Substrate processing device, substrate peeling method, peeling device, and peeling method

Abstract

The present disclosure pertains to a substrate processing device, a substrate peeling method, a peeling device, and a peeling method, and the purpose of the present disclosure is to efficiently achieve static elimination without requiring high costs and a large installation space. This substrate processing device comprises: a stage on which a substrate is placed; and a peeling mechanism for peeling off the substrate from the stage. The stage is configured such that, in an environment surrounded by atmospheric-pressure air, a discharge gas is supplied, through piping inside the stage, to the lower surface of the substrate which is adhered by electrostatic attraction.

Description

Substrate processing apparatus, substrate peeling method, peeling apparatus and peeling method

[0001] The present invention relates to a substrate processing apparatus, a substrate peeling method, a peeling apparatus, and a peeling method.

[0002] During the substrate manufacturing process, when a substrate is removed from a stage on which it is placed, the substrate and the stage may stick together due to electrostatic attraction. Forcibly removing the substrate from the stage can cause cracks or breakage in the substrate.

[0003] To solve the above-mentioned problems, Patent Document 1 discloses a technique for removing static electricity using an ionizer. In this method, ions generated by the ionizer are supplied between the object to be attracted and the stage, thereby preventing the object from sticking to the stage.

[0004] Japanese Patent Application Publication No. 8-262387

[0005] However, the above-mentioned method requires the installation of an ionizer, which results in high costs and a large installation space. Furthermore, because the ionizer uses a discharge needle to generate ions at a specific point, the amount of ions generated is small, making it inefficient for eliminating static electricity from the substrate and stage that are attached to each other over a wide area.

[0006] In order to solve the above-mentioned problems, the present disclosure aims to provide a substrate processing apparatus, a substrate peeling method, a peeling apparatus, and a peeling method that can efficiently remove static electricity without requiring high costs and a large installation space.

[0007] A first aspect of the present disclosure is preferably a substrate processing apparatus comprising a stage on which a substrate is placed and a peeling mechanism for peeling the substrate from the stage, wherein the stage is surrounded by air at atmospheric pressure and supplies a discharge gas to the underside of the substrate, to which the substrate is attached by electrostatic attraction, via piping inside the stage.

[0008] A second aspect of the present disclosure is preferably a substrate peeling method comprising the steps of: creating an environment in which a stage on which a substrate is placed is surrounded by air at atmospheric pressure; after creating the environment surrounded by air at atmospheric pressure, supplying a discharge gas to the underside of the substrate, which has been stuck by electrostatic attraction, through piping inside the stage; and, after supplying the discharge gas, peeling the substrate from the stage using a peeling mechanism.

[0009] A third aspect of the present disclosure preferably comprises a container containing a first charged object and a second charged object, a blower, and a peeling mechanism, wherein the blower supplies a discharge gas to the inside of the container in an environment surrounded by air at atmospheric pressure, and the peeling mechanism is a peeling device that peels off the first charged object and the second charged object.

[0010] A fourth aspect of the present disclosure is preferably a separation method comprising the steps of creating an environment in which the inside of a container containing a first charged object and a second charged object is surrounded by air at atmospheric pressure, supplying a discharge gas into the inside of the container after creating an environment surrounded by air at atmospheric pressure, and separating the second charged object from the first charged object after supplying the discharge gas.

[0011] According to the first to fourth aspects of the present disclosure, a discharge gas is supplied to the underside of the substrate through piping inside the stage, thereby enabling efficient static elimination without requiring high costs or a large installation space.

[0012] FIG. 1 is a cross-sectional view showing a substrate processing apparatus according to a first embodiment of the present disclosure. FIG. 2 is a perspective view showing a stage according to the first embodiment of the present disclosure. FIG. 3 is a cross-sectional view showing the substrate processing apparatus during substrate transport according to the first embodiment of the present disclosure. FIG. 4 is a diagram showing peeling charging. FIG. 5 is a first cross-sectional view showing a peeling process according to the first embodiment of the present disclosure. FIG. 6 is a second cross-sectional view showing the peeling process according to the first embodiment of the present disclosure. FIG. 7 is a cross-sectional view showing a substrate processing apparatus that supplies compressed air to the underside of a substrate. FIG. 8 is a cross-sectional view showing a substrate processing apparatus that supplies compressed air and ions to the underside of a substrate. FIG. 9 is a cross-sectional view showing a substrate processing apparatus that supplies a discharge gas to the underside of a substrate. FIG. 10 is a graph showing an effect of suppressing sticking between a stage and a substrate. FIG. 11 is a top view showing a stage according to a second embodiment of the present disclosure. FIG. 12 is a cross-sectional view showing a substrate processing apparatus according to a third embodiment of the present disclosure. FIG. 13 is a cross-sectional view showing a peeling process according to the third embodiment of the present disclosure. FIG. 14 is a cross-sectional view showing a peeling process according to the fourth embodiment of the present disclosure. FIG. 15 is a cross-sectional view showing a peeling process according to the fourth embodiment of the present disclosure. FIG. 16 is a cross-sectional view showing a clamp jig according to a fifth embodiment of the present disclosure. FIG. 17 is a cross-sectional view showing the substrate processing apparatus before substrate peeling according to the fifth embodiment of the present disclosure. FIG. 18 is a cross-sectional view showing the substrate processing apparatus after substrate peeling according to the fifth embodiment of the present disclosure. FIG. 19 is a cross-sectional view showing a peeling process according to a sixth embodiment of the present disclosure. FIG. 19 is a diagram showing a modified example of the peeling process according to the sixth embodiment of the present disclosure.

[0013] A substrate processing apparatus, a substrate peeling method, a peeling apparatus, and a peeling method according to embodiments will be described with reference to the drawings. The same or corresponding components are designated by the same reference numerals, and repeated description may be omitted.

[0014] 1 is a cross-sectional view showing a substrate processing apparatus according to a first embodiment of the present disclosure. The substrate processing apparatus 100 is a processing apparatus installed in a reaction vessel (not shown).

[0015] The substrate processing apparatus 100 includes a stage 2. The stage 2 is a mounting table on which a substrate 4 (described later) is placed. The stage 2 has, for example, a circular upper surface with a larger radius than the substrate 4 (described later). An oxide film is formed on the surface of the stage 2 by anodizing.

