WO2012090430A1 - Electrostatic adsorption apparatus - Google Patents

Electrostatic adsorption apparatus Download PDF

Info

Publication number
WO2012090430A1
WO2012090430A1 PCT/JP2011/007094 JP2011007094W WO2012090430A1 WO 2012090430 A1 WO2012090430 A1 WO 2012090430A1 JP 2011007094 W JP2011007094 W JP 2011007094W WO 2012090430 A1 WO2012090430 A1 WO 2012090430A1
Authority
WO
WIPO (PCT)
Prior art keywords
substrate
voltage
electrode
adsorption
convex portion
Prior art date
Application number
PCT/JP2011/007094
Other languages
French (fr)
Japanese (ja)
Inventor
栄太郎 森本
Original Assignee
キヤノンアネルバ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by キヤノンアネルバ株式会社 filed Critical キヤノンアネルバ株式会社
Publication of WO2012090430A1 publication Critical patent/WO2012090430A1/en

Links

Images

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/683Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping
    • H01L21/6831Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using electrostatic chucks
    • H01L21/6833Details of electrostatic chucks
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/683Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping
    • H01L21/687Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using mechanical means, e.g. chucks, clamps or pinches
    • H01L21/68714Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using mechanical means, e.g. chucks, clamps or pinches the wafers being placed on a susceptor, stage or support
    • H01L21/6875Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using mechanical means, e.g. chucks, clamps or pinches the wafers being placed on a susceptor, stage or support characterised by a plurality of individual support members, e.g. support posts or protrusions

