This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2022-108485, filed on Jul. 5, 2022, the entire contents of which are incorporated herein by reference.
The present disclosure relates to a liquid processing apparatus.
Patent Document 1 discloses a liquid processing apparatus that applies a coating liquid onto a substrate. This liquid processing apparatus includes: a substrate holder that holds and rotates the substrate; a coating liquid supplier that applies the coating liquid to the substrate held by the substrate holder; a cup arranged outside the substrate holder so as to surround the substrate held by the substrate holder; an exhaust path provided between the substrate holder and an inner peripheral surface of the cup; a coating liquid collector provided above the exhaust path so as to cover the exhaust path and including a vertically-communicating opening; a solvent supplier that supplies a solvent for the coating liquid to the coating liquid collector; and a relay located above the coating liquid collector and protruding from the inner peripheral surface of the cup toward the coating liquid collector.
According to one embodiment of the present disclosure, a liquid processing apparatus that applies a coating liquid onto a substrate, includes: a substrate holder configured to hold and rotate the substrate; a coating liquid supplier configured to supply the coating liquid to the substrate held by the substrate holder; a cup provided to surround the substrate held by the substrate holder; and a solvent supplier configured to supply a solvent for the coating liquid to a coating liquid collector, wherein the cup includes: an outer cup arranged outside the substrate holder; an inner cup arranged on an inner peripheral side of the outer cup below the substrate holder and having a downwardly-extending wall; an exhaust path provided between the outer cup and the inner cup; and the coating liquid collector provided with a plurality of openings through which an exhaust flow passes, the coating liquid collector extending downward below the downwardly-extending wall of the inner cup with a gap between the coating liquid collector and a lower end of the downwardly-extending wall.
The accompanying drawings, which are incorporated in and constitute a portion of the specification, illustrate embodiments of the present disclosure, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the present disclosure.
Reference will now be made in detail to various embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to one of ordinary skill in the art that the present disclosure may be practiced without these specific details. In other instances, well-known methods, procedures, systems, and components have not been described in detail so as not to unnecessarily obscure aspects of the various embodiments.
For example, in a photolithography of a manufacturing process of semiconductor devices, a coating process in which a predetermined coating liquid is applied onto a semiconductor wafer (hereinafter referred to as a “wafer”) as a substrate to form a coating film such as an antireflection film or a resist film is performed.
In the coating process described above, a so-called spin coating method is widely used, in which a coating film is formed on a wafer by supplying a coating liquid from a nozzle to the wafer under rotation and spreading the coating liquid over the wafer by virtue of a centrifugal force. A rotary liquid processing apparatus for performing the spin coating method is provided with a container, called a cup, in order to prevent the coating liquid scattered from a surface of the rotating wafer from scattering to the surroundings. In the cup, evacuation is performed from the bottom thereof so as to prevent the outside of the cup from being contaminated by the flying of the coating liquid in the form of mist, which is scattered from the edge of the rotating wafer.
However, in recent years, there is a case where a coating film having a large film thickness needs to be formed on a wafer using a coating liquid such as a high-viscosity resist liquid. In the case of using such a high-viscosity coating liquid, the coating liquid may be dropped from the edge of the wafer and be partially solidified in a filamentous form when the wafer coated with the coating liquid is rotated to spread the coating liquid. Further, a plurality of coating liquids solidified in a filamentous form (hereinafter referred to as filamentous foreign substances) may be generated in the course of performing the coating process. These filamentous foreign substances may be entangled with each other to form flocculent foreign substances.
There is a concern that these filamentous or flocculent foreign substances may clog an exhaust path. In particular, since the exhaust path in the vicinity of the inner bottom of the cup has many narrower portions than the exhaust path at the upper portion of the cup, it is easy to be clogged with the foreign substances. When the exhaust path is clogged with the foreign substances, a desired exhaust pressure required for exhausting the interior of the cup may not be obtained. Thus, for example, the mist-like coating liquid may fly upward of the cup, which contaminates the outside of the cup.
Therefore, a technique according to the present disclosure prevents an exhaust path from being clogged due to foreign substances generated when performing a spin coating process on a substrate.
Hereinafter, a liquid processing apparatus according to the present embodiment will be described with reference to the drawings. In addition, in this specification and the accompanying drawings, elements having substantially the same functional configuration will be denoted by the same reference numerals, and redundant explanations thereof will be omitted.
