JP2001239199A - Coating film forming device and coating film forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the in-plane uniformity of a film thickness of a resist film in a resist liquid applying device, for example. SOLUTION: The coated region of a wafer W is divided into three regions and the coating film of a resist liquid is formed per the divided region of the wafer W surface by moving the wafer W and/or driving a supply nozzle 6 in a specified application order and/or an application direction so that the application initiating positions of the adjacent divided regions do not adjoin to each other and/or the resist liquid is not continuously applied to the application ending position of one of the adjacent divided regions and the application initiating position of the other adjacent divided region in this order, when the application ending position and the application initiating position adjoin to each other. Consequently, such a phenomenon that the resist liquid is drawn to the application initiating position side, resulting in the increased film thickness of the part on this part, occurs only in the region where the application initiating position is present. Thus, it is possible to enhance the in-plane uniformity of the film thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of applying a liquid, especially a resist liquid, made of a resin or the like dissolved on a substrate to be processed, such as a semiconductor wafer, an LCD substrate or an exposure mask, and forming a film of the liquid. The present invention relates to a coating film forming apparatus to be formed.

[0002]

2. Description of the Related Art A mask for forming a circuit pattern on the surface of a substrate to be processed such as a semiconductor wafer or an LCD substrate is formed by applying a resist solution onto a substrate surface and then resisting light, an electron beam or an ion beam. It is obtained by irradiating the surface and developing. Among them, a spin coating method is mainly used as a method of applying a resist liquid. In this method, for example, as shown in FIG. 21, a substrate, for example, a semiconductor wafer (hereinafter, referred to as “wafer”) W is suction-held on a spin chuck 11 having a vacuum suction function, and the wafer W
After the resist solution 13 is dropped from the nozzle 12 to the center of the wafer W, the resist solution 13 is diffused over the entire wafer W by rotating the wafer W by rotating the wafer W at a high speed,
This is to form a substantially uniform resist liquid film over the entire surface of the wafer W.

In recent years, the line width of circuit patterns has become increasingly finer, and the line width of circuits is proportional to the thickness of the resist film and the exposure wavelength. I have. In the spin coating method, the resist film thickness can be reduced by increasing the rotation speed of the wafer W. For example, in the case of an 8-inch wafer W, the wafer W is rotated at a high rotation speed of 200 to 4000 rpm. ing.

However, this spin coating method has the following problems to be solved. First, in this method, when the size of the wafer W is increased, the peripheral speed at the outer peripheral portion is increased, so that turbulence of air is caused. This causes the exposure resolution to decrease.
For this reason, it is difficult to obtain a constant coating film with a film thickness of 0.4 μm or less by this method, and there is naturally a limit in the production of a semiconductor having a thickness of about several giga or more.

Next, according to this method, in the process of diffusing the resist solution from the center of the wafer W toward the peripheral portion, the solvent contained in the resist solution evaporates sequentially.
For this reason, the viscosity of the resist liquid varies along the diffusion direction, and the thickness of the resist film formed between the central portion and the peripheral portion may vary.

Further, in this method, since the wafer W is rotated at a high speed, a large amount of the resist solution is scattered from the peripheral portion of the wafer W and wasted. According to one example, it is known that only 10% or less of the resist liquid supplied onto the wafer W contributes to the formation of the resist liquid film.

Further, in this method, it is necessary to rotate the wafer W in the cup in order to receive the scattered resist solution. However, the resist solution adhered to the cup may become particles and contaminate the wafer W. This requires frequent cleaning of the cup.

Further, in this method, the resist solution is also applied to a region outside the circuit formation region of the wafer W. However, if the resist solution is left in this region, it may cause the generation of particles in a later process. Therefore, the resist liquid in this region must be removed by a dedicated device called an edge remover immediately after the resist liquid coating step.

For this reason, the present inventors have proposed, as an alternative to the spin coating method, for example, as shown by a solid line in FIG. 22, the nozzle 12 for discharging a resist solution 13 onto the surface of the wafer W and the wafer W, for example. The wafer is reciprocated in the X direction while intermittently feeding at a predetermined pitch in the Y direction.
The method of applying the third method (hereinafter referred to as “one-stroke writing method”) is being studied. In this case, in order to prevent the resist solution from adhering to the peripheral edge and the back surface of the wafer W, a mask member covering an area outside the circuit formation area 14 of the wafer W is covered, so that only the circuit formation area 14 is covered. The resist liquid 13 is applied. In this method, since the wafer W is not rotated, the above-mentioned inconvenience is solved, and the coating can be performed without waste.

[0010]

In the one-stroke coating method, the diameter of the discharge hole of the nozzle 12 is 10 μm to 20 μm in order to reduce the thickness of the resist film.
Although the resist liquid 13 is formed to have a considerably small diameter of about 0 μm, when the resist liquid 13 is discharged from the nozzle 12 and collides with the wafer W, for example, as shown in FIG. The liquids 13 are connected to each other, and a liquid film of the resist liquid 13 is formed on the entire surface of the wafer W.

However, according to this method, Y in FIG.
When the application of the resist liquid 13 is started in the direction indicated by the arrow in the figure from the application start point indicated by a to the application end point indicated by Yb, Y
It has been confirmed that the point a has a larger film thickness than the point Yb. Depending on the type of the resist solution 13, the film thickness at the application start point Ya may be noticeably higher.

The reason for this is that the resist solution 13 is drawn to the previously painted region shown by oblique lines in FIG. 24 due to the spread of the resist solution 13 due to the collision with the wafer W described above, and thus the film thickness at the point Ya becomes large. It is considered to be.

The present invention has been made under such circumstances, and an object of the present invention is to divide a coating region of a substrate to obtain a stable film thickness over the surface of the substrate. Another object is to provide a technique capable of forming a uniform coating film with a high yield of the coating liquid.

[0014]

Therefore, in the present invention,
A substrate holding unit for holding the substrate substantially horizontally, a supply nozzle for supplying a processing liquid to the surface of the substrate held by the substrate holding unit, and the substrate holding unit and a supply nozzle,
A drive mechanism for relatively driving along the surface direction of the substrate, and a control unit for controlling the operation of the drive mechanism, the control unit is provided in each region of the divided application region of the substrate The operation of the substrate holding unit and / or the supply nozzle is controlled via the drive mechanism so as to supply the processing liquid in a predetermined application sequence and / or a predetermined application direction, and the substrate is supplied from the supply nozzle to the substrate. The supply timing of the processing liquid is controlled, and a liquid film of the processing liquid is formed for each divided region of the substrate surface.

