JP2010004009A - Mounting table mechanism, plasma processing apparatus using the same and method of applying voltage to electrostatic chuck - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting table mechanism which reduces the time constant of a chuck equivalent circuit, at the application of a DC voltage to a chuck electrode or cutting off the DC voltage so as to rapidly store or discharge electric charges. <P>SOLUTION: The mounting table mechanism for mounting a workpiece W, undergoing plasma processing in a processing container 52, comprises a mounting table 84, an electrostatic chuck 86 having a chuck electrode 114 therein; a DC high-voltage power supply 120 connected thereto via a power feed line 116; a chuck switch portion 124 intervened to the power feed line; a DC component detection circuit 96 for detecting a DC component of the mounting table; a bypass line 108 for bypassing the DC component detection circuit; a bypass switch portion 110 intervened in the midway of the bypass line to ground the mounting table by making the DC component detecting circuit bypass; and a switch control part 112 for controlling the switch portion. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a plasma processing apparatus that performs plasma processing on an object to be processed such as a semiconductor substrate or a glass substrate of a liquid crystal display device, a mounting table mechanism used therefor, and a method for applying a voltage to an electrostatic chuck.

  In general, when manufacturing a semiconductor integrated circuit or a liquid crystal display device, a film formation process, an etching process, a modification process, an oxidation diffusion process, and the like are repeatedly performed on a semiconductor substrate or a glass substrate.

  Of the various processes described above, for example, an etching process is performed using a plasma processing apparatus (Patent Documents 1 to 3). Here, an example of a conventional plasma processing apparatus will be described with reference to FIG. As shown in FIG. 16, this plasma processing apparatus has a processing vessel 2 made of, for example, an aluminum alloy, and the inside of this processing vessel 2 can be evacuated by an evacuation system (not shown). A shower head portion 4 made of, for example, an aluminum alloy is provided on the ceiling portion of the processing vessel 2 as a gas introducing means for introducing a necessary gas into the processing vessel 2, and on the bottom side of the processing vessel 2, A mounting table mechanism 6 is provided.

  The mounting table mechanism 6 is mainly configured by a mounting table 10 made of, for example, an aluminum alloy and an electrostatic chuck 12 provided on the upper surface side, which is provided via an insulating material 8 made of a ceramic material such as alumina. Has been. A workpiece W made of, for example, a glass substrate or a semiconductor substrate is placed on the electrostatic chuck 12 as a workpiece and can be adsorbed by electrostatic force.

  As described above, the shower head unit 4 and the mounting table 10 are arranged to face each other, and each constitutes an upper electrode and a lower electrode to form a parallel plate type plasma electrode. Specifically, a high-frequency line 14 is connected to the mounting table 10, and a matching circuit 16 and a high-frequency power source 18 of, for example, 13.56 MHz are sequentially interposed in the high-frequency line 14, and plasma is generated by the high-frequency power. Is supposed to generate.

  Further, the mounting table 10 is provided with a DC component detection circuit 22 via a detection line 20. The DC component detection circuit 22 is configured by sequentially connecting a high-frequency cut coil 24, a first resistor 26, and a second resistor 28 to the detection line 20 in series. The capacitor 30 is branched from the connection point with the first resistor 26. The voltage drop of the second resistor 28 is measured by the measuring unit 32 so that the direct current component of the mounting table 10 during plasma processing can be recognized.

  The high frequency power from the mounting table 10 is cut by the high frequency cut coil 24 and the capacitor 30. The DC component detection circuit 22 also has a function for discharging the charges charged in the chuck electrode 34 and the mounting table 10 when the plasma processing is completed and the application of the high frequency power is stopped.

  The electrostatic chuck 12 is configured such that a chuck electrode 34 is embedded in a plate-shaped insulating material made of, for example, polyimide resin or ceramic. A power supply line 36 extends from the chuck electrode 34, and a DC high-voltage power supply 40 is connected to the power supply line 36 through a filter unit 38 that prevents high-frequency power from entering.

  Then, by applying a high DC voltage generated from the DC high voltage power supply 40 to the chuck electrode 34, the workpiece W on the electrostatic chuck 12 is attracted by electrostatic force. The filter unit 38 is configured by sequentially connecting a high frequency cut coil 42 and a resistor 44 to the power supply line 36 in series, and a capacitor 46 is branched from a connection point between the high frequency cut coil 42 and the resistor 44. ing.

  The high frequency power applied to the mounting table 10 is prevented from entering and entering the DC high voltage power source 40 by the high frequency cut coil 42. Further, a chuck switch unit 45 for turning on and off the DC high-voltage power supply 40 is provided on the downstream side of the filter unit 38 of the power supply line 36.

  In such a plasma processing apparatus, when the object to be processed is mounted on the mounting table 10, the chuck switch unit 45 is closed and a high DC voltage is applied from the DC high-voltage power supply 40 to the chuck electrode 34 of the electrostatic chuck 12. Is applied to the chuck electrode 34 and the workpiece W is stably adsorbed by electrostatic force. When the adsorption is performed, high frequency power is applied from the high frequency power source 18 and a predetermined gas, for example, an etching gas is flowed from the shower head unit 4 to generate plasma by the high frequency power, and an etching process using the plasma is performed. Will be done.

  Then, when the etching process is finished, the supply of the etching gas is stopped and the high frequency power applied to the mounting table 10 is shut off. Further, the chuck switch unit 45 is opened to cut off the high DC voltage applied to the chuck electrode 34 of the electrostatic chuck 12, and the charge stored in the chuck electrode 34 and the mounting table 10 is converted into a DC component. After being sufficiently discharged through the detection circuit 22, the object to be processed W is taken out.

Japanese Patent Application Laid-Open No. 08-017808 Japanese Patent Application Laid-Open No. 08-031918 JP 2002-043402 A

  By the way, when attracting the object to be processed, electricity is stored in the chuck electrode 34 of the electrostatic chuck 12 until the electrostatic force is sufficiently increased and stabilized, or when the plasma processing is finished, Although it depends on the surface area of the chuck electrode 34 until the charge stored in the electrostatic chuck 12 is released and stabilized after the application is stopped, a certain amount of time is inevitable in units of seconds. . This is because the chuck equivalent circuit has time constants due to the capacitance components formed between the resistors 26, 28, 44 and the chuck electrode 34 and the mounting table 10.

  In this case, there is no particular problem when the diameter size of the semiconductor substrate is as small as 6 inches or 8 inches. However, when the diameter size is 12 inches (300 mm) or more, the workpiece is adsorbed. A considerable amount of time is required until a sufficient amount of charge is stored in the chuck electrode 34 (charge storage time) or a time until the charge stored in the chuck electrode 34 is sufficiently discharged at the end of the plasma processing (charge release time). Since time is required, there is a problem that the productivity of the product is lowered and the throughput is lowered.

  In particular, when the object to be processed is a glass substrate of a liquid crystal display device, the enlargement of the glass substrate is remarkable, and there is a large glass substrate having a length and width of about 3 m × 3 m. Such a large glass substrate In this case, there has been a problem that the above-described charge storage time and charge release time each require about 50 to 60 seconds, and the throughput must be significantly reduced.

  The present invention has been devised to pay attention to the above problems and to effectively solve them. The object of the present invention is to reduce the time constant of the chuck equivalent circuit when a DC voltage is applied to the chuck electrode and when the DC voltage applied to the chuck electrode is cut off. Storage device and discharge of charge, respectively, to improve product productivity and improve throughput, plasma processing apparatus using the same, and method for applying voltage to electrostatic chuck Is to provide.

  The invention according to claim 1 is a mounting table mechanism that is provided in a processing container that can be evacuated and mounts an object to be processed that is subjected to predetermined plasma processing using plasma generated by high-frequency power. A mounting table made of a conductive member for mounting the object to be processed; an electrostatic chuck disposed on an upper surface of the mounting table and having a chuck electrode provided therein for adsorbing the object to be processed; A DC high voltage power source connected via a power supply line to apply a DC voltage that generates electrostatic force to the chuck electrode, and is interposed in the middle of the power supply line and is closed when the object to be processed is adsorbed. A chuck component, a DC component detection circuit connected to the mounting table for detecting a DC component applied to the mounting table during the plasma processing, and bypassing the DC component detection circuit And a bypass switch that bypasses the DC component detection circuit and grounds the mounting table when the chuck switch unit is switched to the closed state and when the chuck switch unit is switched to the open state. And a switch control unit that controls the two switch units.

