JP3599323B2 - Substrate processing equipment - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a substrate processing apparatus for applying a processing liquid such as a resist liquid to a surface of a substrate to be processed such as a semiconductor wafer.
[0002]
[Prior art]
2. Description of the Related Art In a manufacturing process of a semiconductor device (IC chip) or LCD, a fine pattern is formed with high precision and high density on a surface of a substrate to be processed such as a semiconductor wafer or a glass substrate by using photolithography technology.
[0003]
For example, in the manufacture of semiconductor devices, after a resist liquid is applied to the surface of a semiconductor wafer, the resist liquid is exposed to a predetermined pattern, and further subjected to development processing and etching processing to form a predetermined circuit pattern. .
[0004]
In recent years, the line width of a semiconductor circuit to be formed by a photolithography technique has been increasingly miniaturized, and accordingly, thinning of a resist film and uniformity of the film thickness have been strictly required. That is, since the line width of the circuit to be formed is proportional to the film thickness of the resist solution and the exposure wavelength, it is preferable to make the film thickness of the resist solution as thin and uniform as possible.
[0005]
In the spin coating method, the resist film thickness can be controlled by adjusting the wafer rotation speed. For this reason, in the case of a 300 mm wafer, for example, the wafer is rotated at a considerably high speed of 2000 to 4000 rpm to reduce the thickness.
[0006]
In the spin coating method, since the wafer is rotated at a high speed, the amount of the resist liquid scattered from the edge of the wafer to the outside of the wafer is extremely large. In the spin coating method, the wafer is rotated in a cup in order to receive the scattered resist solution.
[0007]
Further, in this case, the exhaust is performed from the bottom of the cup so that the resist liquid scattered from the edge of the wafer does not form a mist and soar above the cup to contaminate other devices. In other words, the downflow in the clean room is drawn from the upper side of the cup, and an airflow from the upper side to the lower side is formed in the cup, thereby preventing the mist of the resist solution from scattering to the upper side of the cup.
[0008]
[Problems to be solved by the invention]
By the way, in the case of such a resist coating apparatus that rotates the wafer at a high speed, a phenomenon that only the resist film at the peripheral portion of the wafer rises as compared with other portions (thickness jumping phenomenon) may occur.
[0009]
SUMMARY OF THE INVENTION An object of the present invention is to provide a substrate which can effectively prevent the thickness of a coating film on an outer edge portion of a processing target substrate from jumping in a process of thinning the coating film applied on the processing target substrate by centrifugal force. An object of the present invention is to provide a processing device.
[0011]
[Means for Solving the Problems]
According to a first aspect of the present invention, in the substrate processing apparatus for processing a substrate having a first surface and a second surface, a holding and rotation unit for holding and rotating a first surface of the substrate, A liquid supply unit for supplying a liquid to the second surface of the substrate, a container for accommodating the holding / rotating unit, and forcibly exhausting the atmosphere around the substrate by exhausting from the bottom , A third surface having a height substantially equal to the second surface is disposed so as to surround an outer periphery of the substrate to be rotated and to be fixed to an inner peripheral surface of the container. An airflow control plate provided with a through-hole on the third surface , wherein the cross-sectional shape of the airflow control plate in the outer peripheral direction of the held and rotated substrate is increased as the distance from the outer periphery of the substrate increases. The through hole is formed so as to increase in thickness downward, and the through hole is separated from the outer periphery of the substrate by a predetermined dimension. To the conjunction provided at predetermined intervals in the airflow control plate provided on the outer peripheral side of the airflow control plate, a plurality of holes penetrating to the bottom of the airflow control plate.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0014]
FIG. 1 is a schematic configuration diagram showing an example in which the present invention is applied to a resist liquid applying apparatus that applies a resist liquid to a surface of a semiconductor wafer (hereinafter, referred to as “wafer W”). FIG. 2 is a plan view of the apparatus as viewed from above.
[0015]
As shown in FIG. 1, the apparatus has a spin chuck 10 that sucks and holds a wafer W on its upper surface, and that rotates and vertically drives the wafer W. Above the spin chuck 10, a supply nozzle 11 that is held so as to face the wafer W and that drops a resist film on the wafer W is disposed. The nozzle 11 is connected to a resist solution tank 14 via a supply pipe 12 and a control valve 13.
[0016]
The nozzle 11 is held via a holder 17 at the tip of a Z drive mechanism 15 formed in an L shape as shown in the figure. The base end of the Z drive mechanism 15 is held by a Y-direction moving mechanism 16. As shown in FIG. 2, the Y drive mechanism 16 has a Y rail 20 extending to the outside of the cup 1 along the Y direction, and connects the nozzle 11 with the wafer W and the nozzle standby unit 21. You can move between. The nozzle standby section 21 is configured to be able to house the nozzle 11 and to be able to clean the tip of the nozzle 11.
