JPH05259060A - Applicator - Google Patents

Abstract

PURPOSE:To enable the rear side of a body to be worked and the outside and inside of a case to be cleaned at the same time. CONSTITUTION:An applicator is equipped with a rotating/holding means 4 which holds and rotates a body to be worked 2 and an outer case 64A and an inner case 64B which prevent a coating solution L2 from splashing, where a cleaning solution L is spouted out from discharge nozzles 72A and 72B to clean the body to be worked 2, and the rotating/holding means 4 is controlled in number of revolutions by a control means 78. By this setup, cleaning fluid flying from the rear of the body to be worked 2 reaches to the wall of a case 64 or the outer case 64A and the inner case 64B to clean them at the same time.

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 rotating an object to be processed such as a semiconductor wafer to apply a coating liquid.

[0002]

2. Description of the Related Art Conventionally, a resist rotation coating apparatus as shown in FIG. 5 has been tried as a coating apparatus for rotating an object to be processed such as a semiconductor wafer to apply a coating liquid. This coating apparatus holds a semiconductor wafer 2 as an object to be processed horizontally and spin chuck 4 as a rotation holding means for rotating at high speed.
A resist solution supply nozzle 6 for dropping a resist solution as a coating solution onto the semiconductor wafer 2, and an outer container 8 provided so as to surround the semiconductor wafer 2 on the spin chuck 4.
And an inner container 10. Further, below the spin chuck 4, a back surface cleaning nozzle 12 that discharges a cleaning liquid for cleaning the resist liquid adhering to the back surface of the wafer 2 is provided.

The resist solution dropped from the resist solution supply nozzle 6 onto the semiconductor wafer 2 is uniformly applied onto the semiconductor wafer 2 by the rotation of the spin chuck 4, and the excess resist solution is directed to the peripheral direction of the semiconductor wafer 2. The particles are scattered and adhere to the inner wall surfaces of the outer container 8 and the inner container 10. If the resist liquid layers attached to the outer container 8 and the inner container 10 are left to stand, the resist is gradually laminated and dried, and may be peeled from the containers 8 and 10 due to an impact or the like to contaminate the semiconductor wafer 2. is there. For this reason, the containers 8 and 10 are regularly removed and cleaned. However, this work is very time-consuming and time-consuming.

Therefore, in this coating device, the containers 8 and 10 are provided.
A cleaning mechanism is provided for automatically removing the resist attached to the. That is, as shown in FIGS. 5 and 6, in the cups 8 and 10, the introduction path 14 for introducing the cleaning solution L for dissolving the resist and the cleaning solution L introduced through the introduction path 14 are introduced.
An annular liquid reservoir 16 for distributing and supplying the liquid to the entire circumference of the containers 8 and 10 and a large number of small holes 18 for flowing out the cleaning liquid L of the liquid reservoir 16 to the resist adhering surface are formed.
A tube 22 for introducing a cleaning liquid is connected to the introduction path 14 via a joint 20. Then, the cleaning liquid L supplied to the liquid reservoir 16 flows out through each small hole 18, and flows down along the inner peripheral surface of the outer container 8 and the outer peripheral surface of the inner container 10. As another cleaning means, as shown in FIG. 7, the dummy wafer 2 is placed on the spin chuck 4.
There is also known a technique in which the cleaning liquid is supplied from the upper cleaning liquid supply nozzle 20 while the spin chuck 4 is placed and the spin chuck 4 is rotated, and the cleaning liquid is scattered to clean the containers 8 and 10 (Japanese Patent Laid-Open Publication No. 5 (1999) -58).
8-184725, JP-A-62-73630).

[0005]

However, in the former, that is, in the cleaning mechanism shown in FIGS. 5 and 6, the structure of the outer container 8 and the inner container 10 is complicated and not only expensive, but also in processing and mounting. difficult. Further, although the cleaning liquid L is made to flow through the hundreds of small holes 18, the cleaning liquid L easily flows along the path once it has flowed, so that the cleaning liquid L spreads evenly over the entire peripheral surfaces of the containers 8 and 10. There was a problem that it did not flow and uneven cleaning could occur. Furthermore, the cleaning operation of the containers 8 and 10 requires a certain number of wafers, for example, 100 to 200 wafers,
Although it is performed every time resist is applied, not only the resist application process of the wafer cannot be performed during the cleaning operation, but also a waiting time of about 5 to 10 minutes is required to return the container whose temperature has been lowered by the cleaning to room temperature, and the throughput is improved. There was an improvement in that

