JP2003203834A - Device for treating substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for treating substrate, which is able to evenly apply treatment liquid by enlarging a coating region of the treatment liquid in the moving direction. <P>SOLUTION: A device for coating substrate carries out treatment of a substrate W by supplying photoresist liquid to the surface of the substrate W. The device is provided with a spin chuck 1 for rotatably holding the substrate W, a conduction motor 2, and a coating head 10 which has an opening 10a for discharging a photoresist liquid towards the surface of the substrate W and moves from the edge of the substrate W to the center thereof. The head 10 is arranged so as to have an enlarged coating region of photoresist coincide with the moving direction. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer, a glass substrate for a photomask, a glass substrate for a liquid crystal display device, a substrate for an optical disk, a photoresist solution, a polyimide resin, an SOG (Spin On). The present invention relates to a substrate processing apparatus for supplying a processing liquid such as a liquid (also referred to as Glass or a silica-based film forming material) to a substrate to process the substrate, and particularly to a technique for applying the processing liquid to the substrate while moving the processing liquid supply means.

[0002]

2. Description of the Related Art An example of a conventional substrate processing apparatus of this type is shown in FIG. This apparatus rotates the substrate W in a horizontal plane at a constant speed and supplies the photoresist liquid R from a supply nozzle 5 having a discharge section whose horizontal cross-sectional shape is substantially circular, while at the same time, from the center of the substrate W to a radial end. The photoresist liquid R is applied to the surface of the substrate W by moving the supply nozzle 5 at a constant speed toward the edge.

[0003]

However, the conventional device having such a configuration has the following problems. That is, since the substrate W is rotated at a constant speed and the photoresist solution R is supplied while moving the supply nozzle 5 at a constant speed, the photoresist solution R supplied from the supply nozzle 5 to the surface of the substrate W is not changed. The locus is shown in Fig. 6.
It becomes spiral as shown in. At this time, if the moving speed of the supply nozzle 5 is too fast, a portion where the photoresist liquid R is not applied occurs every time the substrate W makes one rotation, causing unevenness,
There is a problem that the photoresist solution R cannot be applied uniformly. On the other hand, the rotation speed of the substrate W needs to be set according to conditions such as the type and viscosity of the photoresist liquid R, and if the rotation speed is made too fast, problems such as inclusion of bubbles in the photoresist liquid R may occur. , You can't speed it up indefinitely. Usually, after the photoresist solution R is supplied as described above, the photoresist film is formed on the surface of the substrate W by rotating the substrate W at a high speed. However, as described above, unevenness and bubbles are generated when the photoresist solution is supplied. If so, defects such as uneven film thickness and pinholes may occur in the formed photoresist film. Moreover, since the horizontal cross-sectional shape of the discharge portion of the supply nozzle 5 is substantially circular, a spiral gap is formed immediately after the supply of the photoresist liquid R, as shown in FIG. Therefore, even if the substrate W is rotated at a high speed thereafter, there is a problem in that the photoresist film is significantly uneven due to the influence thereof.

The present invention has been made in view of the above circumstances, and provides a substrate processing apparatus capable of uniformly applying a processing liquid by enlarging the application area of the processing liquid in the moving direction. The purpose is to do.

[0005]

The present invention has the following constitution in order to achieve such an object. That is, the invention according to claim 1 is a substrate processing apparatus for processing a substrate by supplying a predetermined processing liquid to the surface of the substrate,
A substrate holding unit that holds the substrate rotatably, a processing liquid supply unit that has a discharge port that discharges the processing liquid toward the surface of the substrate held by the substrate holding unit, and a processing liquid held by the substrate holding unit Drive means for horizontally moving the processing liquid supply means along the substrate from the edge side toward the center side of the substrate, wherein the processing liquid supply means is a portion where the processing liquid is applied so as to coincide with the moving direction. It is characterized in that

The invention described in claim 2 is the same as claim 1
2. The substrate processing apparatus according to claim 1, further comprising control means for controlling the drive means so as to increase the moving speed of the processing liquid supply means as it moves from the edge side of the substrate toward the center side. It is characterized by.

The invention described in claim 3 is the same as claim 1
Alternatively, in the substrate processing apparatus according to the second aspect, the discharge port of the processing liquid supply means is opened in a slit shape.

The invention according to claim 4 is the same as claim 3
In the substrate processing apparatus described in the paragraph 1, the longitudinal direction of the discharge port of the processing liquid supply means and the moving direction of the processing liquid supply means are made to coincide with each other.

