JPH06204325A - Electrostatic attraction device and its method - Google Patents

Abstract

PURPOSE:To provide the monitoring method for an electric attraction device which becomes the means of confirmation whether the warpage of wafer is corrected and completely fixed by the electric attraction device. CONSTITUTION:The dielectric and the electrode plate of an electrostatic attraction type sample holding device are divided into two or more parts and formed into paired structures 2 and 5, 3 and 6 and 4 and 7. Power sources 8, 9 and 10, having a power source which independently generates potential difference, and devices 11, 12 and 13, which measure the current flowing to circuits, are provided. The flattened state of a wafer 1 is judged by the measured current value, and the value of voltage is controlled by a controller 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic chucking device and a chucking method therefor, and is particularly suitable for fixing and holding a sample to be subjected to fine processing such as a conductor or a semiconductor such as a silicon wafer. The present invention relates to an electrostatic adsorption device and its adsorption method.

[0002]

2. Description of the Related Art For example, for a sample such as a semiconductor wafer,
When a film is formed by etching, sputtering, vapor phase epitaxy (CVD) or the like, it is necessary to fix and hold the sample at a predetermined position of the device. In particular, when processing a fine pattern on a semiconductor wafer, for the purpose of patterning the wafer, the warp is corrected and flattened, or the spatter and the thermal conductivity at the time of film formation are improved. ,
It is required that the wafer be securely fixed to the holding means.

Conventionally, as a sample holding means for such an application, an electrostatic adsorption device which can be used even in a vacuum and which can generate an adsorption force on the entire back surface of a wafer has been used. Furthermore, because the wafer can be held in a vacuum,
It is also used as a holding device for high-speed transportation in vacuum. This electrostatic adsorption device is configured by stacking (laminating) an electrode plate and a dielectric substance, and by generating a potential difference between the electrode plate and the sample, a Coulomb force is generated and the sample is adsorbed on the dielectric substance. It is to hold it. Regarding such an electrostatic adsorption device, for example, Japanese Patent Laid-Open Nos. 58-114437 and 59-79545 are known.

[0004]

By the way, as already mentioned, when a fine pattern is processed on a semiconductor wafer by etching, sputtering, CVD, etc. in the semiconductor manufacturing process, the warp of the wafer is corrected to flatten it. In order to improve the thermal conductivity, it is necessary to firmly fix the wafer to the holding means. However, in the disclosed example disclosed in Japanese Patent Laid-Open No. 58-114437, the means for confirming whether or not the warp of the wafer has been corrected by the electrostatic attraction device and whether the wafer has been securely fixed is not considered.

Further, in the disclosed example disclosed in Japanese Patent Laid-Open No. 59-79545, according to the value of the current flowing in the circuit constituting the electrostatic attraction device as the electrostatic attraction confirmation means,
Although it is used to confirm whether or not the wafer is fixedly held, different films are formed on the attracted surface of the wafer that has undergone the process depending on the type of the process, and the resistance value is different. The criterion for judging whether or not the current level was truly flattened was not clear and was insufficient. Further, in each of the above-described disclosure examples, the voltage application method, that is, the method of attracting the voltage is not taken into consideration, and the wafer flatness is not effectively corrected.

The present invention has been made in order to solve the above-mentioned problems of the prior art. The object of the present invention is, first of all, to correct the warp of the wafer and to securely suck and fix the object to be held. An object of the present invention is to provide an electrostatic adsorption device that can confirm the above. Secondly, it is to provide a voltage applying method for an electrostatic attraction device capable of monitoring whether or not a held object is securely attracted and fixed, and whether or not it is flattened.

[0007]

In order to achieve the above first object, the structure of the first invention relating to the electrostatic chucking device of the present invention is such that an electrode plate and a dielectric are stacked and In an electrostatic adsorption device that attracts the held object to the dielectric by generating a potential difference between the held object, the electrode plate, or the electrode plate and the dielectric is divided into two or more, and, As a structure in which the divided portions are electrically insulated, a power source for independently generating a potential difference and a means for measuring a current flowing through each circuit are provided.