[0017]
Around the spin chuck 10, there is provided a cup 24 for receiving extra resist liquid scattered during rotation of the wafer W, and the scattered resist liquid is forcibly discharged from a drain tube (not shown). It is supposed to be.
[0018]
As shown in FIG. 1, an airflow control plate 25, which is a main part of the present invention, is disposed in a gap between the wafer W held by the spin chuck 10 and the inner peripheral surface of the cup 24. The airflow control plate 25 is disposed on the side facing the wafer W at substantially the same height as the wafer W, and is bent so as to fall downward at a gradually increasing slope toward the outer peripheral portion. The airflow control plate 25 is held in the cup 1 by fixing the outer peripheral portion to the inner peripheral surface of the cup 24.
[0019]
As shown in FIG. 2, the air flow control plate 25 is formed in a donut shape so as to surround the periphery of the wafer W, and has a plurality of exhaust holes 27 formed at predetermined intervals along a circumferential direction. ing. In addition, this figure has shown the state which cut | disconnected the upper part of the said cup 24 for convenience.
[0020]
FIG. 3 is an enlarged longitudinal sectional view showing the relationship between the outer edge of the wafer W and the airflow control plate 25. The gap t1 between the airflow control plate 25 and the wafer W is provided close so as not to disturb the airflow, and is maintained at, for example, 1 mm to 2 mm. The distance t2 between the outer edge of the wafer W and the exhaust hole 27 is, for example, 10 mm or more and compared with the gap t1 so that the airflow at the outer edge of the wafer does not have a special shape as compared with other surface portions. They are provided far apart. With this, the airflow flowing along the surface of the wafer W continuously flows on the surface of the airflow control plate 25, and flows downward from the exhaust holes 27 provided at positions away from the outer edge of the wafer W. Distribute.
[0021]
As shown in FIG. 1, an exhaust pipe 30 for exhausting the atmosphere in the cup is provided at the bottom of the cup 24. The exhaust pipe 30 is connected to a pump 32 via a control valve 31, and the pump 32 is operated to perform forced exhaust. As a result, the inside of the cup 24 becomes a negative pressure, so that the downflow D in the clean room is drawn into the cup 24 from above the cup 24. As described above, the downflow D is introduced into the bottom of the cup 24 through the exhaust hole 27 of the airflow control plate 25, and is exhausted to the outside through the exhaust pipe 30.
[0022]
According to such a configuration, it is possible to eliminate a special airflow state occurring at the outer edge of the wafer W. That is, the inventors of the present invention considered that the jump in the film thickness at the outer edge of the substrate to be processed is partly due to the generation of a unique airflow at the outer edge of the substrate to be processed.
[0023]
FIG. 8 is a plan view of the conventional apparatus showing the state of the wafer W rotating in the cup 1 and the airflow near the wafer W. When the wafer W is held on the spin chuck 2 and rotated in the direction indicated by the arrow α in the figure, the downflow introduced from above the cup 1 (on the front of the paper) collides with the upper surface of the wafer W, and Is converted into an airflow in a direction β substantially parallel to The wafer W is spirally diffused by the rotational centrifugal force generated by the rotation of the wafer W and guided to the outer edge 4 of the wafer W. Then, the wafer W is guided to the bottom of the cup 1 from the gap 3 between the outer edge 4 of the wafer W and the inner peripheral surface of the cup 1.
[0024]
FIG. 9 is an enlarged longitudinal sectional view showing an airflow state near the outer edge portion 4 of the wafer W in FIG. In the case where the airflow as described above occurs, at the outer edge portion 4 of the wafer W, all of the downflows supplied to the entire surface of the wafer W merge and pass through. As can be seen from this figure, the airflow at the outer edge portion 4 of the wafer W is a unique flow different from the other surface portions of the wafer W.
[0025]
The inventors believe that the peculiar airflow state of the outer edge portion 4 of the wafer W causes a jump in the resist film thickness, and think that the film thickness can be made uniform by eliminating the peculiar airflow. Finally, the device was configured as described above.
[0026]
FIG. 4 is a chart showing a measurement result of a film thickness distribution when a resist liquid is applied to a wafer W having a diameter of 300 mm by this configuration. Compared with the film thickness distribution according to the conventional configuration overlaid on the same chart, it is understood that the jump of the film thickness at the outer edge portion (both ends of the chart) of the wafer W can be reduced from the conventional 20 Å to 5 Å.
