JP2002361155A - Coating device and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the necessity of a cleaning process carried out exclusively for cups installed around a substrate during the formation of a coating film performed by supplying a coating liquid to almost the center of rotation on the substrate surface while rotating the substrate around a vertical shaft. SOLUTION: This coating device is provided with a spin chuck 31 supporting a wafer W almost horizontally, a supply nozzle 62 supplying a resist liquid onto the surface of the wafer, an inner cup 5, in which an opening facing the outer edge of the substrate is formed so as to surround a region near the outer edge of the wafer W, and an outer cup 4, which is installed around the inner cup 5 and connected with an exhaust pipe 43 sucked by a suction means 42. The wafer W to which the resist liquid has been fed is rotated, and the liquid constituents in the resist liquid are carried about to the inside of the inner cup 5 by centrifugal force caused by the rotation. The gas constituents in the coating liquid are sucked to the outer cup 4 by sucking the outer cup 4. As a result, the liquid constituents and the gas constituents of the coating liquid are separated to be collected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus and a method for coating a substrate such as a semiconductor wafer or an LCD substrate (glass substrate for a liquid crystal display) with a coating liquid, for example, a resist liquid.

[0002]

2. Description of the Related Art A mask for forming a desired pattern on a surface of a semiconductor wafer (hereinafter, referred to as a wafer) or a glass substrate (LCD substrate) of a liquid crystal display is formed by applying a resist onto a surface of a substrate such as a wafer, and then applying light, It is obtained by irradiating the resist surface with an electron beam or an ion beam and developing.

For example, FIG. 10 shows an application unit for applying a resist. In the figure, reference numeral 110 denotes a rotatable and vertically movable spin chuck for holding a wafer W substantially horizontally by suction. The resist liquid is supplied to the surface of the wafer W held by the nozzle 111 from the nozzle 111. A cup 112 is provided around the wafer W held by the spin chuck 110 so as to surround the side of the wafer W. A bottom plate 113 is provided below the wafer W so as to surround the spin chuck 110. Is provided.

The peripheral edge of the bottom plate 113 is inclined upward toward the outside so as to approach the rear peripheral area of the wafer W, and then inclined downward toward the outside to form an outer end. Is provided with a ring body 114 having a mountain-shaped cross section which extends substantially vertically downward. Between the ring body 114 thus formed and the cup 112, the side of the wafer W sucked and held by the spin chuck 110,
An exhaust liquid passage 115 is formed which is inclined downward toward the outside and extends substantially vertically downward. The cup 1
A liquid receiving cup 116 is provided on the lower side of the exhaust gas passage 115 so as to be continuous with the exhaust liquid path 115, and an exhaust cup 117 is provided inside the liquid receiving cup 116 adjacent to the liquid receiving cup 116. Have been.

[0005] The liquid receiving cup 116 and the exhaust cup 117 are partitioned by a wall 118 whose upper part is open.
The outer end side of the ring body 114 is
The inside extends substantially vertically to the lower side of the wall portion 118. As a result, the liquid receiving cup 1
16, a flow path that is continuous with the exhaust cup 117 is formed.
The liquid receiving cup 116 and the exhaust cup 117 are sucked by suction means (not shown) via a drain pipe 120 and an exhaust pipe 121 connected to the bottom respectively.

In such a coating unit, the resist liquid is dripped from the nozzle 111 to substantially the center of the wafer W sucked and held by the spin chuck 110, and the resist liquid is diffused by centrifugal force by rotating the wafer W. breath,
Thus, the resist liquid can be applied to the entire surface of the wafer W.

When the resist liquid is applied to the surface of the wafer W in this manner, excess resist liquid is scattered in the peripheral direction of the outer edge of the wafer W, but the liquid receiving cup 116 and the exhaust cup 117 are sucked respectively. As a result, the resist liquid and the solvent, which are the liquid components of the resist as the coating liquid, the mist thereof, and the volatile matter and the air of the solvent which are the gas components both pass through the exhaust liquid passage 15, and first the liquid component is transferred to the liquid receiving cup. The liquid component is drained from the drain pipe 120 via 116, and then the gas component passes through the flow path between the outer edge of the ring body 114 and the wall 118 to reach the exhaust cup 117, and the exhaust pipe 121
The gas is then discharged to the outside of the coating unit in a state where gas and liquid are separated.

