JP2020038901A - Electrostatic chuck device - Google Patents

Abstract

To provide an electrostatic chuck device capable of accurately detecting positional deviation of a substrate with a simple configuration.SOLUTION: An electrostatic chuck device includes a chuck body, a power supply section, and a control section. The chuck body has a support surface on which a substrate can be mounted, a first electrode arranged oppositely to the support surface, and an annular second electrode which is arranged oppositely to the support surface and surrounds the first electrode. The power supply section has a first power supply line capable of supplying first power to the first electrode and a second power supply line capable of supplying second power to the second electrode. The control section controls the power supply section so that a first control mode for sucking the substrate on the support surface by supplying the first power to the first electrode and a second control mode for detecting positional deviation of the substrate on the support surface by supplying the second power to the second electrode can be selectively or simultaneously executed.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electrostatic chuck device capable of electrostatically attracting a substrate.

  Recently, due to the increase in the density of devices formed on a substrate, horizontal (in-plane) positional accuracy with respect to a surface to be processed of a substrate disposed on a processing stage is required. For example, if the processing is started without the substrate being at the proper position, the surface of the stage is also processed during the processing of the substrate, and the recovery time and cost may become a problem. Further, if the substrate is transported in a state where the substrate is not at an appropriate position, there is a possibility that transport failure such as dropping of the substrate may be caused.

  In order to solve such a problem, an electrostatic chuck capable of detecting a position of a substrate on a stage is known. For example, Patent Document 1 has a capacitance detector capable of detecting a capacitance value between a first electrode and a second electrode arranged side by side on a plane. When the electrode covers the electrode and the work edge is positioned on the second electrode, an electrostatic capacitance detecting a distance from a preset origin to the work edge based on the capacitance value detected by the capacitance detector. An electrostatic chuck with a capacitive sensor is disclosed.

  In the above capacitance sensor, the second electrode includes a plurality of electrode pieces having a predetermined width arranged at equal intervals in a first direction, which is a direction in which the first electrode and the second electrode are arranged, and the plurality of electrode pieces in series. And the wiring connected to it. Thus, when the work edge moves in the first direction, the capacitance value detected by the capacitance detector changes stepwise, so that the position of the work edge can be detected with a resolution corresponding to the pitch of the electrode pieces. It is possible.

JP-A-2006-70892

  However, in the electrostatic chuck described in Patent Literature 1, in order to increase the positional accuracy of the substrate, it is necessary to reduce the interval between the electrode pieces arranged in the first direction. Increase and miniaturization are essential. Furthermore, miniaturization of the electrodes causes problems such as a decrease in detection sensitivity and an increase in the cost of manufacturing the electrodes.

  In view of the circumstances as described above, an object of the present invention is to provide an electrostatic chuck device that can accurately detect a displacement of a substrate with a simple configuration.

To achieve the above object, an electrostatic chuck device according to one aspect of the present invention includes a chuck body, a power supply unit, and a control unit.
The chuck body has a support surface on which a substrate can be placed, a first electrode disposed opposite to the support surface, and an annular first electrode disposed opposite to the support surface and surrounding the first electrode. And two electrodes.
The power supply unit is configured to supply a first power supply line that is a DC power supply to the first electrode and a first power supply line that supplies an AC power supply to the second electrode. And a second power supply line capable of supplying the second power.
A first control mode in which the first power is supplied to the first electrode to attract the substrate on the support surface; and the second power is supplied to the second electrode. Then, the power supply unit is controlled so that the second control mode for detecting the displacement of the substrate on the support surface can be selectively or simultaneously executed.

  In the above-mentioned electrostatic chuck device, the second electrode is typically formed to have a size facing the peripheral portion of the substrate placed on the support surface. For this reason, the displacement of the substrate with respect to the reference position on the support surface can be grasped from the electrical characteristics due to the difference in the facing area between the substrate and the second electrode. Moreover, since the second electrode is formed in an annular shape, the amount of displacement of the substrate can be detected in an analog and highly accurate manner based on the facing area without complicating the electrode shape.

  The control unit may detect, in the second control mode, a displacement amount of the substrate on the support surface based on a capacitance between the substrate on the support surface and the second electrode. May be configured.

  The control unit may be configured to control the power supply unit such that the second control mode can be executed before or after the execution of the first control mode.

  The control unit may be configured to control the power supply unit to execute the second control mode during execution of the first control mode.

  The first electrode may have a hollow portion, and the chuck body may further include a third electrode disposed in the hollow portion and configured to be connectable to the second power supply line.

  The chuck body may further include an annular fourth electrode disposed between the first electrode and the second electrode and configured to be connectable to the second power supply line.

