JP2513992B2 - Coating method and coating device used therefor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus for storing a material to be coated in a processing container and applying the coating material while rotating the material to be coated, for example, a resist on a wafer in a semiconductor manufacturing apparatus. The present invention relates to a coating method for coating and a coating device used for the coating method.

[0002]

2. Description of the Related Art In a semiconductor manufacturing apparatus, when a resist is applied on a wafer, the wafer is placed and fixed on a rotatable spin head arranged inside a processing container, and the resist solution is rotated while the wafer is rotated. Is applied to the wafer surface to perform resist coating processing (Japanese Patent Publication No. 53-3718).
9).

On the other hand, in recent years, in order to increase the number of chips that can be formed on one wafer, there is an increasing demand to use a larger diameter wafer such as an 8-inch wafer in place of the conventional 6-inch wafer which has been the mainstream. Alternatively, there is a demand for the use of a square wafer that can efficiently secure chips in order to cope with a liquid crystal screen.

[0004]

Generally, in order to apply the resist thinly and uniformly on a large-diameter wafer, it is generally considered to either change the viscosity of the coating material or increase the rotation speed of the coating material. Had been.

In order to respond to the above demands on the coating apparatus side,
The only method was to increase the number of rotations of the material to be coated, but when the number of rotations was increased, the rotation speed (tangential speed) was greatly different between the center and the peripheral edge of the wafer. And
In particular, if the speed at the peripheral edge of the wafer, where the speed difference from the surrounding space is remarkable, exceeds a predetermined value, evaporation of the solvent as a coating material is accelerated, and the uniformity of resist coating at the peripheral edge is rather impaired. Confirmed by the inventors.

As described above, when applying a resist to a large-diameter wafer, the resist application range is naturally limited only by coping with the number of rotations of the wafer, and the resist of a large-diameter wafer such as an 8-inch wafer is surely removed. Could not do.

By the way, Japanese Patent Laid-Open No. 61-194829 proposes a technique for forcibly introducing a vapor stream of a solvent into the processing container in order to stabilize the quality of the coating film. It has been confirmed by the present inventors that the resist on the large-diameter wafer cannot be reliably performed.

Here, Japanese Patent Application Laid-Open Nos. 51-39737 and 60-143871 disclose techniques for rotationally driving a processing container in which a wafer is placed in the same direction as the wafer. According to these techniques, the evaporation of the solvent on the wafer can be suppressed, and the uniformity of the resist coating can be improved at the peripheral portion of the wafer.

By the way, as disclosed in the above-mentioned publications, when the processing container itself in which the wafer is placed is driven to rotate together with the wafer, a structure for placing the wafer in the processing container is applied. It is difficult to provide in the device itself. This is because, as disclosed in each of the above publications, the turntable that supports the wafer in the processing container or the spin chuck itself is fixed to the processing container. In JP-A-51-39737 and JP-A-60-143871, a turntable or a spin chuck integrated with a processing container is provided.
No method of mounting the wafer is disclosed.

Therefore, an object of the present invention is to integrally rotate the processing container in which the material to be coated is placed together with the material to be coated so as to improve the uniformity of coating, but to keep the inside of the processing container being rotated. It is an object of the present invention to provide a coating apparatus and a coating method using the coating apparatus, in which the material to be coated can be easily arranged and released.

[0011]

The invention according to claim 1 has a processing container having an opening formed in the center and an abutting portion arranged around the opening, and an upper part through the opening. When applying the coating material on the material to be coated by using a coating device having a shaft portion extending to the shaft and a holding means having a holding portion formed at the upper end of the shaft portion, the holding device is held at a position above the processing container. A step of arranging the parts to hold the material to be coated in the holding part, and moving the holding means holding the material to be coated and the processing container up and down relatively, A step of bringing the abutting portion into contact with the abutting portion; a step of bringing the coating material into close contact with the abutting portion by a holding force of the holding means; Coating film on the coated material by the coating material supplied to A spin coating step of forming, characterized by having a.

