JP2005342561A - Slit coating type coater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a slit coating type coater permitting formation of a coating film of a uniform film thickness without adverse effects on surroundings. <P>SOLUTION: The coater has a holding table 20 holding a substrate 1 on the vertically lower plane and a coating head 30 arranged so as to oppose the surface of the substrate 1 held on the table 20 and having a slit-shaped nozzle opening 31 allowing a specified coating solution 2 to flow toward the surface of the substrate 1. The coater applies the solution 2 onto the surface of the substrate 1 by moving the table 20 and the head 30 relatively in the horizontal direction. A liquid-retaining member 50 which retains a liquid 3 containing at least the same solvent as the principal solvent of the solution 2 in the recessed part 51 opening on the side of the substrate 1 is arranged so as to lie in the vicinity of the head 30 and oppose the substrate 1 applied with the solution 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a slit coat type coating apparatus that causes a predetermined solution to flow out from the tip of a nozzle and uniformly coat the solution on the surface of a substrate.

  As a coating apparatus for applying a predetermined solution (solvent) such as a resist material or an insulating material to a substrate such as a semiconductor wafer or a glass substrate, for example, the solution is caused to flow out from the tip of a nozzle by capillary action, and the solution is applied to the surface of the substrate. There is a slit coat type coating apparatus for coating (see, for example, Patent Document 1). In addition, for example, there is a roll coating apparatus that attaches a solution to a coating roll unit made of a rubber roll and coats the solution adhered to the coating roll unit on a substrate (for example, see Patent Document 2).

  After applying the solution over the entire surface of the substrate with such a coating apparatus, generally, for example, by placing the substrate on a hot plate and drying the applied solution, the substrate surface is dried. A coating film is formed.

  And in such a coating device, since the solution apply | coated to the board | substrate begins to dry immediately after application | coating, there exists a problem that a drying nonuniformity, a sink, etc. generate | occur | produce. In particular, when a thin coating film is formed using a material having a relatively low viscosity of the solution to be used, such a problem appears remarkably.

  As a configuration for solving such a problem, for example, Patent Document 2 includes a solvent spray nozzle that covers the periphery of the coating roll portion with a solvent volatilization prevention cover and sprays the solvent in the solvent volatilization prevention cover. There is disclosed a structure or a structure in which a solvent volatilization dish containing a solvent is disposed in a solvent volatilization prevention cover and the solvent volatilization dish is heated.

  By adopting such a structure, drying of the solution (solvent) applied to the substrate may be suppressed. However, the solvent volatilization prevention cover is filled with the volatilized solvent, which may adversely affect the substrate on which the solution has not yet been applied, and may cause manufacturing defects such as the formation of pinholes in the coating film. is there. Moreover, in such a structure, since the solvent which volatilized in the comparatively wide space called the inside of a solvent volatilization prevention cover is filled, there also exists a problem that there exists a possibility of having a bad influence on the surrounding environment, an operator, etc.

JP-A-6-343908 (FIGS. 1-2 and 2-4) Japanese Patent Laid-Open No. 7-47315 (FIGS. 1-2 and 3-4)

  In view of such circumstances, an object of the present invention is to provide a slit coat type coating apparatus capable of forming a coating film having a uniform film thickness without adversely affecting the surrounding environment.

According to a first aspect of the present invention for solving the above-mentioned problems, a holding table for holding a substrate and a surface of the substrate held by the holding table are arranged so as to face each other and predetermined toward the surface of the substrate. A coating head having a slit-like nozzle opening for discharging the coating solution, and the holding table and the coating head are relatively moved in the horizontal direction so that the coating solution is coated on the surface of the substrate. And a liquid containing at least the same main solvent as the main solvent of the coating solution is disposed in the concave portion that is disposed close to the coating head and faces the substrate on which the coating solution has been coated, and opens to the substrate side. A slit coat type coating apparatus having a liquid holding member to be held.
In the first aspect, the substrate coated with the coating solution moves onto the liquid holding member, and the solvent is volatilized from the liquid in the liquid holding member, so that drying of the coating solution applied to the substrate is suppressed.