  The chuck body further includes an annular fourth electrode disposed between the first electrode and the second electrode, and the second electrode line includes the second electrode and the second electrode. The third electrode and the fourth electrode may be connected to each other.

  The control unit may be configured to control the power supply unit to supply the first power to the first electrode and the second electrode in the first control mode. Good.

  The second electrode may be composed of an aggregate of a plurality of electrode pieces. The control unit is configured to detect a displacement amount and a displacement direction of the substrate on the support surface based on a capacitance between the substrate on the support surface and each of the plurality of electrode pieces. You may.

  As described above, according to the present invention, it is possible to accurately detect a displacement of a substrate with a simple configuration.

FIG. 1 is a schematic sectional view of a vacuum processing apparatus 1 provided with an electrostatic chuck device according to a first embodiment of the present invention. FIG. 3 is a schematic plan view of a chuck main body in the electrostatic chuck device. It is a circuit diagram showing an example of composition of a power supply part in the above-mentioned electrostatic chuck device. It is a schematic diagram explaining one effect | action of the said electrostatic chuck apparatus, (a) and (b) have shown embodiment, (c) has shown the comparative example, respectively. It is one experimental result for explaining the operation of the electrostatic chuck device in comparison with a comparative example. It is one experimental result which shows the effect | action of the said electrostatic chuck apparatus in comparison with a comparative example. It is a flowchart explaining the operation | movement procedure of the said vacuum processing apparatus. FIG. 9 is a schematic plan view illustrating an electrode configuration of a chuck main body in an electrostatic chuck device according to a second embodiment of the present invention. FIG. 3 is an enlarged view showing details of an electrode structure in the electrostatic chuck device. FIG. 3 is a circuit diagram of a power supply unit in the electrostatic chuck device. FIG. 9 is a schematic plan view illustrating an electrode configuration of a chuck body in an electrostatic chuck device according to a third embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First embodiment>
FIG. 1 is a schematic sectional view of a vacuum processing apparatus 1 including an electrostatic chuck device 100 according to the first embodiment of the present invention.

  The vacuum processing apparatus 1 has a processing chamber 2. The processing chamber 2 is a vacuum chamber, for example, a sputter chamber in which a sputter cathode 4 holding a target 3 is installed. In addition, the processing chamber 2 may be another film forming chamber such as a vapor deposition chamber or a plasma CVD processing chamber, and is not limited to the film forming chamber, and may be a plasma etching chamber or the like. Although not shown, the processing chamber 2 has an exhaust line for exhausting the processing chamber 2 to a predetermined reduced-pressure atmosphere, a gas introduction line for introducing a predetermined process gas into the processing chamber 2, and a power supply for supplying power to the sputtering cathode 4. Lines and the like are connected.

  The electrostatic chuck device 100 includes a chuck body 10 installed inside the processing chamber 2, a power supply unit 20 that supplies power to the chuck body 10, and a control unit 30 that controls the power supply unit 20.

  As will be described later, the chuck body 10 covers an electrode layer 101 for electrostatically attracting a substrate W to be processed (hereinafter simply referred to as a substrate W) such as a semiconductor wafer or a glass substrate, and covers the surface of the electrode layer 101. And a surface of the dielectric layer 102 is configured as a support surface 10a that supports the substrate W. The chuck main body 10 is installed on a pedestal 5 arranged at the bottom of the processing chamber 2 so as to face the target 3. The power supply unit 20 and the control unit 30 are typically installed outside the processing chamber 2, and are electrically connected between the chuck body 10 and the power supply unit 20 via a feedthrough (not shown). .

  The vacuum processing apparatus 1 further includes a transfer chamber 7 adjacent to the processing chamber 2 via a gate valve 6, and transfers the substrate W between the processing chamber 2 and the transfer chamber 7 by a substrate transfer robot (not shown). It is possible to be configured.

  FIG. 2 is a plan view of the support surface 10a of the chuck body 10. FIG. In the figure, the illustration of the dielectric layer 102 covering the surface of the electrode layer 101 is omitted.

  In the present embodiment, the planar shape of the support surface 10a is circular, and a semiconductor wafer of a predetermined size can be mounted as the substrate W. Typically, the support surface 10a has an outer diameter larger than the size of the substrate W, but may have the same outer diameter as the size of the substrate W. The planar shape of the support surface 10a is not limited to a circle but may be a rectangle, and is typically selected according to the type or shape of the substrate W.