As illustrated in
Further, the cup 110, which accommodates the spin chuck 101 and is exhausted from the bottom thereof, is provided within the processing container 100. The cup 110 receives and collects a liquid scattered or dropping from the wafer W. The cup 110 includes an outer cup 120 as an outer cup arranged outside the spin chuck 101 so as to surround the wafer W held by the spin chuck 101, and an inner cup 130 as an inner cup located on an inner peripheral side of the outer cup 120.
A sidewall 121 as a downwardly-extending cylindrical wall is provided at a lower portion of the outer cup 120. Further, the inner cup 130 includes an annular inclined wall 131 which is inclined down from an inner peripheral end toward an outer peripheral end thereof, and a sidewall 132 as a cylindrical wall extending down from the outer peripheral end of the inclined wall 131. The inclined wall 131 is arranged below the spin chuck 101 and receives the liquid dropping from the wafer W. The sidewall 132 is arranged so as to face an inner peripheral surface of the sidewall 121 of the outer cup 120. A gap is formed between the sidewall 121 and the sidewall 132 to constitute an exhaust path d.
A circular ring-shaped horizontal member 141, a cylindrical vertical member 142, and a circular ring-shaped bottom member 143 located at the bottom of the cup 110 are provided below the inner cup 130. A space surrounded by these members 141, 142 and 143, and the sidewall 132 of the inner cup 130 described above is defined within the cup 110. A cylindrical wall portion 145 having an exhaust port 144 that is in communication with the exhaust path d is provided within the space. The cylindrical wall portion 145 is arranged such that the exhaust port 144 faces the vertical direction (height direction), and an exhaust pipe 146 is connected to the bottom member 143 at a lower end of the cylindrical wall portion 145. That is, an exhaust flow in the cup 110 passes through the cylindrical wall portion 145 and is discharged from the exhaust path d.
A liquid discharge port 147 for discharging the collected liquid therethrough is formed in the bottom member 143 between the sidewall 121 of the outer cup 120 and the vertical member 142. A liquid discharge pipe 148 is connected to the liquid discharge port 147.
The mesh ring 150 as a coating liquid collector is provided below the sidewall 132 of the inner cup 130. The mesh ring 150 collects a resist liquid between the sidewall 132 of the inner cup 130 and the bottom member 143. A material of the mesh ring 150 is, for example, a metal such as stainless steel, but is not particularly limited as long as it has chemical resistance to solvents.
The mesh ring 150 is fixed to the cup 110 in a state where there is a gap between an upper end of the mesh ring 150 and a lower end of the sidewall 132 of the inner cup 130. The upper limit of the size of the gap may be arbitrarily set within a range that does not impair the function of the mesh ring 150 as the coating liquid collector. For example, the upper limit may be set to 10 mm or less. A method of fixing the mesh ring 150 to the cup 110 is not particularly limited, but a desirable fixing method will be described later.
Further, a position of an outer peripheral surface of the sidewall 132 and a position of an outer peripheral surface of the mesh ring 150 in the radial direction of the cup 110 are substantially the same. A relationship of these positions may be changed as appropriate according to the shape of the inner cup 130 and the like such that a solvent flowing down along an outer peripheral surface of the inner cup 130 drops on the mesh ring 150.
As illustrated in
In addition, although the shape of the mesh ring 150 is cylindrical in the present embodiment, the shape of the mesh ring 150 may be changed as appropriate according to the shape of the cup 110. Further, the number, size, arrangement, and the like of the openings 152 of the mesh ring 150 are appropriately determined according to the capacity to collect the resist liquid, the ability to exhaust the cup 110, the shape of the cup 110, and the like. A desirable shape of the openings 152 will be described later.
As illustrated in
The first arm 161 supports a resist liquid supply nozzle 163 as a coating liquid supplier that supplies a resist liquid as a coating liquid. The resist liquid supplied by the resist liquid supply nozzle 163 has a high viscosity of, for example, 50 cp or more. The first arm 161 is movable on the rail 160 by a nozzle driver 164 as a moving mechanism. Thus, the resist liquid supply nozzle 163 may move from a standby part 165 provided outside the outer cup 120 on the Y-direction positive side to a standby part 166 provided outside the outer cup 120 on the Y-direction negative side by passing above a central portion of the wafer W within the outer cup 120. Further, the first arm 161 may be moved up and down by the nozzle driver 164, so that a height of the resist liquid supply nozzle 163 may be adjusted.
