JP2001085506A - Electrostatic chuck and unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate discharge short-circuiting and to make usable continuously from an open air pressure to vacuum when a voltage is applied to the inner electrodes of a channel out of inner electrodes of two channels through electrode terminals of the one channel by inhibiting a potential difference in inner electrodes and electrode terminals of the other channel. SOLUTION: Electrodes of two channels of inner electrodes A11 and inner electrodes B12 are arranged inside an electrostatic chuck 10, and are electrically connected to the outside of the electrostatic chuck through electrode terminals A13 and electrode terminals B14, respectively. The inner electrodes A11 and the inner electrodes B12 are arranged on the same plane inside the electrostatic chuck 10. When a voltage is applied to inner electrodes of one channel, since the inner electrodes of the other channel are independent, no current leaks, and degradation of attracting to an object is prevented. The inner electrodes A11 and the inner electrodes B12 are so arranged that, between a positive electrode and a negative electrode of one channel, an electrode of the other channel is positioned with equal spacing. As a result, the electrostatic chuck is free from discharge short-circuiting and can be used continuously from an open air pressure to vacuum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic chuck and a unit mainly used in a semiconductor manufacturing apparatus for processing a sample such as a silicon wafer or a glass substrate and a flat panel display manufacturing apparatus.

[0002]

2. Description of the Related Art In a conventional semiconductor manufacturing process, there are many steps of processing a sample under a reduced pressure environment. The procedure for loading, processing, and unloading the sample into the semiconductor manufacturing apparatus in this case is roughly the following steps. The sample is held by the sample transport mechanism under the atmospheric pressure, and the pressure is reduced in the load lock chamber from the atmospheric pressure to a vacuum pressure region close to the processing chamber.
Thereafter, the sample is carried into the processing chamber from the load lock chamber under reduced pressure, and is then fixed at a predetermined position to perform a predetermined processing process. After the completion of the processing process, the sample is carried out of the processing process chamber into the load lock chamber, returned from vacuum to atmospheric pressure, and carried out of the semiconductor manufacturing apparatus.

In such a semiconductor manufacturing apparatus, a sample transport mechanism capable of continuously holding a sample in a load lock chamber from atmospheric pressure to a required reduced pressure environment is required. One example satisfying this condition is as follows. An electrostatic chuck is conceivable. In order to reduce the total number of components of the semiconductor manufacturing apparatus, a structure is conceivable in which a single electrostatic chuck can perform both transport in the semiconductor manufacturing apparatus and fixing during a processing process.
That is, the electrostatic chuck has two pairs of internal electrodes.
Electrode terminals are provided at various locations, a voltage is applied from one power supply plug in the load lock chamber, the sample is adsorbed, and the sample is transferred into the processing chamber. At this time, since the load lock chamber and the processing chamber are cut off by a partition wall, a power supply plug is connected to the other electrode terminal at a predetermined position in the processing chamber and a voltage is applied to enable continuous adsorption of the sample. However, one power supply plug is disconnected. Following such a procedure, the processing chamber is isolated by the partition, the degree of vacuum is increased, and the sample is processed.

[0004]

FIG. 7 shows a state where a conventional electrostatic chuck unit is in a reduced pressure state while holding a sample in a load lock chamber 20. Electrode terminals 101 electrically connected to the bipolar internal electrode 100 are provided at two locations on the outer periphery of the electrostatic chuck having a pair of bipolar internal electrodes 100, and a power supply plug 102 is connected to one of the electrode terminals 101a. The other electrode terminal 101b is exposed. At the time of sample transfer, that is, the load lock chamber 20
When the internal pressure is reduced, a voltage is applied from the power source 103 to the bipolar internal electrode 100 through the power supply plug 102 and the electrode terminal 101a, but the other electrode terminal 101b is applied through the bipolar internal electrode 100.
Side is also in a state where the suction voltage is applied.

If the electrode terminal 101b to which the voltage is applied remains exposed in the load lock chamber 20 under reduced pressure, the other electrode terminal is located in a pressure region near 1 × 10 ³ to 1 × 10 ¹ Pa that passes during pressure reduction. Short-circuits occur between the load 101b and between the load lock chamber 20 and the other electrode terminal 101b due to electric discharge, and the attraction force of the electrostatic chuck 10 becomes zero.
And the sample may move.

