JP7579376B2 - Slit nozzle and substrate processing apparatus - Google Patents

Description

This invention relates to a slit nozzle that ejects treatment liquid from a slit-shaped outlet, and a technique for scraping off treatment liquid from the tip of the slit nozzle.

In order to supply a processing liquid such as a resist liquid to a substrate, a slit nozzle having a slit-shaped discharge port is generally used, as described in, for example, Japanese Patent Application Laid-Open No. 2003-233996. Here, the substrate is a wafer level package (WLP).
The present invention relates to substrates for semiconductor packages manufactured in a manufacturing form such as flat panel display (FPD) or panel level packaging (PLP), semiconductor wafers, glass substrates for liquid crystal display devices, and FPDs such as organic EL display devices.
These include substrates for LCDs, optical disks, magnetic disks, magneto-optical disks, glass substrates for photomasks, and substrates for solar cells.

With a slit nozzle, the processing liquid may adhere to the tip of the slit nozzle. If the adhered matter dries and hardens and falls onto the substrate, it will contaminate the substrate. Therefore, in the device described in Patent Document 1, a scraper is used to scrape off the processing liquid that has adhered to the side of the tip of the slit nozzle before the processing liquid is supplied to the substrate from the slit nozzle.

The scraping process using the scraper is a process in which the scraper is moved relative to the slit nozzle while being in contact with the tip of the slit nozzle from below. After this scraping process, traces of processing liquid remain in the scraper's path at the tip of the slit nozzle. For example, when a resist liquid is used as the processing liquid, resist traces remain. These resist traces accumulate each time the scraper is used to scrape off. In the substrate processing apparatus described in Patent Document 1, the resist traces are periodically removed by applying ultrasonic vibrations to the tip of the slit nozzle while the tip is immersed in a cleaning liquid (ultrasonic cleaning process).

JP 2020-37092 A

Here, by suppressing the occurrence of resist marks due to the scraping operation, the frequency of ultrasonic cleaning processing can be reduced. However, in the past, no effective means for reducing the occurrence or amount of resist marks was provided, and there was room for improvement.

This invention has been made in consideration of the above problems, and aims to provide a slit nozzle and substrate processing apparatus that can reduce the occurrence and amount of processing liquid marks at the tip of the slit nozzle when a scraper is brought into contact with and moved relative to the tip of the slit nozzle to which processing liquid has adhered.

The first aspect of this invention is a slit nozzle having a tip portion from which a slit-shaped discharge port is extended for discharging the treatment liquid downward, and after discharging the treatment liquid from the discharge port, the treatment liquid is scraped off from the tip portion by a scraper that moves relatively in the direction of extension of the discharge port while abutting against the tip portion, and the tip portion has a surface treatment area that has been subjected to a liquid-repellent treatment, and the lower end of the surface treatment area coincides with the abutment path traced by the upper end of the scraper due to the relative movement of the scraper with respect to the slit nozzle, or is located below the abutment path, and the upper end of the surface treatment area is located above the abutment path.

A second aspect of the present invention is a substrate processing apparatus, comprising: a slit nozzle having a tip end with an extended slit-shaped outlet for discharging a processing liquid downward; a scraper abutting against the tip end of the slit nozzle;
and a moving mechanism that moves the scraper relative to the slit nozzle in the extension direction of the discharge port while bringing the scraper into contact with the tip portion, wherein the tip portion has a surface treatment area that has been treated to be liquid repellent, and the lower end of the surface treatment area coincides with or is located below the abutment locus described by the upper end of the scraper due to the relative movement of the scraper with the slit nozzle, and the upper end of the surface treatment area is located above the abutment locus.

In the invention configured in this way, a surface treatment area is provided so as to overlap with the contact trajectory drawn by the upper end of the scraper due to the relative movement of the scraper with respect to the slit nozzle. This surface treatment area is an area that has been treated with a liquid repellent treatment on the tip of the slit nozzle. The lower end of the surface treatment area coincides with the contact trajectory or is located below the contact trajectory, and the upper end is located above the contact trajectory. Therefore, due to the liquid repellent effect, no treatment liquid remains along the contact trajectory, or even if it does remain, the remaining amount of treatment liquid is significantly less than in the past.

As described above, according to the present invention, when a scraper is brought into contact with and moved relative to the tip of a slit nozzle to which processing liquid is attached, the occurrence and amount of processing liquid marks at the tip can be reduced.