The second arm 162 supports a solvent supply nozzle 167 for supplying an organic solvent such as thinner onto the wafer W. The second arm 162 is movable on the rail 160 by a nozzle driver 169 as a moving mechanism. Thus, the solvent supply nozzle 167 may move from a standby part 168 provided outside the outer cup 120 on the Y-direction positive side to above the central portion of the wafer W within the outer cup 120. The standby part 168 is provided on the Y-direction positive side of the standby part 165. Further, the second arm 162 may be moved up and down by the nozzle driver 169, so that a height of the solvent supply nozzle 167 may be adjusted.
The solvent supplied from the solvent supply nozzle 167 functions as a pre-wet liquid supplied onto the wafer W during a pre-wet processing, which is performed before coating the resist liquid in order to facilitate the spreading of the resist liquid over the wafer W. Further, the solvent from the solvent supply nozzle 167 is shaken off from the wafer W during the pre-wet processing and drops onto the inner cup 130, and the dropped solvent flows down along the outer peripheral surface of the inner cup 130.
Further, as illustrated in
In this way, since the solvent flowing down along the outer peripheral surface of the inner cup 130 is supplied to the mesh ring 150, a device for supplying the solvent to the outer peripheral surface of the inner cup 130 functions as a solvent supplier that supplies the solvent to the mesh ring 150.
In the present embodiment, the solvent supply nozzle 167 and the back rinse liquid supply nozzle 170 described above function as a solvent supplier. The solvent supplier is not limited to these nozzles 167 and 170, and may be, for example, a mechanism for discharging the solvent from a solvent discharge hole (not illustrated) provided inside the inner cup 130 to the outer peripheral surface of the inner cup 130. Also in this case, the solvent flowing down along the outer peripheral surface of the inner cup 130 is supplied to the mesh ring 150. That is, a configuration of the solvent supplier for supplying the solvent to the mesh ring 150 is not particularly limited.
As illustrated in
The resist coating apparatus 1 according to the present embodiment is configured as described above. The resist coating apparatus 1 may collect the resist liquid flowing down along the outer peripheral surface of the inner cup 130 during a resist coating processing, or the resist liquid solidified in a filamentous form by the mesh ring 150 arranged below the sidewall 132 of the inner cup 130.
Further, the solvent, which is supplied to the wafer W at a timing before or after the resist coating processing, flows down along the outer peripheral surface of the inner cup 130, so that the solvent may be supplied to the mesh ring 150. The solvent supplied to the mesh ring 150 comes into contact with the collected resist liquid or a solidified substance of the resist liquid, thereby diluting the resist liquid or dissolving the solidified substance of the resist liquid. Thus, the resist liquid collected in the mesh ring 150 or the solidified substance of the resist liquid becomes easy to be discharged, which makes it easy to be discharged from the liquid discharge port 147. As a result, the clogging of the exhaust path such as the exhaust port 144 or the exhaust pipe 146 with foreign substances may be prevented.
The schematic configuration of the resist coating apparatus 1 has been described above. Next, another configuration example of the mesh ring 150 will be described.
As illustrated in
In addition, the sidewall 151 and the liquid receiver 153 may be an integral body obtained by integral molding, or may be configured by assembling a plurality of components. The liquid receiver 153 does not have to be a horizontal shape, but may have a horizontal shape from the viewpoint of ease of processing, for example, when the sidewall 151 and the liquid receiver 153 are formed as one component by processing a metal plate such as stainless steel.
As illustrated in
Then, the solvent dropped onto the liquid receiver 153 flows toward an inner peripheral end or an outer peripheral end of an upper surface of the liquid receiver 153 (liquid receiver surface 153a). The solvent directed to the inner peripheral end of the liquid receiver surface 153a is supplied to the inner peripheral surface of the sidewall 151 from the inner peripheral end. On the other hand, the solvent directed to the outer peripheral end of the liquid receiver surface 153a flows along a lower surface of the liquid receiver 153 and is supplied to the outer peripheral surface of the sidewall 151.