The invention according to claim 2 is the same as in claim 1, wherein a vacuum suction portion is used as the holding portion, and in the step of bringing the material to be coated into close contact with the contact portion, The vacuum suction unit is separated from the material to be coated by driving the elevating means, and the material to be coated is brought into close contact with the contact portion by the suction force of the vacuum suction unit.

The invention of claim 3 is based on the invention of claim 2, wherein a region between the material to be coated and the suction surface of the vacuum suction portion is defined as the material to be coated and the contact portion. And a vacuum pressure is applied to the area by the vacuum suction section to bring the coated material into close contact with the contact section.

The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein in the spin coating step, the coating material scattered from the coating material is the coating material. It is characterized in that it is blocked by the contact portion and is prevented from adhering to the inner area of the contact portion in the back surface area of the material to be coated.

The invention according to claim 5 is in a processing container having an opening formed in the center and an abutting portion arranged around the opening, and a coating object is applied on the abutting portion. A step of supporting the material, a step of arranging a vacuum suction section below the material to be coated and facing the material to be coated through the opening, and Sealing the area between the upper surface with the material to be coated and the contact portion, and making the area negative pressure by the vacuum suction portion, to bring the material to be coated into close contact with the contact portion, Then, the processing container is rotated to form a coating film on the material to be coated with the coating material supplied onto the material to be coated.

The invention according to claim 6 is in a processing container having an opening formed in the center and an abutting portion arranged around the opening, wherein the abutting portion is to be coated. A step of supporting the material, a step of bringing the material to be coated into close contact with the abutting portion by a holding force of a holding unit arranged at a position facing the material to be coated through the opening, and then the treatment A rotation coating step of rotating the container to form a coating film on the coating material by the coating material supplied on the coating material; in the rotation coating step, the coating material is scattered from the coating material. The coating material is prevented from being blocked by the contact portion and adhering to the inner area of the contact portion in the back surface area of the coating target material.

The invention according to claim 7 is formed in the center in a coating device which supplies a coating material to the surface of the coating material and rotates the coating material to coat the coating material. A processing container having an opening and an abutting portion arranged around the opening, a rotation driving means for rotationally driving the processing container, a shaft extending upward through the opening, and an upper end of the shaft. Holding means having a holding portion for the material to be coated provided, and elevating means for relatively raising and lowering the processing container and the holding means to bring the material to be coated into contact with the contact portion. It is characterized in that the coating material is supported and fixed to the abutting portion by the holding force of the holding means.

The invention of claim 8 is characterized in that, in claim 7, the holding part is constituted by a vacuum suction part.

The invention according to claim 9 is the invention according to claim 8, wherein the elevating means sets the vacuum suction portion at a position farther from the material to be coated when the processing container is rotated. It is characterized by doing.

The invention according to claim 10 is the invention according to claim 9, wherein the abutting portion is brought into close contact with the material to be coated, so that the material to be coated and the vacuum suction portion are formed. The area between the upper surface and the upper surface is also used as a sealing means for hermetically sealing the area under negative pressure by the vacuum suction unit.

The invention according to claim 11 is the invention according to any one of claims 7 to 10, wherein the abutting portion scatters from the material to be coated during spin coating. Is also used as a coating material adhesion preventing means for preventing the coating material from adhering to the inside area of the contact portion in the back surface area of the coating material.

[0022]

In the present invention, since the processing container rotates together with the material to be coated in the same direction, the relative speed difference becomes small (the relative speed difference is zero at the same number of rotations), and the large diameter Even in the case of the material to be coated, evaporation at the peripheral portion is suppressed, and the coating of the coating material can be reliably performed in the desired area. Further, since the amount of evaporation can be reduced, there is also an effect that the amount of the coating material to be dropped on the material to be coated can be reflectively reduced.