  Thus, in the mounting table mechanism, when applying the DC voltage to the chuck electrode by closing the chuck switch unit, the bypass component that bypasses the DC component detection circuit and grounds the mounting table is closed. Even when the DC voltage applied to the chuck electrode is shut off by opening the switch section, the DC component detection circuit is bypassed and the bypass switch section that grounds the mounting table is closed, so the DC voltage is applied to the chuck electrode. It is possible to reduce the time constant of the chuck equivalent circuit when applying and shutting off the DC voltage applied to the chuck electrode, and as a result, charge storage and charge discharge to the chuck electrode can be performed quickly. Thus, product productivity can be increased and throughput can be improved.

According to a second aspect of the present invention, in the first aspect of the present invention, there is provided a filter unit that is interposed in the middle of the power supply line and prevents the high-frequency power from entering the DC high-voltage power source.
According to a third aspect of the present invention, in the second aspect of the present invention, the filter section includes a resistance element or a resistance element and a capacitance element.

According to a fourth aspect of the present invention, in the second aspect of the present invention, the filter section includes an inductive element or an inductive element and a capacitive element.
According to a fifth aspect of the invention, in the invention according to any one of the first to fourth aspects, the DC component detection circuit is connected to the mounting table via a detection line.

According to a sixth aspect of the present invention, in the invention according to any one of the first to fifth aspects, when the switch control unit switches the chuck switch unit to the closed state, at the same time or prior to the switching. Control is performed so that the bypass switch is switched to a closed state.
According to a seventh aspect of the present invention, in the sixth aspect of the invention, the switch control unit switches the bypass switch unit to an open state when a predetermined time has elapsed after switching the chuck switch unit from an open state to a closed state. It is characterized by controlling as follows.

  According to an eighth aspect of the present invention, in the invention according to any one of the first to seventh aspects, when the switch control unit switches the chuck switch unit to the open state, the switch control unit is predetermined at the same time or after the switching. When the time elapses, the bypass switch unit is controlled to be switched to an open state.

  According to a ninth aspect of the present invention, in the eighth aspect of the invention, the switch control unit switches the bypass switch unit to an open state when a predetermined time has elapsed after switching the chuck switch unit from a closed state to an open state. It is characterized by controlling as follows.

  A tenth aspect of the present invention is a mounting table mechanism that is provided in a processing vessel that can be evacuated and mounts an object to be processed using a plasma generated by high-frequency power. A mounting table made of a conductive member for mounting the object to be processed; an electrostatic chuck disposed on an upper surface of the mounting table and having a chuck electrode provided therein for adsorbing the object to be processed; A DC high-voltage power source connected via a power supply line provided with a filter part that prevents intrusion of high-frequency power in the middle in order to apply a DC voltage that generates an electrostatic force to the chuck electrode, and a medium in the middle of the power supply line A chuck switch unit that is closed when adsorbing the object to be processed, and is connected to the mounting table for detecting a DC component applied to the mounting table during the plasma processing. A DC component detection circuit and a switch control unit for controlling the chuck switch unit, wherein the filter unit is formed by a capacitive element and a dielectric element without including a resistance element. It is a mounting mechanism.

  The invention of claim 11 is the invention according to any one of claims 1 to 10, wherein the DC high-voltage power supply is adapted to apply a plurality of types of DC voltages that can be switched. A potential monitor unit that is provided in the middle of the power supply line and monitors the potential on the chuck electrode side, and a first DC voltage that is a higher voltage among the plurality of types of DC voltages when the chuck switch unit is closed. And a power supply control unit that controls the DC power supply so as to switch to and apply a low DC voltage when the detected value of the potential monitor unit reaches a predetermined value. Features.

  According to a twelfth aspect of the present invention, in the invention of the eleventh aspect, the DC high-voltage power supply is adapted to be able to apply a plurality of types of DC voltages that can be switched, and further controls the DC high-voltage power supply. When the chuck switch is closed, the power supply control unit first applies a first DC voltage, which is a higher voltage of the plurality of types of DC voltages, for a predetermined time. Control is performed so as to switch and apply the low DC voltage to the second DC voltage when the time has elapsed.

According to a thirteenth aspect of the present invention, in the invention according to any one of the first to tenth aspects, the predetermined time is a time when the potential of the chuck electrode is increased after the application of the first DC voltage to the chuck electrode is started. It is characterized in that the length is equal to or shorter than the period until the rated voltage is reached.
The invention of claim 14 is the invention of any one of claims 11 to 13, wherein the first DC voltage is set higher than a rated voltage of the chuck electrode, and the second DC voltage is It is set to the rated voltage.

The invention of claim 15 is the invention of any one of claims 11 to 14, wherein the DC high-voltage power supply has an output voltage so as to output the first DC voltage and the second DC voltage. It is characterized by being made variable.
According to a sixteenth aspect of the present invention, in the invention according to any one of the first to fourteenth aspects, the DC high-voltage power supply outputs a first power supply unit that outputs the first DC voltage, and outputs the second DC voltage. And a second power supply unit.

  The invention according to claim 17 is the invention according to any one of claims 1 to 16, wherein the object to be processed is an insulator.

  The invention according to claim 18 is a plasma processing apparatus for performing a predetermined plasma process on an object to be processed, a processing container capable of being evacuated, and a gas introducing means for introducing a necessary gas into the processing container. An evacuation unit for evacuating the inside of the processing container, and a mounting table mechanism according to any one of claims 1 to 17 for mounting the object to be processed in the processing container. The plasma processing apparatus is characterized in that it is configured.

The invention according to claim 19 is the invention according to claim 18, wherein the gas introducing means comprises a shower head portion, and a parallel plate type upper electrode and lower electrode are formed by the shower head portion and the mounting table of the mounting table mechanism. It is characterized by having formed so that.
A twentieth aspect of the invention is characterized in that, in the nineteenth aspect of the invention, a high frequency power source is connected to the mounting table.

A twenty-first aspect of the invention is characterized in that, in the invention according to any one of the eighteenth to twentieth aspects, a second high-frequency power source is connected to the shower head portion.
According to a twenty-second aspect of the present invention, in the invention according to any one of the eighteenth to twenty-first aspects, the object to be processed is a semiconductor substrate or an insulating substrate.

  According to a twenty-third aspect of the present invention, there is provided an electrostatic chuck provided on a mounting table on which a workpiece to be plasma-treated is placed in a processing vessel that can be evacuated and a high-frequency voltage can be applied. In the method of applying a voltage to the electrostatic chuck, the first DC voltage, which is a higher voltage of a plurality of types of DC voltages, is applied to the chuck electrode of the electrostatic chuck, and at the same time as the first DC voltage is applied. Prior to, the mounting table is grounded, and when a predetermined time elapses from the start of application of the first DC voltage, it is switched to a second DC voltage lower than the first DC voltage and applied. When the predetermined time has elapsed since switching to the second DC voltage, the grounding of the mounting table is cut off, and after the grounding of the mounting table is cut off, a high frequency voltage is applied to the mounting table. Characteristic static A voltage application method to the chuck.

The invention of claim 24 is characterized in that, in the invention of claim 23, the predetermined time from the start of application of the first DC voltage is predetermined.
The invention of claim 25 is the invention of claim 23, wherein the predetermined time from the start of application of the first DC voltage is the chuck after the application of the first DC voltage to the chuck electrode is started. It is characterized by having a length equal to or shorter than the period until the potential of the electrode reaches the rated voltage.
According to a twenty-sixth aspect of the present invention, in the invention according to any one of the twenty-third to twenty-fifth aspects, the predetermined time from the switching to the second DC voltage is a period until the potential of the mounting table is stabilized. It is characterized by time.