[0016] A substrate 4 to be processed is placed on the stage 2. In this example, the substrate 4 is a semiconductor wafer. The substrate 4 is a thin plate having a circular upper surface, and may be, for example, a liquid crystal glass substrate.

[0017] A protective insulating film (not shown) is formed on the substrate 4. The substrate 4 is placed on the stage 2 with the surface on which the protective insulating film is formed facing downward.

[0018] The stage 2 supplies a discharge gas to the underside of the substrate 4, which is attached by electrostatic attraction, through an internal pipe 26. Electrostatic attraction and the discharge gas will be described later. When supplying the discharge gas, the stage 2 is preferably surrounded by air at atmospheric pressure. The reason for this will also be described later.

[0019] The pipe 26 will be described in more detail. The pipe 26 is connected to the vacuum source 21, the gas supply source 22a, and the gas supply source 22. The connection destination of the pipe 26 can be switched by opening at least one of the valves 24a, 24b, and 24c. The pressure in the pipe 26 when connected to the vacuum source 21, the gas supply source 22a, and the gas supply source 22 is controlled by the regulator 23a, 23b, or 23c.

[0020] The valves 24a, 24b and 24c may be electromagnetic valves or air-operated valves.

[0021] The stage 2 performs vacuum suction, supplies compressed gas, or supplies discharge gas via a pipe 26. For example, when the pipe 26 is connected to the vacuum source 21, the stage 2 vacuum-sucks the substrate 4.

[0022] Furthermore, when the pipe 26 is connected to the gas supply source 22, the stage 2 supplies compressed gas to the underside of the substrate 4. The compressed gas may be, for example, compressed air, dry air, or nitrogen gas. As a result, for example, the state in which the substrate 4 is vacuum-attached to the stage 2 is released.

[0023] Furthermore, when the pipe 26 is connected to the gas supply source 22a, the stage 2 supplies a discharge gas to the underside of the substrate 4. The discharge gas is a gas having a discharge start voltage lower than that of a specific gas. When the specific gas is air at atmospheric pressure, the discharge gas is, for example, argon gas, neon gas, or helium gas. As a result, gas is supplied to the underside of the substrate 4. The discharge gas may be supplied at a pressure equal to or higher than atmospheric pressure.

[0024] The substrate processing apparatus 100 also includes a transfer arm 6. The transfer arm 6 recovers the substrate 4 placed on the stage 2. This recovery is performed by vacuum-adsorbing the substrate 4 with a vacuum suction mechanism 62 provided at the tip of the transfer arm 6. When the substrate 4 is stuck to the stage 2, the transfer arm 6 and the vacuum suction mechanism 62 are included in a peeling mechanism that peels the substrate 4 from the stage 2.

[0025] 2 is a perspective view showing a stage according to the first embodiment of the present disclosure, in which a substrate 4 is placed on the stage 2.

[0026] Stage 2 has an opening 27 which is the end of pipe 26. Opening 27 is used as an opening for vacuum suction when pipe 26 is connected to vacuum source 21, as an opening for supplying compressed gas when pipe 26 is connected to gas supply source 22, and as an opening for supplying gas when pipe 26 is connected to gas supply source 22a. The diameter of opening 27 is, for example, φ0.3 mm.

[0027] The stage 2 also has suction grooves 28 on the surface of its upper surface. The suction grooves 28 connect the plurality of openings 27 together, thereby improving the efficiency of vacuum suction, compressed gas supply, or gas supply.

[0028] In addition, AA' and BB' in the figure indicate the positions of cross sections shown in cross-sectional views to be described later.

[0029] The processing steps for the substrate 4 using the substrate processing apparatus 100 will be described. First, the substrate 4 is transported onto the stage 2 by the transport arm 6. After the substrate 4 has been transported, the valves 24b and 24c are closed and the valve 24a is opened, thereby switching the connection destination of the pipe 26 to the vacuum source 21. As a result, the inside of a reaction vessel (not shown) is evacuated, and at the same time, the substrate 4 is vacuum-attached to the stage 2. The strength of the vacuum suction is adjusted by controlling the regulator 23a.

[0030] Next, the substrate 4 is treated with vacuum plasma. The vacuum plasma is supplied by a plasma mechanism (not shown). The substrate 4 becomes charged by this plasma treatment, which can cause the stage 2 and the substrate 4 to stick together due to electrostatic attraction. This electrostatic attraction will be described in detail later.

[0031] 3 is a cross-sectional view showing the substrate processing apparatus during substrate transfer according to the first embodiment of the present disclosure. After the processing step, the substrate 4 is recovered by the transfer arm 6 after a peeling step, which will be described later. At this time, the transfer arm 6 vacuum-sucks the substrate 4 with a vacuum suction mechanism 62 at the tip. As a result, the substrate 4 is separated from the stage 2.

[0032] The following describes sticking of the substrate 4 to the stage 2. When the substrate 4 is collected by the transport arm 6, the substrate 4 may be stuck to the stage 2 due to electrostatic attraction. Forcibly peeling the substrate from the stage 2 can cause cracks or breaks in the substrate.

[0033] Two factors are believed to be responsible for the generation of electrostatic attraction. The first factor is plasma processing. For example, when plasma processing is performed on the surface of the substrate 4, the substrate 4 becomes charged. The substrate processing apparatus 100 does not have a path for discharging the charged charge from the substrate 4. As a result, the charge on the substrate 4 induces a charge of the opposite polarity to that of the substrate 4 on the surface of the stage 2 with which the substrate 4 comes into contact.

[0034] In this case, the electric charges are neutralized at the contact surface between the substrate 4 and the stage 2. However, as the substrate 4 is separated from the stage 2, an electrostatic charge is generated on the substrate 4 and the stage 2. This charge is hereinafter referred to as "peeling charge." This peeling charge generates an electrostatic attraction force between the substrate 4 and the stage 2.

[0035] The second factor is material characteristics. If the triboelectric series of the material on the back surface of the substrate 4 and the material on the surface of the stage 2 are different, electrons are likely to move when the substrate 4 comes into contact with the stage 2. In other words, charges of opposite polarities are generated on the back surface of the substrate 4 and the surface of the stage 2.