According to the present invention, the rotatably driven processing container has the contact portion with which the material to be coated is brought into contact, and has the opening inside the contact portion. Further, a shaft portion extending upward through the opening and a holding means having a holding portion at the upper end of the shaft portion are provided. Therefore, first, in order to arrange the material to be coated in the processing container, the holding portion can be arranged above the processing container and the material to be coated can be held on the holding portion. After that, the holding means holding the material to be coated and the processing container are moved up and down relatively, so that the material to be coated can be placed on the contact portion of the processing container. Further, the holding force of the holding means brings the coated material into close contact with the abutting portion, so that the coated container can be integrally rotated by the rotation driving of the processing container.

If the holding part of the holding means is constituted by a vacuum suction part, the vacuum suction part can be separated from the material to be coated during spin coating. At this time, the material to be coated is closely supported on the contact portion of the processing container by the suction force of the vacuum suction portion.

At this time, the area between the material to be coated and the vacuum suction portion can be sealed by the material to be coated coming into close contact with the contact portion, so that the area can be maintained at a negative pressure.

Further, since the contact portion provided on the processing container comes into close contact with the material to be coated, it is possible to prevent the coating material from scattering inside the contact portion.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the illustrated embodiments.

The drawing is a cross-sectional view of the embodiment apparatus.

In the figure, the apparatus of this embodiment has, as a basic framework thereof, a lower base 1, an upper base 2, and columns 3 which fix the bases 1 and 2 in parallel with each other.

A processing container 10 for mounting and fixing a wafer 4, which is an example of a material to be coated, is composed of first and second containers 11 and 12 which are closed during coating and can be separated from each other except during coating. ing.

The first container 11 arranged on the upper side is supported by the movable plate 13 via the mounting bases 10A and 13A, and can be raised to the position shown by the chain double-dashed line in FIG. The movable plate 13 is provided with a shaft 1 of a lifting drive unit 14 as a second lifting drive unit fixed to the upper base 2.
5 and a guide member 17 having one end of a guide shaft 16 fixed thereto and the other end provided on the upper base 2.
As described above, the above-described up-and-down movement is enabled by slidably supporting the base. The mounting bases 10A and 13A
Are rotatable with each other via a bearing 18. The mounting bases A and 13A and the bearing 182 constitute a driven guide member that rotatably supports the first container 11. A packing 19 is provided on the peripheral portion of the first container 11 to ensure the hermeticity of the processing container 10.

The second container 12 on the lower side is supported by a rotation drive mechanism section 40 as a first rotation drive means or a container rotation drive means having the following structure. That is,
A support base 20 is fixed to the lower base 1, and a rotation block 22 which is a rotation driven shaft rotatable around the support base 20 via a bearing 21 is provided. The second container 12 is fixed to the rotation block 22 so that it can rotate integrally. Also,
A first pulley 23 is fixed around the rotation block 22.

On the other hand, a second motor 24 is arranged on the lower base 1, and a second pulley 26 is fixed around the output shaft 25 which is a rotary drive shaft. By suspending a belt 27 as a tension member between the first and second pulleys 23 and 26, the rotational force of the second motor 24 is transmitted to the rotary block 22. As described above, the rotational power from the second motor 24 is transmitted to the second container 12 side via the belt 27 that is a stretching member. Transfer of the generated heat to the second container 12 side can be reduced. As a result, it is possible to prevent a change in the coating environment temperature that affects the coating characteristics.