Definitions

  • the present invention relates to an electrostatic attraction apparatus provided with an electrostatic chuck used for holding a substrate on a support during the processing of the substrate in a manufacturing process of an electronic component such as a magnetic head having a semiconductor manufacturing process or a process similar thereto.
  • an electrostatic attraction apparatus provided with an electrostatic chuck used for holding a substrate on a support during the processing of the substrate in a manufacturing process of an electronic component such as a magnetic head having a semiconductor manufacturing process or a process similar thereto.
  • an electrostatic attracting apparatus (hereinafter also referred to as “electrostatic chuck”) is used.
  • electrostatic chuck As a method for attracting a high-resistance substrate such as a glass substrate, an electrostatic attracting apparatus (hereinafter also referred to as “electrostatic chuck”) is used.
  • electrostatic chuck Conventionally, a method of adsorbing using a high voltage of 3 kV and 10 kV was taken, but a method of adsorbing at a low voltage of 1 kV is disclosed in Patent Document 1.
  • Patent Document 1 it is described that the adsorption can be performed by heating the glass substrate to make the volume resistivity below a certain value, but the volume resistivity is 1 ⁇ 10 6 ⁇ ⁇ cm to 1 ⁇ 10 14 ⁇ ⁇ cm. It takes an enormous amount of time for the adsorption force to decrease in the range of.
  • the substrate cannot be collected quickly and stably.
  • the volume resistivity can be lowered by raising the temperature, there is a problem that it cannot be processed in a temperature environment of 150 ° C. or higher because the heat resistance of the adhesive for attaching Si to the glass substrate is low.
  • the low temperature treatment is necessary due to the film quality problem, there is a problem that the substrate cannot be recovered quickly and stably.
  • Patent Document 2 As an electrostatic chuck for solving this problem, one disclosed in Patent Document 2 is known.
  • the electrostatic chuck described in Patent Document 2 includes a dielectric plate having convex and concave portions formed on the surface by embossing, an electrode provided in the dielectric plate, and an external power source that applies a voltage to the electrode. I have. Further, the top surface (substrate support surface) of each convex portion is covered with conductor wiring, and the substrate support surface of each convex portion is electrically connected by this conductor wiring, and the conductor wiring is grounded or floated. A switch is provided. Furthermore, the electrode part close
  • the conductor wiring is held in a floating state by a switcher during substrate processing. At the end of the processing of the substrate, the conductor wiring is grounded with a switch, so that the electric charges generated on the embossed protrusions, the back surface of the substrate, and the surface of the dielectric plate are released, and the adsorption power disappears quickly. I am letting.
  • Patent Document 4 discloses a method for improving the point that it is difficult to adjust the reverse voltage application time with respect to the insulating substrate.
  • a voltage is applied to an electrode provided in an electrostatic adsorption device, the insulating substrate is electrostatically adsorbed, processed in a vacuum atmosphere, and then taken out of the insulating substrate.
  • the electrode is separated from the electrostatic chuck while a voltage having a polarity opposite to that at the time of electrostatic chucking is applied to the electrode.
  • Patent Document 2 the Johnson Rabeck force acting between the substrate support surface of each convex portion and the back surface of the substrate in contact with the substrate support surface is a very large adsorption force. For this reason, the electrostatic chuck of Patent Document 2 in which this Johnson Rabeck force does not work has a problem that the attracting force tends to be insufficient. This problem can be solved by removing the conductor wiring covering the substrate support surface of the convex portion so that the Johnson Rabeck force works. However, when the conductor wiring that covers the substrate support surface of the convex portion is removed, it becomes impossible to move the charge quickly by setting the conductor wiring to the ground state with the switch, and until the substrate can be detached due to the residual charge. The problem is that time is delayed.
  • the electrostatic chuck of Patent Document 2 is provided with a conductor wiring that covers and electrically connects the substrate support surface of each convex portion and removes the substrate when removing the substrate, and connects this to the switch.
  • a conductor wiring that covers and electrically connects the substrate support surface of each convex portion and removes the substrate when removing the substrate, and connects this to the switch.
  • the adsorption method of Patent Document 1 can electrostatically adsorb a glass substrate at a low voltage by raising the temperature of the glass substrate. Further, even when the glass substrate is detached, if the temperature of the glass substrate is increased, the volume resistance of the glass substrate is reduced, so that the glass substrate can be detached more easily than at room temperature. It takes a long time for the volume resistance to depart between 1e + 6 ⁇ ⁇ cm and 1e + 11 ⁇ ⁇ cm, for example, when the temperature is restricted due to device fabrication. For this reason, there is a problem in that the substrate cannot be stably detached because the separation method described in Patent Document 4 in which a reverse voltage at the time of adsorption is applied to the adsorption voltage application electrode when the substrate is detached.
  • the present invention has been made in view of the above-mentioned conventional problems. With a simple structure, even when the substrate is a glass substrate such as an insulating material, the substrate can be quickly removed from the electrostatic chuck with sufficient electrostatic adsorption force.
  • An object of the present invention is to provide an electrostatic chucking device including an electrostatic chuck that can be removed.
  • an electrostatic attraction apparatus has a plurality of convex portions capable of supporting a substrate on the top surface and concave portions around the convex portions on the surface.
  • An electrostatic attraction apparatus comprising: a formed dielectric plate; an electrode provided inside the dielectric plate; and a first external power source that applies a substrate attraction voltage to the electrode,
  • the convex portion is provided with a conductor coating on at least the top surface of the convex portion,
  • the first external power source includes a substrate desorption voltage power source capable of applying a reverse voltage having a polarity opposite to the substrate adsorption voltage applied to the electrode to the electrode when the substrate is desorbed.
  • the conductor coating is provided with a second external power supply provided with a substrate desorption voltage power source capable of applying a reverse voltage having a polarity opposite to the substrate adsorption voltage applied to the electrode when the substrate is detached. It is connected to a power source.
  • the plurality of convex portions supporting the substrate on the top surface have a height of 35 ⁇ m or less, and the top surface has an Ra (centerline average roughness) of 0.2 ⁇ m or less.
  • the total surface area is formed so as to have a ratio of 10% or less with respect to the total planar area of the dielectric plate.
  • the substrate has a volume resistivity of 10 14 ⁇ ⁇ cm or less, and an insulating property whose Ra (center line average roughness) of the contact surface with the convex portion is 0.05 ⁇ m or less. It is a substrate.
  • the substrate when adsorbing a substrate, the substrate is adsorbed by a Johnson Rahbek force generated between the convex portion and the substrate and a Coulomb force generated between the concave portion and the substrate. Is possible.
  • a reverse voltage applied to the electrode during substrate adsorption is applied to the first external power source connected to the electrode and the second external power source connected to the conductive film.
  • the back surface of the substrate and the conductor coating have the same potential.
  • the residual attracting force of the substrate disappears, and the substrate can be smoothly removed from the electrostatic chuck in a short time.
  • the top view of the electrostatic chuck of FIG.1 and FIG.2. The figure which shows the state of the electric charge of the surface of the conductor film of the electrostatic chuck shown in FIG. 2, and the back surface of a board
  • substrate The figure which shows the state of the electric charge of the electrostatic chuck shown in FIG. 2 at the time of detachment
  • substrate The figure which shows the equivalent circuit at the time of adsorb
  • FIG. 8A The figure which shows the relationship between the adsorption
  • FIG. The figure which shows the state of the voltage at the time of applying the voltage Vb with the direct-current power supply B to the circuit of FIG. 8A initially, and making it a ground (GND) after that.
  • FIG. 1 is a schematic cross-sectional view of a sputtering apparatus provided with an electrostatic attraction apparatus according to an example of the present invention
  • FIG. 2 is a partially enlarged schematic cross-sectional view of the electrostatic attraction apparatus according to an example of the present invention.
  • the sputtering apparatus shown in FIG. 1 includes a container 1 whose inside can be decompressed by an external exhaust mechanism (not shown), and a target 3 provided on the ceiling of the container 1 via a ring-shaped insulating member 2. Yes.
  • a magnet 5 is provided on the yoke plate 4 on the back side of the target 3.
  • the target 3 is connected to a sputtering power source 6 for applying a voltage.
  • an electrostatic chuck 8 is provided on the substrate temperature adjusting unit 7 fixed to the bottom of the container 1, and the substrate 9 is placed on the electrostatic chuck 8.
  • a cylindrical shield member 10 is disposed along the inner surface of the peripheral wall of the container 1 between the target 3 and the electrostatic chuck 8.
  • the substrate temperature adjusting unit 7 is a member that controls the temperature of the substrate 9 via the electrostatic chuck 8, and includes a thermocouple 12 and a heating / cooling unit 13 connected to the temperature control power supply mechanism 11.
  • the temperature control power supply mechanism 11 operates the heating / cooling unit 13 based on the temperature detected by the thermocouple 12 to heat or cool the electrostatic chuck 8.
  • the electrostatic chuck 8 provided on the substrate temperature adjusting unit 7 includes a dielectric plate 14 whose surface (upper surface) is embossed, an electrode 15 provided inside the dielectric plate 14, and a constant electrode 15. And an external power supply 16b for applying a voltage.
  • a plurality of convex portions 17a and peripheral concave portions 17b are formed by embossing.
  • an outer peripheral ridge 18 is formed on the peripheral edge of the front surface side of the dielectric plate 14 so as to surround the formation region of the convex portion 17a and the concave portion 17b.
  • the convex part 17a and the outer peripheral ridge part 18 are those on which the substrate 9 is placed on the top surface, and have substantially the same height.
  • each convex portion 17a is formed on each convex portion 17a so as to cover at least the top surface.
  • Each conductor coating 19 has irregularities that cause a Johnson Rabeck force between the substrate 9 and the conductor coating 19 by applying a voltage to the electrode 15 described below.
  • the unevenness of the conductor coating 19 functions as a Johnson Rabeck force generator.
  • each conductor coating 19 may cover not only the top surface of each projection 17a but also the side surface of each projection 17a, but the conductor coating 19 is not provided in the recess 17b portion.
  • Each concave portion 17b is electrically independent from the conductor coating 19 formed on each convex portion 17a.
  • a conductor coating 19 is also formed on the top and side surfaces of the outer peripheral ridge 18.
  • the conductor coating 19 formed on the top surface of the outer peripheral ridge portion 18 is preferably provided to facilitate the alignment of the entire height of the outer peripheral ridge portion 18 and the entire height of the convex portion 17a, but may be omitted. it can.
  • the electrode 15 is a unipolar electrode and is connected to an external power source 16b which is a DC power source via a switch 20b, and a constant negative voltage is applied by turning on the switch 20b.
  • the illustrated electrode 15 is a monopolar electrode, it is divided into an inner peripheral side and an outer peripheral side of the dielectric plate 14 to form a bipolar electrode, and a negative voltage is applied to one of them and a positive voltage is applied to the other.
  • the electrode 15 has a smaller diameter than the outer peripheral ridge portion 18, and is positioned only below the region where the convex portions 17 a and the concave portions 17 b are provided, and is not positioned immediately below the outer peripheral ridge portion 18. It has become a thing. Since the electrode 15 is not located below the outer peripheral protrusion 18, the outer peripheral protrusion 18 does not contribute to the adsorption of the substrate 9.
  • the substrate 9 is placed on the top surfaces of the convex portion 17a and the outer peripheral ridge portion 18, and the region surrounded by the outer peripheral ridge portion 18 is between the substrate 9 and the dielectric plate 14.
  • a gap is formed by the recess 17b.
  • a gas supply source 22 is connected to the gap via a gas supply path 21 so that gas (for example, argon gas) can be supplied to the gap.
  • gas for example, argon gas
  • FIG. 2 is a partial enlarged cross-sectional schematic view of an electrostatic attraction apparatus according to an example of the present invention.
  • An external power source 16a is connected to the conductor film 19 covering at least the top surface of each convex portion 17a via a switch 20a.
  • the electrode 15 is connected to the external power supply 20b through the switch 20b.
  • the external power supplies 16a and 16b are respectively a DC power supply 16a1 and 16b1, a DC power supply 16a2 and 16b2 that generate a reverse voltage having a polarity opposite to that generated by the DC power supplies 16a1 and 16b1, and a ground terminal 16a3 and 16b3. Consists of The voltages output from the external power supplies 16a and 16b can be switched by the switches 20a and 20b. In FIG. 1, the ground terminals 16a3 and 16b3 are not shown. For example, when the DC power supplies 16a1 and 16b1 function as substrate adsorption voltage power supplies, the DC power supplies 16a2 and 16b2 function as substrate desorption voltage power supplies.
  • FIG. 3 is a plan view of the electrostatic chuck 8 shown in FIGS. 1 and 2.
  • the convex portion 17 a and the concave portion 17 b are formed radially from the central axis of the electrostatic chucking stage 8 and continuously from the central axis of the electrostatic chucking stage 8.
  • the circumferential portion 272 is formed on a part of the radial portion 271.
  • the convex part 17a and the outer peripheral ridge part 18 are those on which the substrate 9 is placed on the top surface, and have substantially the same height.
  • the convex portions 17 a and the concave portions 17 b formed in the radial portion 271 and the circumferential portion 272 are covered with the conductor film 19.
  • the concave portions 17 b formed other than the radial portion 271 and the circumferential portion 272 are not covered with the conductor film 19.
  • the planar shape of the attracting surface of the electrostatic chuck 8 is circular as a whole as shown in FIG.
  • the substrate 9 is also circular, and the diameters of both are substantially the same.
  • FIG. 4A is a diagram showing a state of charges on the surface of the conductor coating 19 and the back surface of the substrate 9 of the electrostatic chuck shown in FIG.
  • FIG. 4B is a diagram showing the state of electric charges on the surface of the conductor coating 19 and the back surface of the substrate 9 of the electrostatic chuck shown in FIG.
  • the electrostatic chuck 8 will be further described with reference to FIGS. 1 to 4B.
  • the convex portion 17a is usually cylindrical and preferably has a diameter of 2.0 mm or less. The lower limit is determined by the required mechanical strength of the convex portion 17a and processing limitations, but is generally about 0.3 mm. When the diameter of the convex portion 17a is increased, it is difficult to perform rapid charge removal when the substrate 9 is detached.
  • the rapid neutralization is caused by the large number of contact points between the conductor film 19 formed on the top surface of the convex portion 17a and the substrate 9.
  • the maximum surface roughness (Ry) in the unevenness of the conductor coating 19 functioning as the Johnson Rabeck force generating portion is stochastically reduced, and the surface smoothness of the conductor coating 19 is increased. It is considered that the contact point between the substrate 9 and the conductor coating 19 increases. Further, since the smoothness of the conductor coating 19 is increased, the interval between the microscopic gaps between the substrate 9 and the conductor coating 19, that is, the gap between the irregularities functioning as the Johnson Rabeck force generator is also reduced. Accordingly, the Johnson Rabeck force acting between the substrate 9 and the conductor coating 19 is also increased.
  • the surface of the conductor film 19 on the convex portion 17a preferably has a smooth surface in order to obtain a good adsorption action and separation action, and Ry (maximum surface roughness) is 2.5 ⁇ m or less, and Ra ( The centerline average roughness is preferably 0.2 ⁇ m or less. In reality, a completely smooth surface cannot be formed, so there is no particular lower limit. However, from the practical smoothing limit, Ry is 0.2 ⁇ m or more and Ra is 0.02 ⁇ m or more. Further, the volume resistivity of the substrate 9 is preferably 10 14 ⁇ ⁇ cm or less. Moreover, it is preferable that Ra (centerline average roughness) of the board
  • the height of the convex part 17a and the outer periphery protrusion part 18 it is preferable that height is 35 micrometers or less in the range in which the adsorbed board
  • the lower limit of the height is generally about 6.5 ⁇ m.
  • the convex portion 17a has a total area of the top surface of the convex portion 17a of 1% or more and 10% of the total planar area of the electrostatic chuck 8 in order to obtain an appropriate suction force and quick charge removal. It is preferable to be formed so as to have the following ratio.
  • the conductor coating 19 is made of a metal, metal oxide, metal nitride or the like, which is an electrical conductor having a specific resistance of 10 ⁇ 4 ⁇ ⁇ cm or less, and has a specific resistance of 400 ⁇ ⁇ cm or less. preferable. In particular, the specific resistance is preferably 350 ⁇ ⁇ cm or less.
  • the electrostatic chuck 8 according to the present embodiment is configured as a bulk (plate). For this reason, it is not necessary to use different types of insulating materials as in the case of the separation mask of Patent Document 4 described above.
  • the material of the electrostatic chuck 8 has a volume resistivity capable of exhibiting a Johnson Rahbek force of 10 8 to 10 ⁇ ⁇ cm.
  • the conductor film 19 accumulates the same charge as the dielectric surface of the electrostatic chuck 8, and when the substrate 9 is detached from the electrostatic chuck 8, the back surface of the substrate 9 and the conductor film 19 are made to have the same potential so that the substrate remains. Eliminates adsorption power. By eliminating the residual attracting force of the substrate 9, it is possible to smoothly remove the substrate from the electrostatic chuck 8, that is, to improve the stability of substrate separation.
  • the conductor coating 19 on the back surface of the substrate and the surface of the electrostatic chuck can easily act so as to have the same potential. As a result, it is possible to eliminate the residual attracting force of the discharged substrate and to smoothly remove the substrate from the electrostatic chuck (detachment of the substrate).
  • Examples of the structure of the conductor coating 19 include metals such as titanium and tungsten, and oxides or nitrides thereof. Titanium, tungsten, and other materials are resistant to thermal distortion among metals, and are excellent in wear resistance and are not easily deformed. Therefore, they are rubbed due to contact between the substrate and the conductive coating 19 of the electrostatic chuck, and differences in linear expansion. Particles resulting from factors such as these can be suppressed, and wear resistance can be improved.
  • the conductor film 19 can be formed by a film forming method such as sputtering or ion plating.
  • the thickness of the conductor coating 19 is preferably 1.5 ⁇ m or less in order to suppress the resistance in the film thickness direction of the conductor coating 19 to about 10 ⁇ .
  • a practical lower limit is about 0.5 ⁇ m.
  • FIG. 1 a substrate transfer robot, a loading / unloading gate, a lift pin for placing and removing the substrate 9 on the electrostatic chuck 8, a mechanism related to discharge generation, a discharge gas introduction mechanism, and the like are illustrated. It is omitted.
  • the substrate 9 is loaded and placed on the electrostatic chuck 8 in the container 1 from the loading / unloading gate by the substrate transfer robot.
  • the switch 20 b is turned on and a voltage is applied to the electrode 15, different charges are accumulated on the surface of the dielectric plate 14 and the conductor coating 19 and the back surface of the substrate 9.
  • FIGS. 4A and 5A show the state of charge on the surface of the conductor film 19 and the back surface of the substrate 9 when the switch 20b is turned on.
  • a spatial Coulomb force acts between the concave portion 17b on the surface of the dielectric plate 14 and the back surface of the substrate 9, and a fine gap is formed between the conductor coating 19 on the top surface of the convex portion 17a and the back surface of the substrate 9.
  • the Johnson Rabeck force acts on both sides.
  • the substrate 9 is firmly attracted to the electrostatic chuck 8 by the space Coulomb force and the Johnson Rabeck force.
  • the heating / cooling unit 13 is operated by the temperature control power supply mechanism 11 to supply the discharge gas into the vessel 1 while keeping the temperature of the substrate 9 constant, and the sputtering power supply 6 is turned on to perform sputtering.
  • the sputtering power source 6 is turned off, and the switch 20b is turned off to stop the voltage application to the electrode 15. Then, the back surface of the substrate 9 and the conductor film 19 try to be at the same potential via the contact points between the conductor film 19 on the top surface of the plurality of convex portions 17a and the back surface of the substrate 9, and the charge is thereby eliminated.
  • the conductor coating 19 on the top surface of the plurality of convex portions 17 a also tends to have the same potential as the substrate 9. The state of this charge is shown in FIGS. 4B and 5B. However, the substrate 9 cannot be detached from the electrostatic chuck 8 only by turning off the sputtering power source 6 and further turning off the switch 20b.
  • FIG. 6A shows an equivalent circuit when a glass substrate (substrate 9) is adsorbed using a conventional electrostatic attraction apparatus.
  • FIG. 6B shows an equivalent circuit when a glass substrate is adsorbed using the electrostatic attraction apparatus of the present invention. Symbols in the equivalent circuits of FIGS. 6A and 6B are as shown below.
  • C1 and R1 are a capacitor and a resistor under the electrode 15.
  • C2 and R2 are capacitors and resistors above the electrode 15.
  • C3 and R3 are capacitors and resistors of the convex portion 17a.
  • C4 and R4 are a capacitor and a resistance of the conductor film 19 at a portion in contact with the glass substrate (substrate 9).
  • C5 is a capacitor between the dielectric recess 17b and the glass substrate (substrate 9).
  • C6 and R6 are a capacitor and a resistor of the glass substrate (substrate 9) in a portion in contact with the conductor coating 19.
  • C7 and R7 are capacitors and resistors between the glass substrate (substrate 9) and the concave portion 17b.
  • a second external power source 16 b connected to the conductor coating 19 is a first external power source connected to the electrode 15.
  • the glass substrate (substrate 9) is connected to the ground via plasma.
  • the glass substrate (substrate 9) is an insulating material on which an insulating thin film such as a SiN film (for example, a volume resistivity of 10 14 ⁇ ⁇ cm or less) having a larger volume resistivity than that of a normal glass substrate is formed. Assume a substrate.
  • the Johnson Rabeck force is considered to be generated by microscopic irregularities on the surfaces of the conductor coating 19 and the substrate 9.
  • the substrate 9 and the conductor coating 19 are approximately Ra (center line average roughness) formed by unevenness on both surfaces of the conductor coating 19 and the substrate 9.
  • the electrodes are connected by a capacitor C4 having a distance between the electrodes. That is, as shown in FIGS. 6A and 6B, the conductor film 19 and the substrate 9 are equivalent to the parallel circuits C6 and R6, the parallel circuits C4 and R4, and the parallel circuits C3 and R3 connected in series. It is considered a circuit.
  • the portion of the substrate 9 and the recess 17b can be considered as an equivalent circuit in which the parallel circuits C7, R7, C5 and the parallel circuits C2, R2 are connected in series.
  • One end of the parallel circuits C2 and R2 and the other end of the parallel circuits C3 and R3 are connected by a terminal VB, and the other end VA of the parallel circuits C2 and R2 is connected to the ground via the parallel circuits C1 and R1. It can be considered as an equivalent circuit.
  • FIG. 7A shows the relationship between the attracting voltage of the convex portion 17a and the concave portion 17b and time when the switch 20b is connected to the ground terminal 16b3 after the power of the electrode 15 is turned off when the glass substrate (substrate 9) is detached. Show. In FIG. 7A, the dotted line indicates the convex voltage, and the solid line indicates the concave voltage.
  • FIG. 7B shows the electrostatic attraction force and time acting on the convex portions 17a and the concave portions 17b when the switch 20b is connected to the ground terminal 16b3 after the power of the electrode 15 is turned off when the glass substrate (substrate 9) is detached. The relationship is shown. In FIG.
  • the dotted line indicates the convex portion adsorption force
  • the solid line indicates the concave portion adsorption force
  • the alternate long and short dash line indicates the total wafer adsorption force (substrate adsorption force) of the concave portion and the convex portion.
  • the parameter values used for the calculations in FIGS. 7A and 7B were set as follows. Assuming that the capacitance of the glass substrate (substrate 9) is 4 ⁇ 10 ⁇ 7 F, which is larger than the actual capacitance, the height of the convex portion is 8.5 ⁇ m, and the resistivity of the glass substrate (substrate 9) is 1 ⁇ 10 +11 ⁇ The resistivity of the electrostatic chuck 8 is 1 ⁇ 10 +11 ⁇ ⁇ cm, the relative dielectric constant of the electrostatic chuck 8 is 9, the distance from the electrode 15 of the electrostatic chuck to the surface of the substrate 9 is 1 mm, and the protrusion 17a was 1.5% of the entire surface of the electrostatic chuck 8 and the area of the electrostatic chuck 8 was 65411 mm 2 .
  • FIG. 7B shows changes in each voltage and changes in the suction force when the suction voltage is set to 0V.
  • the “recess voltage” was 0.85V and the “convex voltage” was 0.06V. That is, the “convex voltage” was about 1/10 of the “concave voltage”.
  • the suction voltage of the recess 17b becomes 0 V after a predetermined time (1 sec).
  • the adsorption voltage of the convex portion 17a does not become 0 V even after a predetermined time has elapsed (about 24 hours). That is, the attracting voltage of the convex portion 17a does not become 0V unless one day or more elapses, and the glass substrate cannot be detached from the electrostatic chuck during this period.
  • the electrostatic adsorption force of the convex portion 17a is 6 ⁇ 10 ⁇ 3 (Pa ⁇ m 2 ), and the electrostatic adsorption force of the concave portion 17b is 3 ⁇ 10 ⁇ 3 ( Pa ⁇ m 2 ). That is, the electrostatic attraction force of the convex portion 17a was about twice the electrostatic attraction force of the concave portion 17b.
  • the total wafer suction force of the concave portion and the convex portion indicated by the one-dot chain line in FIG. 7B is 9 ⁇ 10 ⁇ 3 (Pa ⁇ m 2 ).
  • the electrostatic attraction force of the concave portion 17b becomes 0 (Pa ⁇ m 2 ) when a predetermined time elapses (about 1 sec).
  • the electrostatic attraction force of the convex portion 17a does not become 0 (Pa ⁇ m 2 ) even when a predetermined time has elapsed (about 24 hours). Therefore, the total electrostatic attraction force of the convex portion 17a and the concave portion 17b does not become 0 (Pa ⁇ m 2 ) even when a predetermined time elapses (about 24 hours).
  • the value of the convex portion adsorption force becomes dominant among the total wafer adsorption force of the concave portion and the convex portion.
  • FIGS. 7A and 7B are examples of calculation. Moreover, the value of 0V includes the meaning of a voltage that can be ignored as the attractive force.
  • FIG. 8A shows a series circuit of a capacitor C and a resistor R.
  • FIG. 8B shows a voltage state when the voltage Vb is initially applied to the series circuit of the capacitor C and the resistor R shown in FIG. 8A by the direct-current power source B and then is grounded (GND). As shown in FIG. 8B, the voltage V does not quickly become zero simply by using the ground (GND). This is presumably because a transient phenomenon determined by the time constant of CR continues.
  • a voltage Vb is first applied by the DC power supply B to the series circuit of the capacitor C and the resistor R shown in FIG.
  • the relaxation time is expected to be much slower in the part where the Johnson Rabeck (JR) force is applied because of the high resistance in parallel. Further, since a different adsorption force of Johnson Rabeck (JR) force and Coulomb force acts on the substrate, a slight voltage remains in the case of Johnson Rabeck (JR) force in which the residual charge effectively acts as the adsorption force. It is assumed that the influence is great when the substrate 9 is detached.
  • the substrate 9 is firmly electrostatically caused by the Coulomb force generated between the concave portion 17 b and the substrate 9 and the Johnson Rahbek force generated between the convex portion 17 a (unevenness of the conductor coating 19) and the substrate 9. It is to be adsorbed by the chuck.
  • the Coulomb force generated in the concave portion 17b is a force inversely proportional to the square of the distance
  • the Johnson Rabeck force generated in the convex portion 17a can obtain a large adsorption force with a smaller voltage.
  • the time constant between the substrate 9 and the convex portion 17a is larger than the time constant between the substrate 9 and the concave portion 17b.
  • the time when the residual charge of the convex portion 17a becomes zero takes much time compared with the time when the residual charge of the concave portion 17b becomes zero.
  • the relaxation of the attracting force is slower in the convex part 17a than in the concave part 17b. Accordingly, the external power supply 16b connected to the electrode 15 when the substrate 9 is detached is switched to a voltage (16b2) opposite to the voltage (16b1) when the substrate 9 is attracted by the switch 20b, and the reverse voltage is supplied to the electrode 15.
  • the reverse voltage is supplied to the electrode 15, and the conductor coating 19 is connected to the terminal 16a2 of the external power source 16a via the switch 20a. Since the reverse voltage opposite to that when the substrate 9 is attracted is supplied to the convex portion 17a, the substrate 9 can be detached more quickly than in the prior art. Since the state of this charge is as shown in FIG. 5B, no problem occurs in terms of separation from the high-resistance glass substrate (substrate 9).
  • the time during which the residual charge of the convex portion 17a becomes zero is determined by the reverse voltage Vb applied to the terminal VC between the terminal VC and the terminal VD.
  • the residual charge in the concave portion 17b is made zero by the reverse voltage Vb applied to the terminal VA
  • the residual charge in the convex portion 17a is made zero by the reverse voltage Vb applied to the terminal VC. It is possible.
  • an electrostatic chuck having a glass substrate (substrate 9) having a volume resistivity of 10 12 ⁇ ⁇ cm at room temperature, a conductor coating (specific resistance 10 ⁇ 4 ⁇ ⁇ cm, Ra 0.2 ⁇ m), and TiN Assuming 8 (volume resistivity 10 8 ⁇ ⁇ cm, ceramic), how to operate the electrostatic chuck shown in FIGS. 1, 2, and 6B will be described.
  • a voltage 16b1 (10 V to 10 kV) is supplied to the electrode 15 from the external power source 16b for about 1 to 10 minutes to attract the substrate 9.
  • a voltage 16b2 (10 V to 10 kV) is supplied to the electrode 15 by the external power supply 16b for about 1 to 10 minutes, and a voltage 16a2 (10 V to 10 kV) is supplied to the terminal VC and the external power supply 16a for about 1 to 10 minutes. After the supply to the extent, the substrate 9 was detached.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Container, Conveyance, Adherence, Positioning, Of Wafer (AREA)
  • Jigs For Machine Tools (AREA)