Further, in the case of a structure in which the vicinity of one electrode terminal 101a to which the power supply plug 102 is connected is exposed in the load lock chamber 20, 1 × 10 ³ to 1 × 10 ¹ which passes at the time of decompression for the same reason as described above. In the pressure region near Pa, a short circuit due to discharge may occur between the one electrode terminal 101a and between the load lock chamber 20 and the one electrode terminal 101a, and the chucking force of the electrostatic chuck 10 may become zero. is there.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to cause a discharge short circuit in a semiconductor manufacturing apparatus and a flat panel display manufacturing apparatus having a sample processing process under reduced pressure. It is an object of the present invention to provide an electrostatic chuck and a unit which can be used continuously from atmospheric pressure to vacuum and can also be used for fixing and transporting a sample.

[0008]

In order to achieve the above object, the present invention provides at least two independent internal electrodes,
An electrode terminal that conducts to each of the internal electrodes; and when a voltage is applied to the internal electrode through one of the at least two systems of internal electrodes, a potential difference occurs between the internal system and the electrode terminal of another system. The feature is that there is no. Two independent internal electrodes inside the electrostatic chuck,
Since it has a structure having electrode terminals that conduct to each internal electrode, even if a voltage is applied to one electrode terminal, no voltage is generated at the other electrode terminal, and an electrostatic chuck that does not short-circuit during pressure reduction can be provided. .

In a preferred aspect of the present invention, in the electrostatic chuck, the at least two systems of internal electrodes are
The electrostatic chuck is arranged in parallel with and in the same plane as the sample suction surface of the electrostatic chuck. Since the internal electrodes are arranged in the same plane as the sample chucking surface of the electrostatic chuck in parallel, the electrodes can be manufactured with one printing screen,
In addition, even if a voltage is applied to one of the at least two internal electrodes, the leakage current to the other internal electrode is reduced, so that the voltage generated at the other internal electrode is reduced and a short circuit occurs when the pressure is reduced. An electrostatic chuck free of the problem can be provided.

In a preferred aspect of the present invention, in the electrostatic chuck, the at least two systems of internal electrodes are alternately arranged in a thin linear shape. Since the internal electrodes are alternately arranged in a thin linear shape, when voltages having different polarities and equal absolute values are applied to one of the at least two internal electrodes, the other electrode is disposed therebetween. Therefore, an electrostatic chuck which has a potential close to 0 and does not short-circuit during pressure reduction can be provided.

According to a preferred aspect of the present invention, in the electrostatic chuck, the at least two systems of internal electrodes are alternately arranged as thin linear concentric circles. Since the internal electrodes are arranged alternately as thin linear concentric circles, when a voltage having a different polarity and the same absolute value is applied to one of the at least two internal electrodes, the other electrode is disposed therebetween. As a result, the potential is close to 0, and an electrostatic chuck that does not short-circuit during pressure reduction can be provided.

According to a preferred aspect of the present invention, in the electrostatic chuck, the at least two systems of internal electrodes have the same shape, and are arranged in separate planes so that the electrodes do not overlap. Since the electrodes are provided in separate planes, the degree of freedom in electrode design is increased, and the electrodes are not overlapped. Therefore, even if a voltage is applied to one of two internal electrodes, the other electrode terminal is applied. And a voltage is not generated, and an electrostatic chuck that does not short-circuit at the time of pressure reduction can be provided.

According to a preferred aspect of the present invention, in the electrostatic chuck, an electrode terminal for conducting to an internal electrode is provided in a deep hole formed in an outer peripheral portion of the electrostatic chuck. Since the electrode terminals are provided in the inner part of the hole provided on the outer periphery of the electrostatic chuck, by connecting a power supply plug that covers the outside with an insulator, the part to which the voltage is applied is not exposed to the outside In addition, an electrostatic chuck that does not short-circuit during pressure reduction can be provided.

According to a preferred aspect of the present invention, in the electrostatic chuck, the power supply plug is covered with an insulator, and the power plug is inserted together with the insulator into a hole formed in an outer peripheral portion of the electrostatic chuck and joined to the electrode terminal. And The power supply plug is covered with an insulator, and the insulator is inserted into a hole formed in the outer periphery of the electrostatic chuck and joined to the electrode terminal, so that the part to which the voltage is applied can be exposed to the outside. Thus, it is possible to provide an electrostatic chuck that does not short-circuit during pressure reduction.