1 is a perspective view illustrating a substrate processing apparatus equipped with a slit nozzle according to a first embodiment of the present invention. FIG. 2 is a side view diagrammatically illustrating the substrate processing apparatus illustrated in FIG. 1. 2 is a top view illustrating an outline of the arrangement of each part of the substrate processing apparatus illustrated in FIG. 1. 1A and 1B are diagrams illustrating a configuration of a cleaning unit that performs nozzle cleaning by a scraping operation. FIG. 1 is a perspective view showing a first embodiment of a slit nozzle according to the present invention. 6 is a diagram showing an example of a scraping operation by a scraper on the slit nozzle shown in FIG. 5 . FIG. FIG. 11 is a perspective view showing a second embodiment of a slit nozzle according to the present invention.

Figure 1 is a perspective view showing a substrate processing apparatus equipped with a first embodiment of the slit nozzle according to the present invention. Figure 2 is a side view showing the substrate processing apparatus shown in Figure 1. Figure 3 is a top view showing the layout of each part of the substrate processing apparatus shown in Figure 1. In order to clarify the directional relationships between the figures, Figures 1, 2, 3 and the following figures are appropriately illustrated with an XYZ Cartesian coordinate system in which the Z direction is the up-down direction and the XY plane is the horizontal plane, and the dimensions and number of each part are exaggerated or simplified as necessary. In addition, some components such as the nozzle support are omitted in Figures 2 and 3.

The substrate processing apparatus 1 is a coating apparatus called a slit coater that uses, for example, a slit nozzle 2 to coat a surface 31 of a substrate 3 with a processing liquid. The processing liquid is, for example, a color resist liquid containing a pigment. The substrate 3 is a glass substrate having a rectangular shape in a plan view. In this specification, the "surface 31 of the substrate 3" refers to the main surface of the substrate 3 on which the processing liquid is applied.

The substrate processing apparatus 1 includes a stage 4 capable of holding a substrate 3 by suction in a horizontal position, a coating processing section 5 that performs a coating process, which is an example of substrate processing, on the substrate 3 held on the stage 4 using a slit nozzle 2, a nozzle maintenance unit 6 that performs a maintenance process on the slit nozzle 2, and a control section 100 that controls each of these sections.

The stage 4 is made of stone such as granite having an approximately rectangular parallelepiped shape, and the (+X) side of its upper surface (+Z side) has a holding surface 41 that is processed into an approximately horizontal flat surface and holds the substrate 3. A large number of vacuum suction ports (not shown) are formed and distributed on the holding surface 41. The substrate 3 is sucked by these vacuum suction ports, so that the substrate 3 is held horizontally in a predetermined position during the coating process. Note that the manner in which the substrate 3 is held is not limited to this, and the substrate 3 may be held mechanically, for example. In addition, a nozzle adjustment area RA is provided on the (-X) side of the area occupied by the holding surface 41 on the stage 4, and the nozzle maintenance unit 6 is arranged in this nozzle adjustment area RA.

The slit nozzle 2 extends in the Y direction. In addition, in the XZ cross section, the tip 21 (sometimes called the lip portion) has a shape that tapers downward. A slit-shaped discharge port 23 extends in the Y direction at the tip 21, and the processing liquid that is pumped from a processing liquid supply mechanism (not shown) is discharged downward from the discharge port 23. In this way, the processing liquid is supplied to the surface 31 of the substrate 3, and the processing liquid is applied to the surface 31 of the substrate 3.

The coating processing section 5 has a nozzle support 51 that supports the slit nozzle 2. The nozzle support 51 has a support member 51a that extends parallel to the Y direction above the stage 4, and two lifting mechanisms 51b that support the support member 51a from both sides in the Y direction and raise and lower the support member 51a. The support member 51a is a rod member made of carbon fiber reinforced resin or the like and has a rectangular cross section. The lower surface of the support member 51a is the mounting location 510 for the slit nozzle 2, and the support member 51a detachably supports the slit nozzle 2 at the mounting location 510. Note that various fastening mechanisms such as latches or screws can be appropriately used as a mechanism for attaching and detaching the slit nozzle 2 to the mounting location 510 of the support member 51a.