Abstract

Provided, with a simple structure, is an electrostatic adsorption apparatus equipped with: sufficient electrostatic adsorption force even when the substrate to be adsorbed is a glass substrate made of insulation material; and an electrostatic adsorption chuck from which a substrate can be removed quickly. The electrostatic adsorption apparatus is equipped with: a dielectric plate on the surface of which is formed a plurality of protruded sections that can support a substrate with the apex faces thereof, and recess sections surrounding the protruded sections; an electrode formed within the dielectric plate; and a first external power supply for applying a substrate adsorption voltage to the electrode. The protruded sections are provided with conductor cover-films on at least the apex faces thereof, and the first external power supply is provided with a substrate-desorption-voltage power supply that can apply, to the electrode, an inverse voltage having a polarity that is inverse with respect to the polarity of the substrate adsorption voltage to be applied to the electrode, upon desorbing the substrate. The conductor cover-films are connected to a second external power supply provided with another substrate-desorption-voltage power supply that can apply, to the conductor cover-films, an inverse voltage having a polarity that is inverse with respect to the polarity of the substrate adsorption voltage to be applied the electrode, upon desorbing the substrate.

Description

静電吸着装置Electrostatic adsorption device
 本発明は、半導体製造工程又はこれに類似する工程を有する磁気ヘッドなどの電子部品製造工程における基板の処理時に、基板を支持体に保持するために用いられる静電チャックを備えた静電吸着装置に関する。 The present invention relates to an electrostatic attraction apparatus provided with an electrostatic chuck used for holding a substrate on a support during the processing of the substrate in a manufacturing process of an electronic component such as a magnetic head having a semiconductor manufacturing process or a process similar thereto. About.
 ガラス基板のように高抵抗の基板を吸着させる方法として静電吸着装置(以下、「静電チャック」ともいう。)が用いられている。従来3kV、10kVの高電圧を用いて吸着させる方法を取っていたが、1kVの低電圧にて吸着される方法が特許文献1に開示されている。特許文献1では、ガラス基板を加熱することで体積抵抗率を一定値以下にすることで吸着できることが記載されているが、体積抵抗率1×10Ω・cm~1×1014Ω・cmの範囲において吸着力が減少するのに膨大な時間がかかる。このため、すばやく安定して基板を回収できないという問題があった。また、温度を上げることで体積抵抗率を下げることができるが、ガラス基板にSiを貼り付ける接着剤の耐熱性が低いため、150℃以上の温度環境で処理することができない問題がある。膜質の問題から低温処理が必要である場合についても同様に速やかに安定して基板を回収できない問題がある。 As a method for attracting a high-resistance substrate such as a glass substrate, an electrostatic attracting apparatus (hereinafter also referred to as “electrostatic chuck”) is used. Conventionally, a method of adsorbing using a high voltage of 3 kV and 10 kV was taken, but a method of adsorbing at a low voltage of 1 kV is disclosed in Patent Document 1. In Patent Document 1, it is described that the adsorption can be performed by heating the glass substrate to make the volume resistivity below a certain value, but the volume resistivity is 1 × 10 6 Ω · cm to 1 × 10 14 Ω · cm. It takes an enormous amount of time for the adsorption force to decrease in the range of. Therefore, there is a problem that the substrate cannot be collected quickly and stably. Although the volume resistivity can be lowered by raising the temperature, there is a problem that it cannot be processed in a temperature environment of 150 ° C. or higher because the heat resistance of the adhesive for attaching Si to the glass substrate is low. Similarly, when the low temperature treatment is necessary due to the film quality problem, there is a problem that the substrate cannot be recovered quickly and stably.
 この問題を解決する静電チャックとして、特許文献2に開示されたものが知られている。特許文献2記載の静電チャックは、表面にエンボス加工により凸部と凹部が形成された誘電体板と、誘電体板に内に設けられた電極と、電極に電圧を印加する外部電源とを備えている。また、各凸部の頂面(基板支持面)は導体配線で覆われ、この導体配線によって各凸部の基板支持面が電気的に接続されていると共に、導体配線を接地状態又はフローティングにする切換器を備えている。更に、各凸部に対応して、凸部に近い電極部分は除去されたものとなっている。特許文献2記載の静電チャックにおいては、基板処理時には導体配線を切換器でフローティング状態に保持する。そして、基板の処理終了の際、切換器で導体配線を接地状態にすることにより、エンボス凸部、基板の裏面、誘電体板の表面で生じた電荷を逃がすようにし、吸着力を早急に消失させている。 As an electrostatic chuck for solving this problem, one disclosed in Patent Document 2 is known. The electrostatic chuck described in Patent Document 2 includes a dielectric plate having convex and concave portions formed on the surface by embossing, an electrode provided in the dielectric plate, and an external power source that applies a voltage to the electrode. I have. Further, the top surface (substrate support surface) of each convex portion is covered with conductor wiring, and the substrate support surface of each convex portion is electrically connected by this conductor wiring, and the conductor wiring is grounded or floated. A switch is provided. Furthermore, the electrode part close | similar to a convex part is removed corresponding to each convex part. In the electrostatic chuck described in Patent Document 2, the conductor wiring is held in a floating state by a switcher during substrate processing. At the end of the processing of the substrate, the conductor wiring is grounded with a switch, so that the electric charges generated on the embossed protrusions, the back surface of the substrate, and the surface of the dielectric plate are released, and the adsorption power disappears quickly. I am letting.
 また、基板をスムーズに離脱させる離脱方法としては、例えば、特許文献3に開示されているように逆電圧を印加する方法が知られている。また、絶縁性基板に対して逆電圧印加時間の調整が困難である点を改良した方法が特許文献4に開示されている。特許文献4の離脱方法は、静電吸着装置に設けられた電極に電圧を印加し、絶縁性基板を静電吸着し、真空雰囲気中で処理を行った後、絶縁性基板を搬出する際に、電極に静電吸着時とは逆極性の電圧を印加した状態で静電吸着装置上から離脱させている。 Further, as a method for detaching the substrate smoothly, for example, a method of applying a reverse voltage as disclosed in Patent Document 3 is known. Further, Patent Document 4 discloses a method for improving the point that it is difficult to adjust the reverse voltage application time with respect to the insulating substrate. In the separation method of Patent Document 4, a voltage is applied to an electrode provided in an electrostatic adsorption device, the insulating substrate is electrostatically adsorbed, processed in a vacuum atmosphere, and then taken out of the insulating substrate. The electrode is separated from the electrostatic chuck while a voltage having a polarity opposite to that at the time of electrostatic chucking is applied to the electrode.
特開2005-32858号公報Japanese Patent Laid-Open No. 2005-32858 特開2004-22889号公報JP 2004-22889 A 特開平4-230051号公報JP-A-4-230051 特開2001-156161号公報JP 2001-156161 A
 しかしながら、特許文献2において、各凸部の基板支持面と、基板支持面に接触する基板の裏面との間に作用するジョンソンラーベック力は非常に大きな吸着力である。このため、このジョンソンラーベック力が働かない特許文献2の静電チャックでは、吸着力が不足しやすい問題がある。この問題は、凸部の基板支持面を覆う導体配線を除去し、ジョンソンラーベック力が働くようにすれば解決できる。しかし、凸部の基板支持面を覆う導体配線を除去した場合、切換器で導体配線を接地状態とすることによる迅速な電荷の移動ができなくなり、残留電荷により、基板が離脱可能となるまでの時間が遅延するという問題を生じる。また、特許文献2の静電チャックは、基板を取り外す時の除電のために、各凸部の基板支持面を覆い且つ電気的に接続する導体配線を設けると共にこれを切換器に接続するという、特別な配線構造を構成しなければならず、構造的に複雑になるという問題もある。 However, in Patent Document 2, the Johnson Rabeck force acting between the substrate support surface of each convex portion and the back surface of the substrate in contact with the substrate support surface is a very large adsorption force. For this reason, the electrostatic chuck of Patent Document 2 in which this Johnson Rabeck force does not work has a problem that the attracting force tends to be insufficient. This problem can be solved by removing the conductor wiring covering the substrate support surface of the convex portion so that the Johnson Rabeck force works. However, when the conductor wiring that covers the substrate support surface of the convex portion is removed, it becomes impossible to move the charge quickly by setting the conductor wiring to the ground state with the switch, and until the substrate can be detached due to the residual charge. The problem is that time is delayed. Further, the electrostatic chuck of Patent Document 2 is provided with a conductor wiring that covers and electrically connects the substrate support surface of each convex portion and removes the substrate when removing the substrate, and connects this to the switch. There is also a problem that a special wiring structure has to be constructed, and the structure becomes complicated.
 また、特許文献4の離脱方法では、基板の材料として、静電チャックを構成する材料と異なる絶縁材料を用いた場合、静電チャックの誘電率と、基板の誘電率との相違により、基板裏面の電荷が逃げ場を失う。その結果、残留吸着力が基板に残るため、静電チャックからの基板の離脱は不安定なものになるという問題もある。 Further, in the separation method of Patent Document 4, when an insulating material different from the material constituting the electrostatic chuck is used as the substrate material, the back surface of the substrate is caused by the difference between the dielectric constant of the electrostatic chuck and the dielectric constant of the substrate. The electric charge loses the escape. As a result, since the residual attracting force remains on the substrate, there is a problem that the separation of the substrate from the electrostatic chuck becomes unstable.
 また、特許文献1の吸着方法は、ガラス基板の温度を上げることによって、低電圧でガラス基板を静電吸着することが可能である。またガラス基板の離脱時にも、ガラス基板の温度を上げれば、ガラス基板の体積抵抗が小さくなるため室温の時よりも離脱しやすくできる。デバイス作成上の都合で温度に制約がある場合など体積抵抗の大きさが1e+6Ω・cm~1e+11Ω・cmの間で離脱するのに大きな時間がかかる。このため基板離脱時に吸着電圧印加電極に吸着時の逆の電圧を印加する特許文献4記載の離脱方法を採らざるをえず、安定して基板を離脱できないという問題があった。 Also, the adsorption method of Patent Document 1 can electrostatically adsorb a glass substrate at a low voltage by raising the temperature of the glass substrate. Further, even when the glass substrate is detached, if the temperature of the glass substrate is increased, the volume resistance of the glass substrate is reduced, so that the glass substrate can be detached more easily than at room temperature. It takes a long time for the volume resistance to depart between 1e + 6 Ω · cm and 1e + 11 Ω · cm, for example, when the temperature is restricted due to device fabrication. For this reason, there is a problem in that the substrate cannot be stably detached because the separation method described in Patent Document 4 in which a reverse voltage at the time of adsorption is applied to the adsorption voltage application electrode when the substrate is detached.
 本発明は、上記従来の問題点に鑑みてなされたもので、簡単な構造にて、基板が絶縁材料等のガラス基板の場合でも十分な静電吸着力と、静電チャックから基板を迅速に取り外すことが可能な静電チャックを備えた静電吸着装置を提供することを目的とする。 The present invention has been made in view of the above-mentioned conventional problems. With a simple structure, even when the substrate is a glass substrate such as an insulating material, the substrate can be quickly removed from the electrostatic chuck with sufficient electrostatic adsorption force. An object of the present invention is to provide an electrostatic chucking device including an electrostatic chuck that can be removed.
 上記目的を達成するために、本発明の一つの側面に係る静電吸着装置は、頂面で基板を支持することが可能な複数の凸部と、該凸部の周囲の凹部とが表面に形成された誘電体板と、該誘電体板の内部に設けられた電極と、前記電極に基板吸着電圧を印加する第1の外部電源とを備えた静電吸着装置であって、
 前記凸部は、少なくとも前記凸部の頂面に導体被膜を備え、
 前記第1の外部電源は、前記電極に印加される前記基板吸着電圧に対して逆の極性を有する逆電圧を、前記基板の脱着時に前記電極に印加可能な基板脱着電圧電源を備えており、
 前記導体被膜は、前記基板の脱着時に、前記電極に印加される前記基板吸着電圧に対して逆の極性を有する逆電圧を前記導体被膜に印加可能な基板脱着電圧電源を備えた第2の外部電源に接続されていることを特徴とする。
In order to achieve the above object, an electrostatic attraction apparatus according to one aspect of the present invention has a plurality of convex portions capable of supporting a substrate on the top surface and concave portions around the convex portions on the surface. An electrostatic attraction apparatus comprising: a formed dielectric plate; an electrode provided inside the dielectric plate; and a first external power source that applies a substrate attraction voltage to the electrode,
The convex portion is provided with a conductor coating on at least the top surface of the convex portion,
The first external power source includes a substrate desorption voltage power source capable of applying a reverse voltage having a polarity opposite to the substrate adsorption voltage applied to the electrode to the electrode when the substrate is desorbed.
The conductor coating is provided with a second external power supply provided with a substrate desorption voltage power source capable of applying a reverse voltage having a polarity opposite to the substrate adsorption voltage applied to the electrode when the substrate is detached. It is connected to a power source.
 上記の静電吸着装置において、前記頂面で基板を支持する複数の凸部は、高さが35μm以下で、頂面のRa(中心線平均粗さ)は0.2μm以下であり、前記頂面の面積の合計値が前記誘電体板の全平面面積に対して10%以下の割合となるように形成されていることを特徴とする。 In the above electrostatic adsorption device, the plurality of convex portions supporting the substrate on the top surface have a height of 35 μm or less, and the top surface has an Ra (centerline average roughness) of 0.2 μm or less. The total surface area is formed so as to have a ratio of 10% or less with respect to the total planar area of the dielectric plate.
 上記の静電吸着装置において、前記基板は、体積抵抗率が1014Ω・cm以下であり、前記凸部との接触面のRa(中心線平均粗さ)が0.05μm以下である絶縁性基板であることを特徴とする。 In the above electrostatic chuck, the substrate has a volume resistivity of 10 14 Ω · cm or less, and an insulating property whose Ra (center line average roughness) of the contact surface with the convex portion is 0.05 μm or less. It is a substrate.
 本発明の静電吸着装置によれば、基板の吸着時には、凸部と基板との間に発生するジョンソンラーベック力と、凹部と基板との間に発生するクーロン力により、基板を吸着することが可能である。基板の脱着時(離脱時)には、電極に接続された第1の外部電源と、導電被膜に接続された第2の外部電源とに、基板吸着時に電極に印加される逆電圧を印加することにより、基板裏面と導体被膜とが同電位となる。この結果、基板の残留吸着力が無くなり、静電チャックから基板を短時間でスムーズに取り外すことが可能になる。 According to the electrostatic attraction apparatus of the present invention, when adsorbing a substrate, the substrate is adsorbed by a Johnson Rahbek force generated between the convex portion and the substrate and a Coulomb force generated between the concave portion and the substrate. Is possible. When the substrate is detached (detached), a reverse voltage applied to the electrode during substrate adsorption is applied to the first external power source connected to the electrode and the second external power source connected to the conductive film. As a result, the back surface of the substrate and the conductor coating have the same potential. As a result, the residual attracting force of the substrate disappears, and the substrate can be smoothly removed from the electrostatic chuck in a short time.
本発明のその他の特徴及び利点は、添付図面を参照とした以下の説明により明らかになるであろう。なお、添付図面においては、同じ若しくは同様の構成には、同じ参照番号を付す。 Other features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings. In the accompanying drawings, the same or similar components are denoted by the same reference numerals.
 添付図面は明細書に含まれ、その一部を構成し、本発明の実施の形態を示し、その記述と共に本発明の原理を説明するために用いられる。 The accompanying drawings are included in the specification, constitute a part thereof, show an embodiment of the invention, and are used to explain the principle of the invention together with the description.