According to a second aspect of the present invention, there is provided the slit coat type coating apparatus according to the first aspect, wherein the liquid holding member is provided so as to be movable in a vertical direction.
In the second aspect, the atmosphere near the substrate can be adjusted to a desired solvent concentration by moving the liquid holding member in the vertical direction.

According to a third aspect of the present invention, in the second aspect, the detection means for detecting at least the concentration of the main solvent in the atmosphere near the surface of the substrate, and the upper and lower sides of the liquid holding member according to the detection result of the detection means. The slit coat type coating apparatus further comprises a moving means for controlling the movement of the direction.
In the third aspect, the concentration of the solvent such as the main solvent in the atmosphere near the surface of the substrate can be automatically maintained constantly.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the liquid holding member includes an opening / closing member provided to open and close the opening of the recess. In the applicator.
In the fourth aspect, the atmosphere in the vicinity of the substrate can be adjusted to a desired solvent concentration by opening and closing the opening / closing member at a predetermined timing.

According to a fifth aspect of the present invention, in the fourth aspect, the detection means for detecting at least the concentration of the main solvent in the atmosphere near the surface of the substrate, and the liquid holding member according to the detection result of the detection means. The slit coat type coating apparatus further comprises driving means for controlling driving of the opening / closing member.
In the fifth aspect, the solvent concentration in the atmosphere in the vicinity of the surface of the substrate can be automatically and always maintained constant.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
FIG. 1 is a perspective view showing a schematic configuration of a slit coat type coating apparatus according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view of a main part of the slit coat type coating apparatus. As shown in FIG. 1, a slit coat type coating apparatus 10 includes a holding table 20 that holds a substrate 1 such as a silicon wafer or a semiconductor substrate, a coating head 30 provided on the substrate 1 side of the holding table 20, and a substrate 1. A storage means 40 for supplying the coating solution 2 to be applied to the coating head 30, and a liquid holding member 50 for holding the predetermined liquid 3 in the recess 51. Although not shown, the holding table 20, the coating head 30, the storage unit 40, the liquid holding member 50, and the like are arranged in a predetermined sealing space.

  The holding table 20 holds the substrate 1 on the lower surface in the vertical direction so that the surface thereof faces downward in the vertical direction. The method for holding the substrate 1 by the holding table 20 is not particularly limited, and examples thereof include a method using suction such as a vacuum pump. The holding table 20 is provided so as to be linearly movable along the surface direction of the substrate 1 by a table driving means such as a driving motor (not shown).

  The coating head 30 has a slit-like nozzle opening 31 that opens upward in the vertical direction and flows out the coating solution 2 supplied from the storage means 40, and a solution reservoir 32 that communicates with the nozzle opening 31. Further, the coating head 30 is held by a device body (not shown) so as to be movable in the vertical direction, and the distance between the tip of the coating head 30 and the surface of the substrate 1 is, for example, the kinematic viscosity of the coating solution 2 or the coating solution 2. In consideration of the wettability with respect to the substrate 1, the thickness of the coating solution 2 applied to the substrate 1, and the like are adjusted as appropriate.

  The storage unit 40 includes a storage tank 41 that holds the coating solution 2, and a supply pipe 42 that has one end connected to the coating head 30 and the other end connected to the storage tank 41. The applied coating solution 2 is supplied to the coating head 30 via the supply pipe 42.

  When the coating solution 2 is supplied from the storage tank 41 of the storage means 40 to the coating head 30 via the supply pipe 42 and the coating solution 2 is filled into the solution pool 32 of the coating head 30, the inside of the solution pool 32 The coating solution 2 rises to the tip of the nozzle opening 31 by capillary action. As a result, the coating solution 2 is uniformly filled in the slit-shaped nozzle openings 31. Then, the coating head 30 is raised from this state and the coating solution 2 protruding from the nozzle opening 31 is brought into contact with the surface of the substrate 1. In this state, the holding table 20 and the coating head 30 are relative to each other in the surface direction of the substrate 1. Move. For example, in the present embodiment, the coating head 30 is fixed and the holding table 20 is linearly moved in the surface direction of the substrate 1, so that the coating head 30 and the holding table 20 are relatively moved. As a result, the coating solution 2 continuously flows out from the nozzle opening 31, and the coating solution 2 is applied to the surface of the substrate 1 with a uniform thickness.