[0027]
Therefore, there is an effect that a processing apparatus which can sufficiently respond to recent demands for miniaturization and high definition of a semiconductor circuit can be obtained.
[0028]
This processing apparatus is preferably applied to the coating and developing system shown in FIGS.
[0029]
As shown in FIG. 5, the coating and developing system includes a cassette unit 60 for sequentially taking out the wafers W from the cassette CR in which the wafers W are stored, and a resist solution coating and developing process for the wafers W taken out by the cassette unit 60. The apparatus includes a process unit 61 for performing a process, and an interface unit 62 for transferring a wafer W coated with a resist solution to an exposure apparatus (not shown).
[0030]
The cassette section 60 is provided with four projections 70a for positioning and holding the cassette CR, and a first sub-arm mechanism 71 for taking out the wafer W from the cassette held by the projections 70a. When the sub-arm mechanism 71 takes out the wafer W, the sub-arm mechanism 71 rotates in the θ direction to change the direction, and can transfer the wafer W to the main arm mechanism 72 provided in the process unit 61. ing.
[0031]
The transfer of the wafer W between the cassette unit 60 and the processing unit 61 is performed via the third processing unit group G3. The third processing unit group G3 is configured by vertically stacking a plurality of process processing units as shown in FIG. That is, the processing unit group G3 includes a cooling unit (COL) for cooling the wafer W, an adhesion unit (AD) for performing a hydrophobic treatment for improving the fixability of the resist solution to the wafer W, and alignment of the wafer W. Alignment unit (ALIM) to perform, an extension unit (EXT) for holding the wafer W on standby, two pre-baking units (PREBAKE) for drying a thinner solvent after resist application, and a post for performing heat treatment after exposure processing The baking unit (POBAKE) and the post-exposure baking unit (PEB) are sequentially stacked from bottom to top.
[0032]
The transfer of the wafer W to the main arm mechanism 72 is performed via the extension unit (EXT) and the alignment unit (ALIM).
[0033]
Also, as shown in FIG. 5, around the main arm mechanism 72, first to fifth processing unit groups G1 to G5 including the third processing unit group G3 surround the main arm mechanism 72. It is provided in. Similarly to the third processing unit group G3 described above, the other processing unit groups G1, G2, G4, and G5 are configured by stacking various processing units in the vertical direction.
[0034]
The first and second processing unit groups G1 and G2 are provided with a development processing device (DEV) and a resist liquid coating device (COT) of this embodiment. As shown in FIG. 6, the first and second processing unit groups G1 and G2 are configured by vertically stacking a resist coating device (COT) and a developing device (DEV).
[0035]
On the other hand, as shown in FIG. 7, the main arm mechanism 72 includes a cylindrical guide 79 extending vertically and a main arm 78 driven up and down along the guide 79. The main arm 78 is configured to rotate in the plane direction and to be driven forward and backward. Therefore, by driving the main arm 78 in the vertical direction, the wafer W can be arbitrarily accessed with respect to each of the processing units of the processing unit groups G1 to G5.
[0036]
The main arm mechanism 72, which has received the wafer W from the cassette unit 60 via the extension unit (EXT) of the third processing unit group G3, first transfers the wafer W to the adhesion unit of the third processing unit group G3. (AD), and subjected to a hydrophobic treatment. Next, the wafer W is unloaded from the adhesion unit (AD) and cooled by the cooling unit (COL).
[0037]
The cooled wafer W is positioned by the main arm mechanism 72 so as to face the resist liquid coating apparatus (COT) of the first processing unit group G1 (or the second processing unit group G2), and is carried in. The wafer W coated with the resist liquid by the resist liquid coating device (COT) is unloaded by the main arm mechanism 72 and transferred to the interface unit 62 via the fourth processing unit group G4.
[0038]
As shown in FIG. 7, the fourth processing unit group G4 includes a cooling unit (COL), an extension cooling unit (EXT · COL), an extension unit (EXT), a cooling unit (COL), and two pre-processing units. A baking unit (PREBAKE) and two post-baking units (POBAKE) are sequentially stacked from bottom to top.
[0039]
The wafer W taken out from the resist liquid coating apparatus (COT) is first inserted into a prebaking unit (PREBAKE), and dried by removing a solvent (thinner) from the resist liquid.
[0040]
Further, this post-baking unit may be installed separately from the resist liquid application device (COT), or may be installed in the resist liquid application device.
[0041]
Next, after being cooled by the cooling unit (COL), the wafer W is transferred to the second sub arm mechanism 64 provided in the interface unit 62 via the extension unit (EXT).