[0009]

The operation of the invention described in claim 1 is as follows. The substrate is rotated by the substrate holding means, and the processing liquid is discharged onto the surface of the substrate by the discharge port of the processing liquid supply means.
The processing liquid supply unit discharges the processing liquid while being moved by the driving unit from the substrate edge side toward the center side, and the processing liquid application site is enlarged so as to coincide with the moving direction. Therefore, it is possible to cover the entire surface of the substrate with the processing liquid without increasing the rotation speed of the substrate or decreasing the moving speed of the processing liquid supply unit. A gap is less likely to be formed in the spiral locus of the treatment liquid on the substrate surface, and the occurrence of unevenness can be suppressed.

According to the second aspect of the present invention, the processing liquid supply means discharges the processing liquid while being moved by the drive means from the edge side of the substrate toward the center side. At this time, the moving speed is controlled by the control means. It is variable. That is, the moving speed of the processing liquid supply unit is controlled to increase as the processing liquid supply unit moves from the edge side of the substrate toward the center side in the radial direction. Since the linear velocity at the coating portion of the treatment liquid along the radial direction of the substrate surface is proportional to the radius, the moving velocity of the treatment liquid supply means is gradually increased toward the center, so that the linear velocity along the radial direction of the substrate surface is increased. The supply amount of the processing liquid at the application site can be made almost constant.

According to the third aspect of the present invention, since the discharge port of the processing liquid supply means is not circular but has a slit shape, the substrate is rotated on the surface of the substrate as the processing liquid supply means moves. A gap is less likely to occur in the spiral locus of the treatment liquid, and the occurrence of unevenness can be suppressed.

According to the fourth aspect of the present invention, by aligning the longitudinal direction of the discharge port of the processing liquid supply means opened in a slit shape with the moving direction of the processing liquid, the processing liquid along the radial direction of the substrate surface can be formed. Since it is possible to increase the portion of the application site to which the processing liquid can be supplied at one time, the processing liquid can be supplied more quickly and with a smaller supply amount.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing a schematic configuration of a substrate coating apparatus which is an example of the substrate processing apparatus according to the present invention. In the following description, a semiconductor wafer will be described as an example of the substrate, but this will be simply referred to as a substrate. A photoresist liquid will be described as an example of the processing liquid supplied to the substrate.

In the figure, reference numeral 1 is a spin chuck for sucking and holding the substrate W in a substantially horizontal posture. The spin chuck 1 has a rotary shaft connected to the lower portion thereof, and is rotated about a rotation center P by an electric motor 2. The electric motor 2 is controlled in rotation by a control unit, which will be described later, and rotates the substrate W integrally with the spin chuck 1 in a horizontal plane. The spin chuck 1 and the electric motor 2 correspond to the substrate holding means in the present invention.

The electric motor 2 is constructed so that it can be raised and lowered by a raising and lowering mechanism 4 arranged at the bottom of a frame 3 of this apparatus. The elevating mechanism 4 includes a linear guide 4a that is erected on the bottom of the frame 3 and a base 4b that is attached to the linear guide 4a so as to elevate and lower and that holds the electric motor 2.
And a ball screw 4c screwed to the base 4b, and an elevating pulse motor 4d for rotationally driving the ball screw 4c. Of these, the elevation pulse motor 4d is controlled in its rotation by a control unit described later, and the height position of the surface of the substrate W adsorbed and held by the spin chuck 1 is the height at which the substrate W is conveyed, and It is configured to rise and fall over a coating height H that is a height when the resist liquid is applied to the surface of the substrate W and a swing-off height L that is a height during a shake-off process performed after coating.

A scattering prevention cup 6 having an upper opening is arranged around the spin chuck 1. This scattering prevention cup 6 is provided when the substrate W is at the swing-off height L.
A drainage zone that has a downwardly inclined guide surface that guides the splashed-off photoresist liquid droplets downward, and that is formed in a ring shape in plan view for collecting the photoresist liquid droplets that are guided downward. Have and.

Above the substrate W, a coating head 10 is provided which is movable in the diameter direction thereof. A slit-shaped ejection port 10 a for ejecting the photoresist liquid is formed on the lower surface of the coating head 10. The length of the ejection port 10a in the longitudinal direction is shorter than the radius of the substrate W, as shown in FIG. The drive mechanism 12 is
A state in which the coating head 10 is moved in the horizontal direction, and in particular, as shown in FIG. 2, a state in which the ejection ports 10a are spaced from the center side of the substrate W toward the edge side along the surface of the substrate W at regular intervals. To move. The drive mechanism 12 is arranged horizontally between both side walls of the frame 3, and
0 is slidably attached to the linear guide 12a,
It is composed of a ball screw 12b screwed to the coating head 10 and a horizontal pulse motor 12c having a rotary shaft linked to the ball screw 12b. The coating head 10 corresponds to the processing liquid supply means in the present invention, and the drive mechanism 12 is provided.
Corresponds to the driving means.