Further, in order to achieve the above first object,
The configuration of the second invention relating to the electrostatic chucking device of the present invention is to stack the electrode plate and the dielectric and to generate a potential difference between the electrode plate and the held object, thereby holding the held object on the dielectric. In an electrostatic attraction device for attracting an object, a dielectric and an electrode plate that generate the attraction force are stacked independently of the dielectric and the electrode plate, respectively, independently of the means that generates the attraction force. Two or more suction confirmation means provided with a power source for generating a potential difference and a means for measuring a current flowing through each circuit are provided so as to be insulated from the electrode plate of the means for generating the suction force.

In order to achieve the above-mentioned second object, the structure of the adsorption method of the electrostatic adsorption device according to the present invention is such that the electrode plate and the dielectric are stacked and the potential difference between the electrode plate and the held object is In the electrostatic adsorption method of adsorbing the held object to the dielectric by generating the above, the electrode plate, or the electrode plate and the dielectric are insulated from each other and divided into two or more, respectively A power supply for generating a potential difference and a suction confirmation means are provided, and the magnitude of the voltage applied to each of the divided electrostatic attraction portions according to the information from the suction confirmation means, and the start time of each voltage application. Are to be changed independently of each other.

More specifically, when it is determined that the object to be held is deformed to have a downward convex shape, the attraction confirmation means first performs electrostatic attraction at the central portion of the electrostatic attraction section divided into two or more. Voltage is applied to the electrodes of the electrostatic chucking section, and then sequentially toward the electrodes of the electrostatic chucking section of the peripheral section until the chucking confirmation means provided in each electrostatic chucking section confirms the chucking of the held object. Is applied.

Further, when it is determined that the held object is deformed into a convex shape, the suction confirmation means, first, one electrostatic attraction of the outermost portion of the electrostatic attraction unit divided into two or more. Voltage is applied to the electrodes of the parts until the adsorption confirmation means confirms the adsorption, and then the static electricity is adsorbed to the electrodes of the electrostatic adsorption part in the central part and the outermost peripheral part on the opposite side to the first adhering part. The adsorption confirmation means provided in the electroadsorption unit applies a voltage until the adsorption of the held object is confirmed. Further, in the electrostatic adsorption device, after the adsorption of the held object is completed, the voltage is gradually reduced to release the adsorption, the voltage is applied again to adsorb the retained object, and then the adsorption is released. The voltage is set to a value slightly higher than the applied voltage.

The additional notes are as follows. The first object is to have a power source for dividing the electrode plate of the electrostatic adsorption type sample holding device, or the dielectric and the electrode plate into two or more by insulating them from each other and independently generating a potential difference. This is achieved by adding a circuit and means for measuring the current flowing through each circuit.

The second object is to have a structure in which the electrostatic attraction portion of the electrostatic attraction device is divided into two or more parts and has a power source for independently generating a potential difference and an attraction confirmation means. Based on the information from (1), control is performed to change the divided electrostatic attraction portions, the magnitude of the voltage applied to each, and the start time of each voltage application. Further, it can be achieved by applying a large voltage only when starting the adsorption and once controlling the voltage so that the voltage is lowered after the adsorption.

[0014]

The sample holding device of the present invention has an electrode plate, or a dielectric and an electrode plate, which are insulated from each other and have a divided structure. Each sample holding device has a power source for independently generating a potential difference and further flows to each circuit. It is configured to measure current. Therefore, it can be determined that the flattening is achieved and the attraction and holding is surely performed when all the current values flowing in the electrostatic attraction portions having the divided structure have the same value. If flattening is not achieved and, for example, the wafer still has a warp, one of the divided electrostatic attraction portions is not in contact with the wafer and no current flows. At this time, the voltage applied to the electrostatic attraction portion may be increased.

Further, when the flattening is not achieved and the warp remains on the wafer, the portion for electrostatic attraction is divided,
By controlling the divided electrostatic adsorption parts, the magnitude of the applied voltage to each, and the start time of each voltage application according to the information from the adsorption monitor, the uniform force is applied to the entire adsorption surface. It is possible to effectively flatten the wafer rather than to generate.