In the central region of the second container 12, there is provided a hollow disk-shaped vacuum adsorption part 30 which protrudes from the inner surface of the second container 12 and functions as an abutting part.
The wafer 4 arranged in the space 0 can be vacuum-sucked. Since the vacuum suction unit 30 is fixed to the second container 12 with screws or the like, it can be rotated integrally with the second container 12. Further, a spin chuck 31 as a holding means is disposed inside the vacuum suction unit 30. The spin chuck 31 is provided with a hole 2 forming a hollow portion formed at the center of the support base 20.
The lower base 1 is connected to a first motor 32 supported by the lower base 1 so as to be able to move up and down. The hole 20A is opened inside the vacuum suction unit 30 of the second container 12. The spin chuck 31 has a holding portion capable of holding the wafer 4 on the upper end side of the shaft portion extending upward through the opening. In the present embodiment, the holding portion is configured as a vacuum suction portion. It should be noted that the lower base 1 has a lifting drive unit 33 and a guide shaft 34 fixed to both sides of the first motor 32, and one of the support frames 35 supporting the first motor 32 is a first lifting drive means. Is fixed to the elevating shaft 33A of the elevating and lowering drive unit 33, and the other is slidably supported along the guide shaft 34 via a bearing 36. As a result, the spin chuck 31 can move up and down and can rotate. Further, a compressor (not shown) is connected to the spin chuck 31 so that the wafer 4 can be vacuum-sucked. Further, in order to enable suction by the vacuum suction unit 30, a negative pressure is connected to the vacuum suction unit 30. The pressure path is also used.

Although the coating material dropping portion is not shown in the apparatus of this embodiment, this dropping portion is applied to the wafer 4 when the first container 11 is raised to the position shown by the chain double-dashed line in FIG. , A predetermined amount of coating material (resist material in this embodiment) is dropped onto the central portion of the wafer 4, and then returns to the initial position.

The operation of the embodiment apparatus configured as described above will be described.

First, the elevating and lowering drive unit 14 is driven to raise the first container 11 to the position shown by the chain double-dashed line in the figure, and the processing container 10 is released. The material is dropped in sequence. After that, the first container 11 is lowered by the driving of the elevation drive unit 14, and the processing container 10 is moved by the first and second containers 11 and 12.
Seal.

Next, a compressor (not shown) is driven,
The vacuum suction unit 30 can be suctioned via the spin chuck 31 and the wafer 4 is suctioned by the vacuum suction unit 30 as shown in the drawing (in this state, the spin chuck 31 is in the vacuum suction unit 30 as shown in FIG. Waiting at a position below the suction surface of). The spin chuck 31 is not in contact with the back surface of the wafer 4, but the region between the wafer 4 and the spin chuck 31 is sealed by the wafer 4 and the vacuum suction unit 30 contacting each other. It is possible to bring the wafer 4 into close contact with the side of the second container 12 by applying a negative pressure to the region. Thereafter, the set diameter of the wafer 4 is set,
The second motor 24 is driven at a rotation speed determined by characteristics such as the viscosity of the resist material and the film thickness to be applied. Then, the rotational force of the second motor 24 is
5, second pulley 26, belt 27, first pulley 23
Is transmitted to the rotary block 22 via the rotary shaft, and the rotary block 22 rotates.

When the rotary block 22 is rotated, the second container 12 and the vacuum suction unit 30 fixed to the rotary block 22 are integrally rotated. Further, the first container 11 is pressed against the second container 12 by the elevating / lowering drive unit 14 and is rotatable via the bearing 18, so that the first container 11 rotates integrally with the second container 12. It will be.

As a result, the wafer 4 and the processing container 10, which are vacuum-sucked by the vacuum suction portion 30, rotate integrally, and the peripheral space inside the processing container 10 rotates together with the wafer 4 at the same speed and in the same direction. It will be.

Here, the main reason why the resist material cannot be reliably applied to the peripheral portion of the wafer 4 having a larger diameter than before is that the peripheral portion of the wafer 4 and its surrounding space are generated when the wafer 4 is rotated at a high speed. This is because the difference in speed becomes extremely large. According to the apparatus of the present embodiment, as described above, the surrounding space is also integrally rotated together with the wafer 4.
Since the speed difference becomes zero and evaporation of the resist material at the peripheral portion of the wafer 4 is suppressed, even if the wafer 4 has a large diameter, the resist material can be surely applied to the peripheral portion. In this spin coating process, excess resist material on the wafer 4 wraps around the wafer from the periphery to the back side,
The back surface of the wafer 4 will be contaminated. However, in the present embodiment, the resist material is prevented from being scattered inward in the radial direction from the vacuum suction portion 30 due to the presence of the vacuum suction portion 30.