[0042]
The second sub arm mechanism 64 that has received the wafer W sequentially stores the received wafer W in the cassette CR. The interface unit transfers the wafer W stored in the cassette CR to an exposure device (not shown), and receives the cassette CR storing the wafer W after the exposure processing.
[0043]
The wafer W after the exposure processing is transferred to the main arm mechanism 72 via the fourth processing unit group G4, and the main arm mechanism 72 needs the wafer W after the exposure. If there is, it is inserted into the post-baking unit (POBAKE), and then inserted into the developing device (DEV) of this embodiment to perform the developing process. The wafer W after the development processing is transferred to any one of the baking units, heated and dried, and then discharged to the cassette unit 60 via the extension unit (EXT) of the third processing unit group G3.
[0044]
The fifth processing unit group G5 is selectively provided, and in this example, has the same configuration as the fourth processing unit group G4. Further, the fifth processing unit group G5 is movably held by the rail 65, so that maintenance processing for the main arm mechanism 72 and the first to fourth processing unit groups G1 to G4 can be easily performed. ing.
[0045]
When the coating film removing apparatus of the present invention is applied to the coating and developing unit shown in FIGS. 5 to 7, parallel processing of a plurality of wafers can be easily performed. Can be performed. In addition, since the processing units are vertically stacked, the installation area of the apparatus can be significantly reduced.
[0046]
Next, another embodiment of the present invention will be described.
[0047]
In this embodiment, the airflow control plate 125 is configured as shown in FIG.
[0048]
In the airflow control plate 125, the thickness t <b> 3 increases downward 128 as the cross-sectional shape of the wafer W in the outer circumferential direction 126 increases away from the outer circumference 127 of the wafer W. For example, the cross-sectional shape of the airflow control plate 125 is triangular, and the interior angle θ of the top 129 of the triangular airflow control plate 125 near the wafer W is approximately 18 ° to approximately 35 °, and more preferably 20 °. ing.
[0049]
The surface 130 of the airflow control plate 125 and the surface of the wafer W are substantially at the same height, but the surface 130 of the airflow control plate 125 is slightly t4 higher than the surface of the wafer W, for example, approximately 0.5 mm to approximately 1.0 mm. It is preferable to increase the height by about 0 mm. Thus, a predetermined gap is provided between the outer periphery 127 of the wafer W and the airflow control plate 125. Further, the gas 131 flowing outward from the outer periphery 127 of the wafer W passes over the front surface 130 of the airflow control plate 125, and the liquid 132 flowing outward from the outer periphery 127 of the wafer W passes over the back surface 133 of the airflow control plate 125. Can be. That is, the airflow control plate 125 according to the present invention can function as a gas-liquid separation plate.
[0050]
As shown in FIG. 11, the plurality of through-holes 125c of the airflow control plate 125 are provided at a predetermined distance from the outer periphery 127 of the wafer W and are provided at predetermined intervals. (Bottom). Note that, as shown in FIG. 12, the through hole 126a may be a ring-shaped slit provided at a predetermined distance from the outer periphery 127 of the wafer W. Reference numeral 126b in FIG. 12 denotes a communication member that connects the airflow control plates 125a and 125b that are divided into two inside and outside by slit-shaped through holes 126a.
[0051]
In this embodiment, in particular, the airflow 140 passing through the through-hole 125c of the airflow control plate 125 entrains the airflow 141 passing through the back surface 133 side of the airflow control plate 125, and the airflow 141 flows downward, and the exhaust pipe 30 (see FIG. 1). Thereby, the mist flying in the space on the back surface 133 side of the airflow control plate 125 can be effectively removed.
[0052]
As still another embodiment of the present invention, as shown in FIG. 13, a rotation drive unit 201 that rotationally drives the airflow control plate 25 is further provided, and under the control of the control unit 202, as shown in FIG. The rotation drive unit 201 rotates the airflow control plate 25 in synchronization with the rotation of the wafer W (in the same direction and at the same speed). Thereby, the coating unevenness on the outer periphery of the wafer W is further reduced, and the rotation speed of the wafer W at the time of applying the resist liquid can be reduced. Will spread.
[0053]
It should be noted that this embodiment can be applied to an apparatus other than such a coating and developing unit. Further, the above-described embodiment can be variously modified without changing the gist of the invention.
[0054]
For example, in the above-described embodiment, the resist liquid applying apparatus for applying a resist liquid to a semiconductor wafer has been described as an example. However, the present invention is not limited to the semiconductor wafer, and the resist liquid is applied to a rectangular glass substrate used for LCD manufacturing. It may be a device for applying. In addition, the present invention can be applied not only to a resist solution but also to a substrate processing apparatus that supplies a developing solution to a substrate, for example. Thereby, particularly, mist can be effectively reduced.