In such a coating film forming apparatus, at least the first and second substrates are moved while relatively moving the substrate and the supply nozzle for supplying the processing liquid onto the substrate along the surface direction of the substrate. A step of supplying a processing liquid to a first region on the substrate divided into regions, and the substrate and a supply nozzle for supplying a processing liquid on the substrate are relatively moved along a surface direction of the substrate. Supplying the processing liquid to the second region such that the application start position is not adjacent to the application end position in the supply process of the first region while moving. A coating film forming method is performed.

In such an invention, the phenomenon that the processing liquid is drawn to the coating start position side and the film thickness of this portion is increased occurs only in the area, and the processing liquid is drawn to the coating start position in the area. Is small, so that the film thickness on the coating start position side is large, the extent is considerably reduced compared to the case where the coating region of the substrate is not divided,
As a result, the in-plane uniformity of the film thickness can be improved.

Here, when the coating start positions of the adjacent coating regions are adjacent to each other, the control unit increases the amount of the processing liquid drawn to the boundary portion, and the film thickness of the portion becomes extremely large. Therefore, it is desirable that the application start positions of the adjacent divided areas do not be adjacent to each other. Further, when the application end position of one of the adjacent divided regions and the application start position of the other region are adjacent to each other, when the application end position and the application start position are successively applied in this order, Since these two regions are applied together, the processing liquid is eventually drawn to the application start position side of the first application region, and the film thickness in this portion becomes considerably thick. It is desirable that the end position and the application start position are not continuously applied in this order.

Here, the driving mechanism intermittently feeds the supply nozzle and the substrate holding portion relatively at a predetermined pitch in a direction substantially parallel to one side of a circuit forming region of the substrate.
The circuit is characterized in that it is moved in a direction substantially perpendicular to one side of the circuit forming region. In this case, the drive mechanism is configured to relatively rotate the supply nozzle and the substrate holding unit around a vertical axis, and the control unit is located at a coating end position of the divided area. Before moving the substrate holding unit and the supply nozzle to the application start position of the divided area to be applied next, control to relatively rotate the supply nozzle and the substrate holding unit around a vertical axis. It may be configured to be performed via a driving mechanism,
In this case, the application direction and the moving direction of the supply nozzle can be aligned, whereby the application can be performed in the set application sequence and application direction.

Further, the driving mechanism moves the supply nozzle and the substrate holding portion relatively so as to draw a spiral on the surface of the substrate held by the substrate holding portion. Is also good. An example of the treatment liquid is a resist liquid. Further, the coating film forming apparatus of the present invention may include a viscosity adjusting means for adjusting the viscosity of the processing liquid, and may supply a processing liquid having a different viscosity to each divided region of the substrate. The viscosity adjusting means adjusts the viscosity of the processing liquid by diluting the processing liquid with a solvent. In the coating film forming apparatus of the present invention, for example, the processing liquid is applied onto the substrate while discharging the processing liquid from the supply nozzle in a linear shape having a small diameter.

[0020]

FIG. 1 shows a coating film forming apparatus according to the present invention applied to a resist liquid coating apparatus for coating a semiconductor wafer (hereinafter, referred to as a "wafer") forming a substrate with a resist liquid as a processing liquid. FIG. 2 is a longitudinal sectional view showing the configuration of the embodiment, and FIG. 2 is a plan view thereof.

In FIG. 1 and FIG. 2, reference numeral 2 denotes a wafer holder serving as a substrate holder.
Is held movably in the Y direction. Frame 3
Is a member formed in a channel shape that opens upward, for example, is formed to be long in the Y direction, and one end side in the Y direction is a resist liquid application section R on which a resist liquid is applied, and the other end side Is a wafer load
It is configured as an unload section L. Also frame 3
Is provided with a pair of Y rails 31 extending over the resist coating section R and the wafer loading / unloading section L. The wafer holder 2 is provided with a Y slider 32 on the Y rail 31. Is held movably in the Y direction via
When the ball screw 34 is rotated by the Y drive motor 33, the ball screw 34 is driven via the nut 35 so as to be freely positioned in the Y direction.

The wafer holder 2 has a main body 21 formed in a cup shape and a wafer suction table 22 for holding the wafer W. The main body 21 is located at a position facing the lower surface of the wafer W. A liquid reservoir channel 23 for storing a solvent (thinner solution) is provided. The liquid reservoir channel 23 is filled with a solvent whose liquid temperature and liquid level are controlled, and the solvent is evaporated to thereby form a wafer W. Is kept in a solvent atmosphere of a predetermined concentration.

The wafer suction table 22 has a holding portion 24 for holding the wafer W on its upper surface. A vacuum device (not shown) is connected to the holding portion 24 so that the wafer W can be vacuum chucked. Has become. The holding unit 24 is connected to a Zθ driving mechanism 25. When the wafer W holder 2 moves to the wafer loading / unloading unit L, the Z driving / θ rotation driving unit 26 controls the Zθ driving mechanism 25. It is operated to perform a Z-direction operation for transferring the wafer W and a θ operation for notch alignment. Further, an ultrasonic vibrator 27 connected to an agitation generator (not shown) for vibrating the wafer W held by suction is provided on the wafer suction table 22.
Has been fixed.

At four corners of the bottom surface of the wafer body 21 surrounding the wafer suction table 22 (wafer W), four forced exhausts connected to an exhaust device (not shown) for controlling the air flow in the main body 21 are provided. Ports 28a to 28d are formed. The exhaust flow rates from the forced exhaust ports 28a to 28d are individually controlled. For example, by performing exhaust from only the two exhaust ports 28a and 28b, the exhaust flow is biased in one direction in the main body 21. A weak air flow is generated, thereby controlling the flow of the solvent volatilized from the applied resist solution, thereby preventing the solvent from excessively volatilizing.