  In addition, a liquid holding member 50 is provided on the substrate 1 side of the holding table 20 together with the application head 30 and the storage unit 40 in the vicinity of the application head 30. The liquid holding member 50 has a concave portion 51 that opens on the surface facing the substrate 1, that is, on the upper side in the vertical direction, and the concave portion 51 contains at least the same main solvent as the main solvent of the coating solution 2. Liquid 3 is retained. For example, in this embodiment, the liquid 3 that is the coating solution 2 itself is stored in the recess 51 of the liquid holding member 50. Of course, the liquid 3 stored in the recess 51 of the liquid holding member 50 may be composed only of the main solvent of the coating solution 2.

  Such a liquid holding member 50 is provided close to the coating head 30 and is disposed so as to face the substrate 1 to which the coating solution 2 is applied when the coating solution 2 is applied to the substrate 1. Yes. Such a liquid holding member 50 is fixed to an apparatus main body (not shown) so as to be movable in the vertical direction (vertical direction). By moving the liquid holding member 50 in the vertical direction, the liquid holding member 50 and The distance from the surface of the substrate 1 can be adjusted.

  In the slit coat type coating apparatus according to the present invention having such a liquid holding member 50, the substrate on which the coating solution 2 is applied by volatilization of the solvent of the liquid 3 held in the recess 51 of the liquid holding member 50. The concentration of the solvent contained in the atmosphere near 1, for example, the concentration of the main solvent of the coating solution 2 is maintained at a desired concentration. In the present embodiment, the solvent concentration in the atmosphere near the substrate 1 is adjusted by moving the liquid holding member 50 in the vertical direction. Thereby, it is possible to prevent the coating solution 2 applied to the substrate 1 from being dried, and it is possible to prevent the coating solution 2 from being dried, uneven coating, sink marks, and the like. Furthermore, the tip of the nozzle opening 31 of the coating head 30 can be prevented from being dried, that is, the coating solution 2 protruding from the nozzle opening 31 can be prevented from being dried, so that the coating solution 2 can be applied to the substrate 1 more favorably.

  In addition, although the recessed part 51 of such a liquid holding member 50 is not specifically limited, For example, it is preferable that it has an area comparable as the board | substrate 1 which apply | coats the coating solution 2. FIG. Moreover, it is preferable that the recessed part 51 is comparatively shallowly formed so that predetermined amount of the liquid 3 can be hold | maintained. Thereby, the solvent concentration in the atmosphere in the vicinity of the substrate 1 can be adjusted to a predetermined concentration relatively easily.

  In the present embodiment, the solvent of the liquid 3 in the recess 51 is volatilized naturally. However, the present invention is not limited to this. For example, air is sent from the lower portion of the recess 51 or the liquid holding member 50 is heated. Thus, the solvent of the liquid 3 may be forcibly volatilized.

  In this embodiment, a shielding plate 60 is provided between the liquid holding member 50 and the coating head 30 so as to cover a part of the surface of the substrate 1 without contacting the surface of the substrate 1. ing. That is, the shielding plate 60 shields the lower space of the substrate 1 between the coating head 30 and the liquid holding member 50. Thereby, when the holding table 20 holding the substrate 1 is moved, it is possible to prevent the tip of the nozzle opening 31 of the coating head 30 from being dried by the air flow accompanying the movement.

  Hereinafter, the slit coat type coating method using such a slit coat type coating apparatus 10 will be described in detail. FIG. 3 is a schematic view showing the operation of the slit coat type coating apparatus. First, as shown in FIG. 3A, the substrate 1 is fixed to the lower surface of the holding table 20, the coating head 30 is raised, and the distance between the surface of the substrate 1 and the tip surface of the nozzle opening 31 of the coating head 30 is set. Adjust so that it is at a predetermined interval. Specifically, the coating head 30 is raised so that the tip of the coating solution 2 protruding from the nozzle opening 31 is slightly higher than the position of the surface of the substrate 1. In this embodiment, the distance between the coating head 30 and the substrate 1 is adjusted by moving the coating head 30. Of course, the coating head 30 is fixed and the holding table 20 is moved. May be.