[0036] In this case, the charges are neutralized at the contact surface between the substrate 4 and the stage 2. However, as the substrate 4 is separated from the stage 2, peeling charges are generated on the substrate 4 and the stage 2. This peeling charge generates an electrostatic attraction force between the substrate 4 and the stage 2.

[0037] It has been confirmed that the adhesion between the stage 2 and the substrate 4 becomes even greater when the substrate 4 is heat-treated. This is presumably because the thermal molecular motion at the contact interface becomes more intense, promoting electron transfer.

[0038] Figure 4 shows peel electrification. The left diagram in Figure 4 shows a state where two charged objects are in contact. At this time, the charges at the contact surface between the two objects are neutralized.

[0039] The right diagram in Figure 4 shows the state in which two objects have been separated. Here, an electric field 502 is generated as the two objects, which were in a neutral state, are separated. The generation of the electric field 502 generates an electrostatic attraction force between the two objects. This is the peel electrification mentioned above.

[0040] The static electricity detected by measuring the charge on the stage 2 reaches the order of kilovolts. In other words, the adhesion between the stage 2 and the substrate 4 due to the electrostatic attraction described above is strong. Therefore, if the substrate 4 is forcibly peeled off from the stage 2, the problem of cracks or breakage occurring in the substrate is serious.

[0041] As a first method for solving the above-mentioned problems, Patent Document 1 discloses a technique for eliminating static electricity using an ionizer. However, this method requires the installation of an ionizer, which creates new problems of cost and installation space requirements. Furthermore, because the ionizer uses a discharge needle to generate ions at a specific point, the amount of ions generated is small, which makes it inefficient for eliminating static electricity from the substrate and stage that are attached to each other over a wide area.

[0042] A second method for solving the above-mentioned problems is known, which involves removing residual charges. This method requires a plasma de-electrification process to remove the charges present on the stage and substrate after plasma processing. As a result, the substrate cannot be immediately removed from the stage, which is inefficient in terms of time. The present disclosure solves these problems.

[0043] 5 is a first cross-sectional view illustrating the peeling process according to the first embodiment of the present disclosure. Here, the peeling process is shown in the A-A' region where the vacuum suction mechanism 62 is not present. That is, the force acting on the substrate 4 in the peeling process is a force that lifts the substrate 4 by the gas supplied through the opening hole 27.

[0044] The upper diagram in Fig. 5 shows the state immediately after the discharge gas is supplied to the underside of the substrate 4. The process leading to this state will be described. First, the area around the stage 2 and the substrate 4 is set to an atmospheric pressure environment. Specifically, the valves 24a and 24b are closed and the valve 24c is opened, thereby switching the connection destination of the pipe 26 to the gas supply source 22. The pressure in the pipe 26 is adjusted in advance by controlling the regulator 23c.

[0045] Here, compressed air is used as the compressed gas supplied by the gas supply source 22. That is, the atmospheric pressure environment is an environment surrounded by air at atmospheric pressure.

[0046] Next, discharge gas 31 is supplied to the lower surface of substrate 4. Here, discharge gas 31 is argon gas. Specifically, valves 24a and 24c are closed and valve 24b is opened, thereby switching the connection of pipe 26 to gas supply source 22a. The pressure in pipe 26 is adjusted in advance by controlling regulator 23b.

[0047] When the discharge gas 31 is supplied to the lower surface of the substrate 4, the pressure between the stage 2 and the substrate 4 becomes positive. As a result, a minute space 30 filled with the discharge gas 31 is generated between the stage 2 and the substrate 4.

[0048] In the minute space 30, as the substrate 4 is separated from the stage 2, a separation charge is generated on the substrate 4 and the stage 2. This separation charge generates an electrostatic attraction force between the substrate 4 and the stage 2.

[0049] This electrostatic attraction is caused by an electric field that is generated when the substrate 4 is separated from the stage 2. This electric field causes the discharge gas 31 to discharge. Argon gas, in particular, has a lower discharge inception voltage than air, so it easily breaks down in the electric field space. As a result, ions 32 are generated between the stage 2 and the substrate 4. In this case, the ions 32 are argon ions.

[0050] The ions 32 neutralize the peeling charges on the stage 2 and the substrate 4. That is, the ions 32 remove the peeling charges on the stage 2 and the substrate 4.

[0051] 5 shows a state in which the stage 2 and a portion of the substrate 4 have been neutralized by ions 32. In this state, a portion of the minute space 30 has been neutralized to form a neutralization space 33. In other words, in the neutralization space 33, sticking between the stage 2 and the substrate 4 is suppressed.

[0052] The static elimination space 33 expands as the supply of the discharge gas 31 increases. Therefore, the static elimination space 33 expands over time. Finally, the substrate 4 is completely separated from the stage 2 and can be collected by the transport arm 6.

[0053] The ions 32 according to the present disclosure are not generated if the distance between the stage 2 and the substrate 4 is too large or too small. The ions 32 are generated efficiently when the distance is in the range of 1 to 300 μm, for example.

[0054] The relationship between the separation distance and the efficiency of generating ions 32 will be described in detail. When the separation distance is large, the electric field between the stage 2 and the substrate 4 is weakened. As a result, the kinetic energy of electrons is reduced, and even when the electrons collide with the discharge gas, they are unable to ionize the discharge gas. In other words, ions 32 are not generated sufficiently. Conversely, when the separation distance is small, the number of collisions between electrons and the discharge gas decreases, and ions 32 are not generated sufficiently.

[0055] As described above, there is a separation distance at which the generation efficiency of ions 32 is maximized. Therefore, the height of the minute space 30 is preferably set to a height at which the generation of ions 32 is maximized. For example, when the discharge gas 31 is argon gas and the pressure in the space between the stage 2 and the substrate 4 is 1 atmosphere, the height of the minute space 30 may be 5 μm.

[0056] The above-described peeling process will proceed in a chain reaction as long as there is even a slight trigger for the peeling mechanism to lift the substrate 4. In other words, it is sufficient that the discharge gas 31 is supplied at a pressure of 1 atmosphere.