In the wafer holder 2, a mask member 4 is held immediately above the wafer W, and the mask member 4 is driven in a direction indicated by an arrow A in FIG. A mask member driving mechanism 41 for inserting and removing from the body 2 is provided. As shown in FIG. 3, the mask member 4 covers an area other than the circuit formation area 40 of the wafer W to prevent the resist solution from being applied to the peripheral portion of the wafer W. The member driving mechanism 41 takes out the mask member 4 contaminated with the resist solution from the resist coating apparatus through the insertion / removal passages 20 and 30 provided in the wafer holder 2 and the frame 3 as shown by an arrow A in FIG. It is transported to a mask member cleaning device indicated by reference numeral 42 in FIG. In FIG. 3, reference numeral 43 denotes a notch formed on the wafer W.

In the drawing, reference numeral 5 denotes a top plate with a temperature control function provided on the frame 3 so as to cover the upper part of the wafer holder 2, for example, a linear heater 51 is buried therein and generates heat at a predetermined temperature. It is configured to be. Accordingly, the top plate 5 has a function of maintaining and controlling the solvent atmosphere filled around the wafer W, and heats a supply nozzle 6 to be described later. It has a function to prevent "cut".

The top plate 5 is positioned so that it can continue to cover the wafer holder 2 only in the resist liquid application section R even if the wafer holder 2 is moved to the maximum in the Y direction. The wafer holder 2 is covered. A slit 52 for allowing the supply nozzle 6 to move in the X direction is formed in the middle of the top plate 5 in the Y direction. The slit 52 has a length corresponding to the width of the wafer W and 6 are provided with a width that allows insertion.

The supply nozzle 6 is provided with a linear slide mechanism 5 erected along the X direction at the upper end of the frame 3.
3. This linear slide mechanism 5
3 is an X rail 54, a slider 55 slidably provided on the X rail 54, a ball screw 56 for driving the slider 55, and a ball screw 56
The supply nozzle 6 is held by the slider 55 at a position corresponding to the slit 52 of the top plate 5, and the lower end of the supply nozzle 6 is held through the slit 52. It extends into the body 2.

The X drive motor 57 and the Y drive motor 33 are configured to be operated synchronously by the nozzle / wafer drive unit 36, and the supply nozzle 6
Is moved while facing a predetermined path of the wafer W. The operation of the Z drive / θ rotation drive unit 26 and the nozzle / wafer drive unit 36 is controlled by a control unit C. Here, the linear slide mechanism 53 (X rail 5) whose drive is controlled by the nozzle / wafer drive unit 36 and the Z drive / θ rotation drive unit 26
4, slider 55, ball screw 56, X drive motor 5
7), Y rail 31, Y slider 32, Y drive motor 33, ball screw 34, nut 35, Zθ drive mechanism 2
5. The Z drive / θ rotation drive unit 26 corresponds to the drive mechanism of the present invention.

Next, the supply nozzle 6 will be described with reference to FIG. For example, the supply nozzle 6 has a double-pipe structure. The inner pipe portion has a resist solution nozzle 61 for supplying the resist solution 60 in a thin line shape, and the outer tube portion has a mist-like shape passing around the resist solution nozzle 61. Is a solvent nozzle 62 for supplying a solvent 64. The resist liquid nozzle 61
Is formed of, for example, a stainless steel material, and the discharge hole 63 is formed to have an extremely small diameter of about 10 μm to 200 μm. In such a supply nozzle 6, a mist-like solvent 64 is discharged around the liquid flow of the resist liquid 60 immediately after the discharge, whereby the periphery of the resist liquid flow is sealed in a solvent atmosphere, and the solvent from the resist liquid flow is removed. The viscosity is kept constant by suppressing volatilization.

In the supply system of the resist solution 60, as shown in FIG.
Is sent to the supply nozzle 6 by a pump 66 such as a bellows pump via a filter device 67 and an opening / closing valve 68, and is discharged from a discharge hole 63 of the nozzle 6. The resist liquid tank 65, the pump 66, the filter device 67, the on-off valve 68, and the supply nozzle 6 are connected by a supply channel 69, and the operations of the pump 66 and the on-off valve 68 are controlled by the control unit C. Has become.

Next, a description will be given of an example of applying a resist solution performed by the above-described apparatus. The present invention divides the application area of the wafer W, and controls the movement of the supply nozzle and the wafer W and the timing of the supply of the resist liquid from the supply nozzle to the wafer W so as to apply the divided area under predetermined conditions. It is characterized by doing.

In this case, the coating area of the wafer W is, for example, as shown in FIG.
This will be specifically described with an example of a case where the image is divided into three as shown in FIG. In this example, the wafer W is aligned with the notch 43 facing left, and the coating area is divided into three equal parts in the Y direction.
It is divided into three areas B and C.

First, the wafer holding body 2 is positioned at the wafer loading / unloading section L, and the holding section 24 is moved up and down to transfer the wafer W from the wafer transfer main arm (not shown) to the wafer suction table 22 so that the wafer W is transferred. Hold by suction. Subsequently, the notch alignment of the wafer W is performed by the Z drive / θ rotation drive unit 26, and then the holding unit 24 is lowered to accommodate the wafer W in the wafer holder 2. Next, the wafer holder 2 is positioned at the resist liquid application section R, and the mask member driving mechanism 41 holds the mask member 4 on the wafer.

First, as shown in FIG. 6A, the resist liquid is applied to the region B of the wafer W in the application direction from the application start position y3 to the application end position y2.
Therefore, first, the wafer holder 2 is moved in a direction substantially parallel to one side of the circuit forming region 40, for example, in the Y direction, and the supply nozzle 6 is positioned at a position corresponding to the coating start position y3. Subsequently, the opening / closing valve 68 is opened, and while discharging the resist liquid 60 from the supply nozzle 6, the circuit is moved in a direction substantially orthogonal to one side of the circuit forming region 40, for example, in the X direction. After the passage, the supply nozzle 6 is reciprocated in the X direction again while being intermittently fed at a predetermined pitch in the Y direction.

With the resist liquid 60 discharged from the supply nozzle 6 onto the wafer W in this manner, the nozzle 6 is moved in a zigzag path to a position corresponding to the coating end position y2. Form a film.
Here, the movement of the wafer holder 2 and the supply nozzle 6 is controlled by the control unit C via the nozzle / wafer driving unit 36, and the opening / closing timing of the opening / closing valve 68 is also controlled by the control unit C.

