JP2588379B2 - Coating device - 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 vessel 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 device for coating.

[0002]

2. Description of the Related Art In a semiconductor manufacturing apparatus, when a resist is coated on a wafer, the wafer is mounted and fixed on a rotatable spin head disposed inside a processing vessel, and the resist solution is rotated while the wafer is rotated. Is supplied to the wafer surface to perform a resist coating process (Japanese Patent Publication No. 53-37189).

On the other hand, in recent years, in order to increase the number of chips that can be formed on one wafer, there has been an increasing demand for using a larger-diameter, for example, an 8-inch wafer instead of the conventional 6-inch wafer. 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.

According to Japanese Patent Application Laid-Open No. 61-194829, a technique for forcibly introducing a vapor stream of a solvent into a processing vessel in order to stabilize the quality of a coating film has been proposed.
It has been confirmed by the present inventors that even this technique cannot reliably resist large-diameter wafers.

Here, JP-A-51-39737 and JP-A-60-143871 disclose a technique for rotating a processing vessel in which a wafer is placed in the same direction as the wafer. According to these techniques, the promotion of evaporation of the solvent on the wafer is suppressed, and the uniformity of resist application at the peripheral portion of the wafer can be improved.

Incidentally, as one of the coating characteristics when forming an appropriate resist coating film on a wafer, it is necessary to control the coating environment temperature as desired. One of the causes of adversely affecting the coating environment temperature is heat generated by the rotary motor. As described in each of the above publications, when the processing container 4 is driven to rotate integrally with the wafer, the influence of the heat of the motor driving the processing container must be considered.

However, according to the coating apparatus disclosed in each of the above publications, the motor shaft of the motor for rotating the processing container is directly connected to the processing container, and the heat generated by this motor transfers the heat generated by the motor to the processing container via the rotating shaft. There was a problem that was transmitted to.

Therefore, an object of the present invention is to rotate the material to be coated and the processing container surrounding the coating material in the same direction to improve the coating characteristics and to reduce the heat of the motor for rotating the processing container. It is an object of the present invention to provide a coating apparatus which is less susceptible to the influence of the coating and which makes it easy to adjust the coating environment temperature.

[0012]

[0013]

[0014]

According to a first aspect of the present invention, there is provided a coating apparatus, comprising: an opening formed at a center; a contact portion of a material to be coated disposed around the opening; A processing container having a rotation driven shaft formed with a hollow portion communicating with the opening, a shaft portion extending upward through the hollow portion and the opening, and the coating material provided at an upper end of the shaft portion A holding unit having a holding unit, and the processing container and the holding unit are relatively moved up and down so that the material to be applied held by the holding unit is brought into contact with the contact portion of the processing container. Lifting / lowering means for bringing into contact with the container, and container rotation driving means for rotating the rotation driven shaft of the processing container supporting the material to be applied on the contact portion, and the container rotation driving means, A rotary drive shaft arranged in parallel with the driven rotary shaft,
And a tension member that spans the rotation drive shaft and the driven rotation shaft to transmit a rotational force.

According to a second aspect of the present invention, there is provided a coating apparatus, wherein an opening formed in the center, an abutting portion of a material to be coated disposed around the opening, and a hollow portion communicating with the opening. A processing container having a driven shaft to be formed, a shaft portion extending upward through the hollow portion and the opening, and a vacuum suction portion for applying the applied material provided at an upper end of the shaft portion, Vacuum suction means having, the processing container and the vacuum suction unit is moved up and down relatively, and the applied material sucked by the vacuum suction is brought into contact with the contact portion of the processing container, Thereafter, elevating means for moving the vacuum suction unit away from the material to be coated, and the cover of the processing container in which the material to be coated is tightly supported on the contact portion by the suction force of the vacuum suction unit. A rotation drive shaft, having a container rotation drive means for rotationally driving, The container rotation drive means includes a rotation drive shaft arranged in parallel with the driven rotation shaft, and a tension member that is transmitted over the rotation drive shaft and the driven rotation shaft to transmit a rotational force. It is characterized by the following.

The coating apparatus according to the third aspect of the present invention includes an opening formed in the center, an abutting portion of a material to be coated disposed around the opening, and a hollow portion communicating with the opening. A processing container having a driven shaft to be formed, a shaft portion extending upward through the hollow portion and the opening, and a vacuum suction portion for applying the applied material provided at an upper end of the shaft portion, The vacuum suction means having the above, the processing container and the vacuum suction unit are relatively moved up and down, and the coating material sucked by the vacuum suction unit is brought into contact with the contact portion of the processing container. Lifting means for moving the vacuum suction unit away from the material to be coated, and the processing container in which the material to be coated is tightly supported on the contact portion by the suction force of the vacuum suction unit. First rotation driving means for driving the rotation driven shaft to rotate, Second rotation driving means for driving the shaft portion of the empty suction means to rotate, the first rotation driving means comprising: a rotation driving shaft arranged in parallel with the driven rotation shaft; And a tension member that is wound around the shaft and the driven shaft to transmit a rotational force.