The supply unit 14 is a mechanism including a tank and a pump (not shown), and pumps the photoresist liquid stored in the tank by a pump. The pressure-fed photoresist liquid is supplied to the coating head 10 via a supply pipe (not shown). In addition,
The electric motor 2, the lifting pulse motor 4d of the lifting mechanism 4, and the horizontal pulse motor 12c of the driving mechanism 12 are
The control unit 16 including a CPU and a memory (not shown) is integrally controlled.

The control unit 16 moves the coating head 10 in the radial direction of the substrate W by the drive mechanism 12, and the movement is performed as follows. That is, when the substrate W is transported or when the substrate W coated with the photoresist solution is shaken off, a retracted position located on the side of the scattering prevention cup 6 (indicated by a dotted line on the left side of FIG. 1). Position) has been moved. When applying the photoresist liquid to the substrate W,
After the height of the substrate W is moved to the coating height position H by the elevating mechanism 4 such that the vertical gap between the surface of the substrate W and the ejection port 10a becomes a constant gap g (hereinafter referred to as coating gap g). The drive mechanism 12 moves the coating head 10 to the center side of the substrate W (position indicated by a solid line in FIGS. 1 and 2) (hereinafter, this position is referred to as a coating start position). Then
A position where the coating head 10 is moved toward the edge side of the substrate W along the radial direction of the substrate W while rotating the electric motor 2 at a constant speed, and the coating head 10 exceeds the edge portion of the substrate W (FIGS. 1 and 1). It stops when it moves to the position indicated by the chain double-dashed line in 2) (hereinafter, this position is referred to as the coating end position).

At this time, the moving speed of the coating head 10 is not constant, but the moving speed is slowed according to the coating portion along the radial direction of the substrate W. Specifically, as shown in FIGS. 2 and 3, when the radius of the substrate W is r and the moving speed of the coating head 10 at the coating start position is V ₁ ,
The speed of the photoresist solution is reduced at a constant rate in accordance with the location where the photoresist solution is applied along the radius to stop the pressure feed of the photoresist solution by the supply unit 14 and the rotation of the substrate W, and the application head 10 at the application end position. The moving speed of is 0. The rate of reducing the speed is appropriately set according to the size of the substrate W and the like. Further, the coating head 10 may be moved to the retracted position without being stopped at the coating end position.

When the photoresist solution is supplied while moving the coating head 10 in the radial direction along the surface of the substrate W which rotates at a constant speed, the linear velocity at the coating site along the radial direction. Is proportional to the radius, the linear velocity increases from the center side of the substrate W toward the edge side, so that the phenomenon that the photoresist liquid becomes thin occurs, but the coating head 10 moves according to the increase. By decreasing the speed, the supply amount of the photoresist liquid can be made almost constant regardless of the application site.
Further, since the coating head 10 is configured such that the longitudinal direction of the ejection port 10a and the moving direction thereof coincide with each other as shown in FIG. 2, a gap is generated in the spiral locus of the photoresist liquid. It is difficult to suppress the occurrence of unevenness.

Next, referring to the flow chart of FIG.
The coating process of the photoresist liquid on the substrate W by the apparatus configured as described above will be described.

Step S1 (carry-in) The control section 16 drives the lifting pulse motor 4d to raise the spin chuck 1. As a result, the spin chuck 1 has its upper surface protruding upward from the upper opening of the scattering prevention cup 6, and its upper surface is positioned slightly below the coating height H. Next, a substrate transport mechanism (not shown) transports the substrate W and places the substrate W on the spin chuck 1. The substrate W is adsorbed and held on the spin chuck 1.

Step S2 (moving to the coating start position) The control unit 16 drives the horizontal pulse motor 12c to move to the retracted position (the position shown by the dotted line on the left side in FIG. 1).
The coating head 10 is moved to a coating start position (position shown by a solid line in FIG. 1) above the rotation center P of the substrate W.

