 in order to make the processing conditions of the cleaning process by the nozzles 5 and 7 different as described later. Is provided so that the height H ₇ (see FIG. 3) from the substrate W to the nozzle 7 is higher than the height H ₅ (see FIG. 3) from the substrate W to the nozzle 5 by this distance adjusting mechanism. It has been adjusted.

FIG. 9 is a diagram showing a cleaning range of the substrate cleaning apparatus of FIG. FIG. 10 is a diagram showing characteristics of the cleaning process executed by the substrate cleaning apparatus of FIG. In the second embodiment, in addition to the cleaning process using droplets from the external mixing nozzle 5 and the internal mixing nozzle 6 shown in FIGS. 9A and 9B, as shown in FIG. The processing region Wc _{1 on the} outer side in the radial direction in the central portion Wc of the substrate is cleaned by droplets from the external mixing nozzle 7. Therefore, the processing area Wc _1, not only cleaning with droplets from the external mixing type nozzle 5 (cleaning properties shown by curve C ₅ in FIG. 10 (a)), the liquid from the external mixing type nozzle 7 becomes the washing treatment with droplets (cleaning characteristics indicated by the curve C ₇ in FIG. 10 (a)) is added, the cleaning process for the processing area Wc ₁ by the interaction of these cleaning processes are accelerated. As a result, the overall cleaning characteristics of the two nozzles 5 and 7 are improved in the removal rate with respect to the processing region Wc _{1 as} indicated by a curve C _{5 + 7} in FIG. 10B. More specifically, the removal rate by the droplets from the nozzle 5 in the substrate central portion Wc decreases toward the outer side in the radial direction (edge side) (due to the droplets from the nozzles 5 and 6). In the cleaning process, the removal rate of the processing area Wc ₁ is the lowest in the entire substrate), and the cleaning process by the droplets from the nozzle 7 is applied to the processing area Wc ₁ to remove the area. The rate is improved.

Note that the overall cleaning characteristics (cleaning characteristics indicated by the curve C _{5 + 7} ) of the nozzles 5 and 7 shown in FIG. 10B are controlled by appropriately combining the processing conditions for the nozzles 5 and 7. Can do. For example, in this embodiment, the height H ₇ from the substrate W to the nozzle ₇ is set to be higher than the height H ₅ from the substrate W to the nozzle 5. Thereby, the removal rate by the droplets from the nozzle 7 is adjusted to be lower than the removal rate by the droplets from the nozzle 5. As a result, the overall cleaning characteristics of the nozzles 5 and 7 can be set so as to be close to the allowable damage level L without exceeding the allowable damage level L.

As described above, in this embodiment, the external mixing type additionally provided in addition to the cleaning process using the droplets from the external mixing type nozzle 5 on the processing region Wc _{1 on the} radially outer side in the central portion Wc of the substrate. since the cleaning process by a droplet from the nozzle 7, can be cleaned the processing region Wc ₁ below acceptable damage level L, and a high detergency (removal rate). That is, the central portion Wc of the substrate is divided into the processing region Wc ₁ on the edge side and the other region (processing region on the central side), and the former is cleaned with droplets from the two nozzles 5 and 7 while the latter is the nozzle. By cleaning only with 5, it is possible to clean the substrate W with a better removal rate without damaging the substrate W. As a result, the processing region Wc _{1 on} the edge side of the substrate center portion Wc, the processing region on the center side of the substrate center portion Wc (the processing region other than the processing region Wc _{1 in} the processing region of the substrate center portion Wc), the substrate edge portion Optimum cleaning corresponding to each processing region of Ws can be performed, and more uniform and high-quality cleaning is possible over the entire surface of the substrate.

In this embodiment, although the change setting processing conditions by the nozzle 7 by adjusting the height H ₇ of the nozzle 7 with respect to the substrate W, setting means of the processing conditions are not limited thereto, Is optional. For example, the processing condition can be adjusted by adjusting the angle of the droplet from the nozzle 7 with respect to the substrate W. Further, it is possible to adjust the processing conditions by adjusting the particle size, speed, etc. of the droplets. As a specific means for changing the particle size, speed, etc. of the droplets in this way, the processing conditions can be changed by adjusting the flow rate of at least one of the processing liquid and nitrogen gas supplied to the nozzle 7. Is possible.