[0016]

Embodiments of the present invention will be described below with reference to FIGS.
Will be described with reference to. [Embodiment 1] FIG. 1 is a cross-sectional view showing the structure of an electrostatic chucking device according to one embodiment of the present invention, and FIG. 2 is an enlarged view of a principal part for explaining a wafer chucking action in the device of FIG. Figure 1,
In reference numeral 2, 1 is a held object that is fixedly held and conveyed, such as a semiconductor wafer (hereinafter simply referred to as a wafer),
Reference numerals 2, 3 and 4 are divided dielectrics constituting the electrostatic adsorption device, reference numerals 5, 6 and 7 are divided electrode plates constituting the electrostatic adsorption device, and 14 is taken from the wafer 1. Conductive portions 8, 9, 10 are used for the wafer 1 and the electrode plates 5, 6, 6.
A power source for generating a potential difference between the
Is an ammeter that detects the current flowing through each circuit. The dielectrics 2, 3 and 4 are stacked and laminated on the electrode plates 5, 6 and 7, and 16 is an insulating material that electrically insulates the divided parts.

The conducting portion 14 is in contact with the wafer 1 via a weak spring system 15 in order to ensure conduction from the wafer 1. The resistivity of the dielectrics 2, 3 and 4 is preferably 10 ⁹ m to 10 ¹¹ Ωcm at the operating temperature. Each of the above-mentioned dielectrics 2, 3, 4, electrode plates 5, 6, 7, power supplies 8, 9, 10,
The ammeters 11, 12, and 13 form an adsorption monitor that should be called an adsorption confirmation sensor. Reference numeral 17 denotes each power source 8 according to the information on the distance sent from each sensor.
It is a control device for controlling the voltage applied by 9 and 10. 18 indicates a ground.

The operation of the monitoring method in the electrostatic attraction device having the above structure will be described. First, the wafer 1 is placed on the attraction surfaces 2 ′, 3 ′, 4 ′ of the electrostatic attraction device, and a predetermined voltage is applied by the power sources 8, 9, 10 to the electrode plate 5, 5.
It is applied between 6, 7 and the wafer 1. Then, the wafer 1 is attracted to the attracting surface 2 ′ by the electrostatic force generated at this time,
Adsorbed and held on 3 ', 4'

Since the dielectrics 2, 3 and 4 are made of the same material and have the same resistivity, if the wafer 1 is surely flattened, each circuit has a dielectric. The same current is flowing per unit area of the body, and the ammeters 11, 12, and 13 detect the same current value when converted into the unit area of each dielectric. That is, for example, the dielectric 2,
If the contact areas with the wafers 3 and 4 are the same, the current values are the same. Although the dielectrics are made of the same material in the above case, the method of the present invention can be achieved by calibrating the current value in advance even if the materials are different.

If the deformation of a part of the wafer 1 is not corrected and it is not in contact with the dielectrics 2, 3 and 4, the current flowing through the circuit constituting the electrostatic adsorption device at that part is not affected. It shows a smaller value than others. For example, as shown in FIG. 2, the wafer 1 is convexly deformed downward, and is not in contact with the dielectric 4 of the electrostatic attraction device in the peripheral portion of the wafer 1. The electrostatic force cannot overcome the deformation force of the wafer 1 and the gap h is open. In this case, the ammeter 13 shows a smaller current value than the ammeter 12. If there is no contact, the current value shows zero.

As described above, the electrostatic attraction device having the divided structure having the independent circuit is used to compare the values of the currents flowing in the respective circuits. Ask them to decide whether they have followed 2 ', 3', 4 '.
By this, the entire surface of the wafer 1 is securely fixed and held, and it is monitored whether or not the flattening is achieved. If the current value detected by one of the ammeters is lower than the other, the applied voltage at that portion may be increased to increase the attraction force. The electrostatic attraction force causes the wafer 1 to warp, and the wafer 1 and the attraction surface 2
When there is a gap between ′, 3 ′ and 4 ′, the value is small and a comparatively large voltage is required, but once it is fixed by suction, there is no gap between the wafer 1 and the suction surface. In addition, the voltage for maintaining the adsorption may be a relatively small voltage.

Therefore, after increasing the voltage, it is possible to determine that the flattening has been achieved by promptly lowering it to the same voltage as the others and showing a current value equivalent to the others. In addition, if the threshold value of a certain voltage is determined and the voltage cannot be flattened even if the voltage is increased more than that value, the control device 17 controls the wafer 1 so that it is judged to be defective because it has too much initial deflection. It will allow the process to proceed more smoothly.