The two lifting mechanisms 51b are connected to both ends of the support member 51a in the longitudinal direction, and each has an AC servo motor and a ball screw. These lifting mechanisms 51b raise and lower the support member 51a and the slit nozzle 2 fixed thereto in the vertical direction (Z direction), and adjust the distance between the discharge port 23 opening at the lower end of the slit nozzle 2 and the substrate 3, i.e., the relative height of the discharge port 23 with respect to the substrate 3. The vertical position of the support member 51a can be detected, for example, by a linear encoder (not shown) consisting of a scale section provided on the side of the lifting mechanism 51b and a detection sensor provided on the side of the slit nozzle 2 facing the scale section.

As shown in FIG. 1, the nozzle support 51 thus configured has a bridge structure spanning the holding surface 41, spanning both the left and right ends of the stage 4 along the Y direction. The coating processing unit 5 has a slit nozzle moving unit 53 that moves the nozzle support 51 in the X direction. The slit nozzle moving unit 53 functions as a relative moving means that moves the nozzle support 51 as a bridge structure and the slit nozzle 2 supported by it along the X direction relative to the substrate 3 held on the stage 4. Specifically, the slit nozzle moving unit 53 has, on each of the ±Y sides, a guide rail 52 that guides the movement of the slit nozzle 2 in the X direction, a linear motor 54 that is a driving source, and a linear encoder 55 for detecting the position of the discharge port 23 of the slit nozzle 2.

The two guide rails 52 are provided at both ends of the stage 4 in the Y direction, and extend in the X direction to include the section in which the nozzle adjustment area RA and the holding surface 41 are provided. The two guide rails 52 guide the movement of the two lifting mechanisms 51b in the X direction. The two linear motors 54 are provided on both sides of the stage 4, and are AC coreless linear motors having a stator 54a and a slider 54b. The stator 54a is provided on the side surface of the stage 4 in the Y direction along the X direction. On the other hand, the slider 54b is fixed to the outside of the lifting mechanism 51b. The two linear motors 54 drive the two lifting mechanisms 51b in the X direction by the magnetic force generated between the stator 54a and the slider 54b.

Each linear encoder 55 also has a scale section 55a and a detection section 55b. The scale section 55a is provided along the X direction below the stator 54a of the linear motor 54 fixed to the stage 4. On the other hand, the detection section 55b is fixed further outward from the slider 54b of the linear motor 54 fixed to the lifting mechanism 51b, and is disposed opposite the scale section 55a. The linear encoder 55 detects the position of the outlet 23 of the slit nozzle 2 in the X direction based on the relative positional relationship between the scale section 55a and the detection section 55b.

The slit nozzle moving unit 53 configured in this manner can move the slit nozzle 2 between above the nozzle adjustment area RA and above the substrate 3 held on the stage 4 by driving the nozzle support 51 in the X direction. The substrate processing apparatus 1 then moves the slit nozzle 2 relative to the substrate 3 while discharging the treatment liquid from the discharge port 23 of the slit nozzle 2, thereby forming a coating layer on the surface 31 of the substrate 3. Note that a region of a predetermined width (a frame-shaped region) from the end of each side of the substrate 3 is a non-coated region that is not to be coated with the treatment liquid. Therefore, the rectangular region of the substrate 3 excluding this non-coated region is the coating region RT to which the treatment liquid should be applied (FIG. 3). Therefore, the treatment liquid is discharged from the discharge port 23 that moves in the upper section of the coating region RT of the substrate 3 among the moving sections of the slit nozzle 2.

In addition, during periods when coating processing is not being performed on the stage 4, such as during the transfer of the substrate 3 between the substrate processing apparatus 1 and the external transport mechanism (periods during which the substrate 3 is loaded and unloaded), the slit nozzle 2 retreats to a nozzle adjustment area RA that is offset in the (-X) direction from the holding surface 41 of the substrate 3 (as shown in FIG. 1). Then, the nozzle maintenance unit 6 performs various maintenance operations on the slit nozzle 2 positioned in the nozzle adjustment area RA.

As shown in FIG. 2, the nozzle maintenance unit 6 is provided in the nozzle adjustment area RA on the (-X) direction side (the right hand side in the figure) of the area occupied by the holding surface 41, and has the function of nozzle cleaning the slit nozzle 2 to remove any deposits that have adhered to the slit nozzle 2. Here, the deposits to be removed include various substances that may adhere to the slit nozzle 2. For example, these deposits include the processing liquid itself and solidified materials formed when the solutes of the processing liquid have dried and solidified.

