Patent Application
20180021804
This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2015-041679, filed in Japan on Mar. 3, 2015, the entire contents of which are incorporated herein by reference.
The present invention relates to a coating treatment method of applying a coating solution to a substrate, a computer storage medium, and a coating treatment apparatus.
In a photolithography process in a manufacturing process of a semiconductor device, for example, a coating treatment of applying a predetermined coating solution, for example, onto a semiconductor wafer (hereinafter, referred to as a “wafer”) as a substrate to form a coating film such as an anti-reflection film, a resist film or the like, exposure processing of exposing the resist film into a predetermined pattern, a developing treatment of developing the exposed resist film, and so on are sequentially performed to form a predetermined resist pattern on the wafer.
In the above-descried coating treatment, a so-called spin coating method is often used which supplies the coating solution from a nozzle onto a center portion of the wafer under rotation, and diffuses the coating solution on the wafer by centrifugal force to form a coating film over the wafer.
However, in the coating treatment of an expensive coating solution like a resist solution, the supply amount needs to be reduced as much as possible, but when the supply amount is decreased, the in-plane uniformity of the coating film deteriorates. Hence, for the in-plane uniformity of the coating film and for the reduction in amount of the coating solution used, a so-called pre-wet treatment of applying a solvent such as a thinner onto the wafer before supply of the coating solution to thereby improve the wettability of the wafer is performed (Patent Document 1).
In the case of performing the pre-wet treatment, the solvent is supplied to the center portion of the wafer before the supply of the resist solution, and then the wafer is rotated to diffuse the solvent over the entire surface of the wafer. Subsequently, the rotation speed of the wafer is accelerated up to a predetermined rotation speed, and the resist solution is supplied to the center portion of the wafer and diffused over the entire surface of the wafer.
[Patent Document 1] Japanese Laid-open Patent Publication No. 2008-71960
Even in the case where the pre-wet treatment is performed, however, if the supply mount of the resist solution is further reduced, the in-plane uniformity of the coating film deteriorates, and therefore there is a limit in reduction of the supply amount of the resist solution.
In particular in the case of using a low-viscosity resist solution having a viscosity of about several cP, the present inventors have confirmed phenomena of the film thickness decreasing at the outer peripheral portion of the wafer and streak-shaped coating mottles occurring if the supply amount is reduced.
The present invention has been made in consideration of the above points, and its object is, when applying a coating solution onto a substrate, to apply the coating solution with a supply amount of the coating solution reduced to a small amount and uniformly within the substrate regardless of the viscosity of the coating solution.
To attain the above object, an aspect of the present invention is a coating treatment method of applying a coating solution onto a substrate, including: a solvent liquid film formation step of forming a first liquid film of a solvent at a middle portion of the substrate and forming a ring-shaped second liquid film having a film thickness larger than a film thickness of the first liquid film of the solvent at an outer peripheral portion of the substrate; a coating solution supply step of supplying the coating solution to a center portion of the substrate while rotating the substrate at a first rotation speed; and a coating solution diffusion step of diffusing the coating solution on the substrate by rotating the substrate at a second rotation speed higher than the first rotation speed while supplying the coating solution.
According to the present inventors, it has been confirmed that when the pre-wet treatment is performed uniformly on the entire surface of the substrate with a solvent, failure such as a decrease in film thickness at the outer peripheral portion of the substrate occurs in particular in the case of using a coating solution having a low viscosity as described above. It is presumed that the failure arises from the fact that pre-wet with the solvent causes, for example, the resist solution as the coating solution to diffuse earlier than expected, and as a result, the resist solution shaken off from the outer peripheral portion of the substrate increases. This tendency becomes more significant as the viscosity of the resist solution becomes lower. Hence, the present inventors earnestly studied this point and have obtained knowledge that the failure such as the decrease in film thickness at the outer peripheral portion of the substrate can be suppressed by making the film thickness of the solvent liquid film at the outer peripheral portion of the substrate larger than that at the middle portion of the substrate. It is considered that the liquid film of the solvent, when formed thick at the outer peripheral portion of the substrate, functions as a kind of wall at the time when the resist solution supplied to the middle portion of the substrate is diffused to the outer peripheral portion of the substrate, and the amount of the resist solution shaken off from the outer peripheral portion of the substrate decreases.