As described above, the electrostatic attraction force is small when the wafer 1 is warped and there is a gap between the wafer 1 and the attraction surface, and a relatively large voltage is required. If fixed by suction, there is no gap between the wafer 1 and the suction surface, and therefore the voltage for maintaining suction may be a relatively small voltage. Therefore, if a large voltage is applied to the control device 17 only when the adsorption is started and the voltage is controlled so that the voltage is once dropped after the adsorption, it is not necessary to apply a voltage higher than necessary to the wafer 1 for a long time. It also saves power.

[Embodiment 2] In the above-mentioned Embodiment 1, the so-called monopolar type electrostatic adsorption device of the type in which each circuit has one electrode plate and which conducts electricity from the wafer has been described.
Similarly, the monitor operation can be performed in the bipolar electrostatic adsorption device as shown in FIG. FIG. 3 is an explanatory diagram showing a configuration of a bipolar electrostatic attraction device according to another embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 1 have the same functions as those of the previous embodiment. In this case, the electrode plates are 5a, 5b, 6a, 6
A voltage is applied between the electrodes of each of b, 7a, and 7b. Further, in the present embodiment, an example of a structure in which both ends and a central part are divided has been shown, but the present invention is not limited to this structure in particular, and the same effect can be obtained even if the structure is divided into concentric circles.

[Embodiment 3] Next, an embodiment of the second invention will be described with reference to FIG. FIG. 4 is a cross-sectional view showing the configuration of the electrostatic attraction device according to still another embodiment of the present invention. In the figure, those having the same reference numerals as those in FIG. In FIG. 4, 1
Reference numeral 9 is a dielectric, and 23 is an electrode plate, which are stacked to form an electrostatic attraction device. Reference numerals 20, 21, 22 are a plurality of independent dielectric bodies (three in this example) having a small cross-sectional area with respect to the dielectric body 19, and 24, 25, 26 are laminated with the dielectric bodies 20, 21, 22 respectively. The electrodes are provided with power supplies 28, 29, 30 and ammeters 31, 32, 33, respectively. That is, the dielectric 1
9, the pair of electrodes 23 is made to play a role of electrostatic attraction, and the pair of dielectrics 20, 21, 22 and electrodes 24, 25, 26 are suction confirmation sensors for confirming whether or not the held object is attracted. That is, it acts as a monitor.

Since the dielectrics 20, 21 and 22 are made of the same material and have the same resistivity, if
If the wafer 1 as the held object is surely flattened, the same current flows in each circuit per unit area of the dielectric. If the dielectrics 20, 21, 22 have the same surface area, the ammeters 31, 32, 33 detect the same current value. When the deformation of a part of the wafer 1 is not corrected and the flattening is not achieved, the current flowing through the circuit that constitutes the electrostatic adsorption device in that part shows a smaller value than the other. If there is no contact, the current value shows zero.

As described above, a dielectric having an independent circuit,
By embedding the electrode pairs 20, 24, 21, 25, 22, and 26 in the dielectrics and electrode pairs 19 and 23 that perform electrostatic adsorption, and comparing the current values flowing in the respective circuits, the wafer 1 , It is determined whether or not it follows the electrostatic attraction surface 19 '. By this, the entire surface of the wafer 1 is securely fixed and held, and it is monitored whether or not the flattening is achieved. If the current value detected by one of the ammeters is lower than the other, the applied voltage to the electrostatic attraction device may be increased to increase the attraction force.

In this embodiment, the dielectric and the electrode plate for electrostatic attraction are each shown as one piece, but as shown in the first embodiment, they are divided into a plurality of pieces and are independently formed. An electric circuit may be provided to independently generate the suction force.

[Fourth Embodiment] In the third embodiment,
The so-called unipolar electrostatic adsorption device, which has a single electrode plate for the electrostatic adsorption device and is electrically connected from the wafer, has been described, but similar monitoring operation is also possible with a bipolar electrostatic adsorption device. is there. FIG. 5 is an explanatory diagram showing a configuration of a bipolar electrostatic attraction device according to still another embodiment of the present invention. In the figure, those having the same reference numerals as those in FIG. 4 have the same functions as those of the previous embodiment. In the apparatus shown in FIG. 5, the electrode plates that perform electrostatic attraction are 23a and 23b, and the electrode plates that monitor adsorption are 20a, 20b, 21a, 21b, and 2.
2 a and 22 b each. Further, as shown in FIG. 3, the same effect can be obtained even with a structure having a plurality of dielectrics and electrode plates that perform electrostatic attraction.