However, some resist liquid adheres to the inner wall surface of the cup 112 and the outer wall surface of the ring body 114. If the adhering resist liquid layer is left as it is, the resist is gradually laminated and dried, and the resist is gradually dried. The wafer W to be coated with the resist liquid may be contaminated. For this reason, the cup 112
A cleaning liquid is supplied to the ring body 114 and the resist liquid layer attached thereto is removed.

However, in this method, since the cleaning liquid easily flows along the path once flowing, the cleaning liquid does not spread and flow over the entire outer surfaces of the cup 112 and the ring body 114, and there is a problem that cleaning unevenness is likely to occur. As shown in FIG. 11, the resist 122 attached to the outer surface of the ring body 114 tends to be difficult to remove. Therefore, the cup 11
In order to completely remove the resist adhering to the ring 2 and the ring body 114, a large amount of cleaning liquid was required.

To solve this problem, for example, a cleaning jig 130 as shown in FIG.
And the cleaning jig 13
A method has been proposed in which a cleaning liquid, for example, a thinner liquid, is supplied into the chamber 0 through an inlet 132 and the resist is removed by rotating the spin chuck 110. In this method, the washing liquid is stored in the storage unit 1 by centrifugal force caused by rotation.
33, and is sprayed by the discharge holes 134 formed therein.
4 is scattered over the entire outer surface, whereby uniform cleaning can be performed.

[0011]

However, in the above-described method, a dedicated cleaning jig 130 is required, and the cleaning jig 130 is placed every time the coating unit is cleaned.
Since it has to be removed, cleaning takes time,
As a result, the throughput decreases. In the above-described coating unit, the mist of the resist liquid scatters toward the side of the outer edge of the wafer W. In the gas-liquid separation structure of this unit, both the drain pipe 120 and the exhaust pipe 121 are sucked. In addition, since the liquid receiving cup 116 and the exhaust cup 117 are provided radially adjacent to each other such that the exhaust cup 117 is on the inside, the exhaust cup 117 and the exhaust Tube 121
The mist of the resist solution also enters.

When the mist of the resist liquid enters the exhaust pipe 121 in this manner, the resist liquid comes into contact with gas and easily dries, and thus the resist is fixed to the inner wall surface of the exhaust pipe 121, and this region cannot be cleaned. Therefore, the adhered resist film grows, the diameter of the exhaust pipe 121 is reduced, and the exhaust pipe 121 is clogged. In such a case, there is a problem that the balance of the exhaust condition value in the film forming process is lost, coating unevenness or the like occurs, and the in-plane uniformity of the coated film is deteriorated.

The present invention has been made under such circumstances, and an object of the present invention is to eliminate the need for a dedicated cleaning step for removing deposits of a coating solution in a cup provided around a substrate holding portion. Another object of the present invention is to provide a technique for reducing the amount of a cleaning liquid.

[0014]

According to the present invention, there is provided a substrate holding portion for holding a substrate substantially horizontally and rotating the substrate around a vertical axis, and applying a coating liquid to a surface of the substrate held by the substrate holding portion. A supply nozzle for supplying, and a first cup having an opening formed opposite the outer edge of the substrate so as to surround a region near the outer edge of the substrate held by the substrate holding unit;
And rotating the substrate to which the coating liquid is supplied on the surface, and by the centrifugal force of this rotation, the liquid component of the coating liquid is scattered inside the first cup on the side of the substrate, whereby the coating is performed. The liquid component of the liquid is separated and collected from the gas component.

In such an invention, the liquid component of the coating solution comprising the coating solution and the solvent of the coating solution is separated and recovered from the gas component in the first cup, and the first cup contains a large amount of the solvent of the coating solution. The adhesion of the coating liquid is suppressed. This eliminates the need for a step of cleaning the cup for the purpose of removing the coating film adhered to the cup, thereby improving the throughput and reducing the amount of cleaning liquid.

Here, the coating processing apparatus includes a second cup provided around the first cup so as to surround a side of the substrate held by the substrate holding portion, and a second cup provided around the first cup. And an exhaust path that is connected to the substrate and that is suctioned by the suction means. The substrate having the surface supplied with the coating liquid is rotated, and the second cup is suctioned by the suction means via the exhaust path. The gas component of the coating solution is
It is desirable that the gas component of the coating liquid is separated and recovered from the liquid component by this.