本発明の一例に係る静電吸着装置を備えたスパッタリング装置の断面模式図。The cross-sectional schematic diagram of the sputtering device provided with the electrostatic attraction apparatus which concerns on an example of this invention. 本発明の一例に係る静電吸着装置の部分拡大断面模式図。The partial expanded sectional schematic diagram of the electrostatic attraction apparatus which concerns on an example of this invention. 図1及び図2に記載の静電チャックの平面図。The top view of the electrostatic chuck of FIG.1 and FIG.2. 基板の吸着時において、図2に示される静電チャックの導体被膜の表面と基板の裏面の電荷の状態を示す図。The figure which shows the state of the electric charge of the surface of the conductor film of the electrostatic chuck shown in FIG. 2, and the back surface of a board | substrate at the time of adsorption | suction of a board | substrate. 基板の離脱時において、図2に示される静電チャックの導体被膜の表面と基板の裏面の電荷の状態を示す図。The figure which shows the state of the electric charge of the surface of the conductor film of the electrostatic chuck shown in FIG. 2, and the back surface of a board | substrate at the time of detachment | leave of a board | substrate. 基板の吸着時において、図2に示される静電チャックの電荷の状態を示す図。The figure which shows the state of the electric charge of the electrostatic chuck shown by FIG. 2 at the time of adsorption | suction of a board | substrate. 基板の離脱時において、図2に示される静電チャックの電荷の状態を示す図。The figure which shows the state of the electric charge of the electrostatic chuck shown in FIG. 2 at the time of detachment | leave of a board | substrate. 従来の静電吸着装置を用いて、ガラス基板を吸着した場合の等価回路を示す図。The figure which shows the equivalent circuit at the time of adsorb | sucking a glass substrate using the conventional electrostatic adsorption apparatus. 本発明の静電吸着装置を用いて、ガラス基板を吸着した場合の等価回路を示す図。The figure which shows the equivalent circuit at the time of adsorb | sucking a glass substrate using the electrostatic adsorption apparatus of this invention. ガラス基板の離脱時に、電極電源をOFFした後の凸部と凹部の吸着電圧と時間との関係を示す図。The figure which shows the relationship between the adsorption | suction voltage of a convex part and a recessed part after turning off an electrode power supply, and time at the time of detachment | leave of a glass substrate. ガラス基板の離脱時に、電極の電源をOFFした後の凸部と凹部に働く静電吸着力と時間との関係を示す図。The figure which shows the relationship between the electrostatic attraction force which acts on the convex part and recessed part after turning off the power supply of an electrode at the time of detachment | leave of a glass substrate, and time. コンデンサーCと抵抗Rの直列回路を示す図。The figure which shows the series circuit of the capacitor | condenser C and the resistance R. FIG. 図8Aの回路に当初直流電源Bにより電圧Vbを印加し、その後、グランド(GND)にした場合の電圧の状態を示す図。The figure which shows the state of the voltage at the time of applying the voltage Vb with the direct-current power supply B to the circuit of FIG. 8A initially, and making it a ground (GND) after that. 図8Aに記載の回路に当初直流電源Bにより電圧Vbを印加した後、直流電源Aにより電圧Vbの逆電圧Vaを印加した場合の、電圧の状態を示す図。The figure which shows the state of a voltage at the time of applying the reverse voltage Va of the voltage Vb by DC power supply A after applying the voltage Vb by DC power supply B initially to the circuit of FIG. 8A.
 以下、本発明の実施形態について説明する。構成要素は例示である。本発明の静電吸着装置をスパッタリング装置に適用した場合を例にして説明する。図1は本発明の一例に係る静電吸着装置を備えたスパッタリング装置の断面模式図、図2は本発明の一例に係る静電吸着装置の部分拡大断面模式図である。 Hereinafter, embodiments of the present invention will be described. The components are exemplary. The case where the electrostatic attraction apparatus of the present invention is applied to a sputtering apparatus will be described as an example. FIG. 1 is a schematic cross-sectional view of a sputtering apparatus provided with an electrostatic attraction apparatus according to an example of the present invention, and FIG. 2 is a partially enlarged schematic cross-sectional view of the electrostatic attraction apparatus according to an example of the present invention.
 まず、図1に基づいてスパッタリング装置の概要を説明する。図1に示されるスパッタリング装置は、外部の排気機構(図示せず)により内部を減圧可能な容器1と、容器1の天井部にリング状絶縁部材2を介して設けられたターゲット3を備えている。ターゲット3の裏面側には、ヨーク板4上に磁石5が設けられている。また、ターゲット3には、電圧を印加するスパッタ電源6が接続されている。 First, the outline of the sputtering apparatus will be described with reference to FIG. The sputtering apparatus shown in FIG. 1 includes a container 1 whose inside can be decompressed by an external exhaust mechanism (not shown), and a target 3 provided on the ceiling of the container 1 via a ring-shaped insulating member 2. Yes. A magnet 5 is provided on the yoke plate 4 on the back side of the target 3. The target 3 is connected to a sputtering power source 6 for applying a voltage.
 ターゲット3に対向する位置には、容器1の底部に固定され基板温度調整部7上に静電チャック8が設けられており、静電チャック8上に基板9が載置されている。また、ターゲット3と静電チャック8間の容器1の周壁の内面に沿って、筒状シールド部材10が配置されている。 At the position facing the target 3, an electrostatic chuck 8 is provided on the substrate temperature adjusting unit 7 fixed to the bottom of the container 1, and the substrate 9 is placed on the electrostatic chuck 8. A cylindrical shield member 10 is disposed along the inner surface of the peripheral wall of the container 1 between the target 3 and the electrostatic chuck 8.
 基板温度調整部7は、静電チャック8を介して基板9の温度を制御する部材で、温度制御電源機構11に接続された熱電対12と加熱・冷却部13を備えている。基板温度調整部7は、熱電対12によって検出された温度に基づいて温度制御電源機構11が加熱・冷却部13を作動させて静電チャック8の加熱又は冷却を行うものとなっている。 The substrate temperature adjusting unit 7 is a member that controls the temperature of the substrate 9 via the electrostatic chuck 8, and includes a thermocouple 12 and a heating / cooling unit 13 connected to the temperature control power supply mechanism 11. In the substrate temperature adjusting unit 7, the temperature control power supply mechanism 11 operates the heating / cooling unit 13 based on the temperature detected by the thermocouple 12 to heat or cool the electrostatic chuck 8.
 基板温度調整部7上に設けられた静電チャック8は、表面(上面)がエンボス加工された誘電体板14と、誘電体板14の内部に設けられた電極15と、電極15に一定の電圧を印加する外部電源16bとを備えている。 The electrostatic chuck 8 provided on the substrate temperature adjusting unit 7 includes a dielectric plate 14 whose surface (upper surface) is embossed, an electrode 15 provided inside the dielectric plate 14, and a constant electrode 15. And an external power supply 16b for applying a voltage.
 誘電体板14の表面には、エンボス加工により、複数の凸部17aと、その周囲の凹部17bとが形成されている。また、誘電体板14の表面側周縁部には、凸部17aと凹部17bの形成領域を囲んで外周突条部18が形成されている。凸部17aと外周突条部18は、頂面に基板9が載置されるもので、ほぼ同じ高さとなっている。 On the surface of the dielectric plate 14, a plurality of convex portions 17a and peripheral concave portions 17b are formed by embossing. In addition, an outer peripheral ridge 18 is formed on the peripheral edge of the front surface side of the dielectric plate 14 so as to surround the formation region of the convex portion 17a and the concave portion 17b. The convex part 17a and the outer peripheral ridge part 18 are those on which the substrate 9 is placed on the top surface, and have substantially the same height.
 図1に記載の凹部17b部分を除いて、各凸部17a部分には、少なくとも頂面を覆って、それぞれ導体被膜19が形成されている。各導体被膜19は、次に述べる電極15に電圧を印加することで、基板9と導体被膜19との間にジョンソンラーベック力を生じさせる凹凸を有するものとなっている。導体被膜19の凹凸は、ジョンソンラーベック力生成部として機能する。また、各導体被膜19は、各凸部17aの頂面だけでなく、各凸部17aの側面部まで覆うものであってもよいが、凹部17b部分には導体被膜19が設けられておらず、それぞれの凹部17b部分は、各凸部17aに形成された導体被膜19から電気的に独立したものとなっている。 1 except for the concave portion 17b shown in FIG. 1, a conductor coating 19 is formed on each convex portion 17a so as to cover at least the top surface. Each conductor coating 19 has irregularities that cause a Johnson Rabeck force between the substrate 9 and the conductor coating 19 by applying a voltage to the electrode 15 described below. The unevenness of the conductor coating 19 functions as a Johnson Rabeck force generator. In addition, each conductor coating 19 may cover not only the top surface of each projection 17a but also the side surface of each projection 17a, but the conductor coating 19 is not provided in the recess 17b portion. Each concave portion 17b is electrically independent from the conductor coating 19 formed on each convex portion 17a.
 図示される例においては、外周突条部18の頂面および側面にも導体被膜19が形成されている。この外周突条部18の頂面に形成された導体被膜19は、外周突条部18の全体高さと凸部17aの全体高さを揃えやすくする上で設けることが好ましいが、省略することもできる。 In the illustrated example, a conductor coating 19 is also formed on the top and side surfaces of the outer peripheral ridge 18. The conductor coating 19 formed on the top surface of the outer peripheral ridge portion 18 is preferably provided to facilitate the alignment of the entire height of the outer peripheral ridge portion 18 and the entire height of the convex portion 17a, but may be omitted. it can.
 電極15は、単極電極で、直流電源である外部電源16bにスイッチ20bを介して接続されており、スイッチ20bをONすることにより、一定のマイナス電圧が印加されるものとなっている。図示される電極15は単極電極となっているが、誘電体板14の内周側と外周側に分割して双極電極とし、いずれか一方にマイナス電圧、他方にプラス電圧を印加するようにすることもできる。また、電極15は、外周突条部18よりも小径となっており、凸部17aと凹部17bを設けた領域の下方にのみ位置し、外周突条部18の直下付近には位置していないものとなっている。外周突条部18の下方に電極15が位置していないことにより、外周突条部18は基板9の吸着に寄与しないものとなっている。 The electrode 15 is a unipolar electrode and is connected to an external power source 16b which is a DC power source via a switch 20b, and a constant negative voltage is applied by turning on the switch 20b. Although the illustrated electrode 15 is a monopolar electrode, it is divided into an inner peripheral side and an outer peripheral side of the dielectric plate 14 to form a bipolar electrode, and a negative voltage is applied to one of them and a positive voltage is applied to the other. You can also Further, the electrode 15 has a smaller diameter than the outer peripheral ridge portion 18, and is positioned only below the region where the convex portions 17 a and the concave portions 17 b are provided, and is not positioned immediately below the outer peripheral ridge portion 18. It has become a thing. Since the electrode 15 is not located below the outer peripheral protrusion 18, the outer peripheral protrusion 18 does not contribute to the adsorption of the substrate 9.
 前記のように、基板9は凸部17aと外周突条部18の頂面上に載置されるもので、基板9と誘電体板14間には、外周突条部18で囲まれた領域に、凹部17bによって隙間が形成される。この隙間には、ガス供給経路21を介してガス供給源22が接続されており、隙間にガス(例えばアルゴンガス)を供給できるようになっている。隙間にガスを供給することで、基板温度調整部7の熱を、静電チャック8及びこの隙間中のガスの熱伝導により基板9に伝え、基板9を所定温度に維持することができるようになっている。 As described above, the substrate 9 is placed on the top surfaces of the convex portion 17a and the outer peripheral ridge portion 18, and the region surrounded by the outer peripheral ridge portion 18 is between the substrate 9 and the dielectric plate 14. In addition, a gap is formed by the recess 17b. A gas supply source 22 is connected to the gap via a gas supply path 21 so that gas (for example, argon gas) can be supplied to the gap. By supplying the gas to the gap, the heat of the substrate temperature adjusting unit 7 is transmitted to the substrate 9 by the heat conduction of the electrostatic chuck 8 and the gas in the gap so that the substrate 9 can be maintained at a predetermined temperature. It has become.
 次に、図2に基づいて静電吸着装置について更に説明する。図2は、本発明の一例に係る静電吸着装置の部分拡大断面模式図である。各凸部17a部分の少なくとも頂面を覆っている導体被膜19には、外部電源16aがスイッチ20aを介して接続されている。また、既述のとおり、電極15には、スイッチ20bを介して外部電源20bが接続されている。 Next, the electrostatic adsorption device will be further described with reference to FIG. FIG. 2 is a partial enlarged cross-sectional schematic view of an electrostatic attraction apparatus according to an example of the present invention. An external power source 16a is connected to the conductor film 19 covering at least the top surface of each convex portion 17a via a switch 20a. As described above, the electrode 15 is connected to the external power supply 20b through the switch 20b.
 外部電源16a、16bは、それぞれ直流電源16a1、16b1と、直流電源16a1、16b1が発生する電圧に対して逆の極性を有する逆電圧を発生する直流電源16a2、16b2と、アース端子16a3、16b3とから構成される。外部電源16a、16bが出力する電圧はスイッチ20a、20bにより、切り替え可能になっている。なお、図1では、アース端子16a3、16b3は図示していない。例えば、直流電源16a1、16b1が、基板吸着電圧電源として機能した場合には、直流電源16a2、16b2は、基板脱着電圧電源として機能する。 The external power supplies 16a and 16b are respectively a DC power supply 16a1 and 16b1, a DC power supply 16a2 and 16b2 that generate a reverse voltage having a polarity opposite to that generated by the DC power supplies 16a1 and 16b1, and a ground terminal 16a3 and 16b3. Consists of The voltages output from the external power supplies 16a and 16b can be switched by the switches 20a and 20b. In FIG. 1, the ground terminals 16a3 and 16b3 are not shown. For example, when the DC power supplies 16a1 and 16b1 function as substrate adsorption voltage power supplies, the DC power supplies 16a2 and 16b2 function as substrate desorption voltage power supplies.
 図3は、図1及び図2に記載の静電チャック8の平面図である。図3に示すように、凸部17aと凹部17bは、静電吸着ステージ8の中心軸から放射状に連続的に形成された放射状部271と、静電吸着ステージ8の中心軸から円周状に延びる円周状部272と、から構成される。尚、円周状部272は、放射状部271の一部に形成されている。凸部17aと外周突条部18は、頂面に基板9が載置されるもので、ほぼ同じ高さとなっている。放射状部271と円周状部272に形成された凸部17aと凹部17bは、導体被膜19で覆われている。放射状部271と円周状部272以外に形成された凹部17bは、導体被膜19で覆われていない。静電チャック8の吸着面の平面形状は、図2に示すように全体としては円形である。そして、基板9も円形であり、両者の径はほぼ一致している。 FIG. 3 is a plan view of the electrostatic chuck 8 shown in FIGS. 1 and 2. As shown in FIG. 3, the convex portion 17 a and the concave portion 17 b are formed radially from the central axis of the electrostatic chucking stage 8 and continuously from the central axis of the electrostatic chucking stage 8. A circumferential portion 272 that extends. The circumferential portion 272 is formed on a part of the radial portion 271. The convex part 17a and the outer peripheral ridge part 18 are those on which the substrate 9 is placed on the top surface, and have substantially the same height. The convex portions 17 a and the concave portions 17 b formed in the radial portion 271 and the circumferential portion 272 are covered with the conductor film 19. The concave portions 17 b formed other than the radial portion 271 and the circumferential portion 272 are not covered with the conductor film 19. The planar shape of the attracting surface of the electrostatic chuck 8 is circular as a whole as shown in FIG. The substrate 9 is also circular, and the diameters of both are substantially the same.
 図4Aは、基板9の吸着時において、図2に示される静電チャックの導体被膜19の表面と基板9の裏面の電荷の状態を示す図である。図4Bは、基板の脱着時(離脱時)において、図2に示される静電チャックの導体被膜19の表面と基板9の裏面の電荷の状態を示す図である。図1~図4Bに基づいて静電チャック8について更に説明すると、凸部17aは、通常円柱形であり、直径2.0mm以下であることが好ましい。下限は、必要な凸部17aの機械的強度や加工上の制限などから定まるが、一般的には0.3mm程度である。凸部17aの直径が大きくなると、基板9の離脱時の迅速な除電が行いにくくなる。詳細な原因は不明であるが、凸部17aの頂面に形成された導体被膜19と基板9との接触点が多いことが迅速な除電をもたらしていると考えられる。凸部17aの直径が小さいと、ジョンソンラーベック力生成部として機能する導体被膜19の凹凸における最大表面粗さ(Ry)が確率的に小さくなり、導体被膜19の表面の平滑性が高まって、基板9と導体被膜19の接触点が増えるものと考えられる。また、導体被膜19の平滑性が高くなることによって、基板9と導体被膜19との間の微視的な隙間の間隔、すなわち、ジョンソンラーベック力生成部として機能する凹凸における隙間の間隔も小さくなり、基板9と導体被膜19との間に作用するジョンソンラーベック力も大きくなる。 FIG. 4A is a diagram showing a state of charges on the surface of the conductor coating 19 and the back surface of the substrate 9 of the electrostatic chuck shown in FIG. FIG. 4B is a diagram showing the state of electric charges on the surface of the conductor coating 19 and the back surface of the substrate 9 of the electrostatic chuck shown in FIG. The electrostatic chuck 8 will be further described with reference to FIGS. 1 to 4B. The convex portion 17a is usually cylindrical and preferably has a diameter of 2.0 mm or less. The lower limit is determined by the required mechanical strength of the convex portion 17a and processing limitations, but is generally about 0.3 mm. When the diameter of the convex portion 17a is increased, it is difficult to perform rapid charge removal when the substrate 9 is detached. Although the detailed cause is unknown, it is thought that the rapid neutralization is caused by the large number of contact points between the conductor film 19 formed on the top surface of the convex portion 17a and the substrate 9. When the diameter of the convex portion 17a is small, the maximum surface roughness (Ry) in the unevenness of the conductor coating 19 functioning as the Johnson Rabeck force generating portion is stochastically reduced, and the surface smoothness of the conductor coating 19 is increased. It is considered that the contact point between the substrate 9 and the conductor coating 19 increases. Further, since the smoothness of the conductor coating 19 is increased, the interval between the microscopic gaps between the substrate 9 and the conductor coating 19, that is, the gap between the irregularities functioning as the Johnson Rabeck force generator is also reduced. Accordingly, the Johnson Rabeck force acting between the substrate 9 and the conductor coating 19 is also increased.
 凸部17a上の導体被膜19表面は、良好な吸着作用と離脱作用を得るために、平滑な表面を有していることが好ましく、Ry(最大表面粗さ)が2.5μm以下、Ra(中心線平均粗さ)が0.2μm以下であることが好ましい。現実的には完全な平滑面は形成できないので特に下限の制限はないが、現実的な平滑化の限界からすると、Ryが0.2μm以上、Raが0.02μm以上である。また、基板9の体積抵抗率は1014Ω・cm以下であることが好ましい。また、凸部17aとの接触面の基板9のRa(中心線平均粗さ)は0.05μm以下であることが好ましい。 The surface of the conductor film 19 on the convex portion 17a preferably has a smooth surface in order to obtain a good adsorption action and separation action, and Ry (maximum surface roughness) is 2.5 μm or less, and Ra ( The centerline average roughness is preferably 0.2 μm or less. In reality, a completely smooth surface cannot be formed, so there is no particular lower limit. However, from the practical smoothing limit, Ry is 0.2 μm or more and Ra is 0.02 μm or more. Further, the volume resistivity of the substrate 9 is preferably 10 14 Ω · cm or less. Moreover, it is preferable that Ra (centerline average roughness) of the board | substrate 9 of a contact surface with the convex part 17a is 0.05 micrometer or less.