According to a preferred embodiment of the present invention, in the electrostatic chuck, the material is made of an alumina sintered body, and its volume resistivity is 10E in a set temperature region during the pressure reduction process.
It is in the range of 9 to 10E11 Ωcm.
In the electrostatic chuck, the material is made of an alumina sintered body, and its volume resistivity is set to be in a range of 10E9 to 10E11 Ωcm in a set temperature region during the depressurization process. An electrostatic chuck capable of absorbing and desorbing within a few seconds can be provided.

According to a preferred aspect of the present invention, there is provided a unit for mounting the electrostatic chuck of the present invention, adsorbing and transporting or treating an object to be attracted, and a power supply plug facing each of the electrode terminals of the electrostatic chuck. Wherein the periphery of the connection portion is covered with an insulator in a state where the power supply plug is connected to the electrode terminal. By these means, it is possible to provide an electrostatic chuck unit that can be used continuously from atmospheric pressure to vacuum without causing a discharge short circuit in a semiconductor manufacturing apparatus having a sample processing process step under reduced pressure.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below. FIG. 1 shows the internal electrode structure of the electrostatic chuck. An internal electrode A1 is provided inside the electrostatic chuck 10.
1 and an internal electrode B12 are provided, and the electrodes are electrically connected to the outside of the electrostatic chuck by electrode terminals A13 and B14, respectively. The internal electrode A11 and the internal electrode B12 are arranged on the same plane inside the electrostatic chuck, and when a voltage is applied to one of the internal electrodes, the other internal electrode is independent and no current leaks. In addition, it is possible to prevent a decrease in the sample adsorption force.

Further, in order to make it easy to understand the polarity of the bipolar application, the pair of internal electrodes in the figure are shown by a broken line and a solid line. The internal electrode A11 and the internal electrode B12 are arranged such that the other electrode is equidistant between one positive electrode and the negative electrode. Consider a case where voltage is applied to the internal electrode A11. The internal electrode A11a, the one indicated by the solid line is the positive electrode, and the internal electrode A1
1b, assuming that the direction indicated by the broken line is applied to the negative electrode,
The internal electrode B12 disposed therebetween is the internal electrode A11.
a, the positive electrode and the distance from the negative electrode 11b and the negative electrode are equal,
Potential. Similarly, when a voltage is applied to the internal electrode B12, when the internal electrode B12a is applied to the positive electrode as indicated by the solid line, the internal electrode B12b is applied to the negative electrode as indicated by the broken line, the internal electrode A11 disposed therebetween is: Internal electrode B12
a, the distance from the positive and negative electrodes 12b and the negative electrode is equal.
Potential. Furthermore, by using alumina whose volume resistivity is controlled to 10E9 to 10E11 Ωcm as a material of the electrostatic chuck, an electrostatic chuck capable of adsorbing and desorbing a sample within several seconds even at 20 ° C.

FIG. 2 shows an example of the internal electrode structure of the electrostatic chuck different from that of FIG. In order to make the polarity of the bipolar application easier to understand as in FIG. 1, the pair of internal electrodes in the figure is shown by a broken line and a solid line. Internal electrode A11 and internal electrode B12
Are arranged concentrically, with the other electrode being equidistant between one positive electrode and the negative electrode. Internal electrode A11
Is applied. Assuming that the internal electrode A11a is applied to the positive electrode as indicated by the solid line, the internal electrode A11b is applied to the negative electrode, and the internal electrode B12 disposed between them is applied to the negative electrode.
b, since the distance from the negative electrode is equal, the potential becomes 0 potential. Similarly, when a voltage is applied to the internal electrode B12,
12a, the solid line indicates the positive electrode, the internal electrode B12b indicates the internal electrode B12b, and the broken line indicates the negative electrode. When the internal electrode A11 is disposed between the internal electrode B12a, the positive electrode and
b, since the distance from the negative electrode is equal, the potential is 0. Further, the volume resistivity of the material of the electrostatic chuck is 10E9-10.
By using alumina controlled to E11 Ωcm, 20
An electrostatic chuck capable of absorbing and desorbing a sample within several seconds even at a temperature of ° C.

