JP2005166792A - Substrate processing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide substrate processing equipment capable of performing a specified cleaning processing while sustaining the cleaning effect without causing any damage on a fine pattern. <P>SOLUTION: The substrate processing equipment is arranged such that processing liquid and gas are introduced to a two fluid nozzle 2, the processing liquid is discharged from the liquid outlet 39a of the two fluid nozzle 2, gas is sprayed to the processing liquid to create processing liquid drops, and the liquid drops are supplied toward the surface of a substrate W. The height H from the substrate W to the nozzle 2 is adjusted such that the cleaning width D of the liquid drops being supplied from the two fluid nozzle 2 falls within a range of 5.0-15.0 mm. According to the arrangement, damage onto a fine pattern formed on the substrate W can be prevented while sustaining the removal rate at substantially the same level as that of the prior art. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a substrate processing apparatus for performing a predetermined cleaning process on a surface of a rotating substrate by supplying droplets of the processing liquid generated by mixing the processing liquid and gas to the surface of the rotating substrate. Is. 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.

  In a manufacturing process of an electronic component such as a semiconductor device or a liquid crystal display device, a droplet of a processing liquid is supplied to the surface of the substrate in order to remove particles attached to the surface of the substrate. For example, Patent Document 1 describes a technique for cleaning a substrate by generating a droplet of a processing liquid generated by mixing a processing liquid and a gas and supplying the droplet to the surface of a substrate to be processed. . That is, when a droplet of the processing liquid is supplied to the substrate surface, particles attached to the substrate surface are physically removed by kinetic energy due to the collision of the droplet with the substrate surface. In Patent Document 1, in order to stabilize the rate at which contaminants such as particles are removed from the substrate surface (hereinafter referred to as “removal rate”), the particle size of the droplets may be set to 1 μm to 100 μm. It is stated that it is effective.

JP-A-8-318181 ([0043], FIG. 5)

  By the way, in recent years, wiring patterns and the like formed on the surface of a substrate have been miniaturized. As a result, even if the removal rate is stabilized using droplets having the above particle diameter, the fine pattern is collapsed. Another problem sometimes occurred. That is, in order to exert a certain cleaning effect without collapsing the fine pattern, it is important to adjust another factor instead of the droplet diameter.

  The present invention has been made in view of the above problems, and an object thereof is to provide a substrate processing apparatus capable of performing a predetermined cleaning process without damaging a fine pattern while maintaining a cleaning effect.

  The present invention is a substrate processing apparatus for performing a predetermined cleaning process on a substrate having a fine pattern formed on the surface thereof. In order to achieve the above object, a processing liquid is discharged from a liquid discharge port, and the liquid A two-fluid nozzle that generates a droplet of the processing liquid by blowing a gas onto the processing liquid discharged from the discharge port and supplies the droplet toward the rotating substrate surface, and a two-fluid nozzle in the radial direction of the substrate surface And a moving mechanism for moving the substrate relative to the substrate, and the cleaning width of the droplets supplied from the two-fluid nozzle on the substrate surface is 5.0 mm to 15.0 mm.

  In the invention configured in this manner, as described later, the knowledge that the cleaning width on the substrate surface by the droplets supplied from the two-fluid nozzle is greatly related to the cleaning effect and the reduction of damage to the fine pattern. Based on this, the cleaning width is set in the range of 5.0 mm to 15.0 mm. For example, when the cleaning width is less than 5.0 mm, the droplets supplied from the two-fluid nozzle are concentrated on the minute area of the substrate surface, and an excellent removal rate is obtained, but the fine pattern is large. It will cause damage. Conversely, if the cleaning width exceeds 15.0 mm, droplets supplied from the two-fluid nozzle will be given to a relatively wide area of the substrate surface, which can reduce damage to the fine pattern, The removal rate will drop rapidly. On the other hand, when the cleaning width is in the range of 5.0 mm to 15.0 mm, it is possible to prevent damage to the fine pattern while maintaining the removal rate at or higher than that of the conventional technology.

  Here, from the viewpoint of high removal rate and better damage prevention, it is desirable to set the cleaning width to 7.0 mm as shown in the examples described later.