The nozzle maintenance unit 6 is equipped with two types of cleaning units 7 and 8. In the cleaning unit 7, a scraper moves in the Y direction along the outer surface of the tip 21 (lip portion) of the slit nozzle 2 while making contact with the outer surface. This causes the scraper to scrape off and remove the processing liquid and the like adhering to the tip 21 of the slit nozzle 2 (scraping operation). The removed processing liquid is collected together with the rinsing liquid in a collection section provided in the cleaning unit 7.

Figure 4 is a schematic diagram showing the configuration of a cleaning unit that performs nozzle cleaning by a scraping operation. The cleaning unit 7 includes an attachment removal section 71, a nozzle cleaning movement section 72, and a recovery section 73.

As shown in the figure, the deposit removal unit 71 has two types of nozzle cleaning members, a spreader 711 and a scraper 712, and a support member 713 that supports the spreader 711 and the scraper 712 in a state facing the tip 21 of the slit nozzle 2. Of these, the spreader 711 has the function of spreading the treatment liquid that is discharged in small amounts from the slit nozzle 2 and adheres to the tip 21 of the slit nozzle 2 over the tip 21 of the slit nozzle 2, and the scraper 712 has the function of removing the treatment liquid from the tip 21 of the slit nozzle 2 downstream of the movement direction Y of the spreader 711. This makes it possible to remove the deposit (treatment liquid) on the tip 21 of the slit nozzle 2. In other words, if a deposit such as a dried and solidified treatment liquid is attached to the inclined surface of the tip 21, the treatment liquid spread by the spreader 711 dissolves the deposit to a certain extent, and the treatment liquid containing this dissolved substance (deposit) is removed by the scraper 712. Thus, in this embodiment, the scraper 712 has the function of removing the treatment liquid adhering to the tip 21 of the slit nozzle 2.

The nozzle cleaning movement unit 72 is connected to the support member 713. This nozzle cleaning movement unit 72 reciprocates the support member 713 in the extension direction Y of the discharge port 23 in response to a movement command from the control unit 100. As a result, the spreader 711 and the scraper 712 reciprocate in the X direction within the movement range MR shown in FIG. 4. This movement range MR is below the tip 21 of the slit nozzle 2 and has a size slightly larger than the Y direction size of the tip 21. When the nozzle cleaning movement unit 72 moves the adhesion removal unit 71 from the (+Y) direction side to the (-Y) direction side, the slit nozzle 2 is located at the cleaning position of the cleaning unit 7, as shown by the dashed line in the same figure. In other words, with the scraper 712 abutting against the tip 21 of the slit nozzle 2, the adhesion removal unit 71 moves from the (+Y) direction side to the (-Y) direction side. As a result, the cleaning process of the tip 21 of the slit nozzle 2 is performed. On the other hand, when the cleaning process is completed and the slit nozzle 2 is separated from the cleaning position of the cleaning unit 7, the deposit removal part 71 moves from the (-Y) direction side to the (+Y) direction side. In this way, the nozzle cleaning movement part 72 functions as the "movement mechanism" of the present invention.

The processing liquid, rinsing liquid, etc. removed from the tip 21 of the slit nozzle 2 by the cleaning process (hereinafter, these will be collectively referred to as "removed processing liquid") flows downward via the adhesion removal section 71. In order to collect this processing liquid, in this embodiment, a collection section 73 is provided. The collection section 73 is composed of a box-shaped structure that opens upward. As a result, the removed processing liquid that falls via the adhesion removal section 71 is collected by the collection section 73.

A discharge section 74 is disposed vertically below the (-Y) direction portion of the recovery section 73 and on the (+X) direction side of the movement range MR. As shown in Fig. 4, the discharge section 74 has a box-shaped receiving member 741 that opens toward the recovery section 73 in the cleaning standby state, and a pipe 742 that extends from the bottom surface of the receiving member 741 to the outside of the substrate processing apparatus 1. In the discharge section 74, the receiving member 741 receives the coating liquid discharged from the recovery section 73, and discharges it via the pipe 742 to a waste liquid processing apparatus (not shown) provided outside the apparatus.

In this way, the processing liquid is removed from the tip 21 of the slit nozzle 2 by the scraper 712, but in the substrate processing apparatus 1, the coating process is carried out after the coating pre-processing, which includes the scraping operation. Also, when a new substrate 3 is held on the stage 4 in place of the coated substrate 3, the coating pre-processing and coating process are carried out in response to a command from the control unit 100. In this way, the scraping operation is carried out repeatedly, and traces of processing liquid are accumulated. For this reason, the other cleaning unit 8 is provided.