The present invention is based on the above knowledge, and according to an aspect of the present invention, a ring-shaped second liquid film having a film thickness larger than a film thickness of the first liquid film formed at the middle portion of the substrate is formed of the solvent at the outer peripheral portion of the substrate, so that the second liquid film functions as a kind of wall at the time when the coating solution supplied to the center portion of the substrate is diffused to the outer peripheral portion of the substrate, and the amount of the coating solution shaken off from the outer peripheral portion of the substrate decreases. As a result, even if the coating solution is low in viscosity and the supply amount of the coating solution is small, the coating solution can be applied uniformly within the substrate. Therefore, according to the present invention, it is possible to apply the coating solution with a supply amount of the coating solution reduced to a small amount and uniformly within the substrate regardless of the viscosity of the coating solution.
An aspect of the present invention according to another viewpoint is a coating treatment method of applying a coating solution onto a substrate, including: a solvent liquid film formation step of forming a liquid film of a solvent at a middle portion of the substrate and forming another ring-shaped liquid film at an outer peripheral portion of the substrate by forming a liquid film of the solvent by supplying the solvent to the middle portion of the substrate and thereafter rotating the substrate at a predetermined rotation speed to shake off the solvent, and then spraying a dry gas to a position deviated from the middle portion of the substrate with the substrate being rotated to remove the solvent at the position deviated from the middle portion of the substrate; a coating solution supply step of supplying the coating solution to a center portion of the substrate while rotating the substrate at a first rotation speed; and a coating solution diffusion step of diffusing the coating solution on the substrate by rotating the substrate at a second rotation speed higher than the first rotation speed while supplying the coating solution.
An aspect of the present invention according to still another viewpoint is a computer-readable storage medium storing a program running on a computer of a control unit controlling a coating treatment apparatus to cause the coating treatment apparatus to execute the coating treatment method.
An aspect of the present invention according to yet another viewpoint is a coating treatment apparatus for applying a coating solution onto a substrate, including: a substrate holding unit that holds and rotates the substrate; a coating solution supply nozzle that supplies the coating solution onto the substrate; a solvent supply nozzle that supplies a solvent onto the substrate; a first moving mechanism that moves the coating solution supply nozzle; and a second moving mechanism that moves the solvent supply nozzle. The coating treatment apparatus further includes a control unit configured to control the substrate holding unit, the coating solution supply nozzle, the solvent supply nozzle, the first moving mechanism, and the second moving mechanism so as to: form a first liquid film of the solvent at a middle portion of the substrate and form a ring-shaped second liquid film having a film thickness larger than a film thickness of the first liquid film of the solvent at an outer peripheral portion of the substrate; supply the coating solution to a center portion of the substrate while rotating the substrate at a first rotation speed; and diffuse the coating solution on the substrate by rotating the substrate at a second rotation speed higher than the first rotation speed while supplying the coating solution.
According to the present invention, it is possible, when applying a coating solution onto a substrate, to apply the coating solution with a supply amount of the coating solution reduced to a small amount and uniformly within the substrate regardless of the viscosity of the coating solution.
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Hereinafter, an embodiment of the present invention will be described.
The coating treatment system 1 has, as illustrated in
In the cassette station 10, a cassette mounting table 20 is provided. The cassette mounting table 20 is provided with a plurality of cassette mounting plates 21 on which the cassettes C are mounted when the cassettes C are transferred in/out from/to the outside of the substrate treatment system 1.
In the cassette station 10, a wafer transfer apparatus 23 is provided which is movable on a transfer path 22 extending in an X-direction as illustrated in
In the treatment station 11, a plurality of, for example, four blocks G1, G2, G3, G4 are provided each including various apparatuses. For example, the first block G1 is provided on the front side (X-direction negative direction side in
For example, in the first block G1, as illustrated in
For example, three apparatuses each of the developing treatment apparatus 30, the lower anti-reflection film forming apparatus 31, the resist coating apparatus 32, and the upper anti-reflection film forming apparatus 33 are arranged side by side in the horizontal direction. Note that the numbers and the arrangement of the developing treatment apparatuses 30, the lower anti-reflection film forming apparatuses 31, the resist coating apparatuses 32, and the upper anti-reflection film forming apparatuses 33 can be arbitrarily selected.