FIG. 3 shows an example of a semiconductor manufacturing apparatus equipped with the electrostatic chuck of the present invention. The electrostatic chuck 10 includes a load lock chamber 20 capable of changing a pressure range from the atmospheric pressure to a vacuum, one or a plurality of processing process chambers 22 which are constantly adjusted to a reduced pressure environment required for a processing process, A transfer chamber 21 which is adjusted under the same vacuum environment as the transfer chamber 22 and passes between the processing chambers 22 and between the load lock chamber 20 and the processing chamber 22 when the sample and the electrostatic chuck are moved. Are installed in a vacuum vessel that communicates via a partition 23 that can connect and open the chambers. The sample carried from the previous process is mounted on the electrostatic chuck 10 that has been moved into the load lock chamber 20. A voltage is applied from the power source A31 to the internal electrode A11 through the power supply plug A34 and the electrode terminal A13 to generate an attraction force and fix the sample. At this time, since the internal electrode B12 is not affected by the voltage applied to the internal electrode A11, the electrode terminal B14 is at zero potential.

FIG. 4 is an enlarged view near the electrode terminal A13 of the electrostatic chuck. Insulator 3 around power supply plug A34
The tip is in contact with the electrode terminal A13 in such a manner as to enter a counterbore opened toward the inside of the electrostatic chuck 10. After the sample is mounted on the electrostatic chuck, the pressure inside the load lock chamber 20 is reduced, and the pressure inside the load lock chamber 20 is brought closer to the pressure regions in the processing process chamber 22 and the transfer chamber 21. At this time, the power supply plug A34 is covered by an insulating structure formed by the insulator 37 and a counterbore of the electrostatic chuck.
The discharge short circuit phenomenon between each power supply plug and between the power supply plug and the load lock chamber can be prevented, and the suction force does not become zero.

FIG. 5 is a schematic view showing a state where the electrostatic chuck has been carried into the transfer chamber 21 from the load lock chamber 20. When the pressure in the load lock chamber 20 sufficiently approaches the pressure in the transfer chamber 21, the partition 23 between the two chambers is opened, and the electrostatic chuck 10 on which the sample is placed is sent into the transfer chamber 21. At this time, the transfer is performed while a voltage is applied to the internal electrode A11 in order to prevent the displacement of the sample. When the electrostatic chuck is fixed at a predetermined position in the moving chamber 21, the electrode terminal B14 and the power supply plug B35 come into contact. Therefore, a voltage having the same potential as that of the internal electrode A11 is applied to the internal electrode B12, and then the voltage application to the internal electrode A11 is stopped.
4 is returned from the transfer chamber 21 side to the load lock chamber 20 side, and the partition 23 is closed. Thus, the internal electrodes A11 and B1
By overlapping the timing of applying the voltage to 2, the non-adsorption time at the time of switching the application of the voltage is eliminated, and the situation where the adsorption force of the sample in the transfer chamber 21 becomes zero can be avoided. When the sample is carried out from the transfer chamber 21 to the load lock chamber 20, a series of steps of energization and pressure control at the time of carrying in the sample are performed in reverse order.

FIG. 6 is a schematic diagram showing a state in which the electrostatic chuck is carried from the moving chamber 21 into the processing chamber 22. The electrostatic chuck in the moving chamber 21 is rotated and positioned so that it can be carried into the processing chamber 22 for performing the first processing. After that, the partition wall 23 between the moving chamber 21 and the first processing chamber 22 is opened, and the electrostatic chuck 10 on which the sample is placed is sent into the processing chamber 22. At this time, the internal electrode B is used to prevent the sample from shifting.
12 is transported while a voltage is applied. When the electrostatic chuck is fixed at a predetermined position in the processing chamber 22, the electrode terminal A13 and the power supply plug C36 come into contact with each other. Therefore, a voltage having the same potential as that of the internal electrode B12 is applied to the internal electrode A11. Thereafter, the application of the voltage to the internal electrode B12 is stopped, and the power supply plug B35 is connected to the processing process chamber 22.
From the side to the transfer chamber 21, and the partition 23 is closed. Similarly to the above, the non-adsorption time at the time of voltage application switching is eliminated by overlapping the voltage application timing to the internal electrodes A11 and B12 in the processing chamber 22, and the sample is removed in the processing chamber 22. The situation where the suction force becomes zero can be avoided. When the sample is carried out of the processing process chamber 22 to the transfer chamber 21, a series of steps of energization and pressure control at the time of carrying in the sample are performed in reverse order.