The other cleaning unit 8 is a device for removing residual deposits that could not be completely removed by the above-mentioned cleaning unit 7, i.e., accumulated traces of processing liquid, from the slit nozzle 2 using cleaning liquid and ultrasonic vibrations. In this cleaning unit 8, cleaning liquid for cleaning the tip 21 of the slit nozzle 2 is stored in a cleaning tank 81. Then, when the cumulative number of scraping operations reaches a certain value, the above-mentioned repeated work is temporarily interrupted and an ultrasonic cleaning process is performed on the slit nozzle 2. In other words, while the tip 21 of the slit nozzle 2 is immersed in the cleaning tank 81, ultrasonic vibrations are applied to the tip 21 via the cleaning liquid, thereby removing the traces of processing liquid.

This ultrasonic cleaning process is one of the main factors that deteriorate the tact time of the substrate processing apparatus 1. Therefore, it is desirable to reduce the frequency of ultrasonic cleaning processes. This frequency varies depending on the accumulation of processing liquid marks. Therefore, suppressing the generation and amount of processing liquid marks caused by the scraping operation by the scraper 712 is effective in reducing the frequency. Therefore, the present inventors have verified the behavior of the remaining processing liquid in the slit nozzle 2 during the scraping operation, and have found that providing a liquid-repellent surface treatment area on the surface of the tip of the slit nozzle so that it overlaps with the abutment trajectory (symbol CT in FIG. 5, which will be described next) drawn by the upper end of the scraper due to the relative movement of the scraper with respect to the slit nozzle is beneficial in suppressing processing liquid marks. Below, the verification content by the present inventors and the surface treatment of the slit nozzle 2 based on the verification will be described in detail with reference to FIG. 5 and FIG. 6.

Figure 5 is a perspective view showing a first embodiment of the slit nozzle according to the present invention. Figure 6 is a schematic diagram showing an example of a scraping operation by a scraper on the slit nozzle shown in Figure 5. The slit nozzle 2 of this embodiment differs greatly from conventionally known nozzles in that the above contact angle condition is satisfied by subjecting a portion of the tip 21 to a liquid-repellent treatment, but the other configurations are basically the same. Note that in Figures 5 and 6, the dimensions of the slit nozzle 2 and the scraper 712 are shown differently from the actual dimensions in order to clarify the contact state between the surface treatment area that has been subjected to the liquid-repellent treatment and the scraper 712. Also, in order to clearly indicate the liquid-repellent treated area, dots are added to that area in Figure 5 for reference.

This slit nozzle 2 is constructed by combining a pair of nozzle base materials machined from stainless steel. In each nozzle base material, a tip portion 21 and a nozzle body portion 22 extending upward from the tip portion 21, i.e., in the (+Z) direction, are integrally formed. As shown in FIG. 6, the tip portion 21 has a tapered convex shape when viewed from the side in the Y direction, which is its longitudinal direction, and has a tip surface 211 provided at its tip (lower end), a lip side surface 212a formed on the (+X) side of the tip surface 211, and a lip side surface 212b formed on the (-X) side. In the following description, when there is no need to distinguish between the lip side surface 212a and the lip side surface 212b, they are simply referred to as the lip side surface 212.

As shown in FIG. 5, the tip surface 211 has a discharge port 23, which is a long slit-shaped opening extending in the Y direction, extending in the Y direction. The nozzle body 22 is fixed and supported by the nozzle support 51 (FIG. 1) with the discharge port 23 facing downward. Therefore, when the processing liquid L is pressure-fed from a processing liquid supply mechanism not shown to the slit nozzle 2, it is sent to the discharge port 23 through an internal flow path formed inside the nozzle body 22 and discharged from the discharge port 23 in the (-Z) direction. The supply operation to the substrate 3 is performed by discharging the processing liquid L from the discharge port 23 of the slit nozzle 2 while moving the slit nozzle 2 in the X direction as shown in FIG. 2. As a result, the processing liquid L is applied to the surface 31 of the substrate 3. At this time, the processing liquid L may adhere to the surrounding area of the discharge port 23 of the slit nozzle 2, that is, the tip 21. The attached processing liquid L dries and becomes a residue, and if this is left, it will hinder good discharge and cause contamination of the film of the processing liquid L formed on the substrate 3.