In the developing treatment apparatus 30, the lower anti-reflection film forming apparatus 31, the resist coating apparatus 32, and the upper anti-reflection film forming apparatus 33, for example, spin coating of applying a predetermined coating solution onto the wafer W is performed. In the spin coating, the coating solution is discharged, for example, from a coating nozzle onto the wafer W and the wafer W is rotated to diffuse the coating solution over the front surface of the wafer W. Note that the configuration of the resist coating apparatus 32 will be described later.
For example, in the second block G2, as illustrated in
For example, in the third block G3, a plurality of delivery apparatuses 50, 51, 52, 53, 54, 55, 56 are provided in order from the bottom. Further, in the fourth block G4, a plurality of delivery apparatuses 60, 61, 62 are provided in order from the bottom.
A wafer transfer region D is formed in a region surrounded by the first block G1 to the fourth block G4 as illustrated in
Further, in the wafer transfer region D, a shuttle transfer apparatus 80 is provided which linearly transfers the wafer W between the third block G3 and the fourth block G4.
The shuttle transfer apparatus 80 is configured to be linearly movable, for example, in the Y-direction in
As illustrated in
The wafer transfer apparatus 100 has a transfer arm that is movable, for example, in the X-direction, the θ-direction, and the vertical direction. The wafer transfer apparatus 100 can move up and down while supporting the wafer W to transfer the wafer W to each of the delivery apparatuses in the third block G3.
In the interface station 13, a wafer transfer apparatus 110 and a delivery apparatus 111 are provided. The wafer transfer apparatus 110 has a transfer arm that is movable, for example, in the Y-direction, the θ-direction, and the vertical direction. The wafer transfer apparatus 110 can transfer the wafer W to/from each of the delivery apparatuses in the fourth block G4, the delivery apparatus 111 and the exposure apparatus 12, for example, while supporting the wafer W by the transfer arm.
Next, the configuration of the above-described resist coating apparatus 32 will be described. The resist coating apparatus 32 has a treatment container 130 whose inside can be hermetically closed as illustrated in
In the treatment container 130, a spin chuck 140 is provided as a substrate holding unit which holds and rotates the wafer W thereon. The spin chuck 140 can rotate at a predetermined speed, for example, by a chuck drive unit 141 such as a motor. Further, the chuck drive unit 141 is provided with, for example, a raising and lowering drive mechanism such as a cylinder so that the spin chuck 140 freely rises and lowers.
Around the spin chuck 140, a cup 142 is provided which receives and collects liquid splashing or dropping from the wafer W. A drain pipe 143 for draining the collected liquid and an exhaust pipe 144 for discharging the atmosphere in the cup 142 are connected to the lower surface of the cup 142.
As illustrated in
On the first arm 151, a resist solution supply nozzle 154 as a coating solution supply nozzle which supplies the resist solution as the coating solution is supported. The first arm 151 is movable on the rail 150 by means of a nozzle drive unit 155 as a first moving mechanism. This allows the resist solution supply nozzle 154 to move from a waiting section 156 provided at the Y-direction positive direction side outer position of the cup 142 to a waiting section 157 provided at the Y-direction negative direction side outer side of the cup 142 through a position above a center portion of the wafer W in the cup 142. Further, the first arm 151 freely rises and lowers by means of the nozzle drive unit 155 to be able to adjust the height of the resist solution supply nozzle 154. Note that as the resist solution in this embodiment, for example, an MUV resist, a KrF resist, an ArF resist or the like is used which is a resist whose viscosity is relatively low, approximately 1 to 300 cP.