  The electrode layer 101 has an adsorption electrode 11 (first electrode) and an annular detection electrode 12 (second electrode) surrounding the adsorption electrode 11. The electrode layer 101 further has a detection reference electrode 13 (third electrode) and a comparison electrode 14 (fourth electrode). The electrode layer 101 is divided into first to fourth electrodes 11 to 14 by patterning a metal layer having a predetermined thickness, such as aluminum or stainless steel, into the illustrated shape. The electrodes 11 to 14 are respectively arranged on the same plane so as to face the support surface 10a, and are electrically insulated from each other by the interposition of the insulating layer 103 between the electrodes 11 to 14.

  The suction electrode 11 is for electrostatically (in the present embodiment, by Coulomb force) suctioning and holding the substrate W on the support surface 10a on the support surface 10a. The attraction electrode 11 occupies the main area of the support surface 10a and has the largest area among the electrodes constituting the electrode layer 101. In the present embodiment, the suction electrode 11 is constituted by a pair of semi-annular electrodes 11a and 11b opposed to each other with a gap in a uniaxial direction. The electrode pair 11a, 11b is formed concentrically with the support surface 10a and has a relatively wide width (width along the radial direction), and has a substantially circular hollow portion 11c at the center.

  The detection electrode 12 is for detecting a relative positional relationship between the support surface 10a and the substrate W. The detection electrode 12 is arranged outside the suction electrode 11 and is formed in an annular shape surrounding the suction electrode 11. The detection electrode 12 is formed concentrically with the support surface 10a and has a relatively narrow width (width along the radial direction). Typically, the outer diameter of the detection electrode 12 is set to the same or substantially the same size as the outer diameter of the substrate W. This makes it possible to detect a deviation of the center position of the substrate W from the center of the support surface 10a with high accuracy, as described later.

  The detection reference electrode 13 is for detecting the position of the substrate W in pairs with the detection electrode 12. The detection reference electrode 13 is disposed in the hollow portion 11c of the suction electrode 11, and has a disk shape concentric with the support surface 10a.

  The comparison electrode 14 is disposed between the suction electrode 11 and the detection electrode 12, and is formed in an annular shape concentric with the support surface 10a. The comparison electrode 14 is typically formed with the same or substantially the same width (width dimension along the radial direction) as the detection electrode 12. The comparison electrode 14 is for detecting a foreign substance being caught between the support surface 10a and the substrate W. The comparison electrode 14 can be omitted as necessary.

  FIG. 3 is a circuit diagram illustrating an example of the configuration of the power supply unit 20.

  As shown in FIG. 3, the power supply unit 20 includes a first power supply line L1 that can supply DC power, which is a first power, to the adsorption electrode 11 (electrode pair 11a, 11b), And a second electrode supply line L2 capable of supplying AC power, which is the second power, to the detection electrode 12, the detection reference electrode 13, and the comparison electrode 14.

  In the present embodiment, the electrode pairs 11a and 11b of the adsorption electrode 11 constitute a bipolar electrode. The first power supply line L1 includes a first DC power supply 211 and a second DC power supply 212 capable of supplying a positive voltage and a negative voltage to the electrode pairs 11a and 11b, respectively, and an electrode pair 11a and 11b and a second DC power supply. Switches 215 and 216 for switching between communication with the first and second DC power supplies 211 and 212 and cutoff.

  In the first power supply line L1, AC blocking resistors 213 and 214 for preventing an AC current from the second power supply line L2 (AC power supply 221) from flowing to the adsorption electrode 11 are provided, for example. It is connected between the first and second DC power supplies 211 and 212 and the switches 215 and 216, respectively. The installation of the AC blocking resistors 213 and 214 is optional. For example, when the substrate W is suctioned by the suction electrode 11, the displacement of the substrate can be measured by the detection electrode 12 or the like at the same time. Good.

  The second power supply line L2 includes an AC power supply 221, an ammeter 229, and switches 226, 227, and 228. The switches 226, 227, and 228 are configured to be capable of switching electrical connections between the second power supply line L2 and the detection electrode 12, the detection reference electrode 13, and the comparison electrode 14, respectively.

  The displacement of the substrate W with respect to the support surface 10a is determined by closing the switches 226 and 227, connecting the detection electrode 12 and the detection reference electrode 13 to the second power supply line L2, and connecting the detection electrode 12 and the detection electrode from the AC power supply 221. By supplying AC power to the reference electrode 13 for use, the capacitance between the substrate W and the detection electrode 12 is measured. In measuring the capacitance, the impedance value of the second current supply line calculated based on the detection value of the ammeter 229 is referred to.