  Further, a cleaning width adjusting mechanism for adjusting the cleaning width may be further provided, and the cleaning width can always be set in the above range (5.0 mm to 15.0 mm) by adjusting the cleaning width by the cleaning width adjusting mechanism. Therefore, even if the cleaning processing conditions (for example, the processing liquid or gas discharge amount, the type of processing liquid, etc.) are changed or changed, the cleaning width is adjusted according to the cleaning processing conditions to always supply appropriate droplets. The cleaning process can be performed in a state. That is, it can respond to various cleaning processing conditions, and can improve the versatility of the substrate processing apparatus.

  Further, the volume median diameter of the droplet supplied from the two-fluid nozzle to the substrate may be in the range of 5 μm to 40 μm. Here, the “volume median diameter” is the particle size of the droplet, and the ratio of the total volume of droplets larger (or smaller) than the particle size to the volume of all observed droplets The particle size is such that is 50%. For example, if the volume median diameter of the treatment liquid droplet is larger than this range, the flow rate of the gas introduced into the two-liquid nozzle is reduced, and the kinetic energy of the treatment liquid droplet is not reduced. It is not possible to reduce the damage to the fine pattern caused by the liquid droplets colliding with the substrate surface. However, this reduces the removal rate. On the other hand, the volume median diameter of the treatment liquid is adjusted so as to be in the range of 5 μm to 40 μm, so that it is formed on the surface of the substrate even if the flow rate of the gas introduced into the two-liquid nozzle is reduced. Damage to the fine pattern can be reduced. Thereby, the substrate can be processed satisfactorily.

  Further, a particle size adjusting mechanism for adjusting the volume median diameter of the droplets supplied from the two-fluid nozzle to the substrate may be further provided. In this case, the droplets may be adjusted by adjusting the volume median diameter by the particle size adjusting mechanism. The volume median diameter can always be set within the above range (5 μm to 40 μm). Therefore, even if the cleaning processing conditions (for example, cleaning width, type of processing liquid, etc.) are changed or changed, the droplet volume median diameter is adjusted according to the cleaning processing conditions to always supply appropriate droplets. The cleaning process can be performed in a state. That is, it can respond to various cleaning processing conditions, and can improve the versatility of the substrate processing apparatus.

  The arrangement state of the two-fluid nozzle with respect to the substrate is arbitrary, but the two-fluid nozzle may be arranged so that, for example, the supply direction of droplets to the substrate substantially coincides with the normal direction of the substrate surface. Then, the moving mechanism may relatively move the two-fluid nozzle substantially parallel to the substrate surface while maintaining such an arrangement posture. Thereby, the droplets from the two-fluid nozzle can be supplied to the substrate surface in a predetermined droplet supply state, and the entire substrate surface can be processed uniformly.

  Furthermore, a flow rate adjusting mechanism for adjusting the supply flow rate of the gas blown to the processing liquid from the liquid discharge port may be provided, and the gas supply flow rate may be adjusted to a predetermined value by the flow rate adjusting mechanism. In this case, it is possible to stabilize the gas supply flow rate, and as a result, it is possible to suppress fluctuations in the cleaning width and volume median diameter of the treatment liquid droplets, thereby further stabilizing the droplet supply state. Can be made.

  As described above, since the cleaning width on the substrate surface of the droplets supplied from the two-fluid nozzle is 5.0 mm to 15.0 mm, the requirement for maintaining the removal rate at least the same level as the prior art, The desire to prevent damage to the fine pattern can be achieved at the same time.

  FIG. 1 is a schematic view showing an embodiment of a substrate processing apparatus according to the present invention. FIG. 2 is a plan view of FIG. The substrate processing apparatus 1 is for cleaning the surface of a substrate W such as a semiconductor wafer, and corresponds to the spin chuck 10 that rotates while holding the substrate W substantially horizontally, and the “processing liquid” of the present invention. Deionized water and nitrogen gas corresponding to the “gas” of the present invention are mixed to generate deionized water droplets, and the two fluids are supplied to the substrate W held by the spin chuck 10. A nozzle 2 and a cup 50 arranged so as to surround the spin chuck 10 are provided.

  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 the rotation drive mechanism 14, and the rotation drive mechanism 14 is operated according to the motor drive by the controller 20 that controls the entire apparatus. Rotate. As a result, the substrate W held by the chuck pins 13 above the spin base 12 rotates around the rotation axis Pa together with the spin base 12.