In such a coating apparatus, for example, a first cup surrounding a region near the outer edge of the substrate, and a second cup provided around the first cup and provided with a suction / exhaust passage are provided. In a coating method including supplying a coating liquid to the surface of a substrate, rotating the substrate around a vertical axis, and diffusing the coating liquid onto the substrate surface by the centrifugal force of the rotation, the coating method includes: A step of applying a solvent of a coating liquid to the front surface, and then a step of applying the coating liquid to the surface of the substrate, and a step of supplying a cleaning liquid to the back side of the substrate,
And at least one of a coating liquid, a solvent for the coating liquid, and a cleaning liquid.
One of the substrates supplied is rotated, and the coating liquid and the solvent of the coating liquid and the liquid component of the cleaning liquid are scattered into the first cup on the side of the substrate by centrifugal force of rotation. The solvent treatment of the liquid and the gas component of the cleaning liquid are sucked and evacuated into the second cup to separate and collect the liquid component and the gas component of the coating liquid. In such an invention, since the liquid component of the coating liquid does not enter the second cup to which the suction / exhaust path is connected, adhesion of the coating liquid to the exhaust pipe 43 is also suppressed, and a highly uniform coating process is performed. be able to.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a coating and developing apparatus provided with a coating processing apparatus according to the present invention will be described below. FIG.
And FIG. 2 shows that the coating and developing apparatus 200 is
1 is a plan view and a schematic view showing the entire configuration of a resist pattern forming apparatus connected to FIG. In the figure, reference numeral 21 denotes a carrier station for loading and unloading a carrier C containing, for example, 25 semiconductor wafers (hereinafter, referred to as wafers) W, which are substrates. Placement part 22 and delivery means 2
3 is provided. The transfer means 23 takes out the wafer W as a substrate from the carrier C, and can move left and right, back and forth, and can move up and down so as to transfer the taken out wafer W to the processing section S1 provided on the back side of the carrier station 21. , And is rotatable about a vertical axis.

A main transport means 24 is provided at the center of the processing section S1. The coating unit 3 and the developing unit 25, which constitute a coating apparatus, are surrounded by the main transport means 24, for example, on the right side when viewed from the carrier station 21. However, shelf units U1, U2, and U3 in which heating / cooling system units and the like are stacked in multiple stages are arranged on the left, front, and back sides, respectively.

The shelf units U1, U2, and U3 are configured by stacking a plurality of units. For example, in addition to a heating unit and a cooling unit, a wafer transfer unit 26 and the like are allocated vertically. The main transport means 2
Numeral 4 is configured to be movable up and down, movable back and forth, and rotatable around a vertical axis, and has a role of transporting the wafer W between the shelf units U1, U2, U3, the coating unit 3 and the developing unit 25. However, in FIG.
3 and main transport means 24 are not shown.

The processing unit S1 includes an interface unit S2
Is connected to the exposure apparatus 210 via the. The interface unit S2 includes a transfer unit 27 and a buffer cassette 28. The transfer unit 27 is configured to be movable up and down, left and right, back and forth, and rotatable around a vertical axis. The wafer W is transferred between the exposure device 210 and the buffer cassette 28.

Next, the flow of the wafer W in the above-described resist pattern forming apparatus will be briefly described. First, a carrier C containing, for example, 25 wafers W is externally transferred by an automatic transfer robot (or an operator) to the carrier mounting section 2.
2 and the carrier C
The wafer W is taken out from the inside. The wafer W is transferred from the transfer unit 23 to the transfer unit 26 of the shelf unit U2.
(See FIG. 2).

Subsequently, the wafer W is sequentially conveyed to each section of the shelf unit U2 (or U1, U3) and subjected to a predetermined process such as a heating process and a cooling process. The resist is applied, and a heating process is performed in the heating unit to evaporate the solvent of the resist. Subsequently, the wafer W is sent from the transfer unit, which is not visible in the drawing of the shelf unit U3, to the exposure apparatus 210 via the interface unit S2, and a predetermined exposure process is performed.

The exposed wafer W is returned to the processing section S1 via a transfer unit (not shown) of the shelf unit U3 by a reverse route, and is subjected to predetermined heating processing and cooling processing. Thereafter, the wafer W is transferred to the developing unit 25 by the main transfer unit 24 and subjected to the developing process. After the developed wafer W is subjected to the heating process and the cooling process, the wafer W is transferred to the transfer unit 23 through the reverse path. And the original carrier C
Will be returned within.