Therefore, the scraper 712 is provided as described above. The scraper 712 is formed of an elastic body such as fluorine-containing rubber. A V-shaped groove 712a, which is a groove having a substantially V-shape, is formed at the upper end of the scraper 712. The V-shaped groove 712a has a shape corresponding to the tip 21 of the slit nozzle 2, and has an inner side surface 712b having an inclination corresponding to the lip side surface 212a, and an inner side surface 712c having an inclination corresponding to the lip side surface 212b. The scraper 712 configured in this manner is disposed with its upper end surface positioned at a height position Pa in the vertical direction Z. Then, when the slit nozzle 2 descends from above, the tip 21 of the slit nozzle 2 enters the V-shaped groove 712a of the scraper 712 as shown in FIG. 6. Then, parts of the lip side surfaces 212a and 212b abut against the inner sides 712b and 712c, respectively. The height positions of each part of the slit nozzle 2 at this time are as shown in FIG. 5. That is, in the vertical direction Z, the tip surface 211 is located at position P0, the contact portion that contacts the upper end of the scraper 712 is located at position Pa, and the lower end and upper end of the liquid-repellent treated area (surface treatment area SA, which will be described in detail next) are located at positions P1 and P2, respectively. These positions P0, Pa, P1, and P2 are expressed by the following inequality in the vertical direction Z:
P0<P1<Pa<P2
The relationship is as shown below.

By moving the scraper 712 in the Y direction while keeping the tip 21 of the slit nozzle 2 in contact with the scraper 712, deposits are scraped off from the tip 21 of the slit nozzle 2 (scraping operation). At this time, the upper ends 712d and 712e of the scraper 712 each trace a contact trajectory that extends in the Y direction. In FIG. 5, only the contact trajectory CT on the (+X) direction side, i.e., the trajectory of the upper end 712d, is shown, but a similar contact trajectory also exists on the (-X) direction side. In the prior art, traces of processing liquid were generated along the contact trajectory CT at the tip 21 of the slit nozzle 2.

5 and 6, the surface of the tip 21 of the slit nozzle 2 is subjected to a liquid-repellent treatment as a surface treatment corresponding to the contact trajectory CT, so that the surface of the tip 21 can repel the treatment liquid L. In this embodiment, the slit nozzle 2 is made of stainless steel, but the following three regions of the surface of the slit nozzle 2 are surface-treated with a silicon-based organic compound. That is, these three regions are indicated by dots in FIG. 5,
a nozzle-side contact area CAn of the lip side surfaces 212a, 212b of the tip portion 21 that contacts the scraper 712;
a lip upper area UA above the nozzle side contact area CAn of the lip side surfaces 212a, 212b of the tip portion 21;
A lower exposed area BA of the nozzle body portion 22;
On the other hand, the surface of the fluorine-containing rubber scraper 712 is not subjected to any particular surface treatment.

In this way, a surface treatment area SA (=nozzle side contact area CAn+lip upper area UA) is formed by applying liquid repellency treatment to the area of the surface of the tip 21 of the slit nozzle 2 that corresponds to the contact locus CT. More specifically, the lower end DE of the surface treatment area SA is located below the contact locus CT, and the upper end is located above the contact locus CT. When the tip 21 of the slit nozzle 2 and the upper end of the scraper 712 are viewed from the side, the contact locus CT overlaps with the surface treatment area SA. Therefore, due to the liquid repellency, no treatment liquid remains along the contact locus CT, or even if it remains, the remaining amount of treatment liquid is significantly less than in the past.

Even if the processing liquid remains on the slit nozzle 2 side along the contact trajectory CT, this processing liquid is located in the surface processing area SA. For this reason, it is difficult for the remaining processing liquid to remain at the height position Pa, and it is easy to move along the inclined surface of the tip 21 due to the influence of gravity as described below. For this reason, the processing liquid remaining on the contact trajectory CT on the slit nozzle 2 side after the scraping process is easy to move downward along the surface of the tapered tip 21, and often adheres below the contact trajectory CT. Therefore, it is scraped off by the scraper 712 in the next scraping process and is reliably removed from the tip 21 of the slit nozzle 2. Therefore, in the substrate processing apparatus 1 that repeatedly performs the pre-coating process and the coating process including the scraping process between the previous ultrasonic cleaning process and the next ultrasonic cleaning process, the above-mentioned liquid repellent treatment can remove the processing liquid that was not scraped off by one scraping process by the subsequent scraping process.