In this way, when the mesh ring 150 includes the liquid receiver 153, more of the solvent flowing down along the outer peripheral surface of the inner cup 130 may be collected, and may be supplied to the mesh ring 150. Therefore, the dilution of the resist liquid or the dissolution of the solidified substance of the resist liquid, collected in the mesh ring 150, is promoted, which makes it possible to enhance the effect of preventing the clogging of the exhaust path with foreign substances.
In addition, the shape of the liquid receiver 153 is not limited to the L-shape as illustrated in
Accordingly, as illustrated in
Further, the liquid receiver 153 may have, for example, any of shapes illustrated in
Next, other shape examples of the openings 152 will be described.
The openings 152 illustrated in
When the openings 152 have such a shape, it is possible to prevent the openings 152 from being blocked by the solvent supplied to the mesh ring 150 and to make it easy to maintain a desired exhaust pressure upon the evacuation of the cup. The reason for this will be explained below with reference to
The solvent supplied to the mesh ring 150 may remain adhered to the sidewall 151 or the openings 152 of the mesh ring 150 without being discharged. At this time, as illustrated in
Even if there is an opening 152a blocked by the liquid film, there is also an opening 152b that is open without the liquid film being formed. Thus, the resist coating process described above can be performed. However, the number of openings 152b through which the exhaust flow may pass is relatively reduced when the blocked opening 152a exists, so that it is difficult to maintain a desired exhaust pressure upon the evacuation of the cup. Therefore, in order to perform the resist coating process while maintaining the exhaust capacity of the cup within an allowable range, it is necessary to increase the frequency of maintenance for removing the liquid film from the blocked opening 152a.
On the other hand, as illustrated in
Further, the opening 152 may have a rectangular shape, and short sides thereof may be located at the upper and lower ends of the opening 152, as illustrated in
On the other hand, when a plurality of rectangular openings 152 are arranged in the height direction of the mesh ring 150 as illustrated in
Therefore, the rectangular opening 152 may extend from the upper end portion to the lower end portion of the sidewall 151 of the mesh ring 150, as illustrated in
Next, an example of a method of fixing the mesh ring 150 will be described.
In the example illustrated in
When attaching the attachment member 180 to the cylindrical wall portion 145, an upper end of the cylindrical wall portion 145 is covered with the attachment member 180, so that the upper surface portion 181 comes into contact with an upper surface of the cylindrical wall portion 145, and an inner peripheral surface of the sidewall portion 182 comes into contact with an outer peripheral surface of the cylindrical wall portion 145. In other words, the attachment member 180 has a shape in which it is fitted to the upper end of the cylindrical wall portion 145, and is configured to be detachable with respect to the upper end of the cylindrical wall portion 145.
As illustrated in
An inner peripheral surface of the mesh ring 150 is provided with bracket portions 155 as mounting portions for the attachment of the attachment member 180, which are formed at the same interval as the two mounting portions 183 described above. The bracket portion 155 has a wall 156 extending downward from the inner peripheral surface of the upper end portion of the sidewall 151, and a horizontal wall 157 protruding inward from a lower end portion of the wall 156. That is, the bracket portion 155 has an L-shape defined by the walls 156 and 157.
When attaching the attachment member 180 to the mesh ring 150, the mounting portion 183 of the attachment member 180 is superimposed on the wall 157 of the bracket portion 155, and both components are fixed to each other by a bolt 184 as a fastener. Then, the upper end of the cylindrical wall portion 145 (
If the mesh ring 150 is fixed to the cylindrical wall portion 145 as described above, the mesh ring 150 may be provided not only when the resist coating apparatus 1 is newly manufactured, but also for an existing resist coating apparatus having no mesh ring 150.
Further, in a case where the mesh ring 150 is detachably fixed to the cylindrical wall portion 145, maintenance of the mesh ring 150 such as replacement or cleaning may be performed easily. In addition to this, the mesh ring 150 may be compatibly used in a plurality of resist coating apparatuses.
Further, in the method of fixing the mesh ring 150 described above, the solvent dropped to the liquid receiver 153 flows on the sidewall 151, but at a location where the bracket portion 155 is formed, as illustrated in
In the above, the method of fixing the mesh ring 150 to the cylindrical wall portion 145 via the attachment member 180 has been described.