  Next, as shown in FIG. 3B, the holding table 20 protrudes from the nozzle opening 31 of the coating head 30 by linearly moving the holding table 20 in the surface direction of the substrate 1, that is, in the horizontal direction by a table driving unit (not shown). When the coating solution 2 comes into contact with the surface of the substrate 1, coating of the coating solution 2 is started. Here, as described above, the air flow on the lower side of the substrate 1 accompanying the movement of the holding table 20 is blocked by the shielding plate 60. That is, the drying of the coating solution 2 protruding from the tip of the nozzle opening 31 is suppressed by the shielding plate 60, so that the coating solution 2 reliably contacts the substrate 1 by the movement of the holding table 20, and the substrate 1 is moved to. Application of the coating solution 2 is started.

  After the application of the coating solution 2 to the substrate 1 is started in this way, the coating solution 2 continuously flows out from the nozzle opening 31 by further moving the holding table 20 as shown in FIG. Then, the coating solution 2 is applied to the entire surface of the substrate 1. Then, the portion of the substrate 1 to which the coating solution 2 is applied sequentially moves to a region facing the liquid holding member 50.

  Here, the coating solution 2 usually starts to dry naturally immediately after being applied to the substrate 1. However, in this embodiment, the liquid holding member 50 is provided in the vicinity of the coating head 30, and the solvent of the liquid 3 held on the liquid holding member 50 is volatilized in the coating solution 2 applied to the substrate 1. It will be arrange | positioned in atmosphere, and the coating solution 2 apply | coated to the board | substrate 1 does not begin to dry immediately after application | coating. That is, the coating solution 2 is maintained at a substantially constant viscosity in each region of the substrate 1 even after being applied to the entire surface of the substrate 1.

  Then, after coating the coating solution 2 over the entire surface of the substrate 1 in this way, although not shown, for example, the substrate 1 is heated by a hot plate or the like to dry the coating solution 2, and further, for example, by a cool plate or the like The substrate 1 is cooled and the coating solution 2 is returned to room temperature. As a result, a coating film having a desired thickness is formed on the surface of the substrate 1.

  As described above, according to the slit coat type coating apparatus according to the present invention, when the coating solution 2 is dried in this way, the coating solution 2 applied to the substrate 1 has a substantially constant viscosity over the entire surface of the substrate 1. Maintained. Accordingly, the coating film having a uniform film thickness can be satisfactorily formed on the surface of the substrate 1 without causing uneven drying and sink marks.

  In addition, since the coating solution 2 applied to the substrate 1 is easy to dry, the coating speed of the coating solution 2 on the substrate 1 could not be increased. However, if the slit coating type coating apparatus according to the present invention is used, Since the drying of the coating solution 2 is suppressed, the coating speed of the coating solution 2 onto the substrate 1 can be remarkably improved.

  Furthermore, with the slit coat type coating apparatus of the present invention, the conditions are stabilized because only the atmosphere in the vicinity of the substrate 1, that is, the solvent concentration in a relatively narrow region is managed. Further, adverse effects on the surrounding environment or workers can be prevented.

(Embodiment 2)
FIG. 4 is a schematic view of a slit coat type coating apparatus according to the second embodiment. In the present embodiment, as shown in FIG. 4, in the vicinity of the substrate 1 to which the coating solution 2 is applied, that is, in the vicinity of the liquid holding member 50, a detection means 70 such as a concentration sensor that detects the solvent concentration in the atmosphere, The second embodiment is the same as the first embodiment except that it further includes a moving unit 80 that controls the vertical movement of the liquid holding member 50 according to the detection result of the detecting unit 70.