Step S3 (setting of coating gap) The elevation pulse motor 4d is driven to finely adjust the height of the substrate W, and the upper and lower sides of the ejection port 10a of the coating head 10 moved above the substrate W and the upper surface of the substrate W are adjusted. The gap in the direction is set to the coating gap g. The coating gap g is determined in consideration of the type of photoresist solution, the rotation speed of the electric motor 2, the moving speed of the coating head 10, the desired film thickness, and the like.

Step S4 (Start of discharging) The supply unit 14 is operated to start pressure-feeding the photoresist liquid to the coating head 10.

Step S5 (Standby) The photoresist liquid starts to be discharged from the discharge port 10a of the coating head 10, and the photoresist liquid adheres to the surface of the substrate W over the entire length of the slit-shaped discharge port 10a to form beads (droplets). ) Is formed. In particular,
The time until the bead is formed may be measured in advance by an experiment or the like, and the waiting time may be set.

Step S6 (Start of rotation) The rotation control of the electric motor 2 is started so that the substrate W rotates at a constant rotation speed.

Step S7 (Start of movement) By driving the horizontal pulse motor 12c, the movement of the coating head 10 from the coating start position to the coating end position is started. At this time, as described above, as it moves from the coating start position to the coating end position, the moving speed thereof is decreased. By decreasing the moving speed, it is possible to make the supply amount of the photoresist liquid at the coating portion along the radial direction of the substrate W substantially constant. Therefore, the photoresist liquid can be applied uniformly. Further, since the ejection port 10a is formed in a slit shape, a spiral trace of the photoresist solution is less likely to have a gap, and unevenness can be suppressed, so that the photoresist solution can be applied more uniformly. It will be possible. Further, by aligning the longitudinal direction of the slit-shaped ejection port 10a and the moving direction thereof, the photoresist solution can be supplied at one time among the photoresist solution application sites along the radial direction of the surface of the substrate W. Since the area can be increased, the photoresist liquid can be supplied faster and with a smaller supply amount.

Step S8 (moving to the retracted position) The coating head 10 that has moved to the coating end position is further moved to the retracted position shown by the dotted line in FIG.

Step S9 (high-speed rotation) First, the elevating pulse motor 4d is driven to set the height position of the substrate W to the shake-off height L located below the coating height position H. As a result, the substrate W is stored in the shatterproof cup 6. Then, by rotating the electric motor 2 at a high speed, the excess amount of the photoresist liquid applied on the surface of the substrate W is shaken off to make the film thickness of the applied film uniform. As described above, since the photoresist solution is uniformly applied to the surface of the substrate W, it is possible to obtain a coating film having a more uniform film thickness by the shake-off process.

Step S10 (unloading) The elevation pulse motor 4d is driven to raise the height position of the substrate W to the coating height position H, and the rotation drive of the electric motor 2 is stopped. Then, the substrate W having the coating film formed on its surface is carried out of the apparatus by a substrate transport mechanism (not shown). Then, the coating process can be sequentially performed on a plurality of substrates by repeating the process from step S1.

Although the coating head 10 is moved from the center side of the substrate W toward the edge side in the above embodiment, the coating head 10 is moved from the edge side of the substrate W toward the center side. You may do it. In that case,
As the coating head 10 moves toward the center of the substrate W, the linear velocity at the coating site gradually decreases, so that the moving speed of the coating head 10 should be increased accordingly (indicated by the dotted line in FIG. 3). Shown). Even with this configuration, the same effect as that of the above-described embodiment can be obtained.

In the above embodiment, the height of the substrate W is adjusted by the elevating mechanism 4 so that the surface of the substrate W and the discharge port 10 can be adjusted.
Although the vertical gap with respect to a is set to the coating gap g, it may be set to the coating gap g by raising and lowering the coating head 10 side in the configuration shown in FIG.

That is, the coating head 10 is supported by the support arm 11a arranged on the side surface thereof, and the support arm 11a slides on the linear guide 11c provided upright between the U-shaped portions of the moving member 11b. It is freely attached and screwed to the ball screw 11d. The upper end of the ball screw 11d is interlocked with the rotary shaft of the pulse motor 11e. Further, on one side surface of the coating head 10, a gap measurement sensor 11f for measuring the vertical distance between the ejection port 10a and the surface of the substrate W is attached.

In such a configuration, a signal is output from the gap measuring sensor 11f to the control section 16, and the rotation of the pulse motor 11e is controlled so that the signal becomes a signal corresponding to the coating gap g and the coating head 10 is controlled. To move up and down. With this configuration, the coating gap g can be set more accurately.