Subsequently, as shown in FIG. 6B, the coating start position y4 is shifted to the coating end position y with respect to the region A of the wafer W.
The resist solution 60 is applied in the application direction toward No.3. For this reason, first, when the application of the region B is completed, the opening and closing valve 6
8, the wafer holder 2 is moved in the y direction, and the supply nozzle 6 is positioned at a position corresponding to the coating start position y4. Subsequently, while the opening / closing valve 68 is opened and the resist liquid 60 is discharged from the supply nozzle 6 to the wafer W, the nozzle 6 is moved to the position corresponding to the coating end position y3 with respect to the wafer W in a zigzag path. A uniform liquid film is formed in the region A.

Thereafter, as shown in FIG. 6C, the area C of the wafer W is moved from the coating start position y1 to the coating end position y.
The resist solution 60 is applied in the application direction toward 2. For this reason, first, when the application of the region A is completed, the opening and closing valve 6
8, the wafer holder 2 is moved in the y direction to position the supply nozzle 6 at the position corresponding to the coating start position y1, and then the opening and closing valve 68 is opened to supply the supply nozzle 6
The nozzle 6 is moved along the zigzag path to the coating end position y2 while discharging the resist solution 60 onto the wafer W from the above, thereby forming a uniform liquid film on the C region of the wafer W,
The on-off valve 68 is closed.

Here, the resist liquid 60 discharged from the supply nozzle 6 onto the wafer W and lands there, generates a certain spread according to the viscosity thereof. By setting the pitch and the application start position and the application end position of each region, a uniform resist film can be formed uniformly on each of the divided regions.

After the application of the resist solution in this manner, the ultrasonic vibrator 27 attached to the wafer suction table 22 is operated to apply the vibration in the ultrasonic band to the wafer W. As a result, agitation is applied to the applied resist liquid film, and the surface of the liquid film is planarized.

Thereafter, the mask member 4 to which the resist liquid has adhered
Is discharged to the mask member cleaning device 42 side, and then the wafer holder 2 is moved from the resist liquid application section R to the wafer load / unload section L. Then, the holding unit 24 is moved up and down to deliver the wafer W to a main arm (not shown), and the wafer W is unloaded from the resist liquid application device. As described above, in the coating film forming apparatus of the present invention, the application area of the wafer W is divided into three parts, and the supply nozzle 6 and the movement of the wafer W and the movement of the wafer W are applied to the divided areas under predetermined conditions. Since the supply timing of the resist liquid is controlled, the in-plane uniformity of the thickness of the resist film can be improved as described below.

That is, as described above, a phenomenon occurs in which the resist liquid 60 discharged from the supply nozzle 6 collides with the wafer W and spreads, and is drawn to the respective coating start positions. However, the application region of the wafer W is divided into regions A, B, and C, and the application sequence and application direction (nozzle advancing direction) of each region are set to predetermined conditions as described later. Therefore, the phenomenon that the resist liquid 60 is drawn to increase the film thickness in this portion occurs only in the region. Accordingly, each of the regions A, B, and C has a smaller area than the entire coating region of the wafer W, and the amount of the resist solution drawn toward the coating start position is small, so that the film thickness on the coating start position side is large. However, the degree is considerably reduced as compared with the case where the wafer W is not divided.

For example, in this example, in the area B, FIG.
As shown in FIG. 7, the film thickness on the application start position y3 side is thicker than the application end position y2 side, and in the region A, as shown in FIG. In the region, as shown in FIG. 7 (c), the coating start position y1 side is thicker, but the width of the film thickness distribution is considerably smaller than when the wafer W is not divided, and the in-plane uniformity of the film thickness is small. Has been raised.

Here, the conditions of the application order and application direction (nozzle advancing direction) of each area are described with reference to the case where the wafer W is divided into a first area 71 and a second area 72 as an example. This will be described with reference to FIG. Even if the application region of the wafer W is divided, the resist liquid is drawn to the application start position side as described above, so that if the start points of the adjacent application regions are adjacent to each other, the resist solution is drawn to this boundary portion. As the amount of the resist solution increases, the film thickness of the portion becomes extremely large (see FIG. 8A). Here, the arrow in the figure indicates the application direction.

Therefore, in order to improve the in-plane uniformity of the film thickness, as shown in FIG. 8B, the application direction is determined so that the application start positions of the adjacent application regions are not adjacent to each other.
Alternatively, it is required to determine the application sequence and the application direction as shown in FIG.

In the above example, the coating start position y4 of the region A
Is determined such that the application order is determined so as to be away from the application start position y3 in the B area (the application direction in the A area is determined), and C
Since the application direction of the region C is determined so that the application start position y1 of the region is separated from the application start point y3 of the region B, the in-plane uniformity of the film thickness is increased.

Further, as shown in FIG. 8C, the application end position of the first area 71 and the application start position of the second area 72 are the same as in the case where the application directions of the adjacent areas are the same. When the application sequence is set so that the application is performed continuously from the first region 71 to the second region 72 in the case where are adjacent to each other, these two regions are applied collectively. The resist solution is drawn to the application start position side of the application region, and the film thickness in this portion becomes considerably large.

Therefore, in this case, the application sequence is set so that the application end position of the first area 71 and the application start position of the second area are not continuously applied, and the second area is applied first. Then, the supply nozzle 6 is applied so as to apply the first area.
The timing of supplying the resist liquid to the supply nozzle 6 by moving the wafer W and opening and closing the opening and closing valve 68 is controlled.

As described above, when the coating start positions of the adjacent coating regions are not adjacent to each other, and when the coating direction is the same in the adjacent regions, the front side of the coating direction (in the example of FIG. As described above, if the application end position in the first region (the first region) and the application start position on the preceding side in the application direction (the second region in the example of FIG. 8C) are not continuously applied, In-plane uniformity of the resist film thickness can be improved,
In this range, the application sequence and the application direction can be freely set.

Therefore, in the above-described example in which the wafer W is divided into three parts, the coating conditions are not limited to the above-described ones. For example, as shown in FIG. After the application is performed in the application direction toward, the area A is applied in the application direction from the application start position y4 to the application end position y3, and then the area C is applied in the application direction from the application start position y2 to the application end position y1. Alternatively, for example, as shown in FIG. 9 (b), first, for the region A, the application start position y4 is changed to the application end position y
After applying in the application direction toward 3, the application is performed in the application direction from the application start position y2 to the application end position y3 for the region B, and then in the application direction from the application start position y1 to the application end position y2 in the region C. Even if it does, the in-plane uniformity of a high film thickness can be ensured.