[Embodiment 5] Next, an embodiment of the electrostatic attraction method of the present invention will be described with reference to FIGS. 6 to 14. In this embodiment, an electrostatic chucking device using the wafer chucking monitor shown in the embodiment of the second invention will be described as an example.
FIG. 6 is an explanatory view showing the overall structure of an electrostatic attraction device according to still another embodiment of the present invention, FIG. 7 is a cross-sectional view showing a state in which the wafer is convexly deformed downward, and FIG. FIG. 9 is a cross-sectional view showing a state where the wafer is attracted, and FIG. 9 is a diagram illustrating a method of applying a voltage to the electrostatic attraction device of FIG.

Since the electrostatic force decreases in proportion to the square of the distance of the gap, flattening may not be achieved when the amount of deformation of the wafer is large and the gap between the wafer and the dielectric is large. In FIG. 6, the dielectrics that perform electrostatic attraction are 34 and 3
It is divided into three parts, 5 and 36, and each has an electrode plate 3
7, 38, 39 and power sources 40, 41, 42 are provided. Dielectrics 34, 35, 36 that perform electrostatic attraction
A pair of a plurality of dielectrics 20, 21, 22 and electrodes 24, 25, 26 having a small cross-sectional area with respect to them, a power supply 28, 29, 30 and an ammeter 31, 32, 33 respectively.
The built-in suction monitor is associated with the suction confirmation means.

First, an example of a specific suction method will be described with reference to FIGS. 7 to 9 when the wafer 1 is deformed to be convex downward. 7 and 8, the illustration of the power supply system as shown in FIG. 6 is omitted. Electrode plate 37,3
A predetermined voltage V1 is applied to 8 and 39 to generate an attractive force. It is sufficient if the flattening is achieved by this, but the flattening is not achieved when the deformation amount of the wafer 1 is large and the gap between the wafer 1 and the dielectric is large.

In such a case, first, the electrode plates 37 at both ends are
The applied voltage to 39 is the adsorption monitor dielectric, electrode pair 2
Increase until 0, 24, 21, 25, 22, 26 detect flattening (voltages V2, V3). In this case, the smaller the gap, the greater the attraction force to the wafer 1,
Areas 43, 4 where the wafer leaves the suction surfaces 34 ', 36'
From 4, it is gradually adsorbed toward the outside and is flattened.

By the way, it is preferable that the applied voltage is small in order to protect the elements on the wafer. Once suctioned and flattened, the wafer 1 and suction surfaces 34 ', 35', 3
6'has no gap, and the suction force is larger than when the wafer 1 was deformed and there was a gap. Therefore, the applied voltage can be reduced only to maintain the adsorption. When the predetermined voltage is determined in advance, it may be lowered to that voltage. In particular, when the predetermined voltage is not determined, it is preferable to use the lowest voltage for maintaining the adsorption because damage to the wafer 1 is reduced. If the wafer 1 separates during the process of dropping it to a predetermined voltage, or if the wafer 1 separates when the voltage is lowered to find the lowest voltage (voltage V
In step 4), the voltages V1, V2, and V3 are applied once again to attract the wafer 1, and the voltage V5 may be set to be slightly higher than the voltage V4 at which the wafer 1 has come off again.

Next, the case where the wafer 1 is deformed to be convex upward will be described with reference to FIGS. 10 to 14. 10 is a sectional view showing a state where the wafer is convexly deformed upward, FIG. 11 is a sectional view showing a state where only the peripheral portion of the wafer is adsorbed, and FIG. 12 is a sectional view showing one peripheral portion of the wafer. FIG. 13 is a cross-sectional view showing a state where the wafer is attracted, FIG. 13 is a cross-sectional view showing a state where the wafer is attracted to the front surface, and FIG. 14 is a diagram illustrating a method of applying a voltage to the electrostatic attraction device of FIG. 10 to 13, the illustration of the power supply system as shown in FIG. 6 is omitted.