According to the mounting table mechanism, the plasma processing apparatus using the mounting table mechanism, and the method for applying a voltage to the electrostatic chuck, the following excellent effects can be obtained.
According to the invention, in the mounting table mechanism, when the chuck switch unit is closed and a DC voltage is applied to the chuck electrode, the DC component detection circuit is bypassed and the bypass switch unit that grounds the mounting table is closed. Even when the DC switch applied to the chuck electrode is shut off by opening the switch unit, the bypass switch unit that bypasses the DC component detection circuit and grounds the mounting table is closed. The time constant of the chuck equivalent circuit when the DC voltage applied to the chuck electrode and the DC voltage applied to the chuck electrode are cut off can be reduced, and as a result, charge storage and charge discharge with respect to the chuck electrode are performed quickly. In this way, product productivity can be increased and throughput can be improved.

A preferred embodiment of a mounting table mechanism according to the present invention, a plasma processing apparatus using the same and a method for applying a voltage to an electrostatic chuck will be described in detail below with reference to the accompanying drawings.
<First Embodiment>
FIG. 1 is a block diagram showing a first embodiment of a plasma processing apparatus using a mounting table mechanism according to the present invention. Here, a case where a plasma etching process is performed on a glass substrate as a plasma process will be described as an example.

  As shown in FIG. 1, the plasma processing apparatus 50 includes a processing container 52 made of, for example, an aluminum alloy, and the processing container 52 is grounded. An opening 54 through which the workpiece W is passed is formed in the side wall of the processing container 52, and a gate valve 56 for opening and closing the opening 54 is attached to the opening 54.

  Further, an exhaust port 58 is provided around the bottom of the processing vessel 52, and an exhaust unit 60 for evacuating the inside of the processing vessel 52 is provided at the exhaust port 58. Specifically, the exhaust means 60 has an exhaust line 62 connected to the exhaust port 58, and a pressure regulating valve 64 and a vacuum pump 66 are sequentially provided in the exhaust line 62 so as to perform processing. The container 52 can be maintained at a predetermined pressure while evacuating the inside of the container 52.

  Further, a shower head portion 68 made of, for example, an aluminum alloy is provided on the ceiling portion of the processing vessel 52 as a gas introducing means for introducing a necessary gas into the processing vessel 52. A gas inlet 70 is provided above the shower head portion 68, and a gas source 74 is connected to the gas inlet 70 via a gas line 72. A gas flow controller 76 such as a mass flow controller is interposed in the middle of the gas line 72 so that a necessary gas, for example, an etching gas flows while controlling the flow rate.

  A plurality of gas ejection holes 78 are formed in the gas ejection surface on the lower surface of the shower head portion 68, and the supplied gas is supplied toward the processing space S below. And in this processing container 52, the mounting base mechanism 80 which concerns on this invention is provided so that the said shower head part 68 may be opposed.

  Specifically, the mounting table mechanism 80 includes a mounting table 84 made of a conductive material such as aluminum provided on the bottom of the processing vessel 52 via an insulating material 82 made of a ceramic material such as alumina, and an upper surface thereof. It is mainly composed of an electrostatic chuck 86 provided on the side. Then, for example, a glass substrate W for a liquid crystal display device is placed on the electrostatic chuck 86 as an object to be processed, and the glass substrate W can be adsorbed by electrostatic force. Here, the size of the glass substrate W is set to about 3 m × 3 m in length and width, for example, and is very large. Here, as the conductive material, for example, an alloy such as stainless steel, carbon, a composite material thereof, and the like can be used in addition to a metal such as aluminum.

  As described above, the shower head portion 68 and the mounting table 84 are arranged to face each other, and constitute an upper electrode and a lower electrode, respectively, to form a parallel plate type plasma electrode. Specifically, a high frequency line 88 is connected to the mounting table 84, and a matching circuit 90 and a high frequency power source 92 of, for example, 13.56 MHz are sequentially interposed in the high frequency line 88, and plasma is generated by the high frequency power. Is supposed to generate.

  The mounting table 84 is provided with a DC component detection circuit 96 via a detection line 94. The detection line 94 may be branched from the downstream side of the matching circuit 90 provided in the high-frequency line 88. The DC component detection circuit 96 is configured by sequentially connecting a high-frequency cut coil 98, a first resistor 100, and a second resistor 102 to the detection line 94 in series. The capacitor 104 is branched from a connection point with the first resistor 100 and the other end is grounded. Then, by measuring the voltage drop of the second resistor 102 with the measuring unit 106, the DC component of the mounting table 84 during the plasma processing can be detected and recognized.

  The high frequency power from the mounting table 84 is cut by the high frequency cut coil 98 and the capacitor 104. The DC component detection circuit 96 also has a function for discharging the charges charged in the chuck electrode 86 and the mounting table 84 when the plasma processing is completed and the application of the high frequency power is stopped.

  The detection line 94 is provided with a bypass line 108 that is characteristic of the present invention and connects the upstream side and the downstream side of the DC component detection circuit 96 of the detection line 94. A bypass switch unit 110 is provided in the middle of the bypass line 108, and this bypass is used when necessary, that is, when a DC voltage applied to the electrostatic chuck 86 is turned on and off as described later. The switch unit 110 is closed, and the mounting table 84 can be directly grounded without using a resistor or a coil. The switch control unit 112 controls the opening / closing operation of the bypass switch unit 110.

  The electrostatic chuck 86 is configured such that the chuck electrode 114 is embedded in a plate-shaped insulating material made of, for example, polyimide resin or ceramic. A power supply line 116 extends from the chuck electrode 114, and a DC high-voltage power supply 120 is connected to the power supply line 116 via a filter unit 118 that prevents high-frequency power from entering.

  Then, by applying a high DC voltage generated from the DC high voltage power source 120 to the chuck electrode 114, the glass substrate W on the electrostatic chuck 86 is attracted by electrostatic force. The output voltage of the DC high-voltage power supply 120 is, for example, about 3 kV, but is not limited to this. Here, the filter unit 118 includes an induction element, that is, a high-frequency cut coil 122.

  The high-frequency power applied to the mounting table 84 by the high-frequency cut coil 112 is prevented from entering and entering the DC high-voltage power supply 120. Further, on the downstream side of the filter unit 118 of the power supply line 116, a chuck switch unit 124 for turning on and off the DC high-voltage power supply 120 is provided.

  The switch control unit 112 also controls the opening / closing operation of the chuck switch unit 124. Also, control of the overall operation of the plasma processing apparatus 50, for example, control of process pressure, control of supply gas supply start / supply stop, control of application of high-frequency power, and instructions for opening / closing operation of each switch unit to the switch control unit 112 And the like are performed by the device control unit 126 including a computer. A computer readable computer program necessary for the operation control is stored in the storage medium 128. The storage medium 128 includes a flexible disk, a CD (Compact Disc), a CD-ROM, a hard disk, a flash memory, a DVD, or the like. Although not shown in the drawings, the mounting mechanism 80 is provided with a lift pin for receiving the object to be processed when the object is carried in and out.

  Next, the plasma etching process performed using the plasma processing apparatus 50 configured as described above will be described with reference to FIGS. FIG. 2 is a timing chart showing the relationship between the switching timing of the chuck switch section and the bypass switch section and the timing of chuck electrode potential and high-frequency power application, and FIG. 3 shows the DC voltage in the electrostatic chuck of the mounting table mechanism. It is a figure which shows a chuck | zipper equivalent circuit.

  First, the overall flow will be described. The glass substrate W, which is the object to be processed, is carried into the processing container 52 through the opened gate valve 56 and the opening 54, and this is mounted by raising and lowering a lifter pin (not shown). It mounts on the mounting base 84, and the inside of the processing container 52 is sealed.

  When the glass substrate W is mounted on the mounting table 84, the chuck switch unit 124 is closed, and a high DC voltage is applied from the DC high voltage power source 120 to the chuck electrode 114 of the electrostatic chuck 86. Charge is sufficiently stored in the electrode 114 to stably adsorb the glass substrate W by electrostatic force. Here, when the chuck switch 124 is closed, the bypass switch 110 is also closed for a predetermined period. When the adsorption is performed, a high frequency power is applied from the high frequency power source 92 and a predetermined gas, for example, an etching gas is supplied from the shower head 68 to generate plasma in the processing space S by the high frequency power. Etching is performed.