  The two-fluid nozzle 2 is disposed above the spin base 12 in order to supply deionized water droplets to the surface of the substrate W thus rotationally driven. More specifically, the deionized water supplied from the two-fluid nozzle 2 toward the substrate W is arranged in parallel with the normal direction (vertical direction in FIG. 1) of the substrate W, and the two-fluid nozzle 2 is It is fixed to the tip side of one arm 21. On the other hand, a nozzle moving mechanism 23 is connected to the base end portion of the arm 21. The nozzle moving mechanism 23 is actuated in response to a control command from the controller 20 to drive the arm 21 to swing around the rotation axis Pb. Therefore, the nozzle moving mechanism 23 moves the two-fluid nozzle 2 relatively in parallel with the substrate surface while maintaining the arrangement posture. More specifically, when the arm 21 is swung by operating the nozzle moving mechanism 23, the nozzle 2 moves from the movement locus Ta in FIG. 2, that is, from the edge position Ka of the substrate to the other edge through the rotation center Pa. It can move along the locus Ta toward the position Fb.

  In this embodiment, the nozzle moving mechanism 23 not only simply swings and drives the arm 21 to move the nozzle 2 relative to the substrate W, but also moves the arm 21 up and down to move the nozzle from the substrate W to the nozzle. The height H up to 2 (see FIG. 3) can be changed. By changing the height H in this way, the cleaning width D on the substrate surface by the droplets supplied from the nozzle 2 toward the substrate W can be adjusted as will be described later. That is, in this embodiment, the nozzle moving mechanism 23 not only functions as a “moving mechanism” of the present invention but also functions as a “cleaning width adjusting mechanism” of the present invention.

  As shown in FIG. 1, the nozzle 2 is connected to a deionized water supply source via a treatment liquid pipe 24 and receives deionized water (DIW) from the deionized water supply source. The processing liquid pipe 24 is provided with a valve 24V capable of adjusting the opening degree, and in response to a command from the controller 20, the flow path of deionized water supplied to the two-fluid nozzle 2 is opened and closed. The flow rate and flow rate of deionized water can be adjusted. Further, a flow meter 24F is interposed downstream of the valve 24V (between the valve 24V and the two-fluid nozzle 2) in the processing liquid pipe 24, and is introduced into the two-fluid nozzle 2 by the flow meter 24F. The flow rate of the processing liquid can be measured.

  The two-fluid nozzle 2 is supplied with high-pressure nitrogen gas from a nitrogen gas supply source via a nitrogen gas pipe 25. The nitrogen gas pipe 25 is provided with a valve 25V whose opening degree can be adjusted, and in response to a command from the controller 20, the flow of the nitrogen gas supplied to the two-fluid nozzle 2 is opened and closed, and the nitrogen gas It is possible to adjust the flow rate and flow velocity of the. In the nitrogen gas pipe 25, a pressure gauge 25P and a flow meter 25F are interposed downstream of the valve 25V (between the valve 25V and the two-fluid nozzle 2) and introduced into the two-fluid nozzle 2. Nitrogen gas pressure and flow rate. The flow rate can be measured.

  As described above, the controller 20 controls the valves 24V and 25V, so that the flow rate and flow rate of deionized water and nitrogen gas supplied to the nozzle 2 can be adjusted. The nozzle 2 is supplied with deionized water and nitrogen gas whose flow rates are adjusted, generates droplets of deionized water, and can supply the droplets toward the substrate W.

  FIG. 3 is a diagram showing a configuration of a two-fluid nozzle employed in the substrate processing apparatus of FIG. In this embodiment, the nozzle 2 is of a so-called external mixing type and can generate droplets of the processing liquid (deionized water) by colliding nitrogen gas with deionized water outside the casing. The two-fluid nozzle 2 includes an outer tube 34 constituting a casing and an inner tube 39 fitted therein, and has a substantially cylindrical outer shape. The inner tube 39 and the outer tube 34 are arranged coaxially sharing the central axis Q. Among these elements, the inside of the inner tube 39 is a liquid supply hole 39b. Further, an annular gap having a central axis Q is formed between the inner tube 39 and the outer tube 34, and a gas supply hole 34b is formed.