  In the slit coat type coating apparatus 10 of this embodiment, when the solvent concentration, which is the detection result detected by the detection means 70, is lower than a preset concentration, the moving means 80 causes the liquid holding member 50 to be removed. When the solvent concentration is higher than the preset concentration, the moving means 80 lowers the liquid holding member 50. Then, by adjusting the distance between the liquid holding member 50 and the substrate 1 in accordance with the solvent concentration in the atmosphere in the vicinity of the substrate 1 as described above, the solvent concentration in the atmosphere in the vicinity of the substrate 1 is always maintained constant. . Thereby, drying of the coating solution 2 applied to the substrate 1 can be more reliably prevented, and a good coating film without unevenness in drying can be formed.

(Embodiment 3)
FIG. 5 is a schematic view of a slit coat type coating apparatus according to the third embodiment. As shown in FIG. 5, in the present embodiment, the liquid holding member 50 is provided with an opening / closing member 52 such as a shutter that can open and close the opening of the recess 51, and the detection is performed instead of the moving unit 80. The second embodiment is the same as the second embodiment except that it includes a driving unit 90 that controls the opening / closing operation of the opening / closing unit 52 according to the detection result of the unit 70. That is, in such a configuration, the drive means 90 opens and closes the opening / closing member 52 and adjusts the solvent volatilization amount of the liquid 3 in the recess 51 in accordance with the solvent concentration that is the detection result detected by the detection means 70. The solvent concentration in the atmosphere in the vicinity of the substrate 1 is always kept constant. Of course, in such a configuration, it is needless to say that the same effects as those of the above-described embodiment can be obtained.

(Other embodiments)
As mentioned above, although embodiment of this invention was described, this invention is not limited to what was mentioned above. For example, in the above-described embodiment, the holding table 20 and the coating head 30 are relatively moved by moving the holding table 20 in the surface direction of the substrate 1. However, the present invention is not limited to this. The holding table 20 may be fixed and the coating head 30 may be moved in the surface direction of the substrate 1. In this case, the liquid holding member 50 is also moved together with the coating head 30.

  In the above-described embodiment, the shielding plate 60 is provided in the region between the liquid holding member 50 and the coating head 30. Of course, the shielding plate 60 may not be provided. Furthermore, although the board | substrate whose surface is a substantially flat surface was illustrated in embodiment mentioned above, it is not limited to this, For example, it cannot be overemphasized that the board | substrate whose surface, such as a lens, is a curved surface can be used.

It is a perspective view which shows schematic structure of the coating device which concerns on Embodiment 1 of this invention. It is principal part sectional drawing of the coating device which concerns on Embodiment 1 of this invention. It is the schematic which shows the coating method which concerns on Embodiment 1 of this invention. It is a figure which shows schematic structure of the coating device which concerns on Embodiment 2 of this invention. It is a figure which shows schematic structure of the coating device which concerns on Embodiment 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate, 2 Coating solution, 3 Liquid, 10 Slit coat type coating device, 20 Holding table, 30 Coating head, 31 Nozzle opening, 40 Storage means, 50 Liquid holding member, 60 Shielding plate

Claims (5)

An application having a holding table for holding a substrate and a slit-like nozzle opening that is arranged so as to face the surface of the substrate held on the holding table and flows a predetermined application solution toward the surface of the substrate The coating solution is applied to the surface of the substrate by the relative movement of the holding table and the coating head in the horizontal direction, and the coating solution is applied in proximity to the coating head. A slit having a liquid holding member that is disposed so as to face the substrate and that holds a liquid containing at least the same main solvent as the main solvent of the coating solution in a recess that opens to the substrate side. Coat type coating device. 2. The slit coat type coating apparatus according to claim 1, wherein the liquid holding member is provided so as to be movable in a vertical direction. The detection means for detecting at least the concentration of the main solvent in the atmosphere near the surface of the substrate according to claim 2, and the moving means for controlling the vertical movement of the liquid holding member according to the detection result of the detection means. A slit coat type coating apparatus, further comprising: The slit coat type coating apparatus according to claim 1, wherein the liquid holding member includes an opening / closing member provided to open and close the opening of the recess. The detection means for detecting at least the concentration of the main solvent in the atmosphere near the surface of the substrate according to claim 4, and the drive means for controlling the drive of the opening / closing member of the liquid holding member according to the detection result of the detection means. A slit coat type coating apparatus, further comprising:

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