There is also a possibility that trouble such as leakage of the cleaning liquid L from the joint 20 may occur. In addition to the above
There is also a problem that it is difficult to control the scattering direction of the cleaning liquid and the container cannot be effectively cleaned. On the other hand, in the latter, that is, in the cleaning mechanism shown in FIG. 7,
Although it is possible to reduce the cleaning time and the consumption of the cleaning liquid, it takes time to load and unload the dummy wafers 24, and a standby space for the dummy wafers 24 and manual loading and unloading are required.
There is a problem that particles attached to the surface of No. 4 adhere to the spin chuck 4 and contaminate the wafer 2. The present invention has been made to pay attention to the above problems and to solve them effectively. An object of the present invention is to provide a coating apparatus capable of simultaneously cleaning the back surface of the object to be processed and the container.

[0007]

In order to solve the above problems, the present invention provides a rotation holding means for holding and rotating an object to be processed, and a rotation holding means provided so as to surround the rotation holding means. In a coating device having a container for preventing scattering of the coating liquid supplied to the body, a cleaning liquid discharge nozzle for discharging a cleaning liquid toward the back surface of the object to be processed held by the rotation holding means, A control means for changing the rotation speed of the rotation holding means when cleaning the back surface of the processing object is provided, and the cleaning liquid hitting the back surface of the processing object is scattered toward the wall surface of the container. It is composed.

[0008]

Since the present invention is configured as described above, when the object to be processed held by the rotation holding means cleans the back surface of the object to be processed in the final step of resist coating, the cleaning liquid is discharged from the cleaning liquid discharge nozzle. While discharging, the rotation speed of the rotation holding means is increased / decreased and changed by the control means. As a result, when the rotation speed is high, the cleaning liquid that has hit the back surface of the object to be processed is relatively horizontally blown by a large centrifugal force and hits the outer wall surface of the container to wash it, whereas when the rotation speed is low, the cleaning liquid is applied. The cleaning liquid that has hit the back surface of the processing body does not fly too far and hits the inner wall surface of the container to wash it. Therefore, it becomes possible to perform the back surface cleaning of the object to be processed and the container cleaning at the same time.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the coating apparatus according to the present invention will be described in detail below with reference to the accompanying drawings. 1 is a sectional view showing a coating apparatus according to the present invention, FIG. 2 is a schematic plan view showing an embodiment in which the present invention is applied to a resist film forming apparatus, and FIG. 3 is a main portion showing a main portion of the apparatus of FIG. FIG. The same parts as those of the conventional device are designated by the same reference numerals. As shown in the figure, this resist film forming apparatus is used for processing an object to be processed, such as a semiconductor wafer 2.
A processing mechanism unit 28 in which a processing mechanism for performing various kinds of processing (hereinafter simply referred to as a wafer) is arranged, and a loading / unloading mechanism 30 for automatically loading / unloading the wafer 2 into / from the processing mechanism unit 28. It is mainly composed of and. The loading / unloading mechanism 30 includes a wafer carrier 32 for storing a wafer 2 before processing, a wafer carrier 34 for storing the wafer 2 after processing, and an arm 36 for sucking and holding the wafer 2.
And a moving mechanism 38 for moving the arm 36 in the X (left and right), Y (front and back), Z (vertical) and θ (rotation) directions,
Wafer 2 is aligned and processing mechanism unit 28
And an alignment stage 40 for transferring the wafer 2 to and from.

The processing mechanism unit 28 is provided with a transport mechanism 44 which is movable along the transport path 42 formed in the X direction from the alignment stage 40. The transport mechanism 44 is provided with a main arm 46 that is movable in the X, Y, and θ directions. On one side of the transport path 42,
Adhesion processing mechanism 48 for performing adhesion processing for improving the adhesion between the wafer 2 and the resist liquid film.
A pre-bake mechanism 50 for heating and evaporating the solvent remaining in the resist applied to the wafer 2 and a cooling mechanism 52 for cooling the heat-treated wafer 2 are provided. Further, on the other side of the transport path 42, a coating mechanism 54 according to the present invention for coating the resist liquid on the surface of the wafer 2.
A (coating device) and a surface coating layer coating mechanism 56 for coating and forming a CEL film or the like on the resist of the wafer 2 are arranged in order to prevent diffused reflection during the exposure process.