<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 the above embodiment, the external mixing nozzle 5 and the internal mixing nozzle are adjusted by adjusting the flow rate of at least one of the processing liquid and nitrogen gas by adjusting the opening of the valves 24V and 26V and / or the valves 25V and 27V. Although it is possible to change the particle size, speed, etc. of the droplets from No. 6, the processing condition setting means is not limited to this. For example, each nozzle moving mechanism 52, 62 may be provided with a mechanism (interval adjustment mechanism) for moving and positioning the arms 51, 61 in the vertical direction, and the type and size of the substrate to be processed by the vertical positioning of the arms 51, 61 The height position of the nozzle with respect to the substrate W can be automatically adjusted according to the height. Further, a mechanism (angle adjustment mechanism) for adjusting the angle of the nozzles may be provided in each of the nozzle moving mechanisms 52 and 62, and the angle of the droplets from the nozzles 5 and 6 with respect to the substrate W can be adjusted. In this way, by adjusting various control factors and changing the processing conditions, it is possible to perform optimal processing according to the type of the substrate W or the processing region on the substrate W.

  In the first embodiment, the external mixing nozzle 5 is moved between the rotation center Pa of the substrate W and the boundary position Ka to clean the substrate central portion Wc, while the internal mixing nozzle 6 is moved to the substrate W. The substrate edge Ws is cleaned by moving between the edge position Ea and the boundary position Kb. However, depending on the type of the substrate W, the size of the processing region, etc., the external mixing type nozzle 5 or the internal mixing type is used. Any one of the nozzles 6 may be fixedly disposed on the substrate W during cleaning.

In the first embodiment, the external mixing nozzle 5 is moved by the first nozzle moving mechanism 52, while the internal mixing nozzle 6 is moved by the second nozzle moving mechanism 62. For example, FIG. 11, the two nozzles 5 and 6 are fixed to one arm 56 and the droplet discharge from each nozzle 5 and 6 is controlled by a common moving mechanism (for example, the first nozzle moving mechanism 52). You may comprise so that it may rock | fluctuate. In this case, with respect to the external mixing type nozzle 5 that cleans the substrate center Wc, droplets are ejected only during the movement locus from the boundary position Ka ₁ through the rotation center Pa to another boundary position Ka _2. Control is sufficient.

  In the first embodiment, the substrate central portion Wc is cleaned with droplets from the external mixing nozzle 5, while the substrate edge Ws is cleaned with droplets from the internal mixing nozzle 6. However, depending on the characteristics of each processing region (whether it is a damage-oriented region or a removal rate-oriented region) and the processing conditions using droplets from the nozzles 5 and 6, the central portion Wc and / Alternatively, the cleaning process may be performed by supplying droplets to the substrate edge Ws. In this way, by using the nozzles 5 and 6 properly or in combination, the cleaning process can be performed such that damage is emphasized or the removal rate is emphasized.

In the second embodiment, the plurality of external mixing nozzles 5 and 7 are provided with a plurality of external mixing nozzles, and the processing region Wc ₁ on the outer side in the radial direction of the substrate center Wc is cleaned. A cleaning process may be performed by providing a plurality of internal mixing nozzles. For example,
The liquid from the external mixing nozzles 5 and 7 is further adjusted by adjusting the height from the substrate W to further include an internal mixing nozzle having a smaller removal rate (damage to the substrate W) than the internal mixing nozzle 6. Instead of the cleaning process using droplets, the processing region Wc ₁ may be cleaned only by the internal mixed nozzle. Also, the processing region of the substrate edge Ws is divided into two in the radial direction, that is, the substrate edge Ws is divided into a processing region closer to the center of the substrate and a processing region on the radial outer side (edge side). The processing region outside the substrate edge portion Ws in the radial direction may be cleaned by, for example, two internal mixing nozzles having different processing conditions.

  Moreover, in the said embodiment, although an internal mixing type nozzle and an external mixing type nozzle are used simultaneously, you may make it use in order. In other words, when one is used, the other operation may be stopped.

  Moreover, in the said embodiment, although nitrogen gas is used as "gas", gaseous components, such as other inert gas and air, can be used.

  The present invention relates to a substrate including a semiconductor wafer, a glass substrate for photomask, a glass substrate for liquid crystal display, a glass substrate for plasma display, an optical disk substrate, etc. produced by mixing a treatment liquid and a gas. It can be applied to an apparatus that performs a predetermined cleaning process on the substrate by supplying it to the entire surface.

1 is a schematic view showing a first embodiment of a substrate cleaning apparatus according to the present invention. It is a top view of the board | substrate cleaning apparatus of FIG. It is a figure which shows the structure of the nozzle of the external mixing system employ | adopted with the board | substrate cleaning apparatus of FIG. It is a figure which shows the structure of the nozzle of the internal mixing system employ | adopted with the board | substrate cleaning apparatus of FIG. It is a figure which shows the cleaning range of the board | substrate cleaning apparatus of FIG. It is a figure which shows the characteristic of the cleaning process performed by the board | substrate cleaning apparatus of FIG. It is a timing chart which shows operation | movement of the board | substrate cleaning apparatus of FIG. It is a top view which shows 2nd Embodiment of the board | substrate cleaning apparatus concerning this invention. It is a figure which shows the cleaning range of the board | substrate cleaning apparatus of FIG. It is a figure which shows the characteristic of the cleaning process performed by the board | substrate cleaning apparatus of FIG. It is a figure which shows the modification of 1st Embodiment of the board | substrate cleaning apparatus concerning this invention.

Explanation of symbols

5, 7 ... External mixing type nozzle 6 ... Internal mixing type nozzle 14 ... Rotation drive mechanism (rotating means)
20 ... Controller (control means)
52... First nozzle moving mechanism (driving means)
62 ... Second nozzle moving mechanism (driving means)
65 ... Mixing chamber (for internal mixing type nozzle) 72 ... Third nozzle moving mechanism (driving means)
541: Liquid discharge port (of external mixing type nozzle) Eb: Edge (position)
Ka, Kb, Ka ₁ , Ka ₂ ... Boundary position (between substrate center and substrate edge) Pa... Rotation center (of substrate) Sa, Sb .. retracted position W .. substrate Wc .. substrate center Ws. Edge

Claims (10)

In the substrate cleaning apparatus for performing a predetermined cleaning process on the substrate by supplying droplets of the processing liquid generated by mixing the processing liquid and the gas to the substrate,
The processing liquid is discharged from the liquid discharge port, and the processing liquid and the gas are mixed in the air by blowing a gas to the processing liquid discharged from the liquid discharge port, thereby generating droplets of the processing liquid. An external mixing nozzle for supplying the droplets toward the substrate;
An internal mixing type nozzle that has a mixing chamber inside, mixes the processing liquid and gas in the mixing chamber to generate droplets of the processing liquid, and supplies the liquid droplets toward the substrate;
Drive means for moving each of the external mixing nozzle and the internal mixing nozzle relative to the substrate;
A substrate cleaning apparatus, comprising: a control unit that adjusts a relative position of each nozzle with respect to the substrate to control a supply position of a droplet from each nozzle.   2. The control unit adjusts the relative position of each nozzle with respect to the substrate so that the supply position of droplets from the external mixing nozzle is different from the supply position of droplets from the internal mixing nozzle. Substrate cleaning equipment.   The control means adjusts the relative position of each nozzle with respect to the substrate so that a droplet supply position from the external mixing nozzle and a droplet supply position from the internal mixing nozzle partially overlap each other. The substrate cleaning apparatus according to 1. The driving means includes a rotating means for rotating the substrate,
The control means adjusts the relative position of the external mixing type nozzle to the substrate so as to supply droplets from the external mixing type nozzle to the central part of the substrate including the rotation center of the substrate. 3. The substrate cleaning apparatus according to claim 1, wherein a relative position of the internal mixing type nozzle with respect to the substrate is adjusted so as to supply droplets from the internal mixing type nozzle to a substrate edge on a radially outer side. While the external mixing type nozzle is provided movably between the rotation center of the substrate and the boundary position between the substrate central portion and the substrate edge while discharging the droplets,
The substrate cleaning apparatus according to claim 4, wherein the driving unit includes a first nozzle moving mechanism that moves the external mixing nozzle between a rotation center of the substrate and the boundary position. While the internal mixing type nozzle is provided movably between the edge of the substrate and the boundary position while discharging the droplets,
The substrate cleaning apparatus according to claim 4, wherein the driving unit includes a second nozzle moving mechanism that moves the internal mixed nozzle between an edge of the substrate and the boundary position. While the internal mixing type nozzle is provided movably between the edge of the substrate and the boundary position while discharging the droplets,
The substrate cleaning apparatus according to claim 5, wherein the first nozzle moving mechanism moves the internal mixed nozzle between an edge of the substrate and the boundary position. The first nozzle moving mechanism is further configured to move the external mixing nozzle between the boundary position and a retracted position on the side of the substrate via the substrate edge.
While the supply of liquid droplets from the external mixing nozzle is stopped, the control means operates while the external mixing nozzle moves on the substrate edge by the operation of the first nozzle moving mechanism. The substrate cleaning apparatus according to claim 5, wherein droplets from the mixed nozzle are supplied to the edge portion of the substrate.   9. The apparatus according to claim 1, further comprising: a plurality of external mixing nozzles that are configured to be able to change processing conditions for droplets supplied from the external mixing nozzle to the substrate and that are changed so that the processing conditions are different from each other. The substrate cleaning apparatus according to any one of the above. 2. A plurality of the internal mixing type nozzles that are configured to be able to change processing conditions by droplets supplied from the internal mixing type nozzles toward the substrate and that are changed so that the processing conditions are different from each other. The substrate cleaning apparatus according to any one of Items 9 to 9.

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