On the second arm 152, a solvent supply nozzle 158 is supported which supplies a solvent. The second arm 152 is movable on the rail 150 by means of a nozzle drive unit 159 as a second moving mechanism. This allows the solvent supply nozzle 158 to move from a waiting section 160 provided on the Y-direction positive direction side outer side of the cup 142 to a position above the center portion of the wafer W in the cup 142. The waiting section 160 is provided at a Y-direction positive direction side of the waiting section 156. Further, the second arm 152 freely rises and lowers by means of the nozzle drive unit 159 to be able to adjust the height of the solvent supply nozzle 158. Note that as the solvent in this embodiment, for example, cyclohexanone being the solvent for the resist solution or the like is used. Further, the solvent does not necessarily need to be a solvent contained in the resist solution, and any solvent can be arbitrarily selected as long as it can appropriately diffuse the resist solution by pre-wet.
On the third arm 153, a dry gas nozzle 161 is supported which blows a dry gas to the wafer W. The third arm 153 is movable on the rail 150 by means of a nozzle drive unit 162 as a gas nozzle moving mechanism. This allows the dry gas nozzle 161 to move from a waiting section 163 provided on the Y-direction negative direction side outer side of the cup 142 to a position above the wafer W in the cup 142. The waiting section 163 is provided on the Y-direction negative direction side of the waiting section 157. Further, the third arm 153 freely rises and lowers by means of the nozzle drive unit 162 to be able to adjust the height of the dry gas nozzle 161. Note that as the dry gas, for example, a nitrogen gas, air dehumidified by a dehumidifier (not illustrated) or the like can be used.
The configurations of the developing treatment apparatus 30, the lower anti-reflection film forming apparatus 31, and the upper anti-reflection film forming apparatus 33 which are other solution treatment apparatuses are the same as that of the above-described resist coating apparatus 32 other than the shapes and the numbers of the nozzles and the solutions supplied from the nozzles are different, and therefore description thereof will be omitted.
The above substrate treatment system 1 is provided with a control unit 200 as illustrated in
In the program storage unit, a program controlling the treatments on the wafer W in the substrate treatment system 1 is stored. Further, the program storage unit also stores a program for realizing a later-described substrate treatment in the substrate treatment system 1 by controlling the operations of the above-described various treatment apparatuses and a drive system of the transfer apparatuses. Note that the above-described programs may be ones which are recorded, for example, in a computer-readable storage medium H such as a computer-readable hard disk (HD), flexible disk (FD), compact disk (CD), magneto-optical disk (MO), or memory card, and installed from the storage medium into the control unit 200.
Next, a wafer treatment performed using the substrate treatment system 1 configured as described above will be described.
First, the cassette C housing a plurality of wafers W is transferred into the cassette station 10 of the substrate treatment system 1 and the wafers W in the cassette C are successively transferred by the wafer transfer apparatus 23 to the delivery apparatus 53 in the treatment station 11.
The wafer W is then transferred to the thermal treatment apparatus 40 in the second block G2 and subjected to a temperature regulation treatment. The wafer W is then transferred by the wafer transfer apparatus 70, for example, to the lower anti-reflection film forming apparatus 31 in the first block G1, in which a lower anti-reflection film is formed on the wafer W (Step S1 in
The wafer W is then transferred to the adhesion apparatus 41 and subjected to an adhesion treatment. The wafer W is then transferred to the resist coating apparatus 32 in the first block G1, in which a resist film is formed on the wafer W (Step S2 in
Here, the resist coating treatment in the resist coating apparatus 32 will be described in detail. For the coating treatment of the resist, the wafer W is first suction-held on the upper surface of the spin chuck 140. Then, the solvent supply nozzle 158 is moved to a position above the center portion of the wafer W, and a solvent Q is supplied onto the wafer W as illustrated in
Note that in order to reduce the time required to bring the first liquid film to a desired thickness, for example, a dry gas may be sprayed as needed to the middle portion of the wafer W by the dry gas nozzle 161 as illustrated in
Then, the solvent supply nozzle 158 is moved, for example, to a position above the outer peripheral portion of the wafer W as illustrated in
Next, as illustrated in
Then, the supply of the resist solution R from the resist solution supply nozzle 154 is continued, and at the point in time when the supply amount of the resist solution R reaches, for example, 0.1 mL, the rotation speed of the wafer W is accelerated from the first rotation speed to the second rotation speed (time t4 in
In this event, the wafer W has been subjected to the pre-wet treatment with the first liquid film M1, and therefore the resist solution R supplied onto the wafer W is quickly diffused toward the outer peripheral portion of the wafer W. When the resist solution R comes into contact with an inner peripheral end portion of the ring-shaped second liquid film M2 as illustrated in
Note that the supply of the solvent Q to the outer peripheral portion of the wafer W is stopped before the resist solution R is supplied to the center portion of the wafer W in this embodiment, but the supply of the resist solution R to the outer peripheral portion of the wafer W only needs to be stopped by the time when the resist solution R comes into contact with the second liquid film M2, and the timing for stop of supply can be arbitrarily set. If the supply of the solvent Q from the solvent supply nozzle 158 to the outer peripheral portion of the wafer W is continued at the time when the resist solution R is diffused, the resist solution R diffused toward the outer periphery of the wafer W and the solvent Q mix together, whereby the resist solution R is diluted. Then, the most of the diluted resist solution R does not fix on the wafer W but is wastefully shaken off from the outer peripheral portion of the wafer W. Accordingly, it is preferable to stop the supply of the solvent Q by the time when the resist solution R comes into contact with the second liquid film M2.