The coating apparatus 54 according to the present invention holds a wafer 2 as an object to be processed on the upper surface thereof, for example, a spin chuck 4 which is a rotary holding means for rotating by holding it by vacuum suction, and the spin chuck 4. It has a spin motor 58 for rotating. A plurality of holding vacuum holes (not shown) connected to a vacuum pump or the like are provided on the upper surface of the spin chuck 4. A bottom plate 62 is provided below the spin chuck 4 so that the rotation shaft 60 of the spin chuck 4 is inserted therethrough. Above the bottom plate 62, the coating liquid L2 supplied to the upper part of the wafer 2 is prevented from scattering. A container 64 for is formed. Specifically, this container 64 is
A first outer cover of the spin chuck 4 whose upper end is slightly higher than the horizontal level of the spin chuck.
It is mainly configured by a container, an annular outer container 64A, a second container extending from the lower part of the spin chuck in the outer peripheral direction thereof, and an annular inner container 64B. Both the outer container 64A and the inner container 64B are formed so as to be gradually inclined toward the outer side in the radial direction of the spin chuck, and are configured to guide the coating liquid adhering to these wall surfaces toward the bottom plate 62. ing.

Further, the bottom plate 62 is formed so as to be gently inclined in one direction, and the container 64 is formed at the uppermost position thereof.
An exhaust pipe 66 for exhausting the inside is connected, and a drain pipe 68 for discharging a coating liquid flowing down in the container, a cleaning liquid described later, and the like is connected at the lowest position. Further, the bottom plate 6 slightly inward in the radial direction from the peripheral portion of the inner container 64B.
A partition 70 is provided on the inner wall 2 in a circular shape so as to prevent the drainage of liquid and the like from entering the inside.

Below the spin chuck 4, a plurality of, for example, two cleaning liquid discharge nozzles 7 for discharging the cleaning liquid L such as thinner toward the back surface of the wafer.
2A and 72B are provided. Specifically, these discharge nozzles 72A and 72B are arranged point-symmetrically with respect to the rotation center of the spin chuck, and the back surface can be effectively cleaned even for a wafer having a large radius such as an 8-inch wafer. Is configured. The number of these discharge nozzles may be one or three or more, and is not limited to that number. In the case of a plurality, these nozzles are arranged at equal intervals along the circumferential direction of the spin chuck.
In this case, the inclination angle θ of each of the discharge nozzles 72A and 72B with respect to the vertical direction is set to, for example, about 45 °, and the cleaning liquid scattered on the back surface of the wafer reaches the inner wall of the outer container 64A when the wafer rotates at high speed, and scatters when it rotates at low speed. The cleaning liquid is configured to reach the outer wall of the inner container 64B. The inclination angle θ is not limited to 45 °, and can be set within the range of 25 to 65 ° in relation to the rotation speed with the spin chuck.

The nozzle position is determined so that the intersection of the extension direction of each nozzle 72A, 72B and the wafer 2 is separated from the outer periphery of the spin chuck 4 by a predetermined distance L3, for example, about 15 mm. Each of the discharge nozzles 72A and 72B is connected to a cleaning liquid supply unit 76 having a cleaning liquid tank, a supply pump and the like via a pipe 74 and the like. Further, the cleaning liquid supply unit 76 is controlled by a control signal from a control unit 78 which is preprogrammed in the cleaning process and the like and is composed of, for example, a microprocessor, and the control unit 78 is the spin motor 5.
8 is also controlled to change the rotation speed of the spin chuck 4 from a low speed to a high speed or vice versa while the back surface cleaning operation of the wafer 2 is being performed, so that the cleaning liquid L that has collided with the back surface of the wafer in the horizontal direction. It is configured so that the scattering angle and the like can be changed. A resist liquid supply nozzle 6 for supplying a coating liquid L2 such as a resist onto the wafer 2 is provided above the spin chuck 4.

Next, the operation of this embodiment configured as described above will be described. First, the unprocessed wafer 2 is unloaded from the wafer carrier 32 by the arm 36 of the loading / unloading mechanism 30 and placed on the alignment stage 40. Next, the wafer 2 on the alignment stage 40 is held by the main arm 46 of the transfer mechanism 44,
The processing mechanisms 48 to 56 are sequentially conveyed and processed.
Then, the processed wafer 2 is returned to the alignment stage 40 by the main arm 46, further carried by the arm 36, and stored in the wafer carrier 34.