[0057] Furthermore, the height of the minute space 30 can be reduced by increasing the pressure at which the discharge gas 31 is supplied. This is because increasing the pressure at which the discharge gas 31 is supplied shortens the mean free path of the discharge gas 31, thereby shortening the separation distance at which the generation efficiency of the ions 32 is maximized.

[0058] For example, if the substrate 4 is weak and there is a high risk of cracks or breakage, it is preferable to make the minute space 30 small. In this case, supplying a discharge gas at 1 atmosphere or more allows the height of the minute space 30 to be reduced, thereby reducing the above-mentioned risk. Specifically, the height is 2.5 μm at 2 atmospheres and 1 μm at 5 atmospheres.

[0059] 6 is a second cross-sectional view illustrating the peeling process according to the first embodiment of the present disclosure. Here, the peeling process is shown in the region B-B' where the vacuum suction mechanism 62 is located. That is, the forces acting on the substrate 4 in the peeling process are the force of the gas supplied through the opening hole 27 to lift the substrate 4 and the suction force of the vacuum suction mechanism 62 to lift the substrate 4.

[0060] The upper diagram in Fig. 6 shows the state immediately after the discharge gas is supplied to the underside of the substrate 4. Here, a minute space 30a is generated by the same process as in the upper diagram in Fig. 5. In the minute space 30a, ions 32 are generated due to the separation of the substrate 4 from the stage 2, as in the minute space 30.

[0061] 6, the above-mentioned attraction force promotes the lifting of the substrate 4. That is, the attraction force causes the minute space 30a to expand more than the minute space 30. Therefore, in the minute space 30a, the generation of peeling charge and the supply of the discharge gas 31 are further promoted.

[0062] 6 shows a state in which the stage 2 and a portion of the substrate 4 have been neutralized by ions 32. In this example, a portion of the minute space 30a has been neutralized to form a neutralization space 33a. In other words, in the neutralization space 33a, the stage 2 and the substrate 4 are prevented from sticking to each other.

[0063] As described above, the generation of peeling charge and the supply of discharge gas 31 are promoted. As a result, the proportion of static charge removal space 33a in the minute space 30a tends to be larger than the proportion of static charge removal space 33 in the minute space 30. Finally, the substrate 4 is completely separated from the stage 2 and is ready to be collected by the transport arm 6.

[0064] As described above, the static electricity removal space 33a is more likely to expand than the static electricity removal space 33. In other words, the area in which the adhesion between the stage 2 and the substrate 4 is suppressed expands more quickly due to the suction force of the vacuum suction mechanism 62. As a result, the peeling process progresses in a chain reaction, and the entire substrate 4 can be peeled off from the stage 2 more efficiently.

[0065] As described above, in this embodiment, the discharge gas 31 is supplied from the piping 26 for vacuum-adsorbing the substrate 4 to the stage 2, so that static electricity can be removed efficiently without requiring high costs or a large installation space.

[0066] Furthermore, in the peeling process according to this embodiment, plasma neutralization processing for removing charges present on the stage and substrate is not required. In other words, since the substrate can be immediately removed from the stage, neutralization can be performed efficiently in terms of time.

[0067] Even if the electrostatic attraction is weak, i.e., the charged potential is low, if the distance between the charged objects is extremely short, a strong electric field is generated that can cause gas discharge. Therefore, in this embodiment, the discharge gas 31 also discharges.

[0068] In this embodiment, the peeling process is performed under atmospheric pressure. Under atmospheric pressure, the number of atoms contained in the discharge gas is overwhelmingly greater than in a vacuum state. Therefore, under atmospheric pressure, a large number of discharge gas atoms are filled, which allows a large number of ions 32 to be generated between the stage 2 and the substrate 4. As a result, the stage 2 and the substrate 4 that have been charged by peeling under atmospheric pressure can be efficiently neutralized.

[0069] Furthermore, in this embodiment, the height of the microspace 30 can be reduced by performing the peeling process under atmospheric pressure. For example, when the discharge gas 31 is argon gas, the mean free path in a vacuum state of 1 Torr is longer than the mean free path under atmospheric pressure. In this case, the separation distance at which the ion 32 generation efficiency is maximized is 5 millimeters. Therefore, when the substrate 4 and the stage 2 are in close contact with each other, dielectric breakdown is unlikely to occur, and the separation distance between the substrate 4 and the stage 2 must be increased. As a result, if the substrate 4 has a low strength, there is a high risk of cracks or breakage occurring in the substrate when the substrate 4 and the stage 2 are separated by the peeling mechanism.

[0070] On the other hand, in this embodiment, the peeling step is performed under atmospheric pressure, so the height of the minute space 30 can be reduced, thereby reducing the above-mentioned risk.

[0071] Here, we will describe an experiment that demonstrates the static elimination effect of ions 32. In this experiment, the stage 2 under different conditions was charged by a discharge gun, and then argon gas was supplied to the upper surface of the stage 2, and the charged potential on the surface of the stage 2 was measured. Note that the environment around the stage 2 was assumed to be surrounded by air at atmospheric pressure.

[0072] The first condition is that the substrate 4 is not placed on the upper surface of the stage 2. Specifically, argon gas is supplied to the upper surface of the stage 2 by directly spraying the argon gas. When argon gas is supplied under this condition, the charge potential on the surface of the stage 2 does not decrease. From this result, it is believed that simply supplying argon gas to a charged object does not have a static elimination effect.

[0073] The second condition is that the charged substrate 4 is placed parallel to the upper surface of the stage 2 at a distance of 1 cm from the upper surface. Specifically, argon gas is supplied to the upper surface of the stage 2 through the opening 27. Even when argon gas is supplied under this condition, the charge potential on the surface of the stage 2 does not decrease. From this result, it is thought that when the electric field between the two objects is weak, ions are not generated by discharge.

[0074] The third condition is a condition in which the charged substrate 4 is placed on the upper surface of the stage 2. Specifically, argon gas is supplied to the upper surface of the stage 2 through the opening hole 27. When argon gas is supplied under this condition, the charged potential on the upper surface of the stage 2 decreases.

[0075] From this result, it is believed that there are two requirements for obtaining the static elimination effect by ions 32. The first requirement is that a first charged object and a second charged object must exist. The second requirement is that a discharge gas at a pressure equal to or greater than atmospheric pressure must be supplied to the extremely narrow space between the first charged object and the second charged object.