As described above, according to the present invention, the uniformity of the film thickness in the application of the resist film can be improved, so that the productivity of the resist film can be improved. Further, by controlling the coating direction and the coating sequence, the uniformity of the film thickness can be improved, so that the control of the profile such as the substrate temperature, which has been conventionally performed to improve the uniformity of the film thickness, becomes unnecessary. Thus, the cost of the apparatus itself can be reduced.

Next, another application example of the present invention will be specifically described with reference to an example in which the application area of the wafer W is divided into five as shown in FIG. In this example, the wafer W is aligned with the notch 43 facing left, the coating region is divided into three in the Y direction, and the central region is further divided into three in the X direction. B,
It is divided into five areas C, D, and E.

First, as shown in FIG. 10A, a coating start position is set near the region A with respect to the region C of the wafer W.
From here, the resist solution 60 is applied in the application direction proceeding to the E region side, and then, as shown in FIG. 10B, the application start position is set for the A region of the wafer W on the side far from the C region. Then, the resist solution 6 is applied in a coating direction proceeding from here to the region C side.
0, and then, as shown in FIG. 10 (c), a coating start position is set for the E region of the wafer W on the side farther from the C region, and the resist is applied in a coating direction proceeding from here to the C region. The liquid 60 is applied.

Thereafter, as shown in FIG.
Is rotated 90 degrees to the left so that, for example, the notch 43 faces downward, a coating start position is set for the region B of the wafer W on a side farther from the region C, and the coating direction proceeds from here to the region C. The resist solution 60 is applied in FIG.
As shown in (b), a coating start position is set on a side far from the region C with respect to the region D of the wafer W, and the resist solution 60 is coated in a coating direction proceeding from this to the region C side. At this time, the movement of the supply nozzle 6 and the wafer holder 2 and the rotation of the wafer W are controlled by the control unit C via the nozzle / wafer drive unit 36 and the Z drive / θ rotation drive unit 26, respectively. The timing of supply of the resist solution 60 is also controlled by the control unit C.

Further, in this example, since the movement width in the X direction of the supply nozzle in the areas B, C, and D is smaller than that in the areas A and E, the supply nozzle 6 as a mask member is moved in accordance with the reciprocating stroke of the supply nozzle 6 in the X direction. It is desirable to use a structure in which the size of the opening changes. As such a mask member, for example, a structure as shown in FIG. 12 can be adopted. In this example, the mask member 8 includes a pair of receiving members 81, 81 provided apart from each other along the X direction. Have
The receiving members 81, 81 are driven so that their intervals change according to the stroke of the supply nozzle 6 in the X direction, and are configured to always be located at the turning point of the supply nozzle 6.

The receiving members 81, 81 have, for example, a channel shape on the upper surface side, as shown in the figure, and have a side wall 82 for preventing dripping of the resist liquid except for the tip end surface. The resist liquid transmitted from the front end face is configured to be suction-removed by a suction hole (not shown).

The receiving members 81, 81 are connected to a receiving member drive mechanism 84 via an L-shaped arm 83 extending along the X direction, for example. , 2 are fixed to a linear slide mechanism indicated by 53, and move in the Y direction integrally with the linear slide mechanism 53. As the receiving member driving mechanism 84, for example, a stepping motor and a linear gear can be used. The receiving member driving mechanism 84 is connected to the control section C, and receives the receiving member 81 such that the stroke of the supply nozzle 6 in the X direction, that is, the width of the B, C, and D regions in the X direction substantially coincides. , 81 are controlled.

Also in this example, by setting an appropriate feed pitch in the Y direction and a coating start position and a coating end position in each area in accordance with the spread amount of the resist liquid on the wafer W, the division is performed. A uniform and uniform resist film can be formed in each region.

In this example, the application area of the wafer W is divided into five parts. However, the application start positions of the adjacent application areas are not adjacent to each other, and the application end position and the front end of the area on the front side in the application direction are not adjacent to each other. The application order and application direction are set so that the application start position in the area is not applied continuously.
The in-plane uniformity of the film thickness increases. At this time, in this example, the supply nozzle 6 is configured to move only in the X direction. However, by rotating the wafer W, the application direction and the movement direction of the supply nozzle 6 can be aligned. Application can be performed in the applied application order and application direction. Further, since the application area of the wafer W is divided into five,
Since the area of the divided region becomes smaller and the width of the thickness distribution of the resist liquid in the divided region becomes smaller, it is necessary to perform a resist liquid coating process with higher in-plane uniformity of the film thickness. Can be.

FIG. 13 shows another example in which the application area of the wafer W is divided into five parts. First, in FIG. 13A, the coating is applied to the region A in the coating direction from the wafer peripheral side to the region C, and then to the region E in the coating direction from the region C to the wafer peripheral side. Subsequently, as shown in FIG. 13 (b), the wafer W is rotated 90 degrees clockwise, and the wafer B is applied in the application direction from the area C to the wafer peripheral side toward the area B, and then the C is applied to the area D. The coating is performed in a coating direction from the region to the wafer peripheral side. Finally, as shown in FIG. 13 (c), the wafer W is rotated 45 degrees counterclockwise, and the remaining C region is moved in the coating direction from the A and B regions to the D and E regions. Instead, it is applied at an angle of 45 degrees to one side of the circuit formation region. Also in this example, the wafer W
By setting an appropriate feed pitch in the Y direction and a coating start position and a coating end position in each region in accordance with the spread amount of the resist solution above, a uniform resist film is uniformly formed in each of the divided regions. Can be formed.

The application start positions of the adjacent application regions are not adjacent to each other, and the application end position of the region on the near side in the application direction and the application start position of the front region are not continuously applied. Since the application sequence and the application direction are set, the in-plane uniformity of the film thickness is improved. Further, in the last area C, the turning position of the nozzle is evenly distributed to the surrounding areas A, B, D, and E, so that the resist at the turning position and each area A,
When the resist applied to B, D, and E is mixed, the swelling of the mixed portion can be reduced, and a uniform film can be formed.

