JPH11145266A - Apparatus and method of electrostatic chucking, and apparatus and method of transferring substrate using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably hold an insulation substrate, without causing errors during transfer of the substrate. SOLUTION: This apparatus for transferring an insulating substrate S comprises a substrate carrier 63 for supporting and carrying the substrate S, a substrate chucking member 71 attached to the carrier 63 having an insulator 72 and electrode 73 provided therein, a d-c power source 76 for applying a d-c voltage to the electrode 73, a means 77 for feeding a voltage to be applied to an electrode S from the power source 76 and ions of a reverse conductivity type onto the substrate S, and drive mechanism for driving the substrate carrier 63. The d-c voltage is applied to the electrode 73 with the ions being fed onto the substrate S so as to transport the insulative substrate chucked to the chucking member 71 owing to the electrostatic force generated between ions on the substrate S and the electrode 73.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic attraction device and an electrostatic attraction method for electrostatically attracting an insulating substrate such as an LCD (liquid crystal display) substrate, and a substrate transporting device and a substrate transporting method using the same. About.

[0002]

2. Description of the Related Art Conventionally, for example, in a process of manufacturing an LCD substrate, etching is performed on the LCD substrate under a reduced pressure atmosphere.
A so-called multi-chamber type vacuum processing apparatus having a plurality of vacuum processing chambers for performing predetermined processing such as ashing is used.

[0003] Such a vacuum processing apparatus includes a load lock chamber provided with a substrate transfer mechanism having a transfer arm for supporting a substrate during transfer, and a plurality of vacuum processing chambers provided around the load lock chamber. The substrate to be processed is carried into each vacuum processing chamber by the transfer arm in the load lock chamber, and the processed substrate is carried out from each vacuum processing chamber.

In such a processing apparatus, the LCD substrate is transported in a state in which the LCD substrate is brought into close contact with an O-ring or the like provided on a transport arm. I have.

[0005]

However, in recent years, the size of the substrate has been increasing, and the transport speed has been increasing due to the demand for an improvement in throughput. In the above-described substrate supporting method, the LCD substrate is shifted during the transport. A transport error occurs. Although it is conceivable to use a mechanical clamp to prevent such a transport error, it takes time to clamp the substrate, which reduces the throughput, and particles from the operating members may adhere to the LCD substrate. .

On the other hand, in the case of a conductive substrate of a semiconductor wafer, it is conceivable to perform electrostatic attraction that does not cause such inconvenience. However, in the case of an insulating substrate such as an LCD substrate, the same as the conductive substrate. In principle, electrostatic attraction is not possible.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an electrostatic suction device and an electrostatic chuck capable of reliably holding an insulating substrate without causing a transport