  During the plasma processing, a potential is generated by the action of the plasma generated in the processing space S. Due to this potential, a current flows through the detection line 94, and this potential is applied to the coil 98 of the DC component detection circuit 96, the first. The current flows through the resistor 100 and the second resistor 102 to the ground side. Then, the voltage drop that occurs when a current flows through the second resistor 102 is measured by the measuring unit 106, whereby the DC voltage of the mounting table 84 is detected.

  At this time, the coil 98 and the capacitor 104 prevent the high frequency power applied to the mounting table 84 from flowing around and flowing to the DC component detection circuit 96 side. Similarly, the action of the high frequency cut coil 122 provided in the power supply line 116 prevents the high frequency power applied to the mounting table 84 from flowing into the DC high voltage power source 120.

  When the etching process is finished, the supply of the etching gas is stopped and the high-frequency power applied to the mounting table 84 is shut off. Further, the chuck switch unit 124 is opened to cut off the high DC voltage applied to the chuck electrode 114 of the electrostatic chuck 86, and the electric charge stored in the chuck electrode 114 and the mounting table 84 is changed to DC. It is sufficiently discharged through the component detection circuit 96. Here, when the chuck switch 124 is opened, the bypass switch 110 is also closed for a predetermined period. When the discharge of the stored charges is completed, the glass substrate W is taken out.

  Here, in the conventional plasma processing apparatus, when the chuck switch unit 45 shown in FIG. 16 is closed and a high DC voltage is applied to the chuck electrode 34, charges are accumulated in the chuck electrode 34 and the mounting table 10. It takes a long time to generate sufficient electrostatic force (charge storage time), and the chuck switch unit 45 is opened and stored in the chuck electrode 34 or the mounting table 10 in order to finish the plasma processing. However, in the case of the plasma processing apparatus 50 of the present invention, the charge storage time and the charge discharge time can be greatly shortened. Can do.

  That is, when the chuck switch unit 124 is switched from the open state to the closed state and when the chuck switch unit 124 is switched from the closed state to the open state, the bypass switch unit 110 provided in the bypass line 108 is kept closed for a predetermined period of time. 84 is directly grounded without passing through the DC component detection circuit 96 including a resistance component, so that the resistance component of the chuck equivalent circuit is made as small as possible. Specifically, when the chuck switch unit 124 is switched to the closed state, the switch control unit 112 controls the bypass switch unit 110 to be switched to the closed state simultaneously with or prior to the switching.

  Further, when the chuck switch unit 124 is switched to the open state, the switch control unit 112 controls the bypass switch unit 110 to be switched to the closed state simultaneously with the switching or prior to switching. As a result, the time constant of the chuck equivalent circuit is reduced, and accordingly, charge storage and charge discharge with respect to the chuck electrode 114 and the mounting table 84 can be performed quickly. Further, the switch control unit 112 switches the bypass switch unit 110 from the closed state to the open state when a predetermined time has elapsed after the chuck switch unit 124 is switched from the open state to the closed state or from the closed state to the open state. To control.

  Here, the relationship between the switching timing of the chuck switch unit 124 and the bypass switch unit 110, the potential of the chuck electrode 114, and the application timing of the high-frequency power will be described with reference to FIG. As shown in FIG. 2, when the chuck switch 124 shown in FIG. 2 (A) is switched from the open state to the closed state, and when switching from the closed state to the open state, the switching is performed as shown in FIG. 2 (B). The bypass switch unit 110 is maintained in the closed state so as to cross the point, and the time constant of the chuck equivalent circuit at this time is reduced by bypassing the DC component detection circuit 96.

  In this case, the bypass switch unit 110 may be switched to be closed simultaneously with the switching of the chuck switch unit 124. However, after the chuck switch unit 124 is switched to the closed state, at least a predetermined time T1. Maintains the closed state of the bypass switch unit 110 until the electrostatic charge is stabilized by sufficiently storing charges in the chuck electrode 114 and the mounting table 84 (see FIG. 2C). Although this predetermined time T1 depends on the area of the chuck electrode 114, it is several seconds to several tens of seconds.

  Further, in the conventional apparatus example, the electric potential of the mounting table 84 fluctuates as the electric charge is stored by charging the chuck electrode 114, and if a high frequency voltage is applied in this state, an abnormal discharge may occur. In this case, the bypass switch unit 110 is closed and grounded until immediately before the high frequency voltage is applied, so that the potential of the mounting table 84 can be stabilized to the ground potential, and the high frequency voltage is applied in this state. The occurrence of abnormal discharge can be suppressed.

  Similarly, after the chuck switch 124 is opened, the charges stored in the chuck electrode 114 and the mounting table 84 are sufficiently discharged for at least a predetermined time T2 (FIG. 2C). Reference), the closed state of the bypass switch unit 110 is maintained. Although the predetermined time T2 depends on the area of the chuck electrode 114, it is several seconds to several tens of seconds. As shown in FIG. 2D, the high frequency power is applied to the mounting table 84 after the electrostatic force is stabilized. During the plasma processing, the bypass switch unit 110 is in an open state, and the DC component detection circuit 96 acts to measure the DC voltage of the mounting table 84.

  Here, a chuck equivalent circuit when the chuck switch 124 is opened and closed (the bypass switch 110 is also closed) will be described with reference to FIGS. FIG. 3 is a diagram showing a chuck equivalent circuit with respect to a DC voltage in the electrostatic chuck of the mounting table mechanism, and FIG. 4 is a diagram showing a change in the potential of the chuck electrode.

  As shown in FIG. 3, a series circuit of an electromotive force E, a resistance component R, and a capacitance component C of the DC high-voltage power source 120 when the chuck switch unit 124 is opened and closed (the bypass switch unit 110 is also closed). Here, since the DC component detection circuit 96 is bypassed, the resistance component R is substantially only the resistance component of the high frequency cut coil 122 provided in the power supply line 116 and is very small. Further, the capacitance component C is determined by the area of the chuck electrode 114 and the area of the upper surface of the mounting table 84, and depends on the size of the device, and thus becomes constant if the size of the device is determined.

  4A shows a state when the chuck switch 124 is switched from open to closed, and FIG. 4B shows a state when the chuck switch 124 is switched from closed to open. For reference, FIG. 4 shows a case of a conventional plasma processing apparatus by a broken line.

Here, the potential e (t) of the chuck electrode 114 is given by the following equation.
e (t) = E [1-e ^{(-t / RC)} ]
Here, e represents a natural logarithm (exp), RC represents a time constant, and t represents time.
As described above, since the resistance component R is very small as compared with the conventional plasma processing apparatus, the time constant “RC” is very small. Therefore, as shown in FIGS. 4A and 4B, in the case of the present invention, the transition time until stabilization is very short.

  As a result of the simulation with the size of the chuck electrode set to 3 m × 3 m in length and width, in the case of the conventional apparatus, the time L1 to stabilization was about 60 seconds, whereas this In the case of the invention, the time L2 to stabilization was about 10 seconds, and it was confirmed that the charge storage time and the charge discharge time can be shortened.

  In the conventional plasma processing apparatus shown in FIG. 16, the resistance component is the resistance component of the first resistor 26, the second resistor 28, the resistor 44, and the coils 24, 42, which is compared with the case of the present invention. Very large value. In addition, since the container component C has the same apparatus size, the apparatus of the present invention and the conventional apparatus are the same.

  As described above, in the mounting table mechanism 80 of the present invention, when the chuck switch 124 is closed and a DC voltage is applied to the chuck electrode 114, the DC component detection circuit 96 is bypassed and the mounting table 84 is grounded. The bypass switch unit that closes the unit 110 and further opens the chuck switch unit 124 to shut off the DC voltage applied to the chuck electrode 114, thereby bypassing the DC component detection circuit 96 and grounding the mounting table 84. Since 110 is closed, the time constant of the chuck equivalent circuit when the DC voltage is applied to the chuck electrode 114 and when the DC voltage applied to the chuck electrode 114 is cut off can be reduced. Product storage and charge discharge to the chuck electrode 114 can be performed quickly to improve product productivity. Raised, thereby improving the throughput.