 凸部17a及び外周突条部18の高さは、吸着された基板9が凹部と接触しない範囲で、高さが35μm以下であることが好ましい。凸部17a及び外周突条部18の高さを低くすることにより、基板9と凹部17bとの間に作用するクーロン力を大きくすることができる。高さの下限は、一般的には6.5μm程度である。 As for the height of the convex part 17a and the outer periphery protrusion part 18, it is preferable that height is 35 micrometers or less in the range in which the adsorbed board | substrate 9 does not contact a recessed part. By reducing the height of the convex portion 17a and the outer peripheral ridge portion 18, the Coulomb force acting between the substrate 9 and the concave portion 17b can be increased. The lower limit of the height is generally about 6.5 μm.
 凸部17aは、適度な吸着力と迅速な除電性が得られるようにする上で、凸部17aの頂面の面積の合計値が静電チャック8の全平面面積の1%以上、10%以下の割合となるように形成されていることが好ましい。 The convex portion 17a has a total area of the top surface of the convex portion 17a of 1% or more and 10% of the total planar area of the electrostatic chuck 8 in order to obtain an appropriate suction force and quick charge removal. It is preferable to be formed so as to have the following ratio.
 導体被膜19は、比抵抗が10-4μΩ・cm以下の電気的導体である金属、金属酸化物、金属窒化物などで構成されているもので、比抵抗が400μΩ・cm以下であることが好ましい。特に比抵抗が350μΩ・cm以下であることが好ましい。本実施形態にかかる静電チャック8は、バルク(プレート)として構成している。このため、先に説明した特許文献4の離間マスクのように、異種の絶縁材料を用いる必要はない。静電チャック8の素材は、10~1010Ω・cmのジョンソンラーベック力を発揮できる体積抵抗率を有する。導体被膜19は、静電チャック8の誘電体表面と同じ電荷を蓄積し、静電チャック8から基板9を取り外す基板離脱時には、基板9の裏面と導体被膜19を同電位することにより基板の残留吸着力を無くす。基板9の残留吸着力を無くすことにより、静電チャック8から基板をスムーズに取り外すこと、すなわち、基板離脱の安定性の向上を図ることが可能になる。 The conductor coating 19 is made of a metal, metal oxide, metal nitride or the like, which is an electrical conductor having a specific resistance of 10 −4 μΩ · cm or less, and has a specific resistance of 400 μΩ · cm or less. preferable. In particular, the specific resistance is preferably 350 μΩ · cm or less. The electrostatic chuck 8 according to the present embodiment is configured as a bulk (plate). For this reason, it is not necessary to use different types of insulating materials as in the case of the separation mask of Patent Document 4 described above. The material of the electrostatic chuck 8 has a volume resistivity capable of exhibiting a Johnson Rahbek force of 10 8 to 10 10 Ω · cm. The conductor film 19 accumulates the same charge as the dielectric surface of the electrostatic chuck 8, and when the substrate 9 is detached from the electrostatic chuck 8, the back surface of the substrate 9 and the conductor film 19 are made to have the same potential so that the substrate remains. Eliminates adsorption power. By eliminating the residual attracting force of the substrate 9, it is possible to smoothly remove the substrate from the electrostatic chuck 8, that is, to improve the stability of substrate separation.
 特に、導体被膜19の比抵抗を、例えば、350μΩ・cm以下とすることにより、基板の裏面と静電チャックの表面の導体被膜19とが、同じ電位になるように作用しやすくなる。その結果、除電された基板の残留吸着力を無くし、静電チャックから基板をスムーズに取り外すこと(基板の離脱)が可能になる。 In particular, by setting the specific resistance of the conductor coating 19 to 350 μΩ · cm or less, for example, the conductor coating 19 on the back surface of the substrate and the surface of the electrostatic chuck can easily act so as to have the same potential. As a result, it is possible to eliminate the residual attracting force of the discharged substrate and to smoothly remove the substrate from the electrostatic chuck (detachment of the substrate).
 逆に、比抵抗が高いと、基板裏面の電荷が逃げ場を失い、その結果、残留吸着力が基板に残るため、静電チャックからの基板の離脱は不安定なものになる。 Conversely, if the specific resistance is high, the charge on the back surface of the substrate loses its escape field, and as a result, the residual adsorption force remains on the substrate, so that the separation of the substrate from the electrostatic chuck becomes unstable.
 導体被膜19の構成としては、例えば、チタン、タングステなどの金属、これらの酸化物又は窒化物を挙げることができる。チタン、タングステンなどの材料は、金属の中でも熱ひずみに強く、また、耐摩耗性に優れた変形しにくい材料であるため、基板と静電チャックの導体被膜19の接触、線膨張の違いによる擦れ等の要因から生じるパーティクルを抑制し、耐摩耗性を向上させることができる。 Examples of the structure of the conductor coating 19 include metals such as titanium and tungsten, and oxides or nitrides thereof. Titanium, tungsten, and other materials are resistant to thermal distortion among metals, and are excellent in wear resistance and are not easily deformed. Therefore, they are rubbed due to contact between the substrate and the conductive coating 19 of the electrostatic chuck, and differences in linear expansion. Particles resulting from factors such as these can be suppressed, and wear resistance can be improved.
 導体被膜19は、スパッタリングやイオンプレーティングなどの成膜法により形成することができる。導体被膜19の厚さは、導体被膜19の膜厚方向の抵抗を10Ω程度に抑えるために、1.5μm以下であることが好ましい。導体被膜19の厚さが1.5μmを超えると、導体被膜19の抵抗が増大すると共に膜応力による膜剥がれを生じやすくなる。現実的な下限は、0.5μm程度である。 The conductor film 19 can be formed by a film forming method such as sputtering or ion plating. The thickness of the conductor coating 19 is preferably 1.5 μm or less in order to suppress the resistance in the film thickness direction of the conductor coating 19 to about 10Ω. When the thickness of the conductor film 19 exceeds 1.5 μm, the resistance of the conductor film 19 increases and film peeling due to film stress tends to occur. A practical lower limit is about 0.5 μm.
 なお、図1において、基板搬送ロボット、搬入・搬出ゲート、静電チャック8上への基板9の載置と取り外しを行うリフトピン、放電発生に関連する機構、放電用ガスの導入機構などの図示は省略されている。 In FIG. 1, a substrate transfer robot, a loading / unloading gate, a lift pin for placing and removing the substrate 9 on the electrostatic chuck 8, a mechanism related to discharge generation, a discharge gas introduction mechanism, and the like are illustrated. It is omitted.
 図1のスパッタリング装置において、基板9は、基板搬送ロボットにより、搬入・搬出ゲートから容器1内の静電チャック8上に搬入されて載置される。容器1内を所定の真空雰囲気にし、スイッチ20bをONにして電極15に電圧を印加すると、誘電体板14、導体被膜19の表面と、基板9の裏面とには異なる電荷が蓄積される。スイッチ20bをONにした時の導体被膜19の表面と、基板9の裏面との電荷の状態を図4A及び図5Aに示す。これにより、誘電体板14表面の凹部17bと基板9の裏面との間に空間クーロン力が作用すると共に、凸部17a頂面の導体被膜19と基板9裏面との間には、微細な隙間を挟んでジョンソンラーベック力が作用する。基板9は、この空間クーロン力とジョンソンラーベック力によって、しっかり静電チャック8に吸着されることになる。 In the sputtering apparatus of FIG. 1, the substrate 9 is loaded and placed on the electrostatic chuck 8 in the container 1 from the loading / unloading gate by the substrate transfer robot. When the inside of the container 1 is put into a predetermined vacuum atmosphere, the switch 20 b is turned on and a voltage is applied to the electrode 15, different charges are accumulated on the surface of the dielectric plate 14 and the conductor coating 19 and the back surface of the substrate 9. FIGS. 4A and 5A show the state of charge on the surface of the conductor film 19 and the back surface of the substrate 9 when the switch 20b is turned on. Thereby, a spatial Coulomb force acts between the concave portion 17b on the surface of the dielectric plate 14 and the back surface of the substrate 9, and a fine gap is formed between the conductor coating 19 on the top surface of the convex portion 17a and the back surface of the substrate 9. The Johnson Rabeck force acts on both sides. The substrate 9 is firmly attracted to the electrostatic chuck 8 by the space Coulomb force and the Johnson Rabeck force.
 基板9を静電チャック8に吸着した後、静電チャック8と基板9間との隙間にガス供給源22から必要量のガスを供給する。これと共に、温度制御電源機構11により加熱・冷却部13を作動させ、基板9の温度を一定に保ちつつ、容器1内に放電用ガスを供給し、スパッタ電源6をONにしてスパッタリングを行う。 After adsorbing the substrate 9 to the electrostatic chuck 8, a necessary amount of gas is supplied from the gas supply source 22 to the gap between the electrostatic chuck 8 and the substrate 9. At the same time, the heating / cooling unit 13 is operated by the temperature control power supply mechanism 11 to supply the discharge gas into the vessel 1 while keeping the temperature of the substrate 9 constant, and the sputtering power supply 6 is turned on to perform sputtering.
 スパッタリングの完了後、スパッタ電源6をOFFにし、更にスイッチ20bをOFFにして電極15への電圧印加を停止する。すると、複数の凸部17a頂面の導体被膜19と基板9の裏面との接触点を介して、基板9の裏面と導体被膜19が同じ電位になろうとし、これによって除電される。また、複数の凸部17a頂面の導体被膜19も基板9と同じ電位になろうとする。また、この電荷の状態を図4B及び図5Bに示す。しかし、スパッタ電源6をOFFにし、更にスイッチ20bをOFFしただけでは、基板9を静電チャック8から離脱することはできない。 After the sputtering is completed, the sputtering power source 6 is turned off, and the switch 20b is turned off to stop the voltage application to the electrode 15. Then, the back surface of the substrate 9 and the conductor film 19 try to be at the same potential via the contact points between the conductor film 19 on the top surface of the plurality of convex portions 17a and the back surface of the substrate 9, and the charge is thereby eliminated. In addition, the conductor coating 19 on the top surface of the plurality of convex portions 17 a also tends to have the same potential as the substrate 9. The state of this charge is shown in FIGS. 4B and 5B. However, the substrate 9 cannot be detached from the electrostatic chuck 8 only by turning off the sputtering power source 6 and further turning off the switch 20b.
 この点を 図6A、図6Bに基づき説明する。図6Aは、従来の静電吸着装置を用いて、ガラス基板(基板9)を吸着した場合の等価回路を示す。図6Bは、本発明の静電吸着装置を用いて、ガラス基板を吸着した場合の等価回路を示す。図6A・図6Bの等価回路内の記号は以下に示すとおりである。 This point will be described with reference to FIGS. 6A and 6B. FIG. 6A shows an equivalent circuit when a glass substrate (substrate 9) is adsorbed using a conventional electrostatic attraction apparatus. FIG. 6B shows an equivalent circuit when a glass substrate is adsorbed using the electrostatic attraction apparatus of the present invention. Symbols in the equivalent circuits of FIGS. 6A and 6B are as shown below.
 C1、R1は電極15の下部のキャパシタ、抵抗である。C2、R2は電極15の上部のキャパシタ、抵抗である。C3、R3は凸部17aのキャパシタ、抵抗である。C4、R4はガラス基板(基板9)と接触する部分の導体被膜19のキャパシタ、抵抗である。C5は誘電体凹部17bとガラス基板(基板9)との間のキャパシタである。C6、R6は導体被膜19と接触する部分のガラス基板(基板9)のキャパシタ、抵抗である。C7、R7はガラス基板(基板9)と凹部17b部分と間のキャパシタ、抵抗である。16aは導体被膜19に接続されている第2の外部電源16bは電極15に接続されている第1の外部電源である。 C1 and R1 are a capacitor and a resistor under the electrode 15. C2 and R2 are capacitors and resistors above the electrode 15. C3 and R3 are capacitors and resistors of the convex portion 17a. C4 and R4 are a capacitor and a resistance of the conductor film 19 at a portion in contact with the glass substrate (substrate 9). C5 is a capacitor between the dielectric recess 17b and the glass substrate (substrate 9). C6 and R6 are a capacitor and a resistor of the glass substrate (substrate 9) in a portion in contact with the conductor coating 19. C7 and R7 are capacitors and resistors between the glass substrate (substrate 9) and the concave portion 17b. A second external power source 16 b connected to the conductor coating 19 is a first external power source connected to the electrode 15.
 なお、ガラス基板(基板9)はプラズマを介してグランドへ接続されているとする。また、上記のガラス基板(基板9)は、通常のガラス基板より体積抵抗率が大きいSiN膜(例えば、体積抵抗率が1014Ω・cm以下)などの絶縁性薄膜が成膜された絶縁性基板を想定している。 It is assumed that the glass substrate (substrate 9) is connected to the ground via plasma. The glass substrate (substrate 9) is an insulating material on which an insulating thin film such as a SiN film (for example, a volume resistivity of 10 14 Ω · cm or less) having a larger volume resistivity than that of a normal glass substrate is formed. Assume a substrate.
 既述の通り、ジョンソンラーベック力は、導体被膜19と基板9とのそれぞれの表面の微視的な凹凸により発生するものと考えられる。これを図6A、図6Bに示す等価回路で示すと、基板9と導体被膜19とは、導体被膜19と基板9との表面の双方の凹凸により形成された、Ra(中心線平均荒さ)程度の電極間距離のキャパシタC4により接続していると考えられる。即ち、図6A、図6Bに示すように、導体被膜19と基板9との部分は、並列回路C6、R6と、並列回路C4、R4と、並列回路C3、R3とが、直列接続された等価回路と考えられる。 As described above, the Johnson Rabeck force is considered to be generated by microscopic irregularities on the surfaces of the conductor coating 19 and the substrate 9. When this is shown by the equivalent circuit shown in FIGS. 6A and 6B, the substrate 9 and the conductor coating 19 are approximately Ra (center line average roughness) formed by unevenness on both surfaces of the conductor coating 19 and the substrate 9. It is considered that the electrodes are connected by a capacitor C4 having a distance between the electrodes. That is, as shown in FIGS. 6A and 6B, the conductor film 19 and the substrate 9 are equivalent to the parallel circuits C6 and R6, the parallel circuits C4 and R4, and the parallel circuits C3 and R3 connected in series. It is considered a circuit.
 一方、基板9と凹部17bとの間には、ギャップが形成されており、基板9は、基板9と凹部17bとの間に発生するクーロン力により静電チャック8に吸着されている。この状態において、基板9と凹部17bの部分は、並列回路C7、R7と、C5と、並列回路C2、R2とが直列接続された等価回路と考えらえる。また、並列回路C2、R2の一端と並列回路C3、R3他端とは、端子VBで接続されており、並列回路C2、R2の他端VAは、並列回路C1、R1を介してアースに接続された等価回路と考えらえる。 On the other hand, a gap is formed between the substrate 9 and the recess 17b, and the substrate 9 is attracted to the electrostatic chuck 8 by a Coulomb force generated between the substrate 9 and the recess 17b. In this state, the portion of the substrate 9 and the recess 17b can be considered as an equivalent circuit in which the parallel circuits C7, R7, C5 and the parallel circuits C2, R2 are connected in series. One end of the parallel circuits C2 and R2 and the other end of the parallel circuits C3 and R3 are connected by a terminal VB, and the other end VA of the parallel circuits C2 and R2 is connected to the ground via the parallel circuits C1 and R1. It can be considered as an equivalent circuit.
 図7Aは、ガラス基板(基板9)の離脱時に、電極15の電源をOFFした後、スイッチ20bをアース端子16b3に接続した際の、凸部17aと凹部17bの吸着電圧と時間との関係を示す。図7Aにおいて、点線は凸部電圧、実線は凹部電圧を示す。図7Bは、ガラス基板(基板9)の離脱時に、電極15の電源をOFFした後、スイッチ20bをアース端子16b3に接続した際の、凸部17aと凹部17bに働く静電吸着力と時間との関係を示す。図7Bにおいて、点線(破線)は凸部吸着力、実線は凹部吸着力、一点鎖線は凹部と凸部の合計のウエハ吸着力(基板吸着力)を示す。 FIG. 7A shows the relationship between the attracting voltage of the convex portion 17a and the concave portion 17b and time when the switch 20b is connected to the ground terminal 16b3 after the power of the electrode 15 is turned off when the glass substrate (substrate 9) is detached. Show. In FIG. 7A, the dotted line indicates the convex voltage, and the solid line indicates the concave voltage. FIG. 7B shows the electrostatic attraction force and time acting on the convex portions 17a and the concave portions 17b when the switch 20b is connected to the ground terminal 16b3 after the power of the electrode 15 is turned off when the glass substrate (substrate 9) is detached. The relationship is shown. In FIG. 7B, the dotted line (broken line) indicates the convex portion adsorption force, the solid line indicates the concave portion adsorption force, and the alternate long and short dash line indicates the total wafer adsorption force (substrate adsorption force) of the concave portion and the convex portion.
 なお、図7A、Bの計算に使用したパラメータ値は以下のような設定にて行った。ガラス基板(基板9)の静電容量を実際よりも大きい4×10-7Fと仮定し、凸部の高さは8.5μm、ガラス基板(基板9)の抵抗率は1×10+11Ω・cm、静電チャック8の抵抗率は1×10+11Ω・cm、静電チャック8の比誘電率は9、静電チャックの電極15から基板9の表面までの距離は1mm、凸部17aの面積は静電チャック8の表面全体の1.5%、静電チャック8の面積を65411mmとした。 The parameter values used for the calculations in FIGS. 7A and 7B were set as follows. Assuming that the capacitance of the glass substrate (substrate 9) is 4 × 10 −7 F, which is larger than the actual capacitance, the height of the convex portion is 8.5 μm, and the resistivity of the glass substrate (substrate 9) is 1 × 10 +11 Ω The resistivity of the electrostatic chuck 8 is 1 × 10 +11 Ω · cm, the relative dielectric constant of the electrostatic chuck 8 is 9, the distance from the electrode 15 of the electrostatic chuck to the surface of the substrate 9 is 1 mm, and the protrusion 17a Was 1.5% of the entire surface of the electrostatic chuck 8 and the area of the electrostatic chuck 8 was 65411 mm 2 .
 このとき、計算より凹部にかかる平衡時の電圧は0.85V、凸部に働く平衡時の電圧は60mVとなる。また、凸部において接触抵抗を6.5×10+7Ω・cm、電極距離をd=0.05μmとした。この電極間にジョンソンラーベック(J―R)力が働くとし、
 F=1/2×ε×(V/d)×S
 上記の式により計算するとF= 6×10-3Nとなる。凹部では3×10-3Nの力が働く。この状態から引き続き、吸着電圧を0Vにしたときの各電圧の変化と、吸着力の変化を表したものが図7Bとなる。
At this time, the equilibrium voltage applied to the concave portion is 0.85 V and the equilibrium voltage acting on the convex portion is 60 mV from the calculation. Further, the contact resistance at the convex portion was 6.5 × 10 +7 Ω · cm, and the electrode distance was d = 0.05 μm. Johnson Rabeck (JR) force works between these electrodes,
F = 1/2 × ε 0 × (V / d) 2 × S
When calculated by the above formula, F = 6 × 10 −3 N. A force of 3 × 10 −3 N works in the recess. From this state, FIG. 7B shows changes in each voltage and changes in the suction force when the suction voltage is set to 0V.