  Since the detection electrode 12 is fixed to the support surface 10a, the value of the capacitance measured by the detection electrode 12 changes according to the relative position of the substrate W with respect to the reference position of the support surface 10a. Therefore, by measuring in advance the capacitance (hereinafter, also referred to as a reference value) when the substrate W is placed at the reference position, the capacitance of the measured value of the capacitance from the reference value can be determined based on the amount of decrease from the reference value. It is possible to detect the amount of displacement of the substrate W from the position. The reference position of the support surface 10a is typically the center 10c of the support surface 10a (see FIG. 4). In this case, the capacitance when the center Wc (see FIG. 4) of the substrate W is located at the center 10c of the support surface 10a corresponds to the reference value.

  The width (width dimension along the radial direction) of the detection electrode 12 is not particularly limited, and can be appropriately set according to the size of the substrate W and the allowable range of the positional deviation. The smaller the width of the detection electrode 12 is, the more accurately the minute displacement of the substrate W can be detected, which is particularly advantageous for a process in which alignment conditions are relatively strict. For example, the shape and size of the detection electrode 12 are set so that the area of the detection electrode 12 is 15% or less of the total area of the substrate W.

  The comparison electrode 14 is based on whether the difference of the capacitance measurement value from the detection electrode 12 from the reference value is due to the displacement of the substrate W, or because the foreign matter is caught or the substrate W is warped. Is used to determine whether

  Since the comparison electrode 14 is located closer to the center of the support surface 10a than the detection electrode 12, when the foreign matter is not caught or the substrate W is not warped, the substrate W is significantly displaced. Except for the case, the entire area of the comparison electrode 14 is in a positional relationship facing the substrate W. Therefore, by measuring the capacitance between the comparison electrode 14 and the substrate W based on the capacitance at this time, it is possible to easily determine the biting of a foreign substance, the warpage or cracking of the substrate W, and the like. it can.

  The capacitance between the substrate W and the comparison electrode 14 is detected from the AC power supply 222 by closing the switches 227 and 228 to connect the comparison electrode 14 and the detection reference electrode 13 to the second power supply line L2. It is measured based on the detection value of the ammeter 229 obtained when AC power is supplied to the reference electrode 13 and the comparison electrode 14.

  At least one of the detection electrode 12, the detection reference electrode 13, and the comparison electrode 14 may have a function as an adsorption electrode. In this case, for example, a third DC power supply 223 and a fourth DC power supply 224 capable of supplying DC power to the detection electrode 12, the detection reference electrode 13, and the comparison electrode 14 via the switches 226 to 228. And fifth DC power supply 225 are connected to second power supply line L2, respectively. The polarity is not particularly limited. In FIG. 3, the third DC power supply 223 is configured as a positive voltage source, and the fourth and fifth DC power supplies 224 and 225 are configured as negative voltage sources.

  The number and position of the ammeters 229 are not limited to the above example, and may be further disposed between the third DC power supply 223 and the ground potential and / or between the fifth DC power supply 225 and the ground potential. Is also good. By measuring the current of each branch circuit in this way, the detection accuracy can be improved.

  The control unit 30 is typically configured by a computer including a CPU, a memory, and the like. The control unit 30 supplies a DC power to the suction electrodes 11 (electrode pairs 11a and 11b) to suction the substrate W on the support surface 10a, and supplies an AC power to the detection electrodes 12. By doing so, the power supply unit 20 is configured to be able to selectively or simultaneously execute the second control mode for detecting the displacement of the substrate W on the support surface 10a. The control unit 30 may be configured as a part of a controller that comprehensively controls the operation of the vacuum processing apparatus 1.

  In the second control mode, the control unit 30 detects the amount of displacement of the substrate W on the support surface 10a based on the capacitance between the substrate W on the support surface 10a and the detection electrode 12. It is composed of

  For example, when the outer diameter of the detection electrode 12 is set to the same value as the outer diameter of the substrate W, as shown in FIGS. The facing area between W and the detection electrode 12 decreases. The control unit 30 calculates an amount of capacitance or impedance between the substrate W and the detection electrode 12 that changes according to the area of opposition between the substrate W and the detection electrode 12 (not shown). Having. From the measurement result, it is possible to detect the amount of positional deviation D between the center Wc of the substrate W and the center 10c of the support surface 10a.

  As a comparative example, as shown in FIG. 4C, consider a detection system in which an electrode 12R that is used for both detecting the position of the substrate W and adsorbing it is formed in a large pattern size over substantially the entire area of the support surface. Also in this detection system, it is possible to detect the amount of displacement of the substrate W by measuring the capacitance or impedance and reading the amount or change in the amount.