  In addition, since the filter unit 118 that prevents high frequency power from entering the DC high voltage power source 120 is configured only by the high frequency cut coil 122 that is an induction element, the filter unit 118 is compared with the conventional plasma processing apparatus. Therefore, the resistance component R (see FIG. 3) in the chuck equivalent circuit can be reduced to further reduce the time constant. As a result, the charge storage time and the charge discharge time can be shortened to further improve the throughput.

Second Embodiment
Next, a second embodiment of the mounting table mechanism of the present invention will be described. FIG. 5 is a block diagram showing a main part of a second embodiment of the mounting table mechanism of the present invention. The same components as those shown in FIGS. 1 and 16 are denoted by the same reference numerals, and the description thereof is omitted.

  In the first embodiment, the filter unit 118 connected to the DC high-voltage power supply 120 is constituted by the high-frequency cut coil 122 that is an induction element, and the DC component is provided by the bypass line 108 in which the bypass switch unit 110 is interposed. Although the detection circuit 96 is bypassed when necessary, the present invention is not limited to this, and the filter unit 118 may be configured similarly to the conventional apparatus shown in FIG.

  That is, as shown in FIG. 5, here, the filter unit 118 is connected in series with the high frequency cut coil 42 and the resistor 44 in the same manner as the filter unit 38 shown in FIG. The other end is branched and grounded at the other end.

  The opening / closing operation of the chuck switch unit 124 and the bypass switch unit 110 in this case is the same as that described with reference to FIG. Also in the case of the second embodiment, as in the case of the first embodiment, the chuck equivalent when the DC voltage is applied to the chuck electrode 114 and the DC voltage applied to the chuck electrode 114 is cut off. The time constant of the circuit can be reduced, and as a result, charge storage and charge discharge with respect to the chuck electrode 114 can be performed quickly to increase product productivity and improve throughput.

  However, as compared with the case of the first embodiment, in the case of the second embodiment, the time constant increases by the amount of increase in the DC component (resistor 44) of the filter unit 118. The charge discharge time is slightly less rapid than in the first embodiment.

<Third Embodiment>
Next, a third embodiment of the mounting table mechanism of the present invention will be described. FIG. 6 is a block diagram showing a main part of a third embodiment of the mounting table mechanism of the present invention. The same components as those shown in FIGS. 1, 5, and 16 are denoted by the same reference numerals, and the description thereof is omitted.

  In the second embodiment shown in FIG. 5, the filter unit 118 is configured in the same manner as the conventional device shown in FIG. 16. However, the present invention is not limited to this, and instead of the resistor 44 in the filter unit 118, as shown in FIG. Another high frequency cutting coil 130 may be provided. That is, in this case, the filter unit 118 includes high frequency cut coils 42 and 130 that are inductive elements and a capacitor 46 that is a capacitive element. In this case, the high frequency is cut by the two high frequency cutting coils 42 and 130.

  The opening / closing operation of the chuck switch unit 124 and the bypass switch unit 110 in this case is the same as that described with reference to FIG. Also in the case of the third embodiment, as in the case of the first and second embodiments, when the DC voltage is applied to the chuck electrode 114 and when the DC voltage applied to the chuck electrode 114 is cut off. The time constant of the chuck equivalent circuit can be reduced, and as a result, the charge storage and the charge discharge with respect to the chuck electrode 114 can be performed quickly, thereby improving the productivity of the product and improving the throughput. it can.

  However, as compared with the case of the second embodiment, in the case of the third embodiment, the time constant becomes smaller by the amount of the decrease of the resistance 44 that is the resistance component of the filter unit 118. The charge discharge time can be made shorter than in the second embodiment.

<Fourth embodiment>
Next, a fourth embodiment of the mounting table mechanism of the present invention will be described. FIG. 7 is a block diagram showing a main part of a fourth embodiment of the mounting table mechanism of the present invention. The same components as those shown in FIG. 1, FIG. 5, FIG. 6 and FIG.

  In the previous third embodiment, the filter unit 118 connected to the DC high-voltage power supply 120 is constituted by the high-frequency cut coils 42 and 130 that are inductive elements and the capacitor 46 that is a capacitive element, and the bypass switch unit 110 is provided. Although the DC component detection circuit 96 is bypassed when necessary by the interposed bypass line 108, the present invention is not limited to this, and the bypass line 108 and the bypass switch unit 110 are not provided as shown in FIG. May be.

  The opening / closing operation of the chuck switch unit 124 in this case is the same as that described with reference to FIG. 2, but the bypass switch unit 110 shown in FIG. 2B is not used in the fourth embodiment. Also in the case of the fourth embodiment, as in the case of the first embodiment, the chuck equivalent when the DC voltage is applied to the chuck electrode 114 and the DC voltage applied to the chuck electrode 114 is cut off. The time constant of the circuit can be reduced, and as a result, charge storage and charge discharge with respect to the chuck electrode 114 can be performed quickly to increase product productivity and improve throughput.

  However, as compared with the case of the third embodiment, in the case of the fourth embodiment, the time constant is increased by the increase of the DC component (resistors 100 and 102) of the DC component detection circuit 96, and as a result, Charge storage time and charge discharge time are slightly less rapid than in the third embodiment. However, also in the case of the fourth embodiment, the resistance component is reduced correspondingly by replacing the resistor 44 in the filter unit 38 with the coil 130 for high frequency cut as compared with the conventional apparatus shown in FIG. As a result, the charge storage time and the charge discharge time can be shortened.

<Fifth Embodiment>
Next, a fifth embodiment of the mounting table mechanism of the present invention will be described. FIG. 8 is a block diagram showing a main part of a fifth embodiment of the mounting table mechanism of the present invention. The same components as those shown in FIG. 1 are denoted by the same reference numerals and the description thereof is omitted.

  In the previous first to fourth embodiments, the shower head portion 68 that is the upper electrode is in a grounded state. However, the present invention is not limited to this, and high frequency power may be applied to the shower head portion 68. . FIG. 8 shows a configuration in the case where high frequency power is applied to the shower head unit 68 using the apparatus shown in FIG. 1 as a representative, but the configuration described here is the same in all the first to fourth embodiments. Can be applied. That is, as shown in FIG. 8, here, the shower head portion 68, which is a gas introduction means, is attached to the ceiling portion of the processing container 52 via the insulating member 134.

  A high frequency line 136 is connected to the shower head unit 68, and a high frequency power source 140 is connected to the other end side with a matching circuit 138 interposed in the middle of the high frequency line 136. As the frequency of the high frequency power supply 140, for example, 450 kHz can be used. As a result, in the fifth embodiment, high frequency power can be applied to both the shower head portion 68 as the upper electrode and the mounting table 84 as the lower electrode from separate power sources.

  The opening / closing operation of the chuck switch unit 124 and the bypass switch unit 110 in this case is the same as that described with reference to FIG. Also in the case of the fifth embodiment, as in the case of the first embodiment, the chuck equivalent when the DC voltage is applied to the chuck electrode 114 and the DC voltage applied to the chuck electrode 114 is cut off. The time constant of the circuit can be reduced, and as a result, charge storage and charge discharge with respect to the chuck electrode 114 can be performed quickly to increase product productivity and improve throughput. In the fifth embodiment, the high-frequency power source 92 (including the matching circuit 90) connected to the mounting table 84 may be omitted without being provided.

<Evaluation for change in chuck electrode potential>
Here, since the simulation was performed by changing the area of the chuck electrode (the area of the mounting table) for the time until the chuck electrode 114 reaches the set voltage after the voltage application to the chuck electrode 114 was started, the evaluation result of the simulation Will be described.

  FIG. 9 is a diagram showing the relationship between the time from the start of voltage application to the chuck electrode until the set voltage is reached and the mounting table area. Here, as an evaluation target, the first embodiment shown in FIG. 1 (filter resistance is changed to a coil + bypass of DC component detection circuit), the second embodiment shown in FIG. 5 (bypass of DC component detection circuit), and FIG. The fourth embodiment (filter resistance is changed to a coil) is shown. As a comparative example, the conventional device shown in FIG. 16 was also evaluated.