Next, an example of the coating unit 3 constituting the coating processing apparatus of the present invention will be described with reference to FIG. 3. Reference numeral 31 denotes a spin chuck which is a substrate holder.
The wafer W is configured to be held substantially horizontally by vacuum suction. The spin chuck 31 can be rotated around a vertical axis by a driving unit 32 including a motor and a lifting unit, and can be moved up and down. The spin chuck 31
In the state in which the wafer W is held by suction on the spin chuck 31, the concave portion 41 surrounds the side portion extending from the wafer W to the spin chuck 31 and extends all around the lower side.
Is provided with an outer cup 4 which forms a second cup having a circular cross-sectional shape, and a bottom surface of a concave portion 41 of the outer cup 4 is provided with an exhaust passage connected to a suction means 42 via an opening / closing valve V1. An exhaust pipe 43 is connected. The suction means 42 and the exhaust pipe 43 form a suction exhaust path.

In the upper central region of the outer cup 41,
An opening 44 through which the wafer W can pass is formed, and an inner end of the opening 44 is, for example, as shown in FIG. 4, near an outer edge of an outer edge of the wafer W held by the spin chuck 31. It is located in the area. A bottom plate 33 surrounding the periphery of the spin chuck 31 is provided below the spin chuck 31, and the bottom plate 33 is connected to the recess 41 of the outer cup 4 in a region corresponding to the peripheral region of the wafer W.

Further, the outer cup 4 has a circular cross section so as to substantially surround a region near the outer edge of the wafer W held by the spin chuck 31 with a small gap therebetween. An inner cup 5 forming one cup is provided. The inner cup 5 faces the outer edge of the wafer W held by the spin chuck 31 and opens over the entire periphery of the outer edge in a region near the outer edge. The upper wall portion 52 and the lower wall portion 53 forming the part 51 are gently inclined downward from the wafer W toward the outside. The liquid receiving portion 54 has a concave shape extending vertically. A drain pipe 55 is connected to the bottom surface of the liquid receiving section 54 via a valve V2.

The inner end of the upper wall 52 of the inner cup 5 is held by a spin chuck 31 as shown in FIG. 4, for example, so that the wafer W can pass through the inside of the inner cup 5. The wafer W is located slightly outside the outer edge of the wafer W and in a region near the upper side. On the other hand, for example, as shown in FIG. 4, the inner end of the lower wall portion 53 of the inner cup 5 enters a region inside the outer edge of the back surface of the wafer W held by the spin chuck 31. As a result, the inner cup 5 substantially surrounds the side portion of the outer edge of the wafer W with a small gap. In this example, the spin chuck 31 is connected to the outer cup 4
Then, the wafer W is raised above the inner cup 5, and the main transfer means 24 transfers the wafer W to the spin chuck 31 at this position.

The spin chuck 31 of the bottom plate 33
A ring-shaped upright wall portion 34 having a concentric circle with the wafer W and a smaller radius than the wafer W is provided on a surface of the wafer W held on the surface facing the back surface side. This standing wall 34
Are provided, for example, on the inner side of the outer edge of the wafer W and slightly inward of the inner end of the lower wall 53. The upright wall portion 34 has, for example, ventilation holes 35 at a plurality of positions in the circumferential direction.

Further, a cleaning solution capable of dissolving the resist, for example, a thinner solution which is a solvent for the resist, is applied to the position of the bottom plate 33 closer to the center than the vertical wall portion 34 so as to be inclined upward outward, for example. A cleaning nozzle 61 for supplying to the back side peripheral area is provided. For example, the nozzle 61 ejects the cleaning liquid from a discharge hole at the tip toward a slight gap between the wafer W and the lower wall 53 of the inner cup 5.

Above the outer cup 41, there is provided a supply nozzle 62 serving as a coating liquid supply nozzle for supplying a coating liquid, for example, a resist liquid, to the wafer surface. This nozzle 62 is shown in FIG. Thus, the first moving mechanism 63 is configured to be able to move between the upper part of the center of the wafer W and the outside of the outer cup. The coating unit is provided with a solvent supply nozzle 64 for supplying, for example, a thinner liquid, which is a solvent for the coating liquid, to the wafer surface, and the nozzle 64 is also moved by a second moving mechanism 65 as shown in FIG. It is configured to be able to move between the upper part of the center of the wafer W and the outside of the outer cup so as not to interfere with the resist liquid supply nozzle.

The driving unit 32, the first moving mechanism 63 and the second moving mechanism 65, the supply nozzle 62,
Each part of the respective supply systems to the cleaning nozzle 61 and the solvent supply nozzle 63 is connected to the control part 66, and transfers the wafer W in accordance with elevating and lowering of the spin chuck 31 by the drive part 32, for example. It is possible to control the respective units in conjunction with each other such that the solvent of the coating liquid or the coating liquid is supplied by the moving mechanism 63 and the second moving mechanism 65.

Next, the operation of the coating unit 3 will be described. First, as shown in FIG. 6A, after the spin chuck 31 is positioned above the outer cup 4 and the wafer W is transferred to the spin chuck 31 by the main transfer means 24, the spin chuck 31 is removed. After lowering to a predetermined position, a pre-wet process is performed as shown in FIG. That is, in a state where the outer cup 4 is sucked by the suction means 42 through the exhaust pipe 43, the solvent supply nozzle 6
4 is positioned above the center of the wafer W, and a thinner liquid 71 which is a solvent
Is supplied, and the spin chuck 31 is rotated at a preset number of rotations. As a result, the thinner liquid 71 spreads in the radial direction of the wafer W due to the centrifugal force, and a liquid film of the thinner liquid is formed on the surface of the wafer W.

Subsequently, a resist liquid coating step is performed. The application of the resist solution is performed while the thinner solution applied by the pre-wet process is present on the wafer surface, as shown in FIG.
As shown in (a), with the suction cup 42 sucking the outer cup 4 through the exhaust pipe 43, the supply nozzle 62 is positioned above the center of the wafer W, and the center of the surface of the wafer W is substantially centered. A resist solution 72 as a coating solution is supplied to the position, and the spin chuck 31 is rotated at a preset number of rotations.
Is performed by rotating.

Thus, the resist liquid 72 spreads in the radial direction of the wafer W due to the centrifugal force, and a liquid film of the resist liquid 72 is formed on the surface of the wafer W. At this time, since the solvent of the coating liquid, for example, the thinner liquid 71 is present on the surface of the wafer W by the pre-wet process, the resist liquid 72 is mixed with the thinner liquid 71 and is in a state of being more easily developed. Thus, the resist liquid is uniformly diffused, so that the resist liquid can be applied uniformly.

Next, a back rinse step is performed. In this step, as shown in FIG. 7B, the outer cup 4 is sucked through the exhaust pipe 43 by the suction means 42, and the inner cup 4 in the peripheral area on the back side of the wafer W and the wafer W are washed by the cleaning nozzle 61. A cleaning solution for dissolving the resist, for example, a thinner solution 73 is ejected toward the gap between the cleaning solution and the W. As a result, the thinner liquid 73 is supplied to the peripheral area on the rear surface side of the wafer W, so that the resist liquid flowing from the front surface side of the wafer W is dissolved in the thinner liquid 73 and removed.

In the pre-wet process and the coating process, a thinner solution and a resist solution are supplied onto the wafer W while sucking the exhaust pipe 42. 8 will be described with reference to a schematic view of the vicinity of the outer edge of the wafer in FIG.

First, the resist solution 72 supplied to the wafer W
Is spread on the surface of the wafer W by the centrifugal force caused by the rotation of the wafer W, and an excess amount is scattered to the side of the wafer W by the centrifugal force as it is. At this time, the coating liquid scatters as a liquid component 74 such as a resist liquid and a solvent, and a gas component 75 such as a volatile component of the solvent and air. In comparison, the wettability to the wafer surface is extremely large. For this reason, the centrifugal force due to the rotation of the wafer W is transmitted, and the centrifugal force causes the wafer W to fly along the plate surface of the wafer W toward the side (side) of the outer edge of the wafer W. The mist of the liquid component 74 also scatters along with the liquid component in a direction immediately beside the outer edge of the wafer W.

On the other hand, the gas component 75 of the coating liquid has extremely low wettability to the wafer surface as compared with the liquid component 74. Therefore, the centrifugal force due to the rotation of the wafer W is hardly transmitted, and the wafer W spreads and spreads from the entire surface of the wafer W due to diffusion by volatilization.

As described above, the liquid component 74 of the coating liquid (including the mist of this liquid component) scatters right beside the wafer W, and the outer edge of the wafer W is located near the outer edge of the wafer W. Since the inner cup 5 is provided so as to substantially surround the side of the inner cup 5, the liquid component 74 scatters toward the inside of the inner cup 5, and is collected in the inner cup 5. In the inner cup 5, a flow path that is gradually inclined downward and then descends substantially vertically is formed, so that the liquid component 74 in the inner cup 5 flows along the flow path, Collect at the bottom. The liquid component 74 thus collected opens the valve V2 of the drain pipe 55 at a predetermined timing and is discharged to the outside.

On the other hand, the gas component 75 is scattered while diffusing into a wider area than the liquid component 74, and is sucked by the outer cup 4 outside the inner cup 5, so that it flows so as to be sucked in here. . At this time, the upper wall portion 52 of the inner cup 5
Between the inner edge of the wafer W and the outer edge of the wafer W is 1.5 mm or more.
Since the inner cup 5 is considerably narrow, about 2 mm, and is not sucked, the inner cup 5 does not easily enter this small gap. In this manner, only the liquid component 74 is scattered in the inner cup 5 and only the gas component 75 is scattered in the outer cup 5, whereby gas-liquid separation of the resist liquid is performed.

Similarly, in the pre-wet process, the liquid component of the solvent is collected in the inner cup 5, and the gas component (the solvent is volatilized) is collected in the outer cup 4, respectively. In the back rinsing step, the solvent sprayed so as to reach the peripheral portion of the wafer W through the gap between the lower portion of the inner cup 5 and the wafer W comes into contact with the peripheral portion on the back surface side of the wafer W, and this region is formed. After cleaning and dissolving and removing the resist solution adhering to the area, the gaseous component in which the solvent evaporates is scattered to the inner cup 5 and passes through the hole 35 of the vertical wall portion 34 by suction of the outer cup 4. And scatter into the outer cup 5. As a result, the liquid component (the solvent and the solvent in which the resist solution is dissolved) is collected in the inner cup 5 and the gas component (the solvent is volatilized) is collected in the outer cup 4 also in the back rinsing step.

In such a coating unit, the outer cup 4
There is an advantage that a cleaning step for removing the resist adhering to the inner cup 5 and the inner cup 5 becomes unnecessary. In other words, when gas flows to the site where the resist solution is attached, evaporation of the solvent is accelerated, and the attached resist is solidified and becomes difficult to remove. However, in the present invention, as described above, the wafer Since gas-liquid separation is performed near the outer edge of W, the liquid component is collected in the inner cup 5 and the gas component is collected in the outer cup 4, so that the state in which the resist is solidified does not occur.

That is, in the inner cup 5, since the solvent has already flowed in the pre-wet process, the resist solution and the solvent flow in the coating process while the inner wall surface of the cup 5 is wet with the solvent. Therefore, at the time of the coating process, the resist liquid is originally unlikely to adhere to the wall surface of the inner cup 5 and the resist liquid is simultaneously flushed with the scattered solvent. Further, since a solvent capable of dissolving the resist is further supplied in the back rinsing step, the resist on the wall surface of the inner cup 5 is washed away by the solvent.

As described above, even though the resist solution is recovered in the inner cup 5, since the solvent is present in a large amount in the pre-wet process, the coating process, and the back-rinsing process, the resist hardly hardens. Thus, the resist solution is washed away by the solvent in these steps, and it is not necessary to newly clean the inner cup 5. In addition, since volatile components of the solvent and air are scattered in the outer cup 4, the resist is prevented from adhering to the inner wall surface of the outer cup 4 and the exhaust pipe 43, and the outer cup 4 does not need to be cleaned.

As described above, both the inner cup 5 and the outer cup 4
There is no need to provide a dedicated cleaning step, and a cleaning jig for cleaning the cup is prepared, and it is not necessary to mount this on the spin chuck 31 to perform cleaning. It is possible to improve the throughput without the trouble and time. In addition, since a cleaning step is not required, a cleaning liquid for cleaning the cup, for example, a thinner liquid is not required, so that the thinner liquid used in the total processing of the coating unit can be reduced, and the processing cost can be reduced.

Further, by utilizing the phenomenon that the resist solution of the wafer W or the mist of the resist solution scatters right beside the outer edge of the wafer W due to the centrifugal force caused by the rotation of the wafer W, it is just beside the outer edge of the wafer W Since the inner cup 5 is provided so as to surround the inner cup 5, the resist liquid and the mist of the resist liquid are scattered into the inner cup 5, and the outer cup 4 does not enter the resist liquid or the mist thereof. For this reason, outer cup 4
Suction through the exhaust pipe 43, the cup 4 or the exhaust pipe 4
3 is prevented from adhering to the resist solution and the mist of the resist solution, thereby preventing the cup 4 and the exhaust pipe 43 from being stained. Further, since the mist of the resist solution does not enter the outer cup 4 in this manner, there is no need to provide a trap tank for trapping the mist and preventing dirt, and the structure of the exhaust pipe 43 can be prevented from becoming complicated.

In the above-described example, the outer cup 4 and the inner cup 5 are formed with a passage area for the wafer W, and are located slightly outside the outer edge of the wafer W held by the spin chuck 31. Since the inner edge of the opening 44 of the outer cup 4 and the inner edge of the opening 51 of the inner cup 5 are located, by positioning the spin chuck 31 above the outer cup 4, Wafer W between main transfer means 24
Can be easily delivered.

Further, in the above-described example, the inner end of the lower wall portion 53 of the inner cup 5 enters the inner side of the outer end edge of the wafer W, so that the resist liquid and the mist of the resist liquid are removed. It can be almost completely recovered in the inner cup 5. Further, in the present invention, the inner cup 5 may be formed so as to substantially surround the side portion of the outer end of the wafer W, and since the opening 51 of the inner cup 5 is small, the diameter of the cup 5 can be reduced. . As described above, when the diameter of the cup 5 is small, the inner surface area is reduced, so that the resist adhesion area is reduced, and the resist liquid is easily washed away by the thinner liquid at the time of pre-wetting or back rinsing. Here, in the conventional cup, the liquid flow path and the gas flow path are provided side by side, and since the gas flow path is inside, when the cup diameter is to be reduced, the outside of the gas flow path is reduced. Since the end position depends on the inside, the diameter of the exhaust pipe cannot be made large, and the exhaust power becomes small, so that gas-liquid separation cannot be performed sufficiently.

As described above, in the present invention, the structure of the inner cup 5 is such that an opening is formed so as to face the side portion of the outer edge of the substrate and to surround a region near the side portion of the substrate. Any structure can be used as long as the liquid component scattered to the side by the centrifugal force due to the rotation of the substrate can be collected. For example, as shown in FIG. 9, when processing the wafer W, the inner cup 8 is provided so as to overlap with the outer edge of the wafer W. Sometimes the inner cup 8 is moved by the moving mechanism 81 to the wafer W
The wafer W may be moved backward in a direction away from the wafer 8 to form an opening larger than the wafer W on the upper surface of the cup 8, and the wafer W may be transferred to the spin chuck 31 as shown in FIG. The opening for opening and closing the wafer may be formed on the upper surface of the cup 8 by another method, for example, by providing an upper wall portion that can be opened and closed in the direction indicated by the dotted arrow in FIG. The outer cup 4 is also provided so as to overlap the outer edge of the wafer W when processing the wafer W, and an opening through which the wafer W can pass is formed on the upper surface of the cup 4 when transferring the wafer. Good.

In the above example, an example in which the inside of the inner cup 5 is not exhausted has been described. However, a suction means may be provided at the other end of the drain tube 55 to exhaust the inside of the inner cup 5. Further, in the above-described example, the configuration in which the cleaning step is not provided has been described. You may make it supply. In this case, a solution in which the thinner liquid and the resist liquid as the liquid components are dissolved is collected in the inner cup 5, and the volatile component of the thinner liquid and the air are collected in the outer cup 4. In this case, it is not always necessary to perform the pre-wet process or the back rinse process.

The present invention can also be applied to a coating treatment using a coating liquid other than a resist liquid such as a developing treatment apparatus and a single wafer cleaning apparatus. For pure water,
Examples of the solvent for the coating liquid used in the cleaning step include pure water and thinner liquid. Furthermore, the substrate used in the present invention may be an LCD substrate or a substrate used in a photomask processing apparatus.

[0053]

According to the present invention, the liquid component of the coating liquid comprising the coating liquid and the solvent of the coating liquid is separated and recovered from the gas component in the first cup, and the solvent of the coating liquid is recovered in the first cup. Since the amount is large, the adhesion of the coating liquid can be suppressed. This eliminates the need for a step of cleaning the cup for removing the coating film attached to the cup, thereby improving the throughput and reducing the amount of cleaning liquid. In addition, since the liquid component of the coating liquid does not enter the second cup to which the suction / exhaust path is connected, the adhesion of the coating liquid to the exhaust pipe 43 is suppressed, and a highly uniform coating process can be performed. .

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a coating and developing apparatus provided with a coating processing apparatus of the present invention.

FIG. 2 is a perspective view showing the coating and developing apparatus.

FIG. 3 is a cross-sectional view showing one embodiment of a coating treatment apparatus of the present invention.

FIG. 4 is an enlarged sectional view showing a main part of the coating processing apparatus.

FIG. 5 is a plan view showing the coating apparatus.

FIG. 6 is a process diagram for explaining the operation of the coating apparatus.

FIG. 7 is a process chart for explaining the operation of the coating treatment apparatus.

FIG. 8 is a cross-sectional view for explaining the operation of the coating processing apparatus.

FIG. 9 is a cross-sectional view and a plan view showing still another embodiment of the coating processing apparatus according to the present invention.

FIG. 10 is a sectional view showing a conventional coating apparatus.

FIG. 11 is a sectional view showing a part of the coating processing apparatus.

FIG. 12 is a cross-sectional view for explaining a method of cleaning the coating processing apparatus.

[Explanation of symbols]

 W wafer 3 coating unit 31 spin chuck 3 cup 4 outer cup 41 recess 43 exhaust pipe 42 suction means 5 inner cup 52 upper wall section 53 lower wall section 54 liquid receiving section 55 drain pipe 61 cleaning nozzle 62 supply nozzle 64 solvent supply nozzle

Continued on the front page (72) Inventor Yuji Fukuda 5-6-6 Akasaka, Minato-ku, Tokyo TBS Release Center Tokyo Electron Limited F-term (reference) 2H025 AB16 EA05 4D075 AC65 BB65Z CA47 DA06 DB13 DC22 DC24 EA05 EA45 EB31 4F042 AA07 BA05 CC04 CC07 CC09 CC10 DA01 DB41 EB07 EB13 EB18 EB24 EB25 5F046 JA02 JA05 JA06 JA08 JA09 JA10 JA15 JA16

Claims (7)

[Claims] A substrate holding portion for holding the substrate substantially horizontally and rotating the substrate around a vertical axis; a supply nozzle for supplying a coating liquid to a surface of the substrate held by the substrate holding portion; A first cup formed with an opening facing the outer edge of the substrate so as to surround a region near the outer edge of the substrate held by the substrate holding unit; The supplied substrate is rotated, and the liquid component of the coating liquid is scattered into the first cup on the side of the substrate by the centrifugal force of the rotation, whereby the liquid component of the coating liquid is converted into a gas component. A coating treatment apparatus characterized by separating and collecting. A second cup provided around the first cup so as to surround a side of the substrate held by the substrate holding portion; and a second cup connected to the second cup, An exhaust path to be sucked by a suction means, wherein the substrate having the surface on which the coating liquid is supplied is rotated so that the second
The gas component of the coating liquid is sucked into the second cup by sucking the cup with suction means through an exhaust path, whereby the gas component of the coating liquid is separated and collected from the liquid component. The coating treatment apparatus according to claim 1, wherein 3. The coating processing apparatus according to claim 1, further comprising a solvent supply nozzle for supplying a solvent of a coating liquid to a surface of the substrate held by the substrate holding unit. 4. The coating processing apparatus according to claim 1, further comprising a cleaning liquid nozzle for supplying a cleaning liquid to a peripheral portion on a rear surface side of the substrate held by the substrate holding section. . 5. An opening through which a substrate can pass is formed on the upper surface of the first cup and / or the second cup, and the opening of the substrate with respect to the substrate holding unit is formed through the opening. 5. The delivery is performed.
The coating treatment apparatus according to any one of the above. 6. The substrate holding portion holds a central portion on the back side of the substrate, and the first cup covers an inner side of an outer edge on the back side of the substrate held by the substrate holding portion. The coating treatment apparatus according to any one of claims 1 to 5, wherein: 7. A coating apparatus comprising: a first cup surrounding a region near an outer edge of a substrate; and a second cup provided around the first cup and provided with a suction / exhaust passage. A coating liquid is supplied to the surface of the substrate, the substrate is rotated around a vertical axis, and the coating liquid is spread on the substrate surface by centrifugal force of this rotation to apply the coating liquid. A step of applying a coating liquid on the surface of the substrate, and a step of subsequently supplying a cleaning liquid to the back surface of the substrate, wherein at least one of the coating liquid, a solvent of the coating liquid, and the cleaning liquid is supplied. By rotating the substrate, the coating liquid and the solvent of the coating liquid and any liquid component of the cleaning liquid are scattered inside the first cup on the side of the substrate by the centrifugal force of rotation,
The liquid component and the gas component of the coating liquid are separated and collected by sucking and exhausting any of the coating liquid, the solvent of the coating liquid, and the gas component of the cleaning liquid into the second cup. Coating method.