  The gas supply hole 34b is opened as an annular gas discharge port 34a at one end of the two-fluid nozzle 2, and an inner tube 39 and an outer tube 34 are formed at the other end of the two-fluid nozzle 2. It is in contact and no opening is formed. The gas supply hole 34b has a substantially constant diameter at the central portion in the axial direction of the two-fluid nozzle 2, but in the vicinity of the gas discharge port 34a, the end of the gas supply hole 34b is converged to a point away from the gas discharge port 34a. The diameter is getting smaller.

  On the other hand, the liquid supply hole 39b opens as a liquid discharge port 39a in the vicinity of the center of the gas discharge port 34a. In the substrate processing apparatus 1, the two-fluid nozzle 2 is attached so that the liquid discharge port 39a and the gas discharge port 34a face downward.

  Further, a processing liquid pipe 24 is connected to the end of the two-fluid nozzle 2 opposite to the liquid discharge port 39a side. The internal space of the processing liquid pipe 24 communicates with the liquid supply hole 39b so that the processing liquid can be introduced into the liquid supply hole 39b. Further, a nitrogen gas pipe 25 is connected to a substantially middle portion in the direction of the central axis Q on the side surface of the two-fluid nozzle 2. The internal space of the nitrogen gas pipe 25 and the gas supply hole 39b communicate with each other so that nitrogen gas can be introduced into the gas supply hole 34b.

  When the processing liquid is supplied from the processing liquid pipe 24 to the two-fluid nozzle 2, the processing liquid is discharged from the liquid discharge port 39a. Further, when nitrogen gas is supplied from the nitrogen gas pipe 25 to the two-fluid nozzle 2, the nitrogen gas is discharged from the gas discharge port 34a. For this reason, the discharged processing liquid advances substantially straight, but the nitrogen gas discharged in an annular shape advances so as to converge toward a convergence point outside the casing (outer tube 34). For this reason, when the processing liquid and the nitrogen gas are supplied simultaneously, the nitrogen gas and the processing liquid collide and mix at the convergence point, and the processing liquid proceeds as droplets. That is, a jet of droplets of the processing liquid is formed.

  Referring to FIG. 1, when cleaning the surface of the substrate W, the substrate W held on the spin chuck 10 is rotated by the rotation driving mechanism 14, and the two-fluid nozzle 2 is moved on the substrate W by the nozzle moving mechanism 23. While moving, droplets of the processing liquid are ejected from the two-fluid nozzle 2 toward the upper surface of the substrate W. Further, the two-fluid nozzle 2 is moved between a position facing the center of the substrate W and a position facing the peripheral edge of the substrate W while supplying droplets of the processing liquid to the surface of the substrate W. Thereby, the entire upper surface of the substrate W is processed uniformly. That is, by introducing high-pressure nitrogen gas into the two-fluid nozzle 2, it is possible to cause a droplet of a processing liquid having a large kinetic energy to collide with the surface of the substrate W. At this time, particles adhering to the surface of the substrate W are physically removed by the kinetic energy of the droplets of the processing liquid.

  By the way, as already described in the section “Problems to be Solved by the Invention”, some of the substrates W have fine wiring patterns formed on the surface thereof, and damage the fine patterns. There is no need to perform the cleaning process with an excellent removal rate. In this embodiment, the cleaning width D (FIG. 3) on the substrate surface of the droplets supplied from the two-fluid nozzle 2 is set in the range of 5.0 mm to 15.0 mm. This is based on the knowledge obtained by the examples described later. That is, when the cleaning width is less than 5.0 mm, the liquid droplets supplied from the two-fluid nozzle 2 are concentrated on the micro area on the substrate surface, so that the micro pattern is seriously damaged and is actually used. Intolerable. Conversely, when the cleaning width exceeds 15.0 mm, the droplets supplied from the two-fluid nozzle 2 are given to a relatively wide area on the surface of the substrate, which can reduce damage to the fine pattern, The removal rate will drop rapidly. On the other hand, when the cleaning width D is within the above range, it is possible to prevent damage to the fine pattern while maintaining the removal rate at or above the same level as in the prior art. These points will be described in detail based on later examples.