[0024]

According to the present invention, the following effects are exhibited by the above configuration. The present invention relates to an electrostatic chuck for transporting and fixing a sample used in a semiconductor manufacturing apparatus, which has at least two systems of internal electrodes, each of which has a structure capable of independently applying a voltage, and one of which has an internal electrode. Even when a voltage is applied to the electrode, the other internal electrode and its electrode terminal have a structure in which the potential is substantially zero, and the periphery of the contact portion between the power supply terminal to each internal electrode of the electrostatic chuck and the power supply plug An electrostatic chuck unit that can be used continuously from atmospheric pressure to vacuum without causing a discharge short circuit by combining power supply plugs and electrode terminals that are covered with an insulator and do not expose terminals or plugs to which voltage is applied. Become. Further, in the above-mentioned electrostatic chuck, the material is made of an alumina sintered body, and the volume resistivity of the material is in the range of 10E9 to 10E11 at room temperature.
The sample can be adsorbed and desorbed even at room temperature of ℃.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing one mode of an internal electrode of an electrostatic chuck according to the present invention.

FIG. 2 is a schematic sectional view showing one mode of an internal electrode of the electrostatic chuck according to the present invention.

FIG. 3 is a schematic structural view of a semiconductor manufacturing apparatus equipped with the electrostatic chuck of the present invention.

FIG. 4 is a schematic structural enlarged view showing a part of the electrostatic chuck of the present invention.

FIG. 5 is a schematic structural view of a semiconductor manufacturing apparatus equipped with the electrostatic chuck of the present invention.

FIG. 6 is a schematic structural view of a semiconductor manufacturing apparatus equipped with the electrostatic chuck of the present invention.

FIG. 7 is a schematic structural view showing one form of a conventional electrostatic chuck.

[Explanation of symbols]

 Reference Signs List 10 electrostatic chuck 11 internal electrode A 12 internal electrode B 13 electrode terminal A 14 electrode terminal B 20 load lock chamber 21 transfer chamber 22 processing chamber 23 partition wall 31 power supply A 32 power supply B 33 power supply C 34 power supply plug A 35 power supply Plug B 36 Power supply plug C 37 Insulator 100 Bipolar internal electrode 101 Electrode terminal 101a Electrode terminal 101b Electrode terminal 102 Power supply plug 103 Power supply

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3C016 GA07 GA10 5F031 CA02 CA05 HA02 HA17 HA18 HA19 PA30

Claims (9)

[Claims] An internal electrode of at least two independent systems, and an electrode terminal electrically connected to each internal electrode,
An electrostatic chuck characterized in that, when a voltage is applied to an internal electrode through one electrode terminal of the at least two systems of internal electrodes, no potential difference occurs between the internal electrode and the electrode terminal of another system. 2. The static chuck according to claim 1, wherein in the electrostatic chuck, the at least two systems of internal electrodes are arranged in parallel with and in the same plane as a sample suction surface of the electrostatic chuck. Electric chuck. 3. The electrostatic chuck according to claim 2, wherein the internal electrodes of the at least two systems are alternately arranged in a thin linear shape in the electrostatic chuck. 4. The electrostatic chuck according to claim 2, wherein the internal electrodes of the at least two systems are alternately arranged as thin linear concentric circles in the electrostatic chuck. 5. The electrostatic chuck according to claim 1, wherein, in the electrostatic chuck, the at least two systems of internal electrodes have the same shape, and are arranged in different planes so that the electrodes do not overlap each other. Chuck. 6. The electrostatic chuck according to claim 1, wherein an electrode terminal electrically connected to the at least two systems of internal electrodes is provided in a hole formed in an outer peripheral portion of the electrostatic chuck. 6. The electrostatic chuck according to any one of 5. 7. The electrostatic chuck according to claim 1, wherein the power supply plug is covered with an insulator, and is inserted together with the insulator into a hole formed in an outer peripheral portion of the electrostatic chuck and joined to an electrode terminal. 7. The electrostatic chuck according to any one of claims 1 to 6. 8. The electrostatic chuck according to claim 1, wherein the material is made of an alumina sintered body, and has a volume resistivity of 10E9 to 10E11 Ωcm in a set temperature range during a pressure reduction process.
The electrostatic chuck according to any one of claims 1 to 7, wherein: 9. A unit that mounts the electrostatic chuck according to claim 1 and adsorbs and transports or processes an object to be attracted, the unit being opposed to the respective electrode terminals of the electrostatic chuck. An electrostatic chuck unit comprising: a power supply plug that is connected to the electrode terminal; and a periphery of the connection portion is covered with an insulator in a state where the power supply plug is connected to the electrode terminal.