In the coating apparatus 54 according to the present invention among the above processing mechanisms, the resist film forming operation is performed as follows. First, the wafer 2 is placed on the spin chuck 4 and held by vacuum suction. Then, by driving the spin motor 58 while holding the wafer 2, the spin chuck 4 and the wafer 2 adsorbed to the spin chuck 4 are rotated at a high speed, for example, at a rotation speed of 2000 rpm, and at the same time, a predetermined amount is supplied from the resist solution supply nozzle 6. Coating liquid L
2 (resist liquid) is dropped and supplied onto the wafer 2. At this time, the atmosphere in the container 64 is exhausted with a predetermined suction force via the exhaust pipe 66. A centrifugal force is applied to the supplied coating liquid by the rotating wafer 2 so that the coating liquid is uniformly spread on the wafer surface from the center of the wafer in the radial direction. Is scattered and adheres to the inner wall surface of the outer container 64A and the outer wall surface of the inner container 64B, and the mist-like coating liquid adheres to the side surface and the back surface of the wafer 2. If left as it is, it may cause particles.

When the coating process for a predetermined time is completed in this way, the control means 78 drives the cleaning liquid supply section 76 to discharge the cleaning liquid L such as thinner from both cleaning liquid discharge nozzles 72A and 72B to discharge the wafer 2 from the wafer 2. The back surface is washed and the side rinse is performed to remove the coating liquid adhering thereto. When this back surface cleaning is performed, the spin motor 58 is controlled by the control means 78 while discharging the cleaning liquid L to increase or decrease the rotation speed of the wafer 2 in a range of 500 to 2000 rpm, for example, and the back surface of the wafer 2 is collided. By gradually increasing or decreasing the centrifugal force applied to the scattered cleaning liquid, the scattered cleaning liquid reaches the inner wall surface of the outer container 64A and the outer wall surface of the inner container, and cleans these surfaces.

That is, as shown in FIG. 3, when the wafer 2 is rotating at a high speed, for example, at 2000 rpm, a relatively large centrifugal force is applied to the cleaning liquid that has collided with the front surface of the wafer. At the same time, it reaches the peripheral portion, is scattered in a substantially horizontal direction as shown by an arrow 80, adheres to the inner wall surface 82 of the outer container 64A, and is washed while flowing down this portion. Then, as the number of rotations of the wafer decreases, the scattering direction of the cleaning liquid gradually inclines downward from the horizontal direction as shown in the drawing, and the cleaning liquid also adheres to the outer wall surface 84 of the inner container 64B. In particular, when the rotation speed of the wafer 2 is set to the lowest, for example, when the rotation speed is 500 rpm, the centrifugal force applied to the cleaning liquid is considerably small, so that the cleaning liquid colliding with the back surface of the wafer is inclined downward from the middle of the radial direction of the wafer as shown by an arrow 86. Then, it falls, adheres to the outer wall surface 84 of the inner container 64B and flows down while being washed.

Such a wafer back surface cleaning operation is performed for the same time as the conventional wafer back surface cleaning operation, for example, 10 seconds,
Then, the thinner is shaken off and dried at high speed.
Then, when the cleaning liquid has been dried, the wafer 2 is transported to the next processing mechanism. As described above, in this embodiment, the cleaning of the back surface of the wafer and the cleaning of the wall surfaces of the outer and inner containers 64A and 64B are performed simultaneously for each operation of forming the resist film on the wafer. It is not necessary to perform a container cleaning operation by setting a special cleaning time each time the wafer is processed, and the throughput of the resist forming process can be improved.

Further, in this embodiment, it is not necessary to adopt a complicated structure for supplying the cleaning liquid to the container 64 as shown in FIG. 4, and the structure of the container 64 can be simplified. Particularly, in this embodiment, since the cleaning liquid discharge nozzles 72A and 72B are arranged at positions symmetrical with respect to the rotation center of the spin chuck, even if the size of the wafer increases, for example, 8 inches, The back surface and the wall surfaces of the outer and inner containers 64A and 64B can be reliably washed. In the above embodiment, the rotation speed of the spin chuck 4 was set to change in the range of 500 to 2000 rpm, but the present invention is not limited to this, and the spray direction of the cleaning liquid is the inclination angle θ of the nozzles 72A and 72B. Since it also depends on the inclination angle θ, the rotation number of the spin chuck is also determined, and the outer and inner containers 64A, 64
The rotation speed is controlled so that the cleaning liquid adheres to the wall surface of B.
At this time, the spin chuck 4 may be moved up and down. By doing so, the upper wall surface of the outer container 64A, and
The upper wall surface of the inner container 64B can be washed more effectively.