  Here, the capacitance C of the parallel plate is represented by C = kS / d (k: relative permittivity, S: facing area, d: facing distance). However, the amount of displacement of the substrate is often very small with respect to the diameter of the substrate, and the amount of change in the facing area S is small. That is, it is difficult for the detection system shown in FIG. 4C to accurately measure the displacement amount of the substrate W.

  On the other hand, in the present embodiment, instead of the electrode structure that increases the capacitance as in the comparative example, the area of the detection electrode is reduced by reducing the area of the detection electrode in order to reduce the resolution. The dynamic range has been reduced. For example, when the dynamic range is 1 μF and the resolution is 10 bits, the resolution is about 1 nF. However, when the dynamic range is 1 nF, the resolution is about 1 pF. It becomes easier to catch a change in capacitance. This makes it possible to measure the displacement amount of the substrate with high accuracy.

  In addition, reducing the area of the detection electrode allows the detection electrode to be separate from the suction electrode, which leads to the elimination of the need for a high-withstand-voltage DC blocking circuit in the detection circuit. In general, reducing the capacitance can increase the frequency of an AC signal used for detection. This makes it possible to use small and inexpensive components for rectification, noise suppression, and the like, and facilitates improvement in S / N.

  Since the detection electrode 12 in the present embodiment is formed in an annular shape along the periphery of the substrate W, the area where the hollow portion of the detection electrode 12 overlaps the substrate is smaller than that of the disk-shaped electrode 12R. Become. This makes it possible to improve the detection sensitivity of the amount of displacement for a certain range of displacement of the substrate W in the in-plane direction.

  Here, assuming that an area (hereinafter, also referred to as an opposing area) when two disc-shaped samples each having a diameter of 100 mm are overlapped so that their respective center points coincide with each other, a change in the opposing area with respect to a shift of the overlapping position. Was measured. On the other hand, one of the two samples was replaced with an annular shape having an outer diameter of 100 mm and an inner diameter of 90 mm, and the ratio of the change of the facing area to the displacement of each overlapping position was calculated in the same manner as described above. The result is shown in FIG.

  As shown in FIG. 5, for a disk-shaped sample indicated by a black circle, the facing area changes linearly with the amount of positional deviation. On the other hand, in the ring-shaped sample indicated by the white circle, the ratio of the change in the facing area is larger in the region where the deviation is up to 10 mm than in the region where the deviation is 10 mm or more. In other words, for a displacement of 10 mm or less, the ring-shaped sample changes the facing area at a relatively large ratio, and thus it can be seen that the detection sensitivity of the displacement based on the area is higher.

  FIG. 6 shows an experimental result obtained by measuring the capacitance of each of the two types of samples as electrodes. Here, a silicon substrate having a diameter of 150 mm (6 inches) was used as a counterpart disk, and a disk-shaped electrode having a diameter of 152.4 mm was used as a disk-shaped sample. As an annular sample, a detection system in which an annular electrode having an outer diameter of 152.4 mm and an inner diameter of 148.6 mm was formed as the detection electrode 12 was manufactured, and the change in the capacitance of the annular electrode with respect to the displacement of the substrate. Was measured. As the measurement conditions, AC power (applied frequency 10 kHz, applied voltage 1 V) was supplied between the detection electrode 12 and the detection reference electrode 13 having the pattern shape shown in FIG. As a measuring device, an LCR meter (HIOKI IM3536) manufactured by Hioki Electric Co., Ltd. was used.

  As shown in FIG. 6, it was confirmed that the change in the area ratio due to the difference in shape between the ring shape and the disk shape appeared as the change ratio of the capacitance as it was. As described above, by making the electrode shape of the detection electrode 12 an annular shape, the rate of change of the capacitance due to the minute displacement of the substrate W can be increased. Can be measured.

  Such an effect is not limited to the case where the outer diameter of the ring is the same as the diameter of the counterpart disk (substrate), and the outer diameter of the ring is not the same as the diameter of the disk (substrate). The same effect can be obtained when the diameter is larger or smaller than the diameter of

  It is preferable that the area of the detection electrode 12 having such an operational effect be 15% or less of the total area of the substrate W. When the capacitance is defined by a capacitance value, the size of the detection electrode 12 is, for a 6-inch wafer, such that a capacitance value of, for example, 10 pF or more and 200 nF or less is obtained in consideration of the background (capacity value when there is no substrate). Is preferred. Thus, for example, the substrate can be divided into about 2000 in units of 100 pF, so that the substrate can be positioned or the amount of displacement can be detected with the accuracy.