Next, still another application example of the present invention will be described, taking as an example a case where the application path of the resist liquid 60 is formed in a spiral shape as shown in FIG. Such a coating path is performed by moving the wafer W to, for example, 20 to 30 rpm.
This is achieved by moving the supply nozzle 6 in the diameter direction (for example, the X direction) of the wafer W while rotating at a low speed of m.

FIG. 15 shows an example of such an application.
A description will be given using an example in which the application area is divided into two in the radial direction so as to be divided by a dotted line in (a), and is divided into two areas: an area A including a central part and an area B on the periphery thereof. I do. First, with respect to the region B of the wafer W, the application start position is set to the peripheral side, and the resist liquid 60 is applied in the application direction going inward in the drawing so as to draw a spiral from here to the center side. With respect to the region A, the application start position is set to the center side, and the resist liquid 60 is applied in the application direction going outward in the drawing so as to draw a spiral toward the peripheral edge in the drawing. At this time, by setting an appropriate pitch and a coating start position and a coating end position of each region in accordance with the spread amount of the resist liquid on the wafer W, a uniform resist film is uniformly formed on each of the divided regions. It is formed.

Also in this example, the application start positions of the adjacent application areas are not adjacent to each other, and the application end position of the area on the near side in the application direction and the application start position of the area on the front side are not continuously applied. Therefore, the in-plane uniformity of the thickness of the formed resist film is increased. In this way, the application direction is set so that the application start positions of the adjacent application regions are not adjacent to each other, and the application start position of the region on the front side and the application start position of the region on the front side are not continuously applied. The application may be performed in any manner as long as the application sequence is determined. For example, as shown in FIG. The resist solution 60 is applied in a coating direction that moves outward in the drawing so as to draw a spiral, and then, with respect to the region A of the wafer W, the coating starting position is set to the center side and a spiral is drawn toward the peripheral edge in the drawing. like,
The application of the resist liquid 60 may be performed in the application direction that proceeds outward in the drawing.

FIG. 16 shows a mixing apparatus 50 that divides a wafer W into five parts as described above and applies a different resist to each region, for example, a resist liquid having a different viscosity when applying a resist liquid having a different viscosity. Is shown. This mixing device 5
Reference numeral 0 denotes a resist tank shown in FIG. 1, a thinner tank 45 storing thinner, a mixed liquid supply pipe 49 for supplying a mixed liquid of resist liquid and thinner to the supply nozzle 6, and a resist liquid supplied to the mixed liquid supply pipe 49. A resist solution supply pipe 48 for supplying a liquid, a thinner supply pipe 37 for supplying a thinner to a mixed liquid supply pipe 49, a resist bellows pump 85 for sucking up the resist liquid in a resist tank 65 and introducing the resist liquid into the resist liquid supply pipe 48. And a thinner bellows pump 46 which sucks up the thinner in the thinner tank 45 and introduces it into the thinner supply pipe 37, a mixer 47 which further stirs and mixes a mixed solution of the resist solution and the thinner, and a mixer which is stirred and mixed by the mixer 47. A viscosity sensor 70 for measuring the viscosity of the liquid, a bellows pump 85 for resist and a bellows pump 4 for thinner
And a control unit 86 for controlling the operation amount of the control unit 6 by, for example, a linear actuator or the like.

The measurement result of the viscosity sensor 70 is transmitted to the control unit 8.
The bellows pumps 85 and 46 are controlled based on the measurement result. Such a mixing device 50 corresponds to the viscosity adjusting means of the present invention, and by using this device 50, the viscosity of the resist is appropriately adjusted by mixing the resist and the thinner, and a resist having a different viscosity for each region is obtained. To supply. As the viscosity sensor 70, for example, a sensor using a torsional vibrator driven by piezoelectric ceramics is used.

According to such a method, when different ICs are formed on one wafer, for example, when five kinds of specific application ICs (ASICs) are formed in each of the above regions on one wafer, A resist having a viscosity suitable for the IC of each area (divided into five) can be applied. That is, since the resists having different viscosities have different concentrations, the sensitivities of the light and the like during the exposure processing of the wafer are different.
A resist having a viscosity suitable for C can be applied.

Further, using such a mixing device 50,
For example, as shown in FIG. 17A, while the supply nozzle 6 is stopped and fixed on the peripheral area of the wafer W, the wafer W is rotated at a low speed of 20 to 30 rpm while the reference numeral 87 is attached to the peripheral edge of the wafer. A resist is applied as shown. Then, as shown in FIG. 17B, a resist is applied to an area other than the peripheral area of the wafer W while moving the supply nozzle 6 as indicated by reference numeral 88. At this time, the viscosity of the resist applied to the peripheral area is set higher than the viscosity of the resist 88 applied to the area other than the peripheral area. When the viscosity of the resist in the peripheral region of the wafer is increased in this manner, a 'bank' of the resist can be formed in the peripheral region, and the occurrence of inconvenience such as the resist flowing from the peripheral edge of the wafer W can be suppressed. .

Further, in addition to making the viscosity of the resist variable, the resist per unit time discharged from the supply nozzle 6 per unit time is controlled by using only the bellows pump for resist 85 shown in FIG. The discharge amount (hereinafter, simply referred to as a discharge amount) may be variable. For example, as shown in FIG. 18A, the coating region on the wafer W is shifted from the center position (notch portion 43) and divided at the position of the dividing line 44 shown by the broken line. 18B, the coating is applied in the coating direction from the dividing line 44 side to the peripheral side of the wafer W, and then, as shown in FIG. Apply in the direction of application.

In this case, the application time in the region A is, for example, 5 seconds. On the other hand, the application time in the region B is, for example, 55 seconds, and the discharge amount of the resist applied to the region B is smaller than the discharge amount of the resist applied to the region A, for example, one half. As a result, a 'bank' made of a resist can be first formed in the region A. Next, by applying a small amount of ink to the region B, the amount of the resist drawn to the reference numeral 89 indicating the application start portion can be reduced, and at the end of the application indicated by the reference numeral 96 in FIG. The end portion 96 and the discharge start portion 97 in the region A with a larger discharge amount than the region B are mixed, so that the whole can be uniformly applied as shown in FIG.

In each of the examples described above, the moving speed (scan speed) of the supply nozzle 6 is fixed, but this can be made variable. This makes it possible to change the scan speed for each region on the wafer W, change the amount of resist supplied on each region on the wafer W, adjust the film thickness, and thus obtain a uniform film thickness. it can.