[0055]
Further, in the above-described embodiment, the substrate is rotated. However, the substrate may not be rotated.
[0056]
【The invention's effect】
As described above, as described above, according to the present invention, it is possible to effectively prevent the application film from jumping up at the outer edge of the substrate to be processed.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram illustrating a resist liquid application apparatus according to an embodiment of the present invention.
FIG. 2 is a plan view of the resist liquid application device shown in FIG.
FIG. 3 is an enlarged longitudinal sectional view showing an outer edge portion of a wafer W and an airflow control plate according to one embodiment.
FIG. 4 is a chart showing a result of verifying a jump of a film thickness of a 300 mm wafer according to an embodiment.
FIG. 5 is a plan view of a coating and developing apparatus to which the resist liquid applying apparatus according to the present invention is applied.
FIG. 6 is a side view of the coating and developing apparatus shown in FIG.
FIG. 7 is a front view for explaining functions in the coating and developing apparatus shown in FIG. 5;
FIG. 8 is a plan view showing a conventional resist liquid applying apparatus.
FIG. 9 is a schematic diagram showing an airflow state at an outer edge portion of a wafer in a conventional resist liquid coating apparatus.
FIG. 10 is an enlarged sectional view of a resist liquid coating apparatus according to another embodiment of the present invention.
FIG. 11 is a plan view of the resist liquid applying apparatus shown in FIG.
FIG. 12 is a plan view showing a modified example of the resist liquid application device shown in FIGS. 10 and 11;
FIG. 13 is a side view of a resist liquid application apparatus according to still another embodiment of the present invention.
FIG. 14 is an explanatory diagram of the resist liquid application device shown in FIG.
[Explanation of symbols]
W: Wafer (substrate to be processed)
D: Downflows G1 to G5: First to fifth processing unit groups 1: Cups (containers)
2. Spin chuck (substrate holding mechanism)
3 ... Gap 4 ... Outer edge 10 ... Spin chuck 11 ... Supply nozzle 12 ... Supply pipe 13 ... Control valve 14 ... Resist liquid tank 15 ... Z drive mechanism 16 ... Y direction moving mechanism 17 ... Holder 20 ... Y rail 21 ... Nozzle standby Unit 24 Cup 25 Air flow control plate 27 Exhaust hole 30 Exhaust pipe 31 Control valve 32 Pump 60 Cassette unit 61 Process unit 62 Interface unit 64 Second sub arm mechanism 65 Rail 70 a Projection Part 71 First sub arm mechanism 72 Main arm mechanism 78 Main arm 79 Guide

Claims (6)

In a substrate processing apparatus for processing a substrate having a first surface and a second surface,
A holding / rotating unit that holds and rotates the first surface of the substrate,
A liquid supply unit for supplying a liquid to the second surface of the substrate;
A container for accommodating the holding / rotating unit and forcibly exhausting the atmosphere around the substrate by exhausting from the bottom,
A third portion is disposed so as to surround the outer periphery of the substrate that is held and rotated, and to have an outer peripheral portion fixed to an inner peripheral surface of the container, and has a height substantially equal to the second surface. An airflow control plate provided with a through hole on the third surface;
With
The cross-sectional shape of the airflow control plate in the outer peripheral direction of the held and rotated substrate is formed such that the thickness increases downward as the distance from the outer periphery of the substrate increases,
The through hole is provided at a predetermined distance from the outer periphery of the substrate, is provided at a predetermined interval on the airflow control plate, is provided on the outer peripheral side of the airflow control plate, and a plurality of through holes penetrate to a lower portion of the airflow control plate. A substrate processing apparatus characterized by being a hole . The substrate processing apparatus according to claim 1 ,
The said 3rd surface is a position higher than the said 2nd surface, The substrate processing apparatus characterized by the above-mentioned. The substrate processing apparatus according to claim 2 ,
A substrate processing apparatus, wherein a difference in height between the third surface and the second surface is approximately 0.5 mm to approximately 1.0 mm. The substrate processing apparatus according to claim 1 ,
A substrate processing apparatus, wherein a predetermined gap is provided between an outer periphery of the held and rotated substrate and the airflow control plate. The substrate processing apparatus according to claim 1 ,
The substrate processing apparatus according to claim 1, wherein the cross-sectional shape is a triangle. The substrate processing apparatus according to claim 5 ,
Interior angle of the top of the substrate near the front Kidan sectional shape is triangular the airflow control plate, a substrate processing apparatus which is a substantially 18 ° ~ approximately 35 °.

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