  The amount of displacement of the substrate W on the support surface 10a may be measured before suction holding, during suction holding, or after suction holding. That is, the control unit 30 supplies the DC power to the suction electrodes 11 (electrode pairs 11a and 11b) to detect the substrate before or after executing the first control mode in which the substrate W on the support surface 10a is sucked. The power supply unit 20 is controlled so that the second control mode for detecting the displacement of the substrate W on the support surface 10a by supplying the AC power to the electrode 12 can be executed.

  By executing the second control mode before the execution of the first control mode, it is possible to detect a displacement of the substrate W that exceeds an allowable range before the processing of the substrate W. It is possible to prevent a film or foreign matter from being caught in advance. Further, by executing the second control mode after the execution of the first control mode, for example, it is possible to detect, for example, cracks or residual adsorption of the substrate W after the film forming process.

  Alternatively, the control unit 30 may be configured to control the power supply unit 20 so that the second control mode can be executed during the execution of the first control mode. By executing the first control mode, the substrate W comes into close contact with the support surface 10a. Therefore, the capacitance between the substrate W and the detection electrode 12 is typically smaller than before the execution of the first control mode. Also increases. On the other hand, if there is no change in the capacitance before and after the execution of the first control mode, if foreign matter is caught or the substrate is warped, the correction may be insufficient. Therefore, by simultaneously executing the first and second control modes, it is possible to easily determine the presence or absence of these events.

  FIG. 7 is a flowchart illustrating an operation procedure of the vacuum processing apparatus 1.

  When the substrate W is placed on the support surface 10a of the chuck body 10, the electrostatic chuck device 100 performs the first position shift measurement (S101), chucking (chuck ON) (S102), and the second position shift measurement After being subjected to the substrate processing (S104), the dechucking (chuck OFF) (S105), and the third displacement measurement (S106), the wafer is unloaded from the processing chamber 2. The chucking and the substrate processing are performed when a good determination is obtained in the first and second displacement measurement, and in the case of a defective determination, the substrate W is re-mounted or an abnormality is notified.

  In the first to third displacement measurement (S101, S103, S106), the switches 226 to 228 in the power supply unit 20 are closed, and the second power supply line L2 is connected to the detection electrode 12 and the detection reference electrode 13. And to the comparison electrode 14. In the present embodiment, after measuring the capacitance between the detection electrode 12 and the substrate W, the capacitance between the comparison electrode 14 and the substrate W is measured, but is not limited to this.

  The pass / fail judgment in the first to third displacement measurement (S101, S103, S106) may be the same, or may be at least partially different. Typically, when the difference between the measurement value of the detection electrode 12 and the reference value is equal to or smaller than a predetermined value, the control unit 30 determines that the deviation amount of the substrate W from the reference position of the support surface 10a is within an allowable range. I do. A different criterion may be adopted as the allowable range for each displacement measurement. The first to third positional deviation measurements (S101, S103, S106) are not limited to being performed entirely, and only some of the steps may be performed.

  If the difference from the value measured by the detection electrode 12 exceeds the above-mentioned predetermined value, whether the displacement of the substrate W exceeds the allowable range based on the value measured by the comparison electrode 14, whether foreign matter is caught or the substrate W It is determined whether excessive warpage has occurred. The type of anomaly notification and the action to be taken may be changed according to the content of the determination. The allowable range of the displacement amount is not particularly limited, and can be appropriately set according to the size and shape of the substrate W, the contents of the vacuum processing, and the like.

  As described above, according to the electrostatic chuck device 100 of the present embodiment, the displacement of the substrate W with respect to the reference position on the support surface 10a is determined by the difference in the facing area between the substrate W and the detection electrode 12. Can be grasped from. Moreover, since the detection electrode 12 is formed in a ring shape, the amount of displacement of the substrate W can be detected in an analog and highly accurate manner based on the facing area without complicating the electrode shape. Further, it is possible to cope with positional deviations in all directions (in-plane directions) parallel to the support surface 10a without requiring a detection electrode structure specialized in a specific axial direction.

  Further, the detection electrode 12, the detection reference electrode 13, and the comparison electrode 14 can function as suction electrodes. Thus, the suction area of the substrate W increases, so that the suction force and the function of correcting the warpage of the substrate W can be improved.

<Second embodiment>
FIG. 8 is an electrode configuration diagram of the chuck body 40 in the electrostatic chuck device 200 according to the second embodiment of the present invention, and FIG. 9 is an enlarged view showing the electrode structures of the detection electrode 112 and the comparison electrode 114. 10 is a circuit diagram of the power supply unit 120.
Hereinafter, configurations different from the first embodiment will be mainly described, and configurations similar to those of the first embodiment will be denoted by similar reference numerals, and description thereof will be omitted or simplified.