After executing the coating operation for a predetermined time, the driving of the second motor 24 is stopped and the elevating and lowering drive section 14 is driven to raise the first container 11 to the position shown by the chain double-dashed line in the figure. The processing container 10 is released. Thereafter, by driving the elevation drive unit 33 attached to the lower base 1 and raising the first motor 36, the spin chuck 31 is raised while the wafer 4 is being sucked, and the wafer 4 is removed from the processing container 10. It is taken out and set at the position indicated by the two-dot chain line in the figure. In this state, a cleaning device (not shown) for cleaning the back surface of the wafer 4 is moved to the back surface side of the wafer 4 and the first motor 36 is driven to perform the back surface cleaning while rotating the wafer 4. ,
It will shift to the subsequent processing steps. In this back surface cleaning step, the wafer 4 is held only by the spin chuck 31. The position at which the back surface of the wafer 4 is held by the spin chuck 31 is inside the position at which the wafer 4 is supported during rotation coating (the position at which the wafer 4 is supported by the vacuum suction unit 30). Therefore, in the back surface cleaning step, the position held by the vacuum suction unit 30 during the spin coating is exposed, and it is possible to remove the resist material that has wrapped around this area during the spin coating. Thus, when the wafer 4 is subsequently transferred or processed in the next step, the wafer 4
It is possible to prevent the transfer arm, the susceptor, and the like from being contaminated by the resist material attached to the back surface of the substrate.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention.

In the above-mentioned embodiment, a so-called nozzle scan system is adopted as the coating material dropping portion, which is capable of moving and scanning inside and outside the upper region of the wafer 4. Instead of this, it is also possible to adopt a fixing method in which the dripping part is fixed to the center of the first container 11.

In addition, in the above-described embodiment, in addition to the conventional spin chuck 31, the vacuum suction unit 30 is provided in the second container 1.
2 and is rotatable together with the processing container 10 and the wafer 4.
Are excellent in that they have the same rotational speed, but are not necessarily limited to this configuration. For example, the suction and rotation of the wafer 4 in the processing container 10 can be performed by the spin chuck 31 without providing the vacuum suction unit 30. In this case, it would be difficult to make the rotational speed of the surrounding space physically the same as that of the driving source, but at least the relative speed difference is greatly reduced as compared with the conventional one, so that the same The effects of the invention can be achieved. Further, in the above-described embodiment, the rotation driving mechanism 40 of the processing container 10 is of a pulley or belt type, but it is needless to say that various other rotation driving means can be used. Further, the coating device to which the present invention is applied is not limited to coating a resist on a semiconductor wafer, but can be applied to various coating devices such as a resist coating on a mask. Since it becomes possible, an excellent effect can be exhibited also in application to a square wafer such as a liquid crystal screen.

[0046]

As described above, according to the present invention, by providing the opening in the center of the processing container which is driven to rotate, the holding means can be arranged by utilizing this opening. By the relative movement up and down with respect to the processing container, the material to be coated can be easily arranged inside and outside the processing container.