[0017]

According to the present invention, since the processing container and the processing container are also rotating in the same direction, the relative speed difference is small (the relative speed difference is zero at the same rotation speed). Even in the case of the material to be applied, evaporation at the peripheral portion is suppressed, and the application of the application material can be reliably performed in the desired region. 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.

Further, according to the present invention, the rotational force on the driving side is transmitted between the rotationally driven shaft provided on the rotationally driven processing container and the rotationally driving shaft provided on the container rotationally driving means. There is provided a stretching member formed of a belt or the like. As described above, since the rotational force from the container rotation driving unit is not transmitted directly to the processing container side by the drive shaft or the like, but is transmitted through a stretching member such as a belt, the motor constituting the container rotation driving unit is used. The heat generated in the process is less likely to be transferred to the processing container. As a result, adverse effects on the coating environment temperature are reduced, and coating quality can be improved.

When the driven shaft provided in the processing vessel is a hollow shaft, the hollow portion of the hollow shaft is used, as defined in claims 1 to 3 , respectively. Thus, the holding means can be arranged. The relative movement between the holding means and the processing container makes it possible to easily arrange the material to be applied inside and outside the processing container.

According to the third aspect of the present invention, the shaft of the holding means, which is disposed inside the hollow driven shaft, can be driven to rotate. The holding means having the shaft portion rotated and driven by the second rotation driving means can be used in the back surface cleaning step after the spin coating step.

[0021]

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

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

In this figure, the apparatus of this embodiment has, as its basic framework, a lower base 1, an upper base 2 and columns 3, 3 for fixing the two bases 1, 2 apart and in parallel.

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

The first container 11 disposed on the upper side is supported by the movable plate 13 via the mounting bases 10A and 13A, and can be raised to a position shown by a two-dot chain 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. Further, a packing 19 is provided on a peripheral portion of the first container 11 so that the processing container 10 can be hermetically sealed.

The lower second container 12 is supported by a rotation driving mechanism 40 as first rotation driving means or container rotation driving means having the following configuration. 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 rotating 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 disposed on the lower base 1, and a second pulley 26 is fixed around an 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 center region of the second container 12, there is provided a hollow disk-shaped vacuum suction part 30 projecting from the inner surface of the second container 12 and functioning as a contact part.
The wafer 4 placed in the chamber 0 can be vacuum-sucked. Since the vacuum suction unit 30 is fixed to the second container 12 with screws or the like, the vacuum suction unit 30 can be integrally rotated 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 20 </ b> A is open inside the vacuum suction part 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. An elevating drive unit 33 and a guide shaft 34 are fixed to both sides of the first motor 32 on the lower base 1, and one of the support frames 35 supporting the first motor 32 is connected to a first elevating drive unit. Is fixed to an elevating shaft 33A of the elevating 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 is vertically movable and rotatable. 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. In the apparatus of the present embodiment, the dropping portion of the coating material is not shown, but this dropping portion is located above the wafer 4 when the first container 11 is raised to the position shown by the two-dot chain line in FIG. Then, a predetermined amount of a coating material (a resist material in the present embodiment) is dropped on the center 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 elevation drive unit 14 is driven to raise the first container 11 to the position shown by the two-dot chain line in the figure. With the processing container 10 released, the setting of the wafer 4 and the resist by the dropping unit are performed. The material is dropped sequentially. 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). Although the spin chuck 31 is not in contact with the back surface of the wafer 4, the region between the wafer 4 and the spin chuck 31 is sealed by the close contact between the wafer 4 and the vacuum suction unit 30. The wafer 4 can be tightly supported on the second container 12 side by setting the area to a negative pressure. 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 rotating block 22 is rotated, the second container 12 and the vacuum suction unit 30 fixed to the rotating block 22 are integrally rotated. Further, the first container 11 is pressed by the second container 12 by the elevation drive unit 14 and is rotatable via the bearing 18, so that the first container 11 rotates integrally with the second container 12. Will be.

As a result, the wafer 4 and the processing container 10 vacuum-sucked by the vacuum suction part 30 rotate integrally, and the surrounding space in the processing container 10 rotates together with the wafer 4 in the same direction at the same speed. Will be.