  The electrostatic chuck device 200 according to the present embodiment includes a chuck body 40, a power supply unit 120, and a control unit 30.

  The chuck body 40 of the present embodiment has a rectangular planar shape, and is configured such that a rectangular substrate such as a glass substrate can be placed on the surface (support surface) thereof. The chuck body 40 has an adsorption electrode 111 (first electrode), a detection electrode 112 (second electrode), and a comparison electrode 114 (fourth electrode).

  The attraction electrode 111 has a rectangular electrode pair 111a and 111b, and forms a bipolar attraction electrode. The detection electrode 112 is formed in a rectangular ring shape so as to surround the adsorption electrode 111. The detection electrode 112 is typically formed in a shape corresponding to the substrate size along the periphery of the substrate placed on the chuck body 40. The comparison electrode 114 is disposed between the suction electrode 111 and the detection electrode 112, and is formed in a rectangular ring shape so as to surround the suction electrode 111.

  The suction electrode 111, the detection electrode 112, and the comparison electrode 114 have the same functions as the suction electrode 11, the detection electrode 12, and the comparison electrode 14 in the above-described first embodiment. Among these, the detection electrode 112 and the comparison electrode 114 are formed in electrode shapes as shown in FIG.

  That is, the detection electrode 112 and the comparison electrode 114 in the present embodiment are each configured by two electrode lines E1 and E2. The two electrode lines E <b> 1 and E <b> 2 form an electrode pair configured to have a constant interval therebetween, and are formed in a ring shape outside the attraction electrode 111. The electrode lines E1 and E2 are formed so as to meander zigzag in one axial direction as shown in FIG. 9, but are not limited thereto, and may be formed linearly.

  One of the electrode lines E1 and E2 functions as an input terminal of the detection AC power, and the other functions as an output terminal thereof. By utilizing the fact that the capacitance between these electrode lines E1 and E2 changes depending on the presence or absence of the substrate W, it is possible to detect the amount of displacement of the substrate with respect to the chuck body 40 (support surface).

  For example, when detecting the displacement of the substrate with the detection electrode 112, the switches 226 and 227 are closed, and the two electrode lines E <b> 1 and E <b> 2 of the detection electrode 112 are connected to the AC power supply 221. The capacitance between the electrode lines E1 and E2 is measured based on the detected value. On the other hand, when detecting the presence or absence of foreign matter biting or the warpage of the substrate W by the comparison electrode 114, the switches 226 and 228 are closed and the two electrode lines E1 and E2 of the comparison electrode 114 are connected to the AC power supply 221. Then, the capacitance between these electrode lines E1 and E2 is measured based on the detection value of the ammeter 229.

  At least one of the detection electrode 112 and the comparison electrode 114 may have a function as an adsorption electrode. In this case, for example, the third DC power supply 223, the fourth DC power supply 224, and the fifth DC power supply capable of supplying DC power to the detection electrode 112 and the comparison electrode 114 via the switches 226 to 228 225 are connected to the second power supply lines L2, respectively.

  The number and the position of the ammeter 229 are not limited to the above example, and may be further, for example, between the detection electrode 112 (E1) and the switch 226 and / or between the comparison electrode 114 (E1) and the switch 226. It may be arranged. Thereby, the detection accuracy can be improved.

  In the example of FIG. 10, the electrode lines E1 and E2 forming the detection electrode 112 and the comparison electrode 114 are connected to DC power supplies having different polarities. Thereby, an electrostatic attraction effect of the substrate utilizing the gradient force can be obtained. Therefore, the interval between the electrode lines E1 and E2 is optimized so as to obtain a desired gradient force.

  In the electrostatic chuck device 200 of the present embodiment configured as described above, the same operation and effect as those of the above-described first embodiment can be obtained. According to the present embodiment, it is not necessary to separately provide a detection reference electrode, so that a sufficient area of the suction electrode 111 can be easily secured.

<Third embodiment>
FIG. 11 is an electrode configuration diagram of the chuck main body 50 in the electrostatic chuck device 300 according to the second embodiment of the present invention. Hereinafter, configurations different from the first embodiment will be mainly described, and configurations similar to those of the first embodiment will be denoted by similar reference numerals, and description thereof will be omitted or simplified.

  The chuck main body 50 according to the present embodiment is different from the first embodiment in that the annular detection electrode 12 is configured by an aggregate of a plurality of electrode pieces. That is, the detection electrode 12 of the present embodiment is formed of an aggregate of four arc-shaped electrode pieces 12a, 12b, 12c, and 12d arranged at equal angular intervals on a concentric circle of the support surface 10a.