[0076] The discharge gas to be supplied must be a gas that can cause dielectric breakdown in an environment surrounded by air at atmospheric pressure, and therefore must be a gas with a discharge inception voltage lower than that of air at atmospheric pressure, such as argon gas, neon gas, or helium gas.

[0077] Alternatively, the discharge gas may be a mixed gas obtained by mixing a gas having a discharge start voltage lower than that of air at atmospheric pressure with a diluent gas. The diluent gas may be, for example, compressed air, dry air, or nitrogen gas. Since the diluent gas is cheaper than the discharge gas, using the mixed gas can reduce costs.

[0078] When a mixed gas is used, the effect of suppressing sticking increases as the partial pressure of the discharge gas increases. Therefore, in the mixed gas according to this embodiment, it is preferable to set the partial pressure of the discharge gas at a level at which the effect of suppressing sticking can be sufficiently obtained.

[0079] Next, we will show how the effect of suppressing sticking between the stage 2 and the substrate 4 changes depending on the type of gas supplied. Figure 7 is a cross-sectional view of a substrate processing apparatus that supplies compressed air to the underside of the substrate. In this example, the stage 2 is connected to a gas supply source 22.

[0080] 8 is a cross-sectional view showing a substrate processing apparatus that supplies compressed air and ions to the underside of a substrate. Here, an ionizer 25 is installed between the stage 2 and the gas supply source 22. The ionizer 25 is a device that generates ions at the tip of a discharge needle to which a high voltage is applied. Therefore, the substrate processing apparatus shown in FIG. 8 can supply ions generated by the ionizer when supplying compressed gas to the underside of the substrate 4.

[0081] 9 is a cross-sectional view showing a substrate processing apparatus that supplies a discharge gas to the underside of a substrate. Here, stage 2 is connected to a gas supply source 22a. The discharge gas is argon gas. That is, the stripping process performed by the substrate processing apparatus shown in FIG. 9 can perform the same process as the stripping process according to this embodiment.

[0082] 10 is a graph showing the suppression effect against sticking between the stage and substrate. Here, the suppression effect against sticking between the stage 2 and substrate 4 is compared when different gases are supplied to the underside of substrate 4. The suppression results are shown by arranging the results of experiments using three substrates 4-1, 4-2, and 4-3, which have the same structure as substrate 4, by type of gas.

[0083] The vertical axis of the graph indicates the length of time that has passed until the vacuum suction mechanism 62 has suctioned the substrate 4-1, 4-2, or 4-3. Because each substrate is thin and elastic, it peels off from the stage 2 in order, starting with the areas with the weakest adhesion. Therefore, the aforementioned time is equal to the time that has passed until the entire back surface of each substrate is peeled off from the stage 2. In other words, the shorter the time shown on the vertical axis, the greater the effect of suppressing adhesion between the stage 2 and the substrate 4.

[0084] The leftmost graph shows the results when compressed air was supplied to the underside of the substrate 4 using the substrate processing apparatus shown in Fig. 7. Under these conditions, it took approximately 20 to 40 seconds for the entire back surface of each substrate to peel off from the stage 2.

[0085] The middle of the graph shows the results when compressed air and ions were supplied to the underside of the substrate 4 using the substrate processing apparatus shown in Fig. 8. Under these conditions, it took about 15 to 25 seconds for the entire back surface of each substrate to peel off from the stage 2.

[0086] The rightmost graph shows the results when argon gas was supplied to the underside of the substrate 4 using the substrate processing apparatus shown in Fig. 9. Under these conditions, the time elapsed until the entire back surface of each substrate was peeled off from the stage 2 was 0 seconds.

[0087] From the above results, it can be seen that supplying argon gas is most effective in preventing sticking between the stage 2 and the substrate 4. As mentioned above, this result is thought to be due to the fact that ions are generated between the front surface of the stage 2 and the back surface of the substrate 4, allowing for efficient static elimination.

[0088] The suppression effect when compressed air and ions were supplied was higher than when compressed air was supplied, but lower than when argon gas was supplied. This result is thought to be due to the fact that the ionizer generates ions only at the tip of the discharge needle, resulting in a small amount of ions being generated. Furthermore, this result is thought to be due to the fact that the ions generated by the ionizer 25 were absorbed by the sidewall of the pipe 26 before reaching the underside of the substrate 4, resulting in a decrease in the number of ions generated by the ionizer 25.

[0089] As described above, in the peeling process according to this embodiment, the electric charges of the two charged objects themselves are neutralized by dielectric breakdown of the discharge gas supplied between them. In other words, this disclosure does not require a plasma neutralization process or an ion generator to remove the electric charges present on the stage and substrate that cause sticking. Therefore, this disclosure can efficiently remove electric charges without requiring high costs or a large installation space.

[0090] Furthermore, in the peeling process according to this embodiment, ions are generated between the front surface of the stage 2 and the back surface of the substrate 4. That is, planar ion generation results in a wide ion generation area. Furthermore, ions are generated near the stage 2 and the substrate 4, which are charged objects, and therefore react efficiently with the charged objects. As a result, static elimination can be performed more efficiently than the method of generating ions at a specific point using a discharge needle, as in Patent Document 1.

[0091] 11 is a top view showing a stage according to a second embodiment of the present disclosure. A stage 2a according to this embodiment differs from the stage 2 in that openings 27 are provided on the top surface thereof in a lattice pattern.

[0092] Due to the configuration of the stage 2a, a minute space 30 in which ions are generated is uniformly generated between the stage 2a and the substrate 4. As a result, static elimination by the ions 32 is uniformly performed between the stage 2a and the substrate 4, so static elimination can be more efficiently performed on the entire surface where sticking has occurred.

[0093] Although the embodiment in which the opening holes 27 are arranged in a grid pattern on the upper surface has been shown, the present invention is not limited to this and any embodiment may be used as long as the minute spaces 30 are uniformly generated between the stage 2 a and the substrate 4. Furthermore, when the minute spaces 30 are uniformly generated, the suction grooves may not be required.