Here, the main reason that the resist material could not be reliably applied to the peripheral portion of the wafer 4 having a larger diameter than the conventional one is that when the wafer 4 is rotated at a high speed, the peripheral portion of the wafer 4 and its surrounding space are not removed. Is significantly increased. 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 the application operation is performed for a predetermined time, the driving of the second motor 24 is stopped, and the elevation drive unit 14 is driven to raise the first container 11 to the position indicated by the two-dot chain line in FIG. 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 the 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-described embodiment, a so-called nozzle scan system which can move and scan the inside and outside of the upper region of the wafer 4 is adopted as the coating material dropping portion. 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 the above embodiment, in addition to the conventional spin chuck 31, a 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, without providing the vacuum suction unit 30, the suction and rotation of the wafer 4 in the processing container 10 can be performed by the spin chuck 31. 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.

[0039]

As described above, according to the present invention, it is possible to provide a coating apparatus capable of reliably applying a coating material to a large-diameter coating material in a desired range. It is possible to reduce the heat generated by a motor or the like for rotating and driving the processing container at the time of coating, which is transferred to the processing container side, and to reduce the adverse effect on the coating environment temperature as compared with the related art.

[0040]

[Brief description of the drawings]

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

[Explanation of symbols]

 4 Coating Material 10 Processing Container 11 First Container 12 Second Container 14 Second Rotation Drive Unit 30 Vacuum Suction Unit (Contact Unit) 31 Spin Chuck (Holding Unit) 40 First Rotation Drive Unit

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Dentsu Omori 5-3-6 Akasaka, Minato-ku, Tokyo Inside Tokyo Electron Co., Ltd. (56) References JP-A-59-33453 (JP, A) JP-A Sho 51-39737 (JP, A)

Claims (3)

(57) [Claims] 1. A processing container having an opening formed in the center, a contact portion of a material to be coated disposed around the opening, and a driven shaft having a hollow portion communicating with the opening. A shaft portion extending upward through the hollow portion and the opening;
Holding portion of the material to be applied provided at the upper end of the shaft portion,
Holding means having: a lifting means for relatively moving the processing container and the holding means up and down, and bringing the applied material held by the holding means into contact with the contact portion of the processing container; A container rotation driving unit that rotationally drives the rotation driven shaft of the processing container that supports the material to be applied on the contact portion; and the container rotation driving unit includes: a rotation driving shaft; A coating apparatus, comprising: a rotary drive shaft arranged in parallel; and a stretching member that is stretched over the rotary drive shaft and the driven shaft to transmit a rotational force. 2. A processing container having an opening formed in the center, an abutting portion of a material to be coated disposed around the opening, and a driven shaft having a hollow portion communicating with the opening. A shaft portion extending upward through the hollow portion and the opening;
A vacuum suction unit having a vacuum suction unit for the material to be applied provided at an upper end of the shaft unit; and the processing container and the vacuum suction unit are relatively moved up and down to be sucked by the vacuum suction. Elevating means for bringing the material to be applied into contact with the contact portion of the processing container, and thereafter bringing the vacuum suction unit away from the material to be applied; and A container rotation drive unit for rotating and driving the rotation drive shaft of the processing container in which the material to be coated is closely contacted and supported on the unit; and wherein the container rotation drive unit includes the rotation drive shaft and A coating apparatus, comprising: a rotary drive shaft arranged in parallel; and a stretching member that is stretched over the rotary drive shaft and the driven shaft to transmit a rotational force. 3. A processing container having an opening formed in the center, an abutting portion of a material to be coated disposed around the opening, and a driven shaft having a hollow portion communicating with the opening. A shaft portion extending upward through the hollow portion and the opening;
A vacuum suction unit having a vacuum suction unit for the material to be applied provided at an upper end of the shaft unit; and a processing container and the vacuum suction unit which are relatively moved up and down to be suctioned by the vacuum suction unit. Lifting / lowering means for bringing the material to be applied into contact with the contact portion of the processing container, and thereafter bringing the vacuum suction part away from the material to be coated; and a suction force of the vacuum suction part. First rotation driving means for rotating and driving the rotation driven shaft of the processing container in which the material to be coated is tightly supported on a contact portion; and second rotation driving means for rotating the shaft of the vacuum suction means. A rotation drive unit, wherein the first rotation drive unit is wound around the rotation drive shaft arranged in parallel with the driven rotation shaft, and the rotation drive shaft and the rotation driven shaft. And a tension member for transmitting rotational force. Apparatus.