  The electrode pieces 12a to 12d are electrically independent of each other, and are individually connected to the power supply unit 20. Similarly, the control unit 30 is configured so that the capacitance can be measured or calculated individually for each of the electrode pieces 12a to 12d. The control unit 30 detects a displacement amount and a displacement direction of the substrate W on the support surface 10a based on a capacitance between the substrate W on the support surface 10a and each of the plurality of electrode pieces 12a to 12c. It is configured as follows.

  In the electrostatic chuck device 300 of the present embodiment configured as described above, since the detection electrode 12 is divided into the plurality of electrode pieces 12a to 12d, not only the amount of displacement of the substrate W with respect to the support surface 10a but also , The direction of the displacement can be detected.

  For example, in FIG. 11, when the substrate W is displaced leftward from the reference position (the center of the support surface 10a), the capacitance values of the electrode pieces 12a and 12b decrease from the reference value, and the electrode pieces 12c and 12c. The capacitance value of 12d is the same as the reference value (increases when the outer diameter is larger than the substrate size). Similarly, when the substrate W is displaced in the right, up, down, and oblique directions in the drawing, the displacement direction of the substrate can be detected by comparing the capacitance values of the electrode pieces 12a to 12d.

  The number of divisions of the detection electrode 12 is not limited to four as described above, and may be two, three, or five or more. Such a configuration can be similarly applied to the detection electrode 112 of the chuck body 40 described in the second embodiment.

  As described above, the embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and it is needless to say that various modifications can be made.

  For example, in the above embodiments, the electrostatic chuck device for a vacuum processing apparatus has been described as an example. However, the present invention is also applicable to a substrate support mechanism for various processing apparatuses other than the vacuum processing.

  Further, the detection electrode 12 and the comparison electrode 14 described in the first embodiment may be configured by a pair of electrode wires, as in the second embodiment. In this case, it is not necessary to provide the reference electrode 13 for comparison, so that a sufficient area of the suction electrode 11 can be easily secured.

DESCRIPTION OF SYMBOLS 1 ... Vacuum processing apparatus 10, 40, 50 ... Chuck main body 11, 111 ... Suction electrode (1st electrode)
12, 112... Detection electrode (second electrode)
12a, 12b, 12c, 12d: electrode piece 13: detection reference electrode (third electrode)
14, 114... Comparison electrode (fourth electrode)
20, 120 power supply unit 30 control unit 100, 200, 300 electrostatic chuck device W substrate

Claims (8)

A support surface on which a substrate can be placed, a first electrode disposed opposite to the support surface, and an annular second electrode disposed opposite to the support surface and surrounding the first electrode. A chuck body having
A first power supply line capable of supplying a first power, a DC power, to the first electrode, and a second power, an AC power, to the second electrode A power supply having a second power supply line capable of
A first control mode in which the first power is supplied to the first electrode to attract the substrate on the support surface, and a second control mode in which the second power is supplied to the second electrode. And a control unit for controlling the power supply unit so that the second control mode for detecting the displacement of the substrate on the surface can be selectively or simultaneously executed. The electrostatic chuck device according to claim 1,
In the second control mode, the control unit detects a displacement amount of the substrate on the support surface based on a capacitance between the substrate on the support surface and the second electrode. Electro chuck device. The electrostatic chuck device according to claim 1 or 2,
The electrostatic chuck device, wherein the control unit controls the power supply unit so as to execute the second control mode before or after execution of the first control mode. The electrostatic chuck device according to claim 1 or 2,
The electrostatic chuck device, wherein the control unit controls the power supply unit so that the second control mode can be executed during execution of the first control mode. The electrostatic chuck device according to claim 1, wherein:
The first electrode has a hollow portion,
The electrostatic chuck device, wherein the chuck body further includes a third electrode disposed in the hollow portion and configured to be connectable to the second power supply line. The electrostatic chuck device according to claim 1, wherein:
The electrostatic chuck device, wherein the chuck body further includes an annular fourth electrode disposed between the first electrode and the second electrode and configured to be connectable to the second power supply line. It is an electrostatic chuck device according to any one of claims 1 to 6,
The electrostatic chuck device, wherein the control unit controls the power supply unit to supply the first power to the first electrode and the second electrode in the first control mode. The electrostatic chuck device according to any one of claims 1 to 7,
The second electrode includes an aggregate of a plurality of electrode pieces,
An electrostatic chuck device configured to detect a displacement amount and a displacement direction of the substrate on the support surface based on a capacitance between the substrate on the support surface and each of the plurality of electrode pieces. .