Further, in the above embodiment, the inclination angles θ of the two cleaning liquid discharge nozzles 72A and 72B are both set to the same value, and the rotation speed of the wafer is changed at the time of cleaning the back surface of the wafer, whereby the inner wall surface of the outer container 64A is changed. Although the cleaning liquid is spattered toward the outer wall surface of the inner container 64B, it may be configured as shown in FIG. Incidentally, FIG.
The same parts as those of the device shown in FIG. That is, one cleaning liquid discharge nozzle 72A
The inclination angle θ2 is set to the same angle as that shown in FIG. 1, and the distance L3 from the peripheral portion of the spin chuck 4 is also set to about 15 mm. The number of rotations of the wafer 2 during the back surface cleaning operation of the wafer is also constant, and the cleaning liquid scattering direction 90 at this time is set.
The rotational speed is set so that the direction is relatively close to the center of the outer wall surface of the inner container 64B.

Then, the inclination angle θ3 of the other cleaning liquid discharge nozzle 72B is set to be larger than the inclination angle θ2 so that the discharged cleaning liquid hits the substantially central portion in the radial direction of the wafer, and is rotated during the cleaning of the back surface of the wafer. The scattering direction 92 of the cleaning liquid is substantially horizontal with respect to the number of wafers. That is, the inclination angle θ3 is
The angle is set so that the cleaning liquid scattered from the back surface of the wafer can reach the inner wall surface of the outer container 64A. Like this, 2
By setting different inclination angles of the two discharge nozzles 72A and 72B in advance, the inner wall surface of the outer container 64A and the outer wall surface of the inner container 64B can be simultaneously formed without changing the rotation speed of the wafer when cleaning the back surface of the wafer. It becomes possible to wash, and the same effects as those of the above-mentioned embodiment can be exhibited. Incidentally, in the present invention, the object to be processed can be applied to not only a semiconductor wafer but also a printed circuit board, an LCD substrate, etc. Further, the present invention is applicable not only to a resist coating apparatus but also to a developing solution coating apparatus, an etching solution coating apparatus. It can also be applied to an apparatus, a magnetic liquid coating apparatus, a cleaning apparatus, and the like.

[0023]

As described above, according to the present invention, the following excellent operational effects can be exhibited. Since the backside cleaning of the object to be processed and the wall surface of the container are performed at the same time, it is not necessary to perform the cleaning operation of the container alone as in the conventional device, and therefore the processing efficiency and production efficiency are greatly improved. Can be made. Further, since the structure of the container itself can be simplified, not only the cost of the apparatus itself can be significantly reduced, but also maintenance can be easily performed.

[Brief description of drawings]

FIG. 1 is a sectional view showing a coating apparatus according to the present invention.

FIG. 2 is a schematic plan view showing an embodiment in which the present invention is applied to a resist film forming apparatus.

3 is a cross-sectional view of a main part showing a main part of the apparatus shown in FIG.

FIG. 4 is a cross-sectional view showing another coating device according to the present invention.

FIG. 5 is a cross-sectional view showing a conventional coating device.

6 is a perspective cross-sectional view of the device shown in FIG.

FIG. 7 is a cross-sectional view showing another conventional coating device.

[Explanation of symbols]

 2 semiconductor wafer (object to be processed) 4 spin chuck (rotation holding means) 54 coating mechanism (coating device) 58 spin motor 64 container 64A outer container (first container) 64B inner container (second container) 72A, 72B cleaning liquid discharge nozzle 76 Cleaning Liquid Supply Unit 78 Control Means 82 Inner Wall Surface 84 Outer Wall Surface L Cleaning Liquid L2 Coating Liquid

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location // G03F 7/16 502

Claims (3)

[Claims] 1. A rotation holding means for holding and rotating an object to be processed, and a container which is provided so as to surround the rotation holding means and which prevents scattering of a coating liquid supplied to the object to be processed. In the coating apparatus having the cleaning liquid discharge nozzle for discharging the cleaning liquid toward the back surface of the object to be processed held by the rotation holding means, and the rotation speed of the rotation holding means when cleaning the back surface of the object to be processed. A coating device provided with a control means for changing the cleaning liquid, and configured to scatter the cleaning liquid hitting the back surface of the object to be processed toward the wall surface of the container. 2. The coating apparatus according to claim 1, wherein a plurality of the cleaning liquid discharge nozzles are formed. 3. A rotation holding means for holding and rotating an object to be processed, and a first member provided around the rotation holding means for preventing the coating liquid supplied to the object to be scattered.
In a coating device having a container and a second container, a first cleaning liquid discharge nozzle set so that a cleaning liquid discharged toward the object to be processed reaches the first container, and a cleaning liquid toward the object to be processed. An application device, comprising: a second cleaning liquid discharge nozzle set so that the discharged cleaning liquid reaches the second container.