[0047]

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 4 Material to be coated 12 Processing container 20A Opening 30 Vacuum adsorption part (contact part) 31 Spin chuck (holding means) 40 Rotation drive means for container

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Den Omori 5-3-6 Akasaka, Minato-ku, Tokyo Within Tokyo Electrotron Co., Ltd. (56) Reference JP-A-61-294819 (JP, A) JP-A Sho 59-33453 (JP, A) JP-A-51-39737 (JP, A)

Claims (11)

(57) [Claims] 1. A processing container having an opening formed in the center and an abutment portion arranged around the opening, a shaft portion extending upward through the opening, and a holding member formed at an upper end of the shaft portion. When applying the coating material on the material to be coated by using a coating device having a holding unit having a section, the holding section is arranged above the processing container, and the coating material is held on the holding section. A step of causing the holding means holding the material to be coated and the processing container to move up and down relatively to bring the material to be coated into contact with the contact portion of the processing container; A step of bringing the coating material into close contact with the abutting portion by a holding force, and then rotating the processing container to apply the coating material on the coating material by the coating material supplied onto the coating material. And a spin coating step for forming a film. Coating method to be. 2. The vacuum suction unit according to claim 1, wherein a vacuum suction unit is used as the holding unit, and the vacuum suction unit drives the elevating means in the step of bringing the coating material into close contact with the abutting unit. The coating method is characterized in that it is separated from the material to be coated by the above method, and the material to be coated is brought into close contact with the contact portion by the suction force of the vacuum suction portion. 3. The vacuum suction device according to claim 2, wherein a region between the material to be coated and the suction surface of the vacuum suction portion is sealed by the material to be coated and the contact portion, and the vacuum suction is performed. A negative pressure is applied to the region by a section to bring the material to be coated into close contact with the contact portion. 4. The coating material according to claim 1, wherein in the spin coating step, the coating material scattered from the coating material is blocked by the abutting portion, A coating method for preventing the coating material from adhering to an inner region of the abutting portion in a back surface region of the coating material. 5. A process container having an opening formed in the center and an abutting portion arranged around the opening, the step of supporting a material to be coated on the abutting portion, A step of disposing a vacuum suction section below the coating material at a position facing the coating material through the opening, and an area between the coating material and an upper surface of the vacuum suction portion is defined as the coating area. A step of sealing with the coating material and the contact portion, and making the area negative by the vacuum suction portion to bring the coating material into close contact with the contact portion; and thereafter, rotating the processing container. And a spin coating step of forming a coating film on the coating target material by the coating material supplied on the coating target material. 6. A process container having an opening formed in the center and an abutting portion arranged around the opening, the step of supporting a material to be coated on the abutting portion, and the opening. A step of bringing the coating material into close contact with the abutting portion by a holding force of a holding unit arranged at a position facing the coating material via the coating container, and then rotating the processing container to apply the coating material. A spin coating step of forming a coating film on the coating material by the coating material supplied onto the coating material, wherein the coating material scattered from the coating material is in contact with the spin coating step. A coating method, which is prevented from being adhered to an inner region of the abutting portion in a back surface region of the coating target material by being blocked by a portion. 7. A coating apparatus for supplying a coating material to the surface of the coating material and applying the coating material by rotating the coating material, wherein an opening formed at the center and a periphery of the opening are provided. A processing container having an abutting portion formed therein, a rotation driving unit that rotationally drives the processing container, a shaft portion that extends upward through the opening, and a holding of the material to be coated provided on an upper end of the shaft portion. A holding means having a portion, and the processing container and the holding means are moved up and down relatively,
An elevating means for bringing the material to be coated into contact with the contact portion, and supporting and fixing the material to be coated to the contact portion by a holding force of the holding means. 8. The coating apparatus according to claim 7, wherein the holding unit is a vacuum suction unit. 9. The coating apparatus according to claim 8, wherein the elevating means sets the vacuum suction section at a position farther from the material to be coated when the processing container is rotated. 10. The contact portion according to claim 9, wherein the contact portion is a region between the coating material and an upper surface of the vacuum suction portion by being brought into close contact with the coating material. The coating device is also used as a sealing unit that hermetically seals the region that is negatively pressured by the vacuum suction unit. 11. The back surface region of the coating material according to claim 7, wherein the coating material scattered from the coating material during spin coating is the back surface area of the coating material. Of these, the coating device is also used as a coating material attachment preventing means for preventing the coating material from adhering to the inner area of the contact portion.