  In this embodiment, the height 21 (see FIG. 3) from the substrate W to the nozzle 2 can be changed by moving the arm 21 up and down by the nozzle moving mechanism 23 in the vertical direction. By changing the height H in this way, the cleaning width D can be adjusted. Therefore, even if the cleaning processing conditions (for example, the processing liquid or gas discharge amount, the type of processing liquid) are changed or changed, the nozzle moving mechanism 23 moves the arm 21 up and down according to the cleaning processing conditions. The height H from the substrate W to the nozzle 2 can be adjusted to keep the cleaning width D in the above range. As a result, the cleaning process can always be performed in an appropriate droplet supply state, and the versatility of the substrate processing apparatus can be improved.

  Further, in this embodiment, since the volume median diameter of the droplet is set within the range of 5 μm to 40 μm in addition to the cleaning width D, the object of the present invention (maintaining the cleaning effect is more reliably maintained). On the other hand, a predetermined cleaning process can be performed without damaging the fine pattern. Here, the “volume median diameter” is the particle size of the droplet, and the ratio of the total volume of droplets larger (or smaller) than the particle size to the volume of all observed droplets The particle size is such that is 50%. By causing droplets of the processing liquid having such a volume median diameter to collide with the substrate W, particles attached to the substrate W are effectively removed without substantially destroying the fine pattern formed on the surface of the substrate W. it can.

  Here, the volume median diameter of the droplet generated by the two-fluid nozzle 2 can be adjusted by the flow rate of the nitrogen gas introduced into the two-fluid nozzle 2 (valve 25V) and the flow rate of the processing liquid (valve 24V). In other words, in this embodiment, the valves 24V and 25V correspond to the “particle size adjusting mechanism” of the present invention, and the droplets ejected from the two-fluid nozzle 2 by adjusting the opening and opening / closing of the valves 24V and 25V by the controller 20 are used. The volume median diameter can be adjusted to 5 μm to 40 μm.

  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 cleaning width D is set to a predetermined range by adjusting the height H from the substrate W to the nozzle 2, but other methods (for example, the shapes and sizes of the discharge ports 34a and 39a, etc.) ), The cleaning width D may be in a predetermined range. Further, the cleaning width D can be variably adjusted by the nozzle moving mechanism 23. However, the variable adjustment itself is not an essential component of the present invention, and the cleaning width D is within a predetermined range. It may be fixed in advance.

  In the above embodiment, the volume median diameter of the droplet is adjusted by the valves 24V and 25V. However, the volume median diameter may be adjusted by only one of them. That is, in the external mixing type two-liquid nozzle, a gas (nitrogen gas) discharged from the outer tube 34 is sprayed on a liquid (processing liquid) discharged from the inner tube 39 in an open space to generate droplets. Therefore, the pressure of the gas introduced into the two-fluid nozzle 2 and the pressure of the liquid do not affect each other. Therefore, the flow rate of the gas introduced into the two-fluid nozzle 2 and the flow rate of the liquid can be adjusted independently.

  Next, examples of the present invention will be shown. However, the present invention is not limited to the following examples as a matter of course, and it is of course possible to implement the invention with appropriate modifications within a range that can be adapted to the gist of the preceding and following descriptions. These are all included in the technical scope of the present invention.

  In this example, a cleaning test of the substrate W was performed using the substrate processing apparatus shown in FIG. More specifically, deionized water is used as the “treatment liquid”, the flow rate is set to 100 (ml / min), the nitrogen gas is set to “gas”, and the flow rate is set to 100 (l / min). Then, a droplet of the treatment liquid was generated and supplied to the surface of the substrate W rotating at 500 rpm. Here, as the substrate W, a substrate on which a wiring pattern having a width of 0.25 μm is formed and about 10,000 silicon (Si) particles having a diameter of 0.1 μm or more are attached is used.

  Further, the height H from the substrate W to the nozzle 2 is changed and set in multiple stages, and the cleaning width D of the droplets on the substrate surface is set to “3.5 mm”, “5.0 mm”, “7.0 mm”, “ It was set to “15.0 mm” and “20.0 mm”, and the particle removal rate and the damage to the fine pattern in each cleaning width D were evaluated. The “particle removal rate” was determined by measuring the number of silicon particles adhering to the substrate W before and after the cleaning test.