Furthermore, the effect of providing the surface treatment area SA so as to overlap the contact trajectory CT can also be explained from the perspective of the contact angle. That is, in this embodiment, the upper end of the scraper 712 contacts the surface treatment area SA to perform the scraping operation of the treatment liquid. Here, when the contact angle is examined, as shown in the partially enlarged view of FIG. 6, the contact angle θn of the treatment liquid L with respect to the nozzle side contact area CAn is larger than the contact angle θs of the treatment liquid L with respect to the scraper side contact area CAs that contacts the tip 21 of the surface of the scraper 712 (contact angle condition). For example, when the contact angles θn and θs were measured when a color resist liquid containing a black pigment was used as the treatment liquid L, the contact angles θn and θs were 42.8°, 29°, and 4°, respectively. In addition, when the liquid repellency was exhibited by surface treatment with a fluorine silicon compound instead of a silicon organic compound, the contact angle θn was measured when a color resist liquid containing a black pigment was used as the treatment liquid L, and the contact angle θn was 63.9°. For reference, the contact angle of the color resist liquid with the stainless steel that makes up the slit nozzle 2 was measured and found to be 6.4°.

As described above, according to this embodiment, the contact angle condition is satisfied, and most of the processing liquid L moves to the scraper 712 side. More specifically, when the processing liquid L adhering to the tip 21 is scraped off by the scraper 712, as shown in the enlarged partial view of FIG. 6, the processing liquid L located between the scraper 712 and the tip 21 moves to the scraper 712 and the tip 21 as the scraper 712 moves in the direction Y. At that time, the contact angle θs on the scraper side is small, and the wettability of the processing liquid to the scraper 712 is good. As a result, more processing liquid flows to the scraper 712 side, and no processing liquid remains on the contact trajectory CT, or even if it remains, the remaining amount of processing liquid is significantly less than in the past.

As a result, the occurrence and amount of processing liquid marks (resist marks when a color resist liquid is used as the processing liquid) caused by the scraping operation can be reduced. As a result, the frequency of ultrasonic cleaning processing by the cleaning unit 8 can be reduced, and the tact time of the substrate processing apparatus 1 can be improved.

In addition, in this embodiment, as described above, the lower end DE of the surface treatment area SA is below the contact trajectory CT, but does not reach the discharge port 23 and its surrounding area as shown in Figures 5 and 6. In other words, the discharge port 23 and its surrounding area are not liquid-repellent treated, and the surface of the material that constitutes the slit nozzle 2, that is, the stainless steel, is exposed. In other words, the discharge port 23 and its surrounding area are maintained in a surface state suitable for coating. This surface state is suitable for forming a bead of the treatment liquid, for example, at the start of the coating process. As a result, the coating process can be performed smoothly. In order to achieve such an effect, it is desirable to set the distance from the tip surface 211 to the lower end DE to about several mm, but it is desirable to determine this distance according to the type of treatment liquid.

In addition, the lower exposed area BA of the nozzle body 22 is also treated with a liquid repellent coating, which prevents the treatment liquid from splashing off the substrate 3 and adhering to the lower exposed area BA during the coating process.

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 surface treatment area SA is provided so that the upper end is connected to the lower exposed area BA and the lower end DE is located below the contact locus CT. The shape and range of this surface treatment area SA are not limited to this, and for example, as shown in FIG. 7, the lower end DE may coincide with the contact locus CT (second embodiment). In addition, although not shown, the upper end may be located halfway between positions P1 and P2 in the vertical direction Z.

In addition, in this embodiment, the lower exposed area BA is treated to be liquid repellent, but this is not directly related to reducing the occurrence and amount of processing liquid marks. Therefore, this liquid repellent treatment may be omitted.

In the above embodiment, a small amount of processing liquid is discharged from the slit nozzle 2 and spread over the tip 21 by the spreader 711, but there are cases where this discharge of processing liquid is not necessary. For example, this is the case when the tip 21 of the slit nozzle 2 is wet with a cleaning liquid or a rinsing liquid by a rinsing liquid supply unit, ultrasonic cleaning, a nozzle cleaner, or the like. In this case, the cleaning liquid spread by the spreader 711 dissolves the deposits to a certain extent without discharging the processing liquid, and the processing liquid containing the dissolved deposits (deposits) is removed by the scraper 712.