FIG. 9A shows the arrival time until the set voltage is reached, and FIG. 9B shows the shortening rate of each arrival time when the arrival time of the conventional apparatus is used as a reference. Here it is changed variously table area and (≒ chuck electrode area) to 0.2m ² ~8.7m ^2. The applied voltage to the chuck electrode 114 is set to 3000V.

As shown in FIG. 9A, when the mounting table area is set so as to increase sequentially from 0.2 m ² to 8.7 m ² , the arrival time until reaching the set voltage gradually increases. ing. This is because the capacitance component formed between the chuck electrode and the mounting table gradually increases.

Here, considering each embodiment when the mounting table area is the same, for example, when the mounting table area is 8.7 m ² , the arrival time is 13.5 sec in the first embodiment and 29.5 sec in the second embodiment. The fourth embodiment is 44.3 sec, and the comparative example is 58.3 sec. Therefore, it can be understood that the order in which the effect of shortening the arrival time is favorable is the order of the first embodiment, the second embodiment, and the third embodiment, and the first embodiment is the best. The mounting table area this point true for all cases of 0.2m ² ~8.7m ^2.

  Here, as shown in FIG. 9B, when attention is paid to the shortening rate of each arrival time based on the arrival time of the conventional apparatus, it is constant for each embodiment regardless of the mounting table area. That is, the shortening rate of the first embodiment is 23 to 25% regardless of the mounting table area, and the shortening rate of the second embodiment is 76 to 78% regardless of the mounting table area. The ratio is 51 to 53% regardless of the mounting table area.

  Therefore, as described above, the reduction rate of the arrival time is substantially constant regardless of the mounting table area (≈chuck electrode area). Therefore, the plasma processing apparatus having a larger mounting table area has a shorter time to be shortened. As a result, if the present invention is applied to a plasma processing apparatus that performs plasma processing on a glass substrate having a large area with a size of about 3 m × 3 m, for example, the effect of shortening the arrival time can be greatly increased. Can understand.

<Sixth Embodiment>
Next, a sixth embodiment of the mounting table mechanism of the present invention will be described. FIG. 10 is a configuration diagram showing a main part of a sixth embodiment of the mounting table mechanism of the present invention. Note that the same reference numerals are given to the same components as those in the previous embodiment, and the description thereof is omitted.

  In each of the previous embodiments, the output voltage of the DC high-voltage power supply 120 was constant, for example, 3 kV. However, the present invention is not limited to this, and a plurality of types of DC voltages that can be switched and output can be applied. Good. When charge is stored in the chuck electrode 114, first, a high DC voltage is applied, and after a while, switching is performed to apply a normal low voltage DC voltage. ) May be performed quickly.

  FIG. 10 shows the main part of such a sixth embodiment. As shown in FIG. 10, in this sixth embodiment, the DC high-voltage power supply 120 can output and apply a plurality of types of DC voltages that can be switched. Here, the DC high-voltage power supply 120 has, for example, a variable output voltage, and can output DC voltages of various voltages within a range of 3 kV to 5 kV, for example. Specifically, as will be described later, 3 kV, which is a rated voltage when the chuck electrode 114 is normally applied, and 5 kV, which is higher than this, are used.

  Further, in the sixth embodiment, a potential for detecting the potential on the chuck electrode 114 side between the filter unit 118 formed by the resistance element 160 and the chuck switch unit 124 in the middle of the power supply line 116. A monitor unit 150 and a power source control unit 152 that controls the DC high-voltage power source 120 based on the output value of the potential monitor unit 150 are provided.

  Since the potential monitor unit 150 is formed of a resistance element or the like and it is difficult to directly detect the potential of the chuck electrode 114, here, the potential monitor unit 150 is connected to the power supply line 116 between the filter unit 118 and the chuck switch unit 124. It is installed. Therefore, it is inevitable that an error corresponding to a voltage drop in the filter unit 118 on the downstream side (chuck electrode 114 side) occurs in the detection value in the potential monitor unit 150. Although a large design change is required in an actual device, the potential monitor unit 150 may be provided in the middle of the power supply line 116 on the downstream side of the filter unit 118. In this case, the voltage drop of the filter unit 118 may be reduced. The error can be eliminated.

  Further, the power supply control unit 152 receives a confirmation signal when the chuck switch unit 124 is closed from the switch control unit 112, and the detection value sent from the potential monitor unit 150 becomes a predetermined value. In this case, the first DC voltage having a high voltage, for example, 5 kV, is switched from the second DC voltage having a low voltage, for example, 3 kV, and output.

  Next, the operation of the sixth embodiment will be described. First, prior to the description of the specific operation, a high voltage is first applied to the chuck electrode 114, and then the potential of the potential monitor unit 150 when switched to a low voltage, that is, the potential at the point P1 in FIG. The change will be described. FIG. 11 is a graph showing a change in potential at the point P1, which is a potential monitoring unit, after applying a DC voltage to the chuck electrode. FIG. 11A shows a change when a constant DC voltage of 3 kV is applied. FIG. 11B shows a change when a 5 kV DC voltage is applied only for the first slight period and then switched to 3 kV and applied by a solid line. Here, as the characteristics of the chuck electrode 114, the size is 3 m × 3 m in length and width, and the rated voltage is 3 kV. In FIG. 11, an empirical predicted value of the potential of the chuck electrode 114 is indicated by a one-dot chain line.

  As shown in FIG. 11A, when a constant DC voltage of 3 kV is applied to the chuck electrode 114 from the beginning, the potential at the point P1 gradually increases according to the time constant of the circuit as the charge is stored in the chuck electrode 114. It rises and takes 3 hours to reach 3 kV and stabilizes. Here, it takes about 15 seconds to reach 3 kV which is the same as the rated voltage of the chuck electrode 114. Incidentally, assuming that the applied voltage is the same at 3 kV, the size of the chuck electrode 114 is 9.8 sec when the size is 2.2 m × 2.5 m, and 8.0 sec when the size is 2.0 m × 2.3 m.

  On the other hand, as shown in FIG. 11B, the chuck electrode 114 is initially 5 kV which is a DC voltage (first DC voltage) higher than the rated voltage of the chuck electrode 114 for a predetermined period T4. When a voltage of 3 kV which is a low DC voltage (second DC voltage) is applied for a while after that, the potential at the point P1 rises more rapidly than in the case of FIG. The peak value immediately before switching becomes, for example, about 4 kV, and by switching to a low voltage after a predetermined period T4, the potential at the point P1 gradually decreases after reaching the peak and reaches 3 kV and stabilizes. ing.

  Here, paying attention to the potential of the chuck electrode 114, when the potential at the point P1 is about 4 kV, the potential of the chuck electrode 114 reaches 3 kV which is the rated voltage, and at this time, by switching to the DC voltage of 3 kV, the chuck electrode It can be seen that the potential of 114 can be maintained at 3 kV as it is. In the sixth embodiment, the potential of the chuck electrode 114 is increased more quickly by using the characteristics as described above.

  Next, the operation of the sixth embodiment using the characteristics shown in FIG. 11 will be described. FIG. 12 is a timing chart showing the switching timing of each switch unit, the potential of the potential monitor unit 150, and changes in the chuck applied voltage, and FIG. 13 is a flowchart for explaining the operation in the sixth embodiment.

  In FIG. 12, the opening / closing operation of the chuck switch section 124 in FIG. 12A, the opening / closing operation of the bypass switch section 110, the potential of the chuck electrode 114 in FIG. 12C, and the application of the high frequency power in FIG. The situation is the same as shown in FIG. 12E shows the potential detected by the potential monitor 150, and FIG. 12F shows the chuck applied voltage output from the DC high-voltage power supply 120.

  First, the switch control unit 112 grounds the mounting table 84 by closing the bypass switch unit 110 provided in the middle of the bypass line 108 (S1). Next, the switch control unit 112 closes the chuck switch unit 124 provided in the middle of the power supply line 116 so that the DC high voltage power source 120 applies a first DC voltage to the chuck electrode 114, that is, a high DC voltage. Application of 5 kV is started (S2). Steps S1 and S2 may be performed simultaneously.