 図7Aに示すように、吸着電圧を0Vにした直後、「凹部電圧」は0.85V、「凸部電圧」は0.06Vであった。即ち、「凸部電圧」は「凹部電圧」の1/10程度であった。また、凹部17bの吸着電圧は、所定時間経過(1sec)すると0Vになる。しかし、凸部17aの吸着電圧は、所定時間経過(約24時間)しても、0Vにならない。即ち、凸部17aの吸着電圧は1日以上経過しないと0Vにならず、この間は、ガラス基板を静電チャックから離脱できない。 As shown in FIG. 7A, immediately after the adsorption voltage was set to 0V, the “recess voltage” was 0.85V and the “convex voltage” was 0.06V. That is, the “convex voltage” was about 1/10 of the “concave voltage”. Further, the suction voltage of the recess 17b becomes 0 V after a predetermined time (1 sec). However, the adsorption voltage of the convex portion 17a does not become 0 V even after a predetermined time has elapsed (about 24 hours). That is, the attracting voltage of the convex portion 17a does not become 0V unless one day or more elapses, and the glass substrate cannot be detached from the electrostatic chuck during this period.
 図7Bに示すように、吸着電圧を0Vにした直後、凸部17aの静電吸着力は6×10-3(Pa・m)、凹部17bの静電吸着力は3×10-3(Pa・m)であった。即ち、凸部17aの静電吸着力は凹部17bの静電吸着力の約2倍であった。吸着電圧を0Vにした直後において、図7Bの一点鎖線で示される凹部と凸部の合計のウエハ吸着力は、9×10-3(Pa・m)となる。また、凹部17bの静電吸着力は所定時間経過(約1sec)すると0(Pa・m)になる。しかし、凸部17aの静電吸着力は、所定時間経過(約24時間)しても、0(Pa・m)にならない。従って、凸部17aと凹部17bの合計の静電吸着力は、所定時間経過(約24時間)しても、0(Pa・m)にならない。時間の経過に伴って、凹部と凸部の合計のウエハ吸着力のうち、凸部吸着力の値が支配的になる。この静電吸着力のため、電極15の電源をOFFした後、スイッチ20bをアース端子16b3に接続しただけでは、ガラス基板の離脱することはできない。尚、ガラス基板の体積抵抗値は1010~1014Ω・cmという大きな範囲で変化するため、図7A、Bは計算の一例である。また、0Vという値は吸着力として無視できる電圧の意味も含む。 As shown in FIG. 7B, immediately after the adsorption voltage is set to 0 V, the electrostatic adsorption force of the convex portion 17a is 6 × 10 −3 (Pa · m 2 ), and the electrostatic adsorption force of the concave portion 17b is 3 × 10 −3 ( Pa · m 2 ). That is, the electrostatic attraction force of the convex portion 17a was about twice the electrostatic attraction force of the concave portion 17b. Immediately after the suction voltage is set to 0 V, the total wafer suction force of the concave portion and the convex portion indicated by the one-dot chain line in FIG. 7B is 9 × 10 −3 (Pa · m 2 ). Further, the electrostatic attraction force of the concave portion 17b becomes 0 (Pa · m 2 ) when a predetermined time elapses (about 1 sec). However, the electrostatic attraction force of the convex portion 17a does not become 0 (Pa · m 2 ) even when a predetermined time has elapsed (about 24 hours). Therefore, the total electrostatic attraction force of the convex portion 17a and the concave portion 17b does not become 0 (Pa · m 2 ) even when a predetermined time elapses (about 24 hours). As time elapses, the value of the convex portion adsorption force becomes dominant among the total wafer adsorption force of the concave portion and the convex portion. Because of this electrostatic attraction force, the glass substrate cannot be detached simply by connecting the switch 20b to the ground terminal 16b3 after the electrode 15 is turned off. Since the volume resistance value of the glass substrate changes in a large range of 10 10 to 10 14 Ω · cm, FIGS. 7A and 7B are examples of calculation. Moreover, the value of 0V includes the meaning of a voltage that can be ignored as the attractive force.
 この点を、図8Aから図8Cを用いて説明する。図8Aは、コンデンサーCと抵抗Rの直列回路を示す。図8Bは、図8Aに記載のコンデンサーCと抵抗Rの直列回路に当初直流電源Bにより電圧Vbを印加し、その後、グランド(GND)にした場合の電圧の状態を示す。図8Bに示すように、グランド(GND)にしただけでは、電圧Vはすばやくゼロにはならない。これは、CRの時定数により決定する過渡現象が続くためと考えられる。図8Cは、図8Aに記載のコンデンサーCと抵抗Rの直列回路に当初直流電源Bにより電圧Vbを印加した後、直流電源Aにより、電圧Vbに対して逆の極性を有する電圧Vaを印加した場合の、電圧Vの状態を示す。図8Bのグランド(GND)にした場合と比較して、図8Cの場合は、電圧Vはすばやくゼロに近づく。 This point will be described with reference to FIGS. 8A to 8C. FIG. 8A shows a series circuit of a capacitor C and a resistor R. FIG. 8B shows a voltage state when the voltage Vb is initially applied to the series circuit of the capacitor C and the resistor R shown in FIG. 8A by the direct-current power source B and then is grounded (GND). As shown in FIG. 8B, the voltage V does not quickly become zero simply by using the ground (GND). This is presumably because a transient phenomenon determined by the time constant of CR continues. In FIG. 8C, a voltage Vb is first applied by the DC power supply B to the series circuit of the capacitor C and the resistor R shown in FIG. 8A, and then a voltage Va having a polarity opposite to that of the voltage Vb is applied by the DC power supply A. Shows the state of the voltage V. Compared to the ground (GND) in FIG. 8B, in the case of FIG. 8C, the voltage V quickly approaches zero.
 以上から、緩和される時間はジョンソンラーベック(JR)力が作用する部分の方が、高抵抗が並列されているため非常に遅いと予想される。また、基板には、ジョンソンラーベック(JR)力とクーロン力の異質の吸着力が働くため、残留電荷が有効的に吸着力として働くジョンソンラーベック(JR)力の場合、微少な電圧が残ることは、基板9の離脱の際、影響が大きいことが想定される。 From the above, the relaxation time is expected to be much slower in the part where the Johnson Rabeck (JR) force is applied because of the high resistance in parallel. Further, since a different adsorption force of Johnson Rabeck (JR) force and Coulomb force acts on the substrate, a slight voltage remains in the case of Johnson Rabeck (JR) force in which the residual charge effectively acts as the adsorption force. It is assumed that the influence is great when the substrate 9 is detached.
 上記のとおり、基板9は、凹部17bと基板9との間に発生するクーロン力と凸部17a(導体被膜19の凹凸)と基板9との間に発生するジョンソンラーベック力によって、しっかり静電チャックに吸着されることにいる。図7A、Bに示すように、凹部17bに発生するクーロン力は、距離の2乗に反比例した力なので凸部17aに発生するジョンソンラーベック力の方がより小さい電圧で大きな吸着力を得られる。しかし、基板9と凸部17aとの間の時定数は、基板9と凹部17bとの間の時定数よりも大きい。このため、凸部17aの残留電荷がゼロになる時間は、凹部17bの残留電荷がゼロになる時間に比べて大幅に時間がかかる。このため、凹部17bと凸部17aとに同じ逆電圧を印加した場合、吸着力の緩和は凸部17aのほうが凹部17bよりも遅くなる。従って、基板9の離脱時に電極15に接続された外部電源16bを、スイッチ20bにより基板9の吸着時の電圧(16b1)と逆の電圧(16b2)に切り替え、電極15に逆電圧を供給するようにした特許文献4の方法では、基板9の吸着力発生の為の電極15と同一の電極15に逆極性の電圧を印加するため、凸部17aと凹部17bに発生する残留電圧を同時に無くすように適度な逆電圧をかけることは困難である。また、凸部17aと凹部17bに発生する残留電圧をなくすために、更に大きな逆電圧を電極15に一定時間かけることで凹部17bの残留電荷がなくなったとき、凸部17aに残留電荷が残ってしまう。反対に凸部17aの残留電荷をなくすように、電極15に一逆電圧を一定時間かけたときは凹部17bに残留電荷が残る。このため、逆電圧を電極15に一定時間かけただけでは、基板の凸部17aと凹部17bの残留電荷を同時になくすことができない。 As described above, the substrate 9 is firmly electrostatically caused by the Coulomb force generated between the concave portion 17 b and the substrate 9 and the Johnson Rahbek force generated between the convex portion 17 a (unevenness of the conductor coating 19) and the substrate 9. It is to be adsorbed by the chuck. As shown in FIGS. 7A and 7B, since the Coulomb force generated in the concave portion 17b is a force inversely proportional to the square of the distance, the Johnson Rabeck force generated in the convex portion 17a can obtain a large adsorption force with a smaller voltage. . However, the time constant between the substrate 9 and the convex portion 17a is larger than the time constant between the substrate 9 and the concave portion 17b. For this reason, the time when the residual charge of the convex portion 17a becomes zero takes much time compared with the time when the residual charge of the concave portion 17b becomes zero. For this reason, when the same reverse voltage is applied to the concave part 17b and the convex part 17a, the relaxation of the attracting force is slower in the convex part 17a than in the concave part 17b. Accordingly, the external power supply 16b connected to the electrode 15 when the substrate 9 is detached is switched to a voltage (16b2) opposite to the voltage (16b1) when the substrate 9 is attracted by the switch 20b, and the reverse voltage is supplied to the electrode 15. In the method disclosed in Patent Document 4, a voltage having a reverse polarity is applied to the same electrode 15 as the electrode 15 for generating the attraction force of the substrate 9, so that the residual voltage generated in the convex portion 17a and the concave portion 17b is eliminated at the same time. It is difficult to apply an appropriate reverse voltage to In addition, in order to eliminate the residual voltage generated in the convex portion 17a and the concave portion 17b, when the remaining charge in the concave portion 17b disappears by applying a larger reverse voltage to the electrode 15 for a certain time, the residual charge remains in the convex portion 17a. End up. On the contrary, when a reverse voltage is applied to the electrode 15 for a certain period of time so as to eliminate the residual charge in the convex portion 17a, the residual charge remains in the concave portion 17b. For this reason, only by applying a reverse voltage to the electrode 15 for a certain period of time, the residual charges on the convex portions 17a and the concave portions 17b of the substrate cannot be eliminated simultaneously.
 この点を、図6Aの等価回路で説明すると、端子VBと端子VD間の電圧を緩和する為に逆電圧を電極15にかけると、凹部17bと基板9との間のキャパシタC5の電圧がすばやく小さくなる、一定時間以上逆電圧を印加すると印加した逆電圧により再度、凹部17bと基板9との間に吸着力が発生する。逆電圧印加時間を調整することで端子VBと端子VE間の電圧を小さくすることができるが、その時端子VCと端子VD間の電圧は時定数の大きい並列接続のためある程度残り、吸着力が残っている。端子VCと端子VD間の電圧を極めて小さくなるまで逆電圧を印加する時間を調整すると、今度は、端子VBと端子VE間に逆電圧極性の電圧が発生する為、基板9に吸着力が残ってしまう。このように、端子VCと端子VD間の電圧と端子VBと端子VE間の電圧を同時になくすことは困難である。 This point will be described with reference to the equivalent circuit of FIG. 6A. When a reverse voltage is applied to the electrode 15 in order to relax the voltage between the terminal VB and the terminal VD, the voltage of the capacitor C5 between the recess 17b and the substrate 9 is quickly increased. When a reverse voltage is applied for a certain period of time or less, an attracting force is generated again between the recess 17b and the substrate 9 due to the applied reverse voltage. By adjusting the reverse voltage application time, the voltage between the terminal VB and the terminal VE can be reduced. At that time, the voltage between the terminal VC and the terminal VD remains to some extent because of the parallel connection with a large time constant, and the adsorption power remains. ing. If the time for applying the reverse voltage is adjusted until the voltage between the terminal VC and the terminal VD becomes extremely small, a voltage having a reverse voltage polarity is generated between the terminal VB and the terminal VE. End up. Thus, it is difficult to eliminate the voltage between the terminal VC and the terminal VD and the voltage between the terminal VB and the terminal VE at the same time.
 一方、基板9の吸着時には、外部電源16bにより電圧(16b1)を電極15に供給し、基板の離脱時には、基板9の離脱時には、スイッチ20bをOFFにして電極15への電圧印加を停止し、導体被膜19を、スイッチ20aを介してアース端子(16a3)に接続する特許文献2の方法では、基板9の抵抗が大きいときには、基板接触部には、ジョンソンラーベック力により大きな吸着力が発生し、アースに落としただけでは基板9側に電流が流れない為、凸部吸着力がなくなるのに時間がかかる点で問題がある。 On the other hand, when the substrate 9 is attracted, the voltage (16b1) is supplied to the electrode 15 by the external power supply 16b. When the substrate is detached, when the substrate 9 is detached, the switch 20b is turned off to stop the voltage application to the electrode 15. In the method of Patent Document 2 in which the conductor coating 19 is connected to the ground terminal (16a3) via the switch 20a, when the resistance of the substrate 9 is large, a large adsorbing force is generated at the substrate contact portion due to the Johnson Rabeck force. There is a problem in that it takes time to eliminate the convex portion adsorption force because current does not flow to the substrate 9 side simply by dropping to the ground.
 この点を、図6Aの等価回路で説明すると、R6が大きいときに、端子VCからアースに落とすことで、C4、C6の電荷は抜けやすくなるが、C4、C6、R4、R6部の大きな時定数のため電荷が抜けるのに長時間かかる。これに対し、本発明のように、基板9の吸着時には、外部電源16bにより電圧(16b1)を電極15に供給し、基板9の離脱時に電極15に接続された外部電源16bを、スイッチ20bにより基板9の吸着時の電圧(16b1)から逆電圧(16b2)に切り替え、電極15に逆電圧を供給し、更に、導体被膜19を、スイッチ20aを介して外部電源16aの端子16a2に接続すれば、凸部17aに基板9の吸着時と逆の逆電圧が供給されることになるので、従来よりもすばやく基板9の離脱ができるようになる。この電荷の状態は図5Bに示す通りとなるので、高抵抗のガラス基板(基板9)における離脱の点で問題は発生しない。 This point will be described with reference to the equivalent circuit of FIG. 6A. When R6 is large, the charge of C4 and C6 is easily released by dropping from the terminal VC to the ground, but when C4, C6, R4 and R6 are large, Because it is a constant, it takes a long time for the charge to escape. On the other hand, as in the present invention, the voltage (16b1) is supplied to the electrode 15 by the external power supply 16b when the substrate 9 is attracted, and the external power supply 16b connected to the electrode 15 is removed by the switch 20b when the substrate 9 is detached. If the voltage (16b1) at the time of adsorption of the substrate 9 is switched from the reverse voltage (16b2), the reverse voltage is supplied to the electrode 15, and the conductor coating 19 is connected to the terminal 16a2 of the external power source 16a via the switch 20a. Since the reverse voltage opposite to that when the substrate 9 is attracted is supplied to the convex portion 17a, the substrate 9 can be detached more quickly than in the prior art. Since the state of this charge is as shown in FIG. 5B, no problem occurs in terms of separation from the high-resistance glass substrate (substrate 9).
 この点を、図6Bの等価回路で説明する。図6Bの等価回路の場合、基板9の吸着時には、外部電源16bにより電極15に電圧Vaを印加することにより、基板9を吸着する。基板9の離脱時には、外部電源16aにより、端子VAだけでなく、端子VCにも吸着時の逆電圧Vbを印加することが可能となる。これにより、凹部17bの残留電荷がゼロになる時間は、端子VAと端子VB間、端子VBと端子VE間については、端子VAに印加される逆電圧Vbにより決まる。また、凸部17aの残留電荷がゼロになる時間は、端子VCと端子VD間については、端子VCに印加される逆電圧Vbにより決まる。このように、本発明においは、凹部17bの残留電荷は、端子VAに印加される逆電圧Vbにより、凸部17aの残留電荷は、端子VCに印加される逆電圧Vbにより、それぞれゼロにすることが可能である。 This point will be described with reference to the equivalent circuit of FIG. 6B. In the case of the equivalent circuit of FIG. 6B, when the substrate 9 is attracted, the substrate 9 is attracted by applying the voltage Va to the electrode 15 from the external power source 16b. When the substrate 9 is detached, the reverse voltage Vb at the time of adsorption can be applied not only to the terminal VA but also to the terminal VC by the external power source 16a. Thereby, the time for which the residual charge in the recess 17b is zero is determined by the reverse voltage Vb applied to the terminal VA between the terminals VA and VB and between the terminals VB and VE. Further, the time during which the residual charge of the convex portion 17a becomes zero is determined by the reverse voltage Vb applied to the terminal VC between the terminal VC and the terminal VD. Thus, in the present invention, the residual charge in the concave portion 17b is made zero by the reverse voltage Vb applied to the terminal VA, and the residual charge in the convex portion 17a is made zero by the reverse voltage Vb applied to the terminal VC. It is possible.
 次に、基板9として、室温で体積抵抗率1012Ω・cmのガラス基板(基板9)と、導体被膜(比抵抗10-4μΩ・cm、Ra0.2μm)、TiNを備えた静電チャック8(体積抵抗率10Ω・cm、セラミック)を想定した場合、図1、図2、図6Bに示す静電吸着装置をどうように動作させるかについて説明する。 Next, as a substrate 9, an electrostatic chuck having a glass substrate (substrate 9) having a volume resistivity of 10 12 Ω · cm at room temperature, a conductor coating (specific resistance 10 −4 μΩ · cm, Ra 0.2 μm), and TiN Assuming 8 (volume resistivity 10 8 Ω · cm, ceramic), how to operate the electrostatic chuck shown in FIGS. 1, 2, and 6B will be described.
 基板9の吸着時には、電極15に、外部電源16bにより電圧16b1(10V~10kV)を約1分から10分程度供給し、基板9の吸着を行う。基板の離脱時には、電極15に、外部電源16bにより電圧16b2(10V~10kV)を約1分から10程度供給し、端子VCに、外部電源16aに電圧16a2(10V~10kV)を約1分から10分程度供給した後、基板9を離脱した。 When the substrate 9 is attracted, a voltage 16b1 (10 V to 10 kV) is supplied to the electrode 15 from the external power source 16b for about 1 to 10 minutes to attract the substrate 9. When the substrate is detached, a voltage 16b2 (10 V to 10 kV) is supplied to the electrode 15 by the external power supply 16b for about 1 to 10 minutes, and a voltage 16a2 (10 V to 10 kV) is supplied to the terminal VC and the external power supply 16a for about 1 to 10 minutes. After the supply to the extent, the substrate 9 was detached.
 本発明は上記実施の形態に制限されるものではなく、本発明の精神及び範囲から離脱することなく、様々な変更及び変形が可能である。従って、本発明の範囲を公にするために、以下の請求項を添付する。 The present invention is not limited to the above embodiment, and various changes and modifications can be made without departing from the spirit and scope of the present invention. Therefore, in order to make the scope of the present invention public, the following claims are attached.
 本願は、2010年12月27日提出の日本国特許出願特願2010-289263を基礎として優先権を主張するものであり、その記載内容の全てを、ここに援用する。 This application claims priority on the basis of Japanese Patent Application No. 2010-289263 filed on Dec. 27, 2010, the entire contents of which are incorporated herein by reference.