Next, an example of a coating / developing apparatus in which the above-described developing apparatus is incorporated in a unit will be described with reference to FIGS.
This will be described with reference to FIG. 19 and 20, reference numeral 9 denotes a loading / unloading stage for loading / unloading a wafer cassette. For example, a cassette C containing 25 sheets is placed by an automatic transfer robot, for example. A transfer arm 90 for the wafer W is provided in a region facing the loading / unloading stage 9 so as to be freely rotatable in X, Y directions and θ (rotation about a vertical axis). Further, behind the transfer arm 90, a coating / developing unit U1 is located on the right side, for example, as viewed from the loading / unloading stage 9, and heating / cooling is located on the left, front and rear sides. System units U2, U3, and U4 are arranged, respectively, and for transferring a wafer W between a coating / developing system unit and a heating / cooling system unit, for example, freely movable up and down, movable left and right, and back and forth. A wafer transfer arm MA rotatably arranged about a vertical axis is provided. However, in FIG. 20, the unit U2 and the wafer transfer arm MA are not drawn for convenience.

In the coating / developing system unit, for example, two developing units 91 are provided in an upper stage, and a coating unit 92 provided with two above-mentioned coating film forming apparatuses is provided in a lower stage. In a heating / cooling system unit, a heating unit, a cooling unit, a hydrophobizing unit, and the like are provided above and below.

The above-described portion including the coating / developing system unit and the heating / cooling system unit is referred to as a clean track. 94 is connected. The interface unit 93 can be moved up and down, for example.
The wafer W is transferred between the clean track and the exposure device 94 by a wafer transfer arm 95 configured to be movable left / right, forward / backward, and rotatable about a vertical axis.

The flow of wafers in this apparatus will be described. First, a wafer cassette C containing a wafer W is loaded into the loading / unloading stage 9 from the outside, and a wafer transfer arm is set.
The wafer W is taken out of the cassette C by the system 390 and transferred to the wafer transfer arm MA via the transfer table which is one of the shelves of the heating / cooling unit U3 described above. Next, after a hydrophobic treatment is performed in the processing section of one shelf of the unit U3, a resist liquid is applied by the application unit 92 to form a resist film. The wafer W coated with the resist film is heated by the heating unit and then interposed.
Sent to the exposure device 94 via the face unit 93,
Here, exposure is performed through a mask corresponding to the pattern.

Thereafter, the wafer W is heated by the heating unit, cooled by the cooling unit, and subsequently cooled by the developing unit 9.
The resist film is sent to the developing device 1 and subjected to a development process, thereby forming a resist mask. Thereafter, the wafer W is returned to the cassette C on the loading / unloading stage 9.

As described above, according to the present invention, a predetermined coating order and / or a predetermined coating order are applied to each of the divided coating regions of the wafer W.
Alternatively, the resist liquid may be supplied in a predetermined coating direction to form a liquid film of the resist liquid in each of the divided regions on the surface of the wafer W. In this case, the resist liquid is drawn to the coating start position side, and Since the phenomenon that the film thickness of the portion becomes large occurs only in the region, as a result, the in-plane uniformity of the film thickness can be improved.

In the present invention, the application is not limited to the above-described application example. The application start positions of the adjacent divided areas are not adjacent to each other, and / or the coating end of one of the adjacent divided areas is completed. If the position and the application start position of the other area are adjacent to each other, if the application end position and the application start position are not continuously applied in this order, the divided areas can be freely set. In this case, the application order and / or the application direction can be determined, and in this case, in-plane uniformity of a higher film thickness can be obtained.

The supply nozzle 6 and the wafer W are relatively moved. For example, the supply nozzle 6 may be fixed and the wafer W may be driven in the X and Y directions.
Also, the drive mechanism of the supply nozzle 6 and the wafer holder 2 is not limited to the above example, and a belt drive mechanism or the like may be used, for example.

Further, in the above example, the open / close valve 68
The timing of supplying the resist liquid to the supply nozzle 6 is controlled by opening and closing the nozzle. However, the present invention is not limited to such a configuration. For example, the operation of the pump 67 is controlled by the control unit C without providing the opening and closing valve 68. Thus, the timing of supplying the resist liquid to the supply nozzle 6 may be controlled.

Furthermore, although the description has been made by taking a resist solution as an example of a processing solution, the present invention is not limited to this. For example, an interlayer insulating film material, a high conductive material, a low dielectric material, a ferroelectric material, a wiring material , An organic metal material, a metal paste such as a silver paste, or the like. The substrate is not limited to a semiconductor wafer, but may be an LCD substrate or an exposure mask. Here, substantially horizontal in the present invention includes a substantially horizontal state, and substantially parallel includes a substantially parallel state.

In the above embodiment, the mixing device 50 is used to adjust the resist viscosity as shown in FIG. 16, but the present invention is not limited to this. May be used for resist coating or viscosity adjustment.

[0083]

According to the present invention, the application area of the substrate is divided, and the processing liquid is supplied to each of the divided areas in a predetermined application order and / or a predetermined application direction, and the divided areas are divided. Since the liquid film of the processing liquid is formed for each region, the in-plane uniformity of the thickness of the formed liquid film can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of an embodiment of a coating film forming apparatus of the present invention.

FIG. 2 is a plan view showing the coating film forming apparatus.

FIG. 3 is a perspective view for explaining a coating path of a resist liquid.

FIG. 4 is a cross-sectional view illustrating a resist liquid supply nozzle.

FIG. 5 is a plan view illustrating a divided region of a coating region of a wafer W.

FIG. 6 is a plan view for explaining a coating example of a wafer W.

FIG. 7 is a plan view for explaining a coating example of a wafer W.

FIG. 8 is a plan view for explaining an application example of a wafer W.

FIG. 9 is a plan view for explaining an application example of a wafer W.

FIG. 10 is a plan view for explaining another application example of the wafer W.

FIG. 11 is a plan view for explaining another application example of the wafer W.

FIG. 12 is a perspective view showing another example of the mask member.

FIG. 13 is a plan view for explaining another application example of the wafer W.

FIG. 14 is a perspective view for explaining still another application example of the wafer W.