In addition, in the above embodiment, the present invention is applied to a substrate processing apparatus 1 that performs nozzle cleaning using an adhesion removal unit 71 having a spreader 711 and a scraper 712, but the present invention can also be applied to a substrate processing apparatus that has only a scraper 712.

In the above embodiment, the present invention is applied to a substrate processing apparatus 1 that supplies processing liquid from a slit nozzle 2 while the substrate 3 is held by a stage 4, but the present invention can also be applied to a floating transport type substrate processing apparatus that floats and transports a substrate while supplying processing liquid to the substrate from a slit nozzle.

In addition, in the above embodiment, the deposit removal unit 71 including the scraper 712 moves in the Y direction relative to the slit nozzle 2, but the scraping operation may be performed by moving the slit nozzle 2 in the Y direction. In other words, the present invention can be applied to a substrate processing apparatus in which the scraper 712 moves relative to the slit nozzle 2 in the extension direction Y of the discharge port 23.

This invention can be applied to slit nozzles that eject processing liquid from a slit-shaped outlet, and to substrate processing techniques in general that scrape off processing liquid from the tip of a slit nozzle.

REFERENCE SIGNS LIST 1...substrate processing apparatus 2...slit nozzle 3...substrate 8...cleaning unit (cleaning section)
21: tip portion (of slit nozzle) 23: discharge port 72: nozzle cleaning moving portion (moving mechanism)
100: Control unit 712: Scraper CT: Contact trajectory DE: Lower end (of surface treatment area) L: Treatment liquid SA: Surface treatment area Y: Extension direction Z: Up-down direction

Claims (6)

A slit nozzle having a tip end portion with an extended slit-shaped discharge port for discharging a treatment liquid downward, and after the treatment liquid is discharged from the discharge port, the treatment liquid is scraped off from the tip end portion by a scraper that moves relatively in a direction in which the discharge port extends while contacting the tip end portion,
the tip portion has a surface treatment area that has been subjected to a liquid repellent treatment,
The lower end of the surface treatment area coincides with a contact locus drawn by an upper end of the scraper due to relative movement of the scraper with respect to the slit nozzle, or is located below the contact locus;
A slit nozzle, characterized in that an upper end of the surface treatment area is located above the abutment locus. The slit nozzle according to claim 1,
a nozzle substrate having the tip portion,
The slit nozzle, wherein the surface treatment region is a region of the surface of the nozzle base material that corresponds to at least the region with which the scraper comes into contact , and that is surface treated with a silicon-based organic compound or a fluorine-based silicon-based organic compound. a slit nozzle having a tip end from which a slit-shaped outlet for discharging a treatment liquid downward is provided;
A scraper that abuts on the tip of the slit nozzle;

a moving mechanism that moves the scraper relative to the slit nozzle in an extension direction of the discharge port while bringing the scraper into contact with the tip portion;
Equipped with
the tip portion has a surface treatment area that has been subjected to a liquid repellent treatment,
The lower end of the surface treatment area coincides with a contact locus drawn by an upper end of the scraper due to relative movement of the scraper with respect to the slit nozzle, or is located below the contact locus;
4. The substrate processing apparatus according to claim 1, wherein an upper end of the surface processing area is located above the contact locus. The substrate processing apparatus according to claim 3,
The scraper is entirely made of fluorine-containing rubber,
the slit nozzle has a nozzle base having the tip portion, and a surface treatment region in which a surface of the nozzle base corresponding to at least the region with which the scraper contacts is surface-treated with a silicon-based organic compound or a fluorine-silicon-based organic compound, said substrate processing apparatus. The substrate processing apparatus according to claim 3,
a processing liquid supply unit that supplies the processing liquid to the slit nozzle and discharges the processing liquid from the discharge port;
a control unit that controls the processing liquid supply unit and the movement mechanism so that a scraping process in which the scraper is brought into contact with the tip portion of the slit nozzle from which the processing liquid is discharged from the discharge port and the processing liquid is scraped off from the tip portion by relative movement of the scraper, is repeated;
The substrate processing apparatus includes: The substrate processing apparatus according to claim 5 ,
A cleaning unit for cleaning the tip portion is provided,
The control unit controls the cleaning unit so that the tip portion is cleaned after the scraping process is repeated a plurality of times.

Images