Claims (3)

  1.  頂面で基板を支持することが可能な複数の凸部と、該凸部の周囲の凹部とが表面に形成された誘電体板と、該誘電体板の内部に設けられた電極と、前記電極に基板吸着電圧を印加する第1の外部電源とを備えた静電吸着装置であって、
     前記凸部は、少なくとも前記凸部の頂面に導体被膜を備え、
     前記第1の外部電源は、前記電極に印加される前記基板吸着電圧に対して逆の極性を有する逆電圧を、前記基板の脱着時に前記電極に印加可能な基板脱着電圧電源を備えており、
     前記導体被膜は、前記基板の脱着時に、前記電極に印加される前記基板吸着電圧に対して逆の極性を有する逆電圧を前記導体被膜に印加可能な基板脱着電圧電源を備えた第2の外部電源に接続されている
     ことを特徴とする静電吸着装置。
    A plurality of convex portions capable of supporting the substrate on the top surface, a dielectric plate formed on the surface with concave portions around the convex portions, electrodes provided inside the dielectric plate, and An electrostatic attraction apparatus comprising a first external power source for applying a substrate attraction voltage to the electrode,
    The convex portion is provided with a conductor coating on at least the top surface of the convex portion,
    The first external power source includes a substrate desorption voltage power source capable of applying a reverse voltage having a polarity opposite to the substrate adsorption voltage applied to the electrode to the electrode when the substrate is desorbed.
    The conductor coating is provided with a second external power supply provided with a substrate desorption voltage power source capable of applying a reverse voltage having a polarity opposite to the substrate adsorption voltage applied to the electrode when the substrate is detached. An electrostatic adsorption device characterized by being connected to a power source.
  2.  前記頂面で基板を支持する複数の凸部は、高さが35μm以下で、頂面のRa(中心線平均粗さ)は0.2μm以下であり、前記頂面の面積の合計値が前記誘電体板の全平面面積に対して10%以下の割合となるように形成されていることを特徴とする請求項1に記載の静電吸着装置。 The plurality of convex portions that support the substrate on the top surface have a height of 35 μm or less, the top surface Ra (centerline average roughness) is 0.2 μm or less, and the total area of the top surfaces is 2. The electrostatic attraction apparatus according to claim 1, wherein the electrostatic attraction apparatus is formed so as to have a ratio of 10% or less with respect to a total plane area of the dielectric plate.
  3.  前記基板は、体積抵抗率が1014Ω・cm以下であり、前記凸部との接触面のRa(中心線平均粗さ)が0.05μm以下である絶縁性基板であることを特徴とする請求項1に記載の静電吸着装置。 The substrate is an insulating substrate having a volume resistivity of 10 14 Ω · cm or less and an Ra (centerline average roughness) of a contact surface with the convex portion of 0.05 μm or less. The electrostatic attraction apparatus according to claim 1.
PCT/JP2011/007094 2010-12-27 2011-12-20 Electrostatic adsorption apparatus WO2012090430A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2010-289263 2010-12-27
JP2010289263A JP2014075372A (en) 2010-12-27 2010-12-27 Electrostatic attraction device