In addition, the mesh ring 150 may be fixed so as not to come into contact with the cup 110 except for a fixing portion between the mesh ring 150 and the cylindrical wall portion 145 (the attachment member 180 in the example of
In particular, when the mesh ring 150 is not in contact with the bottom member 143 of the cup 110 (
In addition, the mesh ring 150 and the cylindrical wall portion 145 may be fixed without providing the attachment member 180. In this case, the fixing portion (not illustrated) between the mesh ring 150 and the cylindrical wall portion 145 may be positioned lower than the upper end of the cylindrical wall portion 145. Thus, the solvent flowing to the fixing portion between the mesh ring 150 and the cylindrical wall portion 145 is easy to be discharged without overflowing the upper end of the cylindrical wall portion 145, which prevents the solvent from flowing into the exhaust port 144.
The liquid processing apparatus according to the present disclosure has been described above by taking the resist coating apparatus 1 as an example. In addition, the liquid processing apparatus according to the present disclosure may also be applied to liquid processing apparatuses for processing target substrates other than semiconductor wafers, such as flat panel display (FPD) substrates and mask reticles for photomasks.
According to the present disclosure in some embodiments, it is possible to prevent clogging of an exhaust path by foreign substances generated during a spin coating process of a substrate.
The embodiments disclosed herein should be considered to be exemplary and not limitative in all respects. The above embodiments may be omitted, replaced, or modified in various forms without departing from the scope of the appended claims, configuration examples within the technical scope of the present disclosure, and the gist thereof. For example, the constituent elements of the above embodiments may be arbitrarily combined. From this arbitrary combination, actions and effects related to each element of the combination are naturally obtained, and other actions and effects that are clear to those skilled in the art from the description in this specification are obtained.
Further, the effects described herein are merely illustrative or exemplary and not limiting.
In other words, the technology of the present disclosure may produce other effects that are clear to those skilled in the art from the description of this specification in addition to or instead of the above effects.
In addition, the following configuration examples also belong to the technical scope of the present disclosure.
(1) A liquid processing apparatus that applies a coating liquid onto a substrate, includes: a substrate holder configured to hold and rotate the substrate; a coating liquid supplier configured to supply the coating liquid to the substrate held by the substrate holder; a cup provided to surround the substrate held by the substrate holder; and a solvent supplier configured to supply a solvent for the coating liquid to a coating liquid collector, wherein the cup includes: an outer cup arranged outside the substrate holder; an inner cup arranged on an inner peripheral side of the outer cup below the substrate holder and having a downwardly-extending wall; an exhaust path provided between the outer cup and the inner cup; and the coating liquid collector provided with a plurality of openings through which an exhaust flow passes, the coating liquid collector extending downward below the downwardly-extending wall of the inner cup with a gap between the coating liquid collector and a lower end of the downwardly-extending wall.
(2) In the liquid processing apparatus of (1) above, the coating liquid collector includes a liquid receiver at an upper end portion of the coating liquid collector to receive the solvent dropping from the downwardly-extending wall.
(3) In the liquid processing apparatus of (2) above, the liquid receiver protrudes outward from an outer peripheral surface of the downwardly-extending wall.
(4) In the liquid processing apparatus of (2) or (3) above, the liquid receiver has a horizontal shape.
(5) In the liquid processing apparatus of any one of (1) to (4) above, an upper end of each of the plurality of openings has a horizontal shape.
(6) In the liquid processing apparatus of any one of (1) to (5) above, each of the plurality of openings has a rectangular shape, and short sides of the rectangular shape are located at upper and lower ends of each of the plurality of openings.
(7) In the liquid processing apparatus of any one of (1) to (6) above, the plurality of openings extend from an upper end portion to a lower end portion of the coating liquid collector, and the plurality of openings are arranged at an interval along a circumferential direction of the coating liquid collector.
(8) In the liquid processing apparatus of any one of (1) to (7) above, further comprising: a cylindrical wall portion provided below the inner cup and having an exhaust port communicating with the exhaust path, wherein the coating liquid collector is fixed to the cylindrical wall portion.
(9) In the liquid processing apparatus of (8) above, the coating liquid collector is not in contact with the cup except for a fixing portion between the coating liquid collector and the cylindrical wall portion.
Number | Date | Country | Kind |
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2022-108485 | Jul 2022 | JP | national |