  From this point, the state described above with reference to FIG. 11 is entered. That is, by applying 5 kV, the chuck electrode 114 is rapidly charged, and the potential rapidly rises. The switch control unit 112 informs the power supply control unit 152 when the chuck switch unit 124 is closed. This prevents the power supply control unit 152 from malfunctioning.

  Next, the potential detected by the potential monitor unit 150 provided in the middle of the power supply line 116 is input to the power supply control unit 152. The power supply control unit 152 determines in advance the potential detected by the potential monitor unit 150. It is determined whether or not it reaches a predetermined value, for example, 4 kV, and waits until it reaches 4 kV (NO in S3). If 4 kV is reached (YES in S3), the DC high-voltage power supply 120 is controlled. Then, the first DC voltage (5 kV) is switched to the second DC voltage (3 kV) having a lower voltage than this (S4). This 3 kV is the rated voltage of the chuck electrode 114. At this time, the potential of the chuck electrode 112 is about 3 kV of the rated voltage as described with reference to FIG. 11, and therefore, the charging can be quickly performed to the rated voltage quickly.

  Further, the period T4 in which the DC voltage of 5 kV is applied here is about 4 sec as a result as described with reference to FIG. Needless to say, the time of 4 sec varies depending on the size of the electrostatic chuck 86, the size of the first DC voltage, and the like.

  After switching to the second DC voltage in this way, the apparatus waits for a predetermined time T5, for example, about 5 to 10 seconds until the potential at the mounting table 84 is stabilized (NO in S5). When waiting for T5 (YES in S5), the grounding of the mounting table 84 is cut off by opening the bypass switch 110 (S6). The predetermined time T5 is a time required until the potential of the mounting table 84 is stabilized as described above. Then, a high frequency voltage from the high frequency power supply 92 is applied to the mounting table 84 (S7), and plasma processing is performed.

  As described above, in the sixth embodiment, when the chuck electrode 114 is charged (charged), the first DC voltage (for example, 5 kV) having a high voltage is first applied, and after a while, the above-described first DC voltage is applied. Since the second DC voltage (for example, 3 kV) lower than the first DC voltage is applied, the chuck electrode 114 can be charged more quickly. In FIG. 12C, a change in the potential of the chuck electrode 114 in the case of FIG. 2C is shown by a one-dot chain line, and the chuck is more quickly about 10 seconds than in the case of FIG. The charging to the electrode 114 was completed. The sixth embodiment can be applied to all the first to third and fifth embodiments except for the fourth embodiment of FIG. 7 in which the bypass line 108 is not provided.

<Seventh embodiment>
Next, a seventh embodiment of the mounting table structure of the present invention will be described. FIG. 14 is a configuration diagram showing the main part of the seventh embodiment of the mounting table structure of the present invention. Note that the same components as those in the previous sixth embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the sixth embodiment shown in FIG. 10, the potential monitor unit 150 is provided in the middle of the power supply line 116, and the power supply control unit 152 switches the applied DC voltage with reference to the detected value. In the seventh embodiment, the time is measured after the chuck switch 124 is closed, and the DC voltage to be applied is switched when a certain time has elapsed.

  That is, as shown in FIG. 14, here, the power supply line 116 is not provided with the potential monitor unit 150 provided in FIG. 10. Instead, the power supply control unit 152 is provided with a timer function (not shown). The elapsed time is measured by the timer function starting from a signal indicating that the chuck switch 124 is closed from the switch controller 112. Then, in response to the measurement time of the timer function having passed a predetermined time, the power supply control unit 152 applies a first DC voltage (5 kV) to a second DC voltage (5 kV) to the DC high-voltage power supply 120. A command is issued so that the output is switched to 3 kV).

  Here, the predetermined time for the switching is a length less than or equal to the period until the potential of the chuck electrode 114 reaches the rated voltage after the application of the first DC voltage to the chuck electrode 114 is started. Then, as determined from the graph shown in FIG. 11, the predetermined period is set to 4 sec, for example. The time of 4 seconds can be further shortened by configuring the filter unit 118 with an inductive element, and as described above, it also varies depending on the size of the chuck electrode 114 and the size of the first DC voltage. In addition, the predetermined time is set to be variable.

  The operation of the seventh embodiment is performed after the chuck switch unit 124 is closed instead of the determination of the detection value of the potential monitor unit 150 in step S3 of the flowchart of the sixth embodiment shown in FIG. The only difference is that it is determined whether (for example, 4 sec) has elapsed? The other steps are the same as those in the flowchart shown in FIG. Further, the switching timing of each switch unit and the mode of change of each voltage are the same as the timing chart shown in FIG. The seventh embodiment can be applied to all the first to third embodiments described above except for the fourth embodiment of FIG. 7 in which the bypass line 108 is not provided.

  Incidentally, in the sixth and seventh embodiments shown in FIGS. 10 and 14, a variable power supply capable of changing the output voltage is used as the DC high-voltage power supply 120, but instead of this, the DC high-voltage power supply shown in FIG. The first power supply unit 154A that outputs a first DC voltage, for example, 5 kV, and the second power supply unit 154B that outputs a second DC voltage, for example, 3 kV, are provided in parallel, The power supply units 154A and 154B may be switched and output by a switch unit 156 controlled by the power supply control unit 152. Here, the above 5 kV and 3 kV are merely examples, and it is needless to say that the numerical values are not limited thereto.

  In the sixth and seventh embodiments shown in FIGS. 10 and 14, the switch control unit 112 and the power supply control unit 152 are provided separately to facilitate understanding of the present invention. Of course, they may be provided integrally.

In each of the above embodiments, the plasma etching process has been described as an example of the plasma process. However, the present invention is applied to all plasma processing apparatuses that include an electrostatic chuck and perform plasma processing by generating plasma with high-frequency power. Can be applied. In each of the above embodiments, the mounting table 84 is not provided with a heating unit. However, for example, a resistance heater is provided on the mounting table 84 as a heating unit so that the object to be processed is heated to a predetermined temperature. It may be.
In addition, although a glass substrate for a liquid crystal display device, which is an insulator, has been described as an example of an object to be processed here, the present invention is not limited thereto, and other insulator substrates such as a ceramic substrate or a semiconductor wafer (semiconductor substrate) ) Can also be applied to the present invention.

It is a block diagram which shows 1st Embodiment of the plasma processing apparatus using the mounting base mechanism which concerns on this invention. It is a timing chart which shows the relationship between the timing of switching of the switch part for chuck | zipper and the switch part for bypass, and the timing of application of the potential of a chuck electrode, and high frequency electric power. It is a figure which shows the chuck | zipper equivalent circuit with respect to the DC voltage in the electrostatic chuck of a mounting base mechanism. It is a figure which shows the change of the electric potential of a chuck electrode. It is a block diagram which shows the principal part of 2nd Embodiment of the mounting base mechanism of this invention. It is a block diagram which shows the principal part of 3rd Embodiment of the mounting base mechanism of this invention. It is a block diagram which shows the principal part of 4th Embodiment of the mounting base mechanism of this invention. It is a block diagram which shows the principal part of 5th Embodiment of the mounting base mechanism of this invention. It is a figure which shows the relationship between time from the voltage application start to a chuck electrode until it reaches a setting voltage, and a mounting table area. It is a block diagram which shows the principal part of 6th Embodiment of the mounting base mechanism of this invention. It is a graph which shows the change of the electric potential of the point P1 which is an electric potential monitor part after applying a DC voltage to a chuck electrode. It is a timing chart which shows the change timing of each switch part, the voltage of a potential monitor part, and the change of a chuck applied voltage. It is a flowchart for demonstrating the operation | movement in 6th Embodiment. It is a block diagram which shows the principal part of 7th Embodiment of the mounting base structure of this invention. It is a figure which shows the modification of DC high voltage power supply. It is a block diagram which shows an example of the conventional plasma processing apparatus.