After the wafer W is rotated for the predetermined time (times t5 to t6 in
Thereafter, the wafer W is rotated at the third rotation speed for a predetermined time, for example, about 0.2 seconds, and then accelerated up to a fourth rotation speed that is higher than the third rotation speed and lower than the second rotation speed (time t7 in
Thereafter, a solvent is discharged as a rinse solution from a not-illustrated rinse nozzle to a rear surface of the wafer W to clean the rear surface of the wafer W (Step T5 in
After the resist film is formed on the wafer W, the wafer W is then transferred to the upper anti-reflection film forming apparatus 33 in the first block G1, in which an upper anti-reflection film is formed on the wafer W (Step S3 in
Then, the wafer W is transferred by the wafer transfer apparatus 100 to the delivery apparatus 52, and transferred by the shuttle transfer apparatus 80 to the delivery apparatus 62 in the fourth block G4. The wafer W is then transferred by the wafer transfer apparatus 110 in the interface station 13 to the exposure apparatus 12 and subjected to exposure processing in a predetermined pattern (Step S5 in
Then, the wafer W is transferred by the wafer transfer apparatus 70 to the thermal treatment apparatus 40 and subjected to a post-exposure bake treatment. Thus, the resist is subjected to a deprotection reaction with an acid generated at an exposed portion of the resist film. The wafer W is thereafter transferred by the wafer transfer apparatus 70 to the developing treatment apparatus 30 and subjected to a developing treatment (Step S6 in
After the developing treatment ends, the wafer W is transferred to the thermal treatment apparatus 40 and subjected to a post-bake treatment (Step S7 in
According to the above embodiment, the ring-shaped second liquid film M2 having a film thickness larger than that of the first liquid film M1 formed at the middle portion of the wafer W is formed at the outer peripheral portion of the wafer W of the solvent Q, so that at the time when diffusing the resist solution R supplied to the center portion of the wafer W over the wafer W, the second liquid film M2 can function as a kind of wall with respect to the resist solution R to suppress the diffusion of the resist solution R. Therefore, even if the viscosity of the resist solution R is a low viscosity such as about several cP, the resist solution R shaken off from the outer peripheral portion of the wafer W can be minimized to prevent a decrease in film thickness of the resist film at the outer peripheral portion of the wafer W and occurrence of streak-shaped coating mottles. As a result, the resist solution R can be diffused uniformly within the wafer W to form a resist film uniformly within a plane.
Note that the rotation speed of the wafer W is accelerated up to, for example, about 2000 rpm when forming the first liquid film M1 in the above embodiment, but the method of forming the first liquid film M1 is not limited to the content of this embodiment, and an arbitrary method can be selected as long as the method can form a liquid film of the solvent Q having a desired thickness at the middle portion of the wafer W. For example, the film thickness of the first liquid film M1 may be adjusted by keeping the rotation speed of the wafer W at the rotation speed at the time when supplying the solvent Q to the center portion of the wafer W, approximately 30 rpm in this embodiment after supplying the solvent Q to the center portion of the wafer W, and adjusting the time during which the wafer W is rotated. Alternatively, as has been described, the film thickness of the first liquid film M1 may be adjusted by spraying the dry gas to the middle portion of the wafer W by the dry gas nozzle 161.