[0094] 12 is a cross-sectional view showing a substrate processing apparatus according to a third embodiment of the present disclosure. A substrate processing apparatus 200 according to this embodiment differs from the substrate processing apparatus 100 in that the substrate 4 is separated from the stage 2 using lift pins 8. That is, the lift pins 8 are included in the separation mechanism in this embodiment.

[0095] The substrate processing apparatus 200 includes lift pins 8. The lift pins 8 support the substrate 4 placed on the stage 2 from below at the tips of their support portions that penetrate the stage 2. The lift pins 8 have, for example, three support portions, and are therefore able to support the substrate 4. The height h is a specific height to which the tips of the lift pins 8 are raised. Details of the height h will be described later.

[0096] Moreover, it is preferable that the lift pins 8 are located near the opening holes 27. The reason for this will be described later.

[0097] Although the lift pin 8 has a plurality of support portions for supporting the substrate 4, the present invention is not limited to this. For example, the lift pin 8 may be a combination of a plurality of pins each having one support portion for supporting the substrate 4, and may be any other type of pin as long as the substrate 4 can be supported by the support portions.

[0098] 13 is a cross-sectional view illustrating a peeling process according to the third embodiment of the present disclosure. Here, the peeling process is illustrated in the vicinity of the lift pins 8. That is, the forces acting on the substrate 4 in the peeling process are the force of the gas supplied through the opening holes 27 to lift the substrate 4 and the supporting force of the lift pins 8 to lift the substrate 4.

[0099] The upper diagram of Fig. 13 shows the state immediately after the discharge gas is supplied to the underside of the substrate 4. Here, a minute space 30b is generated by a process similar to that shown in the upper diagram of Fig. 5. In the minute space 30b, ions 32 are generated due to the separation of the substrate 4 from the stage 2, as in the minute space 30.

[0100] 13, the aforementioned supporting force promotes the lifting of the substrate 4. That is, the supporting force causes the minute space 30b to expand more than the minute space 30. Therefore, the generation of peeling electrification and the supply of the discharge gas 31 are further promoted in the minute space 30b.

[0101] 13 shows a state in which the stage 2 and a portion of the substrate 4 have been neutralized by ions 32. In this case, a portion of the minute space 30b has been neutralized to form a neutralization space 33b. In other words, in the neutralization space 33b, the stage 2 and the substrate 4 are prevented from sticking to each other.

[0102] As described above, the generation of peeling charge and the supply of discharge gas 31 are promoted. As a result, the proportion of static charge removal space 33b in minute space 30b tends to expand more than the proportion of static charge removal space 33 in minute space 30. Finally, substrate 4 is completely separated from stage 2 and supported by lift pins 8. That is, substrate 4 is ready to be retrieved.

[0103] As described above, the static charge removal space 33b is more likely to expand than the static charge removal space 33. That is, the support force of the lift pins 8 causes the region where the adhesion between the stage 2 and the substrate 4 is suppressed to expand more quickly. As a result, the peeling process progresses in a chain reaction, and the entire substrate 4 can be efficiently peeled off from the stage 2.

[0104] As described above, the peeling step according to this embodiment is facilitated by the supporting force, so it is preferable that the lift pins 8 are located near the opening holes 27.

[0105] On the other hand, if the lift pins 8 and the opening holes 27 are far apart, it becomes difficult for the discharge gas to fill the space between the substrate 4 and the stage 2. As a result, if the lift pins 8 are suddenly raised, the sticking is not sufficiently suppressed, which causes the problem of cracks or breakage occurring in the substrate.

[0106] Therefore, in this case, rather than raising the lift pins 8 all at once, it is preferable to raise the tips of the lift pins 8 to a specific height h, maintain this position for several seconds, and then gradually separate the substrate 4 from the stage 2. This specific height h is preferably equal to the separation distance at which the ion 32 generation efficiency is maximized. For example, when the discharge gas 31 is argon gas and the pressure in the space between the stage 2 and the substrate 4 is 1 atmosphere, the specific height is preferably 5 μm. Alternatively, in this case, it is preferable to gradually raise the lift pins 8 so that the distance between the substrate 4 and the stage 2 changes stepwise between 5 and 300 μm, and then separate the substrate 4 from the stage 2.

[0107] 14 is a cross-sectional view showing a substrate processing apparatus according to a fourth embodiment of the present disclosure. A substrate processing apparatus 300 according to this embodiment differs from the substrate processing apparatus 100 in that the substrate 4 is separated from the stage 2b using a transfer arm 6a that does not have a vacuum suction mechanism 62. In other words, the transfer arm 6a is included in the separation mechanism in this embodiment.

[0108] The substrate processing apparatus 300 includes a stage 2b. The radius of the upper surface of the stage 2b is smaller than that of the stage 2. Therefore, when the substrate 4 is placed on the stage 2b, the entire outer edge of the substrate 4 is located outside the stage 2b.

[0109] The substrate processing apparatus 300 also includes a transfer arm 6a. In a cross-sectional view, the transfer arm 6a has two support portions that support the outer edge of the substrate 4. Therefore, the transfer arm 6a can use the support portions to support the outer edge of the substrate 4 located outside the stage 2b, thereby retrieving the substrate 4 from the stage 2b.

[0110] It is also preferable that the support portion of the transfer arm 6a be located near the opening 27. The reason for this will be described later.

[0111] 15 is a cross-sectional view illustrating a peeling process according to the fourth embodiment of the present disclosure. Here, the peeling process is illustrated in the vicinity of the support portion of the transfer arm 6 a. That is, the forces acting on the substrate 4 in the peeling process are the force of the gas supplied through the opening hole 27 to lift the substrate 4 and the support force of the transfer arm 6 a to lift the substrate 4.

[0112] The upper diagram of Fig. 15 shows the state immediately after the discharge gas is supplied to the underside of the substrate 4. Here, a minute space 30c is generated by the same process as in the upper diagram of Fig. 5. In the minute space 30c, ions 32 are generated due to the separation of the substrate 4 from the stage 2b, just as in the minute space 30.

[0113] 15, the aforementioned supporting force promotes the lifting of the substrate 4. That is, the supporting force causes the minute space 30c to expand more than the minute space 30. Therefore, the generation of peeling electrification and the supply of the discharge gas 31 are further promoted in the minute space 30c.