Further, in the above embodiment, the coating head 10 is horizontally movable over the range exceeding the diameter of the substrate W, but if it is movable at least from the coating start position to the retracted position in FIG. Good.

Although the semiconductor wafer has been described as an example of the substrate, a glass substrate for a photomask, a glass substrate for a liquid crystal display device, a substrate for an optical disc, or the like can be used. In addition to the photoresist liquid, the treatment liquid may be a polyimide resin or a silica-based film forming material.

[0039]

As is apparent from the above description, according to the present invention as set forth in claim 1, the processing liquid supply means moves the processing liquid while being moved by the driving means from the substrate edge side toward the center side. The surface of the substrate is discharged without increasing the rotation speed of the substrate or lowering the moving speed of the processing liquid supply means, because the application portion of the processing liquid is enlarged so as to match the moving direction. The whole can be covered with processing liquid,
It is difficult to form a gap in the spiral locus of the processing liquid on the surface of the substrate due to the rotation of the substrate and the movement of the processing liquid supply means, and it is possible to suppress the occurrence of unevenness. Therefore, the treatment liquid can be applied uniformly, and the film thickness of the coating film formed on the substrate surface can be made uniform.

According to the second aspect of the present invention, the control means increases the moving speed of the processing liquid supply means as the application portion of the processing liquid moves from the edge side to the center side of the substrate, whereby the substrate is processed. It is possible to make the supply amount of the treatment liquid at the application site along the radial direction of the surface substantially constant. Therefore, the treatment liquid can be uniformly applied to the surface of the substrate.

According to the third aspect of the present invention, the discharge port of the processing liquid supply means is formed in a slit shape so that a gap does not easily occur in the spiral locus of the processing liquid and unevenness is suppressed. Therefore, the treatment liquid can be applied more uniformly. Therefore, the treatment liquid can be uniformly applied at a faster speed and with a smaller supply amount.

Further, according to the invention as set forth in claim 4, among the application portions of the treatment liquid along the radial direction of the substrate surface, it is possible to increase the portion to which the treatment liquid can be applied at one time. The treatment liquid can be applied faster and with a smaller supply amount. Further, it is possible to prevent a gap from being generated in the spiral locus of the processing liquid on the surface of the substrate due to the rotation of the substrate and the movement of the processing liquid supply means, and it is possible to prevent the occurrence of unevenness. Therefore, the treatment liquid can be uniformly applied at a faster speed and with a smaller supply amount.

[Brief description of drawings]

FIG. 1 is a front view showing a schematic configuration of a substrate coating apparatus which is an example of a substrate processing apparatus according to the present invention.

FIG. 2 is a diagram for explaining movement of a coating head.

FIG. 3 is a graph showing a change in moving speed of a coating head according to a coating site.

FIG. 4 is a flowchart showing a coating process of a photoresist liquid.

FIG. 5 is a side view showing a modified example of the coating head.

FIG. 6 is a perspective view showing a substrate processing apparatus according to a conventional example.

[Explanation of symbols]

W ... Substrate 1 ... Spin chuck (substrate holding means) 2 ... Electric motor (board holding means) 4 ... Lifting mechanism 10 ... Coating head (processing liquid supply means) 10a ... Discharge port 12 ... Drive mechanism (drive means) 14 ... Supply Department 16 ... Control unit (control means) H ... Application height L… Shake-off height

Claims (4)

[Claims] 1. In a substrate processing apparatus for processing a substrate by supplying a predetermined processing liquid to the surface of the substrate, a substrate holding means for rotatably holding the substrate, and a substrate holding means for holding the substrate. A processing liquid supply unit having a discharge port for discharging the processing liquid toward the surface, and the processing liquid supply unit horizontal from the edge side toward the center side of the substrate along the substrate held by the substrate holding unit. A substrate processing apparatus, comprising: a driving unit for moving the processing liquid, wherein the processing liquid supply unit enlarges a processing liquid application site so as to coincide with a moving direction. 2. The substrate processing apparatus according to claim 1, wherein the drive means is controlled so that a moving speed of the processing liquid supply hand is increased as the processing liquid supply hand is moved from an edge side of the substrate toward a center side. A substrate processing apparatus, comprising: 3. The substrate processing apparatus according to claim 1, wherein the discharge port of the processing liquid supply means has a slit-like opening. 4. The substrate processing apparatus according to claim 3, wherein the longitudinal direction of the ejection port of the processing liquid supply means and the moving direction of the processing liquid supply means are aligned with each other. .