In the case where the film thickness of the first liquid film M1 is adjusted by the dry gas, the shape of the dry gas nozzle 161 supplying the dry gas is not limited to the content of this embodiment, but an arbitrary method can be selected as long as the method can form a liquid film having a desired thickness at the middle portion of the wafer W by the solvent Q. For example, the film thickness, in particular at the middle portion, of the first liquid film M1 may be adjusted by providing a long dry gas nozzle 170 extending in a diameter direction of the wafer W as illustrated in
Alternatively, the diameter of the dry gas nozzle 161 may be set, for example, to about 60 to 200 mm in a manner to cover a portion above the middle portion of the wafer W, and the dry gas nozzle 161 having such a large diameter may supply the dry gas to the middle portion of the wafer W. Further, it can be also suggested to supply the dry gas to the middle portion of the wafer W by an almost disk-shaped dry gas nozzle 171 having a diameter of about 60 to 200 mm and having a plurality of gas supply ports (not illustrated) formed at its lower surface as illustrated in
Besides, for adjusting the film thickness of the first liquid film M1, what is sprayed to the wafer W does not necessarily need to be the dry gas. As illustrated in
Note that though the first liquid film M1 is formed first on the entire surface of the wafer W and then the second liquid film M2 is formed by supplying the solvent Q to the outer peripheral portion of the wafer W in the above embodiment, an arbitrary formation order of the first liquid film M1 and the second liquid film M2 may be selected as long as the second liquid film M2 having a film thickness larger than that of the first liquid film M1 can be formed at the outer peripheral portion of the wafer W. For example, the ring-shaped second liquid film M2 is formed first by supplying the solvent Q to the outer peripheral portion of the wafer W with the wafer W being rotated as illustrated in
Note that the state where the first liquid film M1 and the second liquid film M2 are not in contact with each other is illustrated in
Note that the liquid-form solvent Q is supplied from the solvent supply nozzle 158 in the above embodiment, but the solvent Q does not necessarily need to be supplied in the liquid form and, for example, vapor or mist of the solvent Q may be supplied. For example, the first liquid film M1 may be formed at the middle portion of the wafer W by disposing a solvent supply nozzle 190 having the same configuration as that of the above-described dry gas nozzle 171 having an almost disk shape at a position above the middle portion of the wafer W as illustrated in
Besides, when forming the first liquid film M1, for example, an almost disk-shaped template 191 having a flat lower surface may be disposed at a position above the middle portion of the wafer W as illustrated in
Note that though the appearances using the template 191 having a diameter smaller than that of the wafer W are illustrated in
Though the diffusion of the resist solution R is suppressed by making the film thickness of the second liquid film M2 formed at the outer peripheral portion of the wafer W larger than the film thickness of the first liquid film formed at the middle portion of the wafer W in the above embodiment, for example, a plurality of other liquid films M3 in concentric circles having almost the same film thickness may be formed on the wafer W as illustrated in
The other liquid films M3 as describe above can be realized, for example, by disposing a dry gas nozzle 193 provided with a plurality of discharge ports 192, at a position above the wafer W with the liquid film having the predetermined film thickness formed thereon as illustrated in
For forming the ring-shaped second liquid film M2 on the wafer W, the solvent Q is supplied to the outer peripheral portion of the wafer W while the wafer W is being rotated at the predetermined rotation speed in the above embodiment, the method of forming the liquid film of the solvent Q into the ring shape is not limited to the content of this embodiment. For example, a supporting arm 211 as a supporting unit, which can rotate the solvent supply nozzles 158 by a rotation drive mechanism 210 using the vertical axis passing through the center axis of the wafer W as a rotation axis as illustrated in
Note that the state in which the supporting arm 211 is provided with two solvent supply nozzles 158 is illustrated in
Further, in the case of rotating the solvent supply nozzles 158 by the supporting arm 211, the wafer W may be rotated in a direction opposite to the rotation direction of the supporting arm 211. This increases the relative rotation speed of the solvent supply nozzles 158 relative to the wafer W, thereby making it possible to form the second liquid film M2 more quickly.