[0114] 15 shows a state in which the stage 2b and a portion of the substrate 4 have been neutralized by ions 32. In this example, a portion of the minute space 30c has been neutralized to form a neutralization space 33c. In other words, in the neutralization space 33c, the stage 2b and the substrate 4 are prevented from sticking to each other.

[0115] As described above, the generation of peeling charge and the supply of discharge gas 31 are promoted. As a result, the proportion of static charge removal space 33c in minute space 30c tends to be larger than the proportion of static charge removal space 33 in minute space 30. Finally, substrate 4 is completely separated from stage 2b and supported by transport arm 6a. In other words, substrate 4 is ready to be retrieved.

[0116] As described above, the static charge removal space 33c is more likely to expand than the static charge removal space 33. That is, the supporting force of the transport arm 6a causes the region where adhesion between the stage 2b and the substrate 4 is suppressed to expand more quickly. As a result, the peeling process progresses in a chain reaction, and the entire substrate 4 can be efficiently peeled off from the stage 2b.

[0117] As described above, the peeling step according to this embodiment is facilitated by the supporting force, so it is preferable that the support portion of the transfer arm 6 a is located near the opening hole 27 .

[0118] On the other hand, if the transport arm 6a and the opening hole 27 are far apart, it becomes difficult for the discharge gas to fill the space between the substrate 4 and the stage 2. As a result, if the transport arm 6a is suddenly raised, the sticking is not sufficiently suppressed, which can cause the problem of cracks or breakage in the substrate.

[0119] Therefore, in this case, rather than raising the transfer arm 6a all at once, it is preferable to raise the tip of the transfer arm 6a to a specific height h', maintain this position for several seconds, and then gradually separate the substrate 4 from the stage 2. This specific height h' is preferably equal to the separation distance that maximizes the ion 32 generation efficiency. For example, when the discharge gas 31 is argon gas and the pressure in the space between the stage 2 and the substrate 4 is 1 atmosphere, the specific height is preferably 5 μm. Alternatively, in this case, it is preferable to gradually raise the transfer arm 6a so that the distance between the substrate 4 and the stage 2 changes stepwise between 5 and 300 μm, and then separate the substrate 4 from the stage 2.

[0120] 16 is a cross-sectional view showing a clamp jig according to a fifth embodiment of the present disclosure. This embodiment differs from the substrate processing apparatus 100 in that the substrate 4 is peeled off from the stage 2b using a transport arm 6a and a clamp jig 9. In other words, the clamp jig 9 is included in the peeling mechanism in this embodiment.

[0121] The clamp jig 9 is a jig that holds the outer edge of the substrate 4. Here, the clamp jig 9 is shown holding the substrate 4 inside. The clamp jig 9 has a substrate support portion 92 that directly supports the substrate 4. The substrate support portion 92 is, for example, a ring-shaped portion that has an outer periphery with a radius larger than that of the substrate 4 and an inner periphery with a radius smaller than that of the substrate 4 and larger than that of the stage 2b.

[0122] The clamp jig 9 also has a transport support part 94 that is supported by the transport arm 6a. The transport support part 94 is, for example, a ring-shaped part having an inner periphery with a radius larger than that of the substrate 4. The clamp jig 9 is configured by connecting the substrate support part 92 and the transport support part 94 with a cylindrical side wall.

[0123] 17 is a cross-sectional view showing a substrate processing apparatus 400 before substrate peeling according to a fifth embodiment of the present disclosure. The substrate processing apparatus 400 includes a support table 96 on which a clamp jig 9 is placed. The support table 96 is, for example, a ring-shaped table having an inner periphery with a radius larger than that of the stage 2b. In this manner, before the substrate 4 is peeled from the stage 2a, the clamp jig 9 is placed on the support table 96.

[0124] 18 is a cross-sectional view showing the substrate processing apparatus after substrate peeling in accordance with the fifth embodiment of the present disclosure. In the cross-sectional view, the transport arm 6a has two support portions that support the transport support portion 94. Therefore, the transport arm 6a can retrieve the substrate 4 from the stage 2b by using the support portions to support the transport support portion 94 located outside the stage 2b.

[0125] The peeling process according to this embodiment is similar to the peeling process according to the fourth embodiment, except that the substrate 4 is supported via the clamp jig 9 rather than directly by the transfer arm 6 a. That is, the forces acting on the substrate 4 in the peeling process according to this embodiment are the force of the gas supplied through the opening hole 27 to lift the substrate 4 and the supporting force of the substrate support part 92 to lift the substrate 4.

[0126] Therefore, in the peeling process according to this embodiment, the entire substrate 4 can be efficiently peeled off from the stage 2b, as in the peeling process according to embodiment 4. Furthermore, in this embodiment, the substrate 4 is not directly supported by the transfer arm 6a, but is supported via a clamp jig 9. As a result, the force that the substrate 4 receives can be reduced, and therefore, even if the substrate 4 has low strength, the risk of cracks or breakage can be reduced.

[0127] 19 is a diagram illustrating a peeling process according to a sixth embodiment of the present disclosure. Here, a mode is shown in which a first charged object 602, which is a particle, and a second charged object 604, which is a particle, are peeled off.

[0128] Although embodiments 1 to 5 show aspects of removing the peeling charge generated between the substrate and the stage, the targets of the charge removal according to the present disclosure are not limited to the substrate and the stage. This embodiment shows an aspect in which the targets of the charge removal according to the present disclosure are a first charged object and a second charged object contained in the same container, or a container containing a first charged object and a first charged object.

[0129] The left diagram in Fig. 19 shows the state before the discharge gas is supplied. A container 600 contains a first charged object 602 and a second charged object 604 that are stuck to each other. The container 600 also has a peeling mechanism (not shown) inside.

[0130] The diagram on the right of Figure 19 shows the state after the discharge gas has been supplied. First, the inside of the container 600 is surrounded by air at atmospheric pressure. Next, the discharge gas 606 is supplied into the container 600. The discharge gas 606 is supplied, for example, by an air blower connected to the container 600.