Explanation of symbols

46 Capacitor (capacitive element)
DESCRIPTION OF SYMBOLS 50 Plasma processing apparatus 52 Processing container 60 Exhaust means 68 Shower head part (gas introduction means)
DESCRIPTION OF SYMBOLS 80 Mounting base mechanism 84 Mounting base 86 Electrostatic chuck 92 High frequency power supply 94 Detection line 96 DC component detection circuit 98 High frequency cut coil 100 1st resistance 102 2nd resistance 108 Bypass line 110 Bypass switch part 112 Switch control part 114 Chuck electrode 116 Feed line 118 Filter unit 120 DC high voltage power supply 122 High frequency cut coil (inductive element)
124 Switch unit for chuck 126 Device control unit 130 Coil for high frequency cut (inductive element)
150 potential monitor unit 152 power supply control unit 154A first power supply unit 154B second power supply unit 156 switch unit W glass substrate (object to be processed)

Claims (26)

In a mounting table mechanism for mounting an object to be processed that is provided in a processing container that is evacuated and is subjected to a predetermined plasma processing using plasma generated by high-frequency power,
A mounting table made of a conductive member for mounting the object to be processed;
An electrostatic chuck which is disposed on the top surface of the mounting table and has a chuck electrode provided therein to adsorb the object to be processed;
A direct-current high-voltage power source connected via a feed line to apply a direct-current voltage that generates electrostatic force to the chuck electrode;
A switch unit for chuck that is interposed in the middle of the power supply line and is closed when the workpiece is adsorbed;
A DC component detection circuit connected to the mounting table to detect a DC component applied to the mounting table during the plasma treatment;
A bypass line that bypasses the DC component detection circuit;
A bypass switch unit that is interposed in the middle of the bypass line and bypasses the DC component detection circuit when the chuck switch unit is switched to a closed state and when the chuck switch unit is switched to an open state, and grounds the mounting table.
A switch control unit for controlling the two switch units;
A mounting table mechanism characterized by comprising: The mounting table mechanism according to claim 1, further comprising a filter unit interposed in the middle of the power supply line to prevent the high-frequency power from entering the DC high-voltage power source. The mounting table mechanism according to claim 2, wherein the filter unit includes a resistance element or a resistance element and a capacitance element. The mounting table mechanism according to claim 2, wherein the filter unit includes an inductive element or an inductive element and a capacitive element. 5. The mounting table mechanism according to claim 1, wherein the DC component detection circuit is connected to the mounting table via a detection line. 6. The switch control unit, when switching the chuck switch unit to a closed state, controls to switch the bypass switch unit to a closed state simultaneously with the switching or prior to switching. The mounting table mechanism according to claim 5. 7. The switch control unit according to claim 6, wherein the bypass switch unit is controlled to be opened when a predetermined time has elapsed after the chuck switch unit is switched from the open state to the closed state. Mounting table mechanism. 2. The switch control unit, when switching the chuck switch unit to an open state, controls to switch the bypass switch unit to a closed state simultaneously with the switching or prior to switching. The mounting table mechanism according to claim 7. 9. The switch control unit according to claim 8, wherein the bypass switch unit is switched to an open state when a predetermined time has elapsed after the chuck switch unit is switched from a closed state to an open state. Mounting table mechanism. In a mounting table mechanism for mounting an object to be processed that is provided in a processing container that is evacuated and is subjected to a predetermined plasma processing using plasma generated by high-frequency power,
A mounting table made of a conductive member for mounting the object to be processed;
An electrostatic chuck which is disposed on the top surface of the mounting table and has a chuck electrode provided therein to adsorb the object to be processed;
A DC high-voltage power supply connected via a power supply line provided with a filter part that prevents intrusion of high-frequency power in the middle in order to apply a DC voltage that generates electrostatic force to the chuck electrode;
A switch unit for chuck that is interposed in the middle of the power supply line and is closed when the workpiece is adsorbed;
A DC component detection circuit connected to the mounting table to detect a DC component applied to the mounting table during the plasma treatment;
A switch control unit for controlling the chuck switch unit,
The mounting table mechanism characterized in that the filter section is formed by a capacitive element and a dielectric element without including a resistance element. The DC high-voltage power supply is adapted to be able to apply a plurality of types of DC voltages that can be switched,
Furthermore, a potential monitor unit that is provided in the middle of the power supply line and monitors the potential on the chuck electrode side;
When the chuck switch is closed, a first DC voltage that is a higher voltage of the plurality of types of DC voltages is applied, and a low voltage is detected when the detection value of the potential monitor reaches a predetermined value. A power supply control unit that controls the DC power supply so as to switch and apply the second DC voltage;
The mounting table mechanism according to claim 1, wherein the mounting table mechanism is provided. The DC high-voltage power supply is adapted to be able to apply a plurality of types of DC voltages that can be switched,
The power supply control unit further controls the DC high-voltage power supply, and the power supply control unit initially includes a first DC having a higher voltage of the plurality of types of DC voltages when the chuck switch unit is closed. The mounting table according to any one of claims 1 to 10, wherein a voltage is applied and control is performed so that the second DC voltage is switched to a low voltage when a predetermined time elapses. mechanism. The predetermined time is a length of not more than a period until the potential of the chuck electrode reaches a rated voltage after the application of the first DC voltage to the chuck electrode is started. 12. The mounting table mechanism according to 12. 14. The first DC voltage is set higher than a rated voltage of the chuck electrode, and the second DC voltage is set to the rated voltage. The mounting table mechanism according to the item. 15. The output voltage of the DC high-voltage power supply is variable so that the first DC voltage and the second DC voltage can be output. The mounting table mechanism described. 15. The DC high-voltage power supply includes a first power supply unit that outputs the first DC voltage, and a second power supply unit that outputs the second DC voltage. The mounting table mechanism according to any one of the above. The mounting table mechanism according to claim 1, wherein the object to be processed is an insulator. In a plasma processing apparatus for performing a predetermined plasma process on an object to be processed,
A processing vessel that can be evacuated;
Gas introduction means for introducing a necessary gas into the processing container;
Exhaust means for evacuating the inside of the processing vessel;
The mounting table mechanism according to any one of claims 1 to 17, for mounting the object to be processed in the processing container,
A plasma processing apparatus characterized by comprising: The gas introduction means comprises a shower head portion, and is configured to form a parallel plate type upper electrode and lower electrode by the shower head portion and the mounting table of the mounting table mechanism. 18. The plasma processing apparatus according to 18. The plasma processing apparatus according to claim 19, wherein a high-frequency power source is connected to the mounting table. 21. The plasma processing apparatus according to claim 18, wherein a second high-frequency power source is connected to the shower head unit. The plasma processing apparatus according to claim 18, wherein the object to be processed is a semiconductor substrate or an insulator substrate. In the method of applying a voltage to an electrostatic chuck provided on a mounting table on which a workpiece to be plasma-treated is placed in a processing vessel that has been evacuated and a high-frequency voltage can be applied.
A first DC voltage, which is a higher voltage among a plurality of types of DC voltages, is applied to the chuck electrode of the electrostatic chuck, and the mounting table is mounted simultaneously with or prior to the application of the first DC voltage. Try to ground
Switching to a second DC voltage lower than the first DC voltage when a predetermined time has elapsed from the start of application of the first DC voltage,
When the predetermined time has elapsed from the switching to the second DC voltage, the grounding of the mounting table is cut off, and after the grounding of the mounting table is cut off, a high frequency voltage is applied to the mounting table. Applying voltage to the electrostatic chuck. The method of applying a voltage to an electrostatic chuck according to claim 23, wherein the predetermined time from the start of application of the first DC voltage is predetermined. The predetermined time from the start of application of the first DC voltage is equal to or less than a period until the potential of the chuck electrode reaches a rated voltage after starting application of the first DC voltage to the chuck electrode. The method for applying a voltage to an electrostatic chuck according to claim 23, wherein the voltage is a length. The electrostatic discharge according to any one of claims 23 to 25, wherein the predetermined time from the switching to the second DC voltage is a time until the potential of the mounting table is stabilized. Voltage application method to the chuck.

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