As an example, a test of applying a resist solution onto a wafer W by the coating treatment method according to this embodiment was carried out using an ArF resist having a viscosity of 1.0 cP as the resist solution R and cyclohexanone as the solvent Q. In this case, the film thickness of the first liquid film M1 was changed by changing the supply amount of the resist solution R by an increment of 0.05 mL between 0.20 mL and 0.30 mL, and changing the time during which the wafer W was rotated at a rotation speed of 2000 rpm between times t1 to t2 in
Further, as a comparative example, the same test was carried out also in the case of uniformly pre-wetting the entire surface of the wafer W with the solvent Q as in the conventional art, and then supplying the resist solution R to the center portion of the wafer W. Note that the same resist solution R and the same solvent Q were used also in the comparative example.
As a result of the test, in the comparative example, the film thickness uniformity of the resist film within the wafer W was a desired value in the case of setting the supply amount of the resist solution R to 0.20 mL, but coating mottles possibly caused from deficiency in supply amount of the resist solution R were found at the outer peripheral portion of the wafer W.
On the other hand, in any of the cases of setting the supply amount of the resist solution R to 0.20 mL to 0.30 mL when setting the time during which the wafer W was rotated at a rotation speed of 2000 rpm to 2 seconds and 5 seconds using the coating treatment method according to this embodiment, the film thickness uniformity within the wafer W was ensured, and the coating mottles at the outer peripheral portion of the wafer W as those found in the comparative example were not found. In addition, it was confirmed that the film thickness uniformity within the wafer W was improved in the case of setting the rotation time to 5 seconds more than in the case of setting the rotation time to 2 seconds. It is considered that making the film thickness of the first liquid film M1 smaller suppresses excessive diffusion of the resist solution R at the middle portion of the wafer W to thereby suppress a decrease in film thickness of the resist film at the outer peripheral portion of the wafer W.
In the case of setting the time during which the wafer W was rotated at a rotation speed of 2000 rpm to 8 seconds, the film thickness uniformity of the resist film within the wafer W was a desired value, but coating mottles possibly caused from deficiency in supply amount of the resist solution R were found at the outer peripheral portion of the wafer W. It is considered that the rotation time of the wafer W was long and the most of the solvent Q was shaken off from the outer peripheral portion of the wafer W, and as a result, the first liquid film M1 was not appropriately formed. In other words, it is considered that the coating treatment method according to this embodiment was not performed. Accordingly, from the result, it was confirmed that a coating film uniform within the wafer W can be formed by the coating treatment method according to this embodiment. Note that according to the present inventors, the first liquid film M1 only needs to be formed to prevent the front surface of the wafer W from getting dry, and the lower limit value of the film thickness of the first liquid film M1 only needs to be more than 0 mm as has been described. Further, the upper limit value of the first liquid film M1 is preferably set to less than 2 mm as has been described from the viewpoint of suppressing excessive diffusion of the resist solution R at the middle portion of the wafer W.
A preferred embodiment of the present invention has been described above with reference to the accompanying drawings, but the present invention is not limited to the embodiment. It should be understood that various changes and modifications are readily apparent to those skilled in the art within the scope of the spirit as set forth in claims, and those should also be covered by the technical scope of the present invention. The present invention is not limited to the embodiment but can take various forms. The present invention is also applicable to the case where the substrate is a substrate other than the wafer, such as an FPD (Flat Panel Display), a mask reticle for a photomask or the like.
The present invention is useful in applying a coating solution onto a substrate.
1 substrate treatment system
30 developing treatment apparatus
31 lower anti-reflection film forming apparatus
32 resist coating apparatus
33 upper anti-reflection film forming apparatus
40 thermal treatment apparatus
41 adhesion apparatus
42 edge exposure apparatus
140 spin chuck
154 resist solution supply nozzle
158 solvent supply nozzle
161 dry gas nozzle
200 control unit
Q solvent
M1 first liquid film
M2 second liquid film
R resist solution
W wafer
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-041679 | Mar 2015 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2016/053335 | 2/4/2016 | WO | 00 |