  FIG. 4 is a graph showing the relationship between the cleaning width of the droplets supplied from the two-fluid nozzle on the substrate surface and the removal rate. As is clear from the graph, when the cleaning width D is 15 mm or less, a cleaning effect equal to or higher than that of the conventional technique (removal rate = 97%) can be obtained. The rate will drop. This is presumably because the droplets supplied from the two-fluid nozzle 2 are dispersed over a relatively wide area of the substrate surface.

  As for damage to fine patterns, as summarized in Table 1, although the cleaning width is 5.0 mm, damage can be suppressed to the extent that it can withstand actual use, but if it is less than that, it can withstand actual use. The fine pattern is damaged to the extent that it cannot be done. This is presumably because the droplets supplied from the two-fluid nozzle 2 are concentrated in a minute region on the substrate surface as the cleaning width D is narrowed.

  From these results, it can be seen that the cleaning width D on the substrate surface by the droplets supplied from the two-fluid nozzle 2 is greatly related to the cleaning effect and the reduction of damage to the fine pattern. It can be seen that by setting the thickness within the range of 5.0 mm to 15.0 mm, it is possible to prevent damage to the fine pattern while maintaining the removal rate at the same level or higher as that of the prior art. Further, from the viewpoint of higher removal rate and better damage prevention, it is desirable to set the cleaning width D to 7.0 mm.

  As described above, in the above-described embodiment, the cleaning process is performed as the “predetermined process” using deionized water as the “process liquid”. However, the type of the process liquid is not limited to this. For example, the etchant The present invention can be applied to a substrate processing apparatus that performs an etching process as a “predetermined process” using the “process liquid”. The “treatment liquid” may be a chemical solution such as a mixed solution of ammonia, hydrogen peroxide solution, and water. Further, the “gas” is not limited to nitrogen gas, and gas components such as inert gas and air can be used.

It is the schematic which shows one Embodiment of the substrate processing apparatus concerning this invention. It is a top view of FIG. It is a figure which shows the structure of the two-fluid nozzle employ | adopted with the substrate processing apparatus of FIG. It is a graph which shows the relationship between the washing | cleaning width on the substrate surface by the droplet supplied from a two-fluid nozzle, and a removal rate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate processing apparatus 2 ... Two-fluid nozzle 23 ... Nozzle movement mechanism (movement mechanism, cleaning width adjustment mechanism)
24V, 25V ... Valve (particle size adjustment mechanism)
39a ... Liquid discharge port D ... Cleaning width (by droplet) W ... Substrate

Claims (7)

In a substrate processing apparatus that performs a predetermined cleaning process on a substrate having a fine pattern formed on its surface,
The processing liquid is discharged from the liquid discharge port, and a gas is sprayed on the processing liquid discharged from the liquid discharge port to generate a droplet of the processing liquid, and the droplet is supplied toward the rotating substrate surface. A two-fluid nozzle,
A moving mechanism for moving the two-fluid nozzle relative to the substrate in the radial direction of the substrate surface;
The substrate processing apparatus, wherein a cleaning width on the substrate surface by droplets supplied from the two-fluid nozzle is 5.0 mm to 15.0 mm.   The substrate processing apparatus according to claim 1, wherein the cleaning width is 7.0 mm.   The substrate processing apparatus according to claim 1, further comprising a cleaning width adjusting mechanism that adjusts the cleaning width.   The substrate processing apparatus according to claim 1, wherein a volume median diameter of a droplet supplied from the two-fluid nozzle to the substrate is 5 μm to 40 μm.   The substrate processing apparatus according to claim 4, further comprising a particle size adjusting mechanism that adjusts a volume median diameter of a droplet supplied from the two-fluid nozzle to the substrate.   The two-fluid nozzle is arranged so that the supply direction of the droplets to the substrate substantially coincides with the normal direction of the substrate surface, and the moving mechanism keeps the two-fluid nozzle in the arrangement posture. 6. The substrate processing apparatus according to claim 1, wherein the substrate processing apparatus is relatively moved in parallel with the substrate surface.   The substrate processing apparatus according to claim 1, further comprising a flow rate adjusting mechanism that adjusts a supply flow rate of a gas blown to the processing liquid discharged from the liquid discharge port to a predetermined value.

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