A predetermined voltage V1 is applied to the electrode plates 37, 38 and 39.
Is applied to generate a suction force. When the amount of deformation of the wafer 1 is large and the gap between the wafer 1 and the dielectric is large, as shown in FIG. 11, only the peripheral portion of the wafer 1 is adsorbed to the adsorption surfaces 34 'and 36', and the central portion is not adsorbed. In order to correct the deformation of the wafer 1 in the central portion, the wafer 1 has to extend by the amount of the deformation toward the peripheral portion. However, in this case, since the wafer 1 is adsorbed and constrained at the peripheral portion, it is difficult to correct the deformation even if the voltage applied to the central electrode plate 38 is increased. Therefore, the applied voltage is once dropped (t2), and the voltage is applied again to either one of the adsorption portions at the end of the wafer 1.

In this embodiment, a voltage is applied to the electrode plate 39 of the dielectric 36 (FIG. 12). The voltage is applied until the dielectric and electrode pairs 22 and 26 which are adsorption monitors detect adsorption (V1). In this case, the wafer 1 is attracted to the suction surfaces 36 ', 3 as it goes to the central portion of the wafer as shown in the figure.
It is away from 5 '. Next, the electrode plate 3 on the central attraction surface
8. Adsorption monitor pair of dielectric and electrode 21, 25
The voltage is applied until V detects the adsorption (V2). As already described, the smaller the gap, the greater the attraction force to the wafer 1, so that the wafer 1 is gradually attracted inward from the portion 47 separated from the attraction surfaces 35 'and 36.

Finally, the electrode plate 37 on the adsorption surface 34 '
Then, a voltage is applied until the adsorption monitor detects the adsorption by the pair of dielectric and electrode 20, 24 (V3). By doing so, it becomes possible to effectively achieve the flattening. Further, as described in the embodiment of FIGS. 7 to 9, if the device is used at a predetermined voltage or the lowest voltage for maintaining adsorption, the element protection on the wafer and power saving can be achieved.

In this way, the dielectric that is the adsorption monitor,
From electrode pairs 20, 24, 21, 25, 22, 26,
In response to the signal indicating whether or not it has been attracted, the controller 17 controls the voltage applied to the electrodes 37, 38, 39 of each of the divided electrostatic attraction units.
If it is controlled by the method, effective electrostatic adsorption can be performed, damage to the wafer 1 can be minimized, and power consumption can be saved.

The present invention relates to a method for effectively performing electrostatic adsorption. In the present embodiment, an example using an adsorption monitor including a dielectric, an electrode, a power supply, and an ammeter has been described, but the adsorption monitor method is not particularly limited, and for example, a displacement sensor, a capacitance sensor, or the like may be used. The same effect can be obtained as a monitoring means.

[0041]

As described above in detail, according to the present invention, it is possible to provide an electrostatic chucking device capable of correcting the warp of a wafer and confirming that the held object is securely sucked and fixed. it can. Further, according to the present invention, it is possible to provide a voltage application method for an electrostatic attraction device capable of monitoring whether or not the held object is securely attracted and fixed, and whether or not the held object is flattened.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of an electrostatic attraction device according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part for explaining a wafer suction action in the apparatus of FIG.

FIG. 3 is an explanatory diagram showing a configuration of a bipolar electrostatic attraction device according to another embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a configuration of an electrostatic attraction device according to still another embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a configuration of a bipolar electrostatic attraction device according to still another embodiment of the present invention.

FIG. 6 is an explanatory diagram showing an overall configuration of an electrostatic attraction device according to still another embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a state in which the wafer is convexly deformed downward.

FIG. 8 is a cross-sectional view showing a state where a wafer is attracted.

9 is a diagram illustrating a method of applying a voltage to the electrostatic attraction device of FIG.

FIG. 10 is a cross-sectional view showing a state where the wafer is convexly deformed upward.

FIG. 11 is a cross-sectional view showing a state where only the peripheral portion of the wafer is sucked.

FIG. 12 is a cross-sectional view showing a state where one peripheral portion of the wafer is sucked.

FIG. 13 is a cross-sectional view showing a state where a wafer is adsorbed on the entire surface.