[0131] When the supplied discharge gas 606 flows into the interior of the container 600, it also flows between the first charged object 602 and the second charged object 604. That is, the force of the airflow of the discharge gas 606 separates the first charged object 602 and the second charged object 604. As a result, separation charging occurs. The discharge gas 606 undergoes dielectric breakdown due to the electric field generated by the separation charging. As a result, ions 32 (not shown) are generated inside the container 600.

[0132] The ions 32 neutralize the first charged object 602 and the second charged object 604. That is, the ions 32 neutralize the first charged object 602 and the second charged object 604, which have been charged due to separation. As a result, the first charged object 602 changes into a first object 602a to be neutralized, and the second charged object 604 changes into a second object 604a to be neutralized.

[0133] Finally, the first static eliminator 602a and the second static eliminator 604a are detached by the detachment mechanism. Since the first static eliminator 602a and the second static eliminator 604a have been detached, they can be easily detached.

[0134] If the first charged object 602 and the second charged object 604 are small particles, the separation mechanism may be an airflow generated by a blower. That is, the force acting on the first charged object 602 and the second charged object 604 in the separation process is the force of the airflow described above.

[0135] 20 is a diagram illustrating a modified example of the separation step according to the sixth embodiment of the present disclosure. Here, the second charged object is a container 610 that contains a first charged object 602. That is, this modified example illustrates a mode in which first charged object 602, which is a particle, is separated from container 610.

[0136] The left diagram in Figure 20 shows the state before the discharge gas is supplied. A container 610 contains a first charged object 602. The first charged object 602 is attached to the container 610. The container 610 also has a peeling mechanism (not shown) inside.

[0137] The right diagram in Figure 20 shows the state after the discharge gas has been supplied. First, the inside of the container 610 is surrounded by air at atmospheric pressure. Next, the discharge gas 606 is supplied into the container 610. The discharge gas 606 is supplied, for example, by a blower connected to the container 610.

[0138] When the supplied discharge gas 606 flows into the interior of the container 610, it also flows between the first charged object 602 and the container 610. That is, the force of the airflow of the discharge gas 606 separates the first charged object 602 from the container 610. As a result, separation charging occurs. The discharge gas 606 undergoes dielectric breakdown due to the electric field generated by the separation charging. As a result, ions 32 (not shown) are generated inside the container 610.

[0139] The ions 32 neutralize the first charged object 602 and the container 610. That is, the ions 32 neutralize the first charged object 602 and the container 610, which have been charged by peeling. As a result, the first charged object 602 changes into a first charge-neutralized object 602a, and the container 610 changes into a charge-neutralized container 610a.

[0140] Finally, the first static eliminating object 602a and the container 610a are separated by the separation mechanism. Since the first static eliminating object 602a and the container 610a have been neutralized, they can be easily separated.

[0141] As described above, the targets for static elimination according to the present disclosure are not limited to the substrate and the stage, but may be any charged objects that are stuck to each other. Therefore, the static elimination method according to the present disclosure is not limited to substrate processing, but can also be applied to suppressing sticking due to peel electrification.

[0142] Although the present disclosure describes an embodiment in which the substrate and the stage or the first and second charged objects are separated in an environment surrounded by air at atmospheric pressure, this is not limiting. The present disclosure may also be an embodiment in which the objects are separated in an environment surrounded by a specific gas at atmospheric pressure, such as nitrogen. In this case, the supplied discharge gas must have a lower discharge start voltage than the specific gas at atmospheric pressure.

[0143] 2 Stage 2a Stage 2b Stage 4 Substrate 4-1 Substrate 6 Transfer arm 6a Transfer arm 8 Lift pin 9 Clamp jig 26 Pipe 27 Opening hole 31 Discharge gas 62 Vacuum suction mechanism 100 Substrate processing apparatus 200 Substrate processing apparatus 300 Substrate processing apparatus 400 Substrate processing apparatus 600 Container 602 First charged object 604 Second charged object 606 Discharge gas 610 Container 610a Container

Claims

1. A substrate processing apparatus comprising: a stage for placing a substrate; and a peeling mechanism for peeling the substrate from the stage, wherein the stage is surrounded by air at atmospheric pressure and supplies a discharge gas to the underside of the substrate, which is attached by electrostatic force, through internal piping.

2. The substrate processing apparatus according to claim 1, wherein the discharge gas is a gas having a discharge start voltage lower than that of air at atmospheric pressure.

3. The substrate processing apparatus according to claim 1, wherein the discharge gas is a mixed gas obtained by mixing a dilution gas with a gas having a discharge start voltage lower than that of air at atmospheric pressure.

4. The substrate processing apparatus according to any one of claims 1 to 3, wherein the peeling mechanism comprises a transport arm and a vacuum suction mechanism provided at the tip of the transport arm for vacuum-suctioning the substrate.

5. The substrate processing apparatus according to any one of claims 1 to 3, wherein the peeling mechanism has a lift pin.

6. The substrate processing apparatus according to any one of claims 1 to 3, wherein the peeling mechanism has a transport arm that supports the outer edge of the substrate using a support part.

7. The substrate processing apparatus according to any one of claims 1 to 3, wherein the peeling mechanism has a clamp jig.

8. The substrate processing apparatus according to claim 1, wherein openings serving as outlets of the piping are arranged in a grid pattern on the upper surface of the stage.

9. A substrate peeling method comprising the steps of: creating an environment in which a stage on which a substrate is placed is surrounded by air at atmospheric pressure; after creating the environment surrounded by air at atmospheric pressure, supplying a discharge gas to the underside of the substrate, which has been stuck by electrostatic attraction, through piping inside the stage; and after supplying the discharge gas, peeling the substrate from the stage using a peeling mechanism.

10. A separation device comprising a container that contains a first charged object and a second charged object, a blower, and a separation mechanism, wherein the blower supplies a discharge gas into the inside of the container in an environment surrounded by air at atmospheric pressure, and the separation mechanism separates the first charged object from the second charged object.

11. A separation method comprising the steps of: creating an environment in which the inside of a container that contains a first charged object and a second charged object is surrounded by air at atmospheric pressure; supplying a discharge gas into the inside of the container after creating the environment surrounded by air at atmospheric pressure; and separating the second charged object from the first charged object using a separation mechanism after supplying the discharge gas.

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