FIG. 15 is a perspective view for explaining still another application example of the wafer W.

FIG. 16 is a control configuration diagram showing a mixing device that changes the viscosity of a resist.

FIG. 17 is a plan view showing an application example when applying using the mixing device.

FIG. 18 is a plan view showing another example of application when applying using the mixing device.

FIG. 19 is a plan view showing a coating and developing apparatus provided with the coating film forming apparatus of the present invention.

FIG. 20 is a schematic perspective view showing the coating and developing apparatus.

FIG. 21 is a side view showing a conventional resist liquid coating apparatus.

FIG. 22 is a plan view showing a one-stroke writing method of applying a resist solution.

FIG. 23 is a side view showing how the resist solution is supplied onto the wafer W.

FIG. 24 is a side view showing a film thickness distribution of a resist film on a wafer W.

[Explanation of symbols]

 W Semiconductor wafer 2 Wafer holder 26 Z drive / θ rotation drive unit 3 Frame 36 Nozzle / wafer drive unit 4,8 Mask member 5 Top plate 5a Slit 50 Mixing device 6 Supply nozzle 60 Resist solution 63 Discharge hole 65 Resist solution tank 68 Open / close valve

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/16 501 G03F 7/16 501 H01L 21/027 B05C 11/08 // B05C 11/08 H01L 21 / 30 564Z (72) Inventor Yukihiko Ezaki 2655 Tsukure, Kikuyo-cho, Kikuchi-gun, Kumamoto Prefecture Inside the Kumamoto Office of Tokyo Electron Kyushu Co., Ltd. In-house (72) Inventor Nohisa Koga 2655 Tsukure, Kikuyo-cho, Kikuchi-gun, Kumamoto Prefecture Tokyo Electron Kyushu Co., Ltd. (72) Inventor Hirofumi Okuma Kikuchi-gun, Kumamoto Prefecture Yomachi make 2655 address Tokyo Electron Kyushu Co., Ltd. Kumamoto workplace (72) inventor 飽本 Masami Kumamoto Prefecture Kikuchi-gun, Kikuyo-machi make 2655 address Tokyo Electron Kyushu Co., Ltd. Kumamoto workplace

Claims (14)

[Claims] A substrate holding section for holding the substrate substantially horizontally; a supply nozzle for supplying a processing liquid to a surface of the substrate held by the substrate holding section; and a substrate holding section and a supply nozzle. A driving mechanism for relatively driving the substrate along a surface direction thereof, and a control unit for controlling the operation of the driving mechanism. The operation of the substrate holding unit and / or the supply nozzle is controlled via the drive mechanism so that the processing liquid is supplied to each region in a predetermined application order and / or a predetermined application direction, and A coating liquid forming apparatus configured to control a timing of supplying the processing liquid to the substrate, and forming a liquid film of the processing liquid for each of the divided regions on the substrate surface. 2. The processing unit according to claim 1, wherein the control unit controls the processing liquid in a predetermined application order and / or a predetermined application direction for each of the divided areas so that the application start positions of the adjacent divided areas are not adjacent to each other. The coating film forming apparatus according to claim 1, wherein the apparatus is configured to control the operation of the substrate holding unit and / or the supply nozzle via the driving mechanism so as to supply the liquid. 3. The control section, when the application end position of one of the adjacent divided areas and the application start position of the other area are adjacent to each other, determines the application end position and the application start position. The substrate holding unit via the driving mechanism so that the processing liquid is supplied to each of the divided areas in a predetermined application order and / or a predetermined application direction so as not to continuously apply in this order. The coating film forming apparatus according to claim 1, wherein the apparatus is configured to control an operation of a supply nozzle. 4. The circuit forming region while intermittently feeding the supply nozzle and the substrate holding portion relatively at a predetermined pitch in a direction substantially parallel to one side of the circuit forming region of the substrate. The coating film forming apparatus according to any one of claims 1 to 3, wherein the apparatus is moved in a direction substantially perpendicular to one side of the coating film. 5. The driving mechanism is configured to relatively rotate the supply nozzle and the substrate holding unit around a vertical axis, and the control unit is located at a coating end position of the divided area. Before moving the substrate holding unit and the supply nozzle to the coating start position of the divided area to be coated next, the supply nozzle and the substrate holding unit are relatively rotated about a vertical axis. The coating film forming apparatus according to any one of claims 1 to 4, wherein the control is performed via a driving mechanism. 6. The apparatus according to claim 6, wherein the driving mechanism relatively moves the supply nozzle and the substrate holding unit so as to draw a spiral on a surface of the substrate held by the substrate holding unit. Item 4. The coating film forming apparatus according to any one of Items 1 to 3. 7. The method according to claim 1, further comprising a viscosity adjusting means for adjusting the viscosity of the processing liquid, wherein the processing liquid having a different viscosity is supplied to each of the divided areas of the substrate. The coating film forming apparatus according to the above. 8. The coating film forming apparatus according to claim 7, wherein the viscosity adjusting means adjusts the viscosity of the processing liquid by diluting the processing liquid with a solvent. 9. The method according to claim 1, wherein the processing liquid is applied to the substrate while discharging the processing liquid from the supply nozzle into a thin linear shape on the substrate. apparatus. 10. The coating film forming apparatus according to claim 1, wherein the processing liquid is a resist liquid. 11. A substrate and a supply nozzle for supplying a processing liquid onto the substrate are relatively moved along a surface direction of the substrate, and the substrate is divided into at least first and second regions. A step of supplying a processing liquid to a first region; and a step of relatively moving a substrate and a supply nozzle for supplying a processing liquid onto the substrate along a surface direction of the substrate, Supplying the treatment liquid to the second region so that the application start position is not adjacent to the application end position in the region supply step. 12. The step of supplying a processing liquid to the first and second regions includes moving the substrate intermittently in a Y direction substantially orthogonal to the X direction while moving the supply nozzle in the X direction. The method according to claim 11, wherein the processing liquid is supplied from the supply nozzle onto the substrate. 13. The step of supplying a processing liquid to the first and second regions includes a step of supplying a processing liquid from a supply nozzle onto a substrate while changing the viscosity of the processing liquid for each of the divided regions. The method for forming a coating film according to claim 11, wherein the method comprises: 14. The method according to claim 11, wherein the processing liquid is a resist liquid.