FIG. 14 is a diagram illustrating a method of applying a voltage to the electrostatic attraction device of FIG.

[Explanation of symbols]

1 wafers 2, 3, 4, 19, 20, 21, 22, 3
4,35,36 Dielectric 5,6,7,23,24,25,26,37,38,3
9 electrode plates 8, 9, 10, 27, 28, 29, 30, 40, 41,
42 power supply 11, 12, 13, 31, 32, 33 ammeter 16 insulating material 17 controller

Claims (8)

[Claims] 1. An electrostatic chucking device for stacking an electrode plate and a dielectric material and causing a potential difference between the electrode plate and the held object to attract the held object to the dielectric material, The electrode plate is divided into two or more parts, and the divided part is electrically insulated, and a power source for independently generating a potential difference and a means for measuring a current flowing in each circuit are provided. An electrostatic chucking device. 2. An electrostatic attraction device for stacking an electrode plate and a dielectric material, and causing a potential difference between the electrode plate and the held object to attract the held object to the dielectric material, wherein the electrode Divide the plate and the dielectric into two or more, and
An electrostatic adsorption device characterized in that a power source for independently generating a potential difference and a means for measuring a current flowing through each circuit are provided as a structure in which the divided portions are electrically insulated. 3. An electrostatic adsorption device for stacking an electrode plate and a dielectric material, and causing a potential difference between the electrode plate and the held object to attract the held object to the dielectric material. The dielectric and the electrode plate are stacked independently of each other in the dielectric and the electrode plate for generating force, and the power source for generating the potential difference and the current flowing in each circuit are respectively independent of the means for generating the attraction force. 2. An electrostatic adsorption device, characterized in that two or more adsorption confirmation means provided with a measurement means are provided so as to be insulated from the electrode plate of the means for generating the adsorption force. 4. An electrostatic adsorption method for stacking an electrode plate and a dielectric, and causing a potential difference between the electrode plate and the held object to attract the held object to the dielectric, at least the The electrode plate is configured to have a power source that independently insulates each other and divides into two or more, and that independently generates a potential difference and an adsorption confirmation unit, and electrostatically divided by the information from the adsorption confirmation unit. A method for attracting an electrostatic attraction device, wherein the magnitude of a voltage applied to each attraction portion and the start time of each voltage application are independently changed. 5. An electrostatic adsorption method in which an electrode plate and a dielectric are stacked, and a potential difference is generated between the electrode plate and the held object to attract the held object to the dielectric, wherein the electrode The plate and the dielectric are insulated from each other and divided into two or more parts, each of which has a power source for independently generating a potential difference and an adsorption confirmation means, and is divided by the information from the adsorption confirmation means. A method for attracting an electrostatic attraction device, characterized in that the magnitude of a voltage applied to each electrostatic attraction portion and the start time of each voltage application are independently changed. 6. The attraction confirmation means, when it judges that the held object is deformed in a downward convex shape, first, the electrostatic attraction portion of the central portion of the electrostatic attraction portion divided into two or more is detected. Voltage is applied to the electrodes, and then sequentially toward the electrodes of the electrostatic attraction section in the peripheral portion, the attraction confirmation means provided in each electrostatic attraction section applies voltage until the attraction of the held object is confirmed. The adsorption method for an electrostatic adsorption device according to claim 4, wherein 7. The suction confirmation means, when it judges that the held object is deformed into a convex shape, first, one electrostatic suction of the outermost part of the electrostatic suction portion divided into two or more. Voltage is applied to the electrode of the part until the adsorption confirmation means confirms the adsorption,
Then, the attraction confirmation means provided in each electrostatic attraction portion sequentially attracts the held object toward the electrode of the electrostatic attraction portion of the central portion and the outermost peripheral portion on the opposite side from the first attraction. 5. A voltage is applied until confirmation is made.
Alternatively, the electrostatic adsorption device according to any one of 5 above. 8. In the electrostatic adsorption device, after the adsorption of the held object is completed, the voltage is gradually reduced to release the adsorption,
Apply voltage again to adsorb the held object, then
8. The adsorption method for an electrostatic adsorption device according to claim 4, wherein the voltage is set to a value slightly higher than the released voltage.