Publications (1)

Publication Number Publication Date
WO2012090430A1 true WO2012090430A1 (en) 2012-07-05

Family

ID=46382571

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2011/007094 WO2012090430A1 (en) 2010-12-27 2011-12-20 Electrostatic adsorption apparatus

Country Status (2)

Country Link
JP (1) JP2014075372A (en)
WO (1) WO2012090430A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108242421A (en) * 2016-12-27 2018-07-03 株式会社迪思科 Electrostatic chuck apparatus and Electrostatic Absorption method

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102008581B1 (en) * 2017-11-29 2019-08-07 캐논 톡키 가부시키가이샤 Film forming apparatus, film forming method and manufacturing method of organic el display apparatus
KR101960194B1 (en) * 2017-11-29 2019-03-19 캐논 톡키 가부시키가이샤 Film forming apparatus, film forming method and manufacturing method of organic el display device
JP7108464B2 (en) * 2018-05-25 2022-07-28 株式会社ディスコ chuck table
JPWO2020027104A1 (en) * 2018-07-30 2021-08-02 出光興産株式会社 Photoelectric conversion module
JP7170449B2 (en) * 2018-07-30 2022-11-14 東京エレクトロン株式会社 Mounting table mechanism, processing device, and operating method of mounting table mechanism
KR102251891B1 (en) * 2020-12-08 2021-05-13 주식회사 기가레인 Apparatus for supporting substrate and method for transferring substrate using the same

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005032858A (en) * 2003-07-09 2005-02-03 Toto Ltd Electrostatic chucking method of glass substrate and electrostatic chuck
JP2006157032A (en) * 2006-01-12 2006-06-15 Toto Ltd Electrostatic chuck, electrostatic attraction method, heating/cooling treatment device and electrostatic attraction treatment device
JP2007173596A (en) * 2005-12-22 2007-07-05 Ngk Insulators Ltd Electrostatic chuck
JP2009272646A (en) * 2007-09-11 2009-11-19 Canon Anelva Corp Sputtering device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005032858A (en) * 2003-07-09 2005-02-03 Toto Ltd Electrostatic chucking method of glass substrate and electrostatic chuck
JP2007173596A (en) * 2005-12-22 2007-07-05 Ngk Insulators Ltd Electrostatic chuck
JP2006157032A (en) * 2006-01-12 2006-06-15 Toto Ltd Electrostatic chuck, electrostatic attraction method, heating/cooling treatment device and electrostatic attraction treatment device
JP2009272646A (en) * 2007-09-11 2009-11-19 Canon Anelva Corp Sputtering device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108242421A (en) * 2016-12-27 2018-07-03 株式会社迪思科 Electrostatic chuck apparatus and Electrostatic Absorption method
CN108242421B (en) * 2016-12-27 2022-10-04 株式会社迪思科 Electrostatic chuck device and electrostatic adsorption method

Also Published As

Publication number Publication date
JP2014075372A (en) 2014-04-24

Similar Documents

Publication Publication Date Title
JP4418032B2 (en) Electrostatic chuck
WO2012090430A1 (en) Electrostatic adsorption apparatus
KR100511854B1 (en) Electrostatic chuck device
JP5323317B2 (en) Electrostatic chuck method
JP4951677B2 (en) Wafer transfer device
JP4061131B2 (en) Electrostatic adsorption device
JP5417428B2 (en) Electron microscope and sample holding method
JP4010541B2 (en) Electrostatic adsorption device
JP6016349B2 (en) Substrate holder and vacuum processing apparatus
JP2012524417A (en) Charge removal between substrate and electrostatic clamp
JPH08167643A (en) Sample holding device and its dust removal method
JP5996276B2 (en) Electrostatic chuck, suction method and suction device
JP6069768B2 (en) Electrostatic chuck device and control method thereof
JP2000340640A (en) Non-contacting electrostatically attracting apparatus
GB2293689A (en) Electrostatic chuck
KR20110064665A (en) Dipole type electrostatic chuck by using electric field gradient
JP7150510B2 (en) electrostatic chuck
JP2004253402A (en) Electrostatic chuck
JP2011071211A (en) Method of measuring self-bias of processing object, and method and device for separating processing object using the same
JP2013098276A (en) Substrate holder and vacuum processing apparatus
KR20040040103A (en) ESC Assembly with Lift Pins of Conductive Material
KR101467107B1 (en) Chucking system of electrostatic chuck including fine electrodes
JPH10233435A (en) Electrostatic chuck
JP2000049145A (en) Wafer holding apparatus and method
KR20100090560A (en) Johnsen-rahbek type electrostatic chuck having current suppressing structure and fabrication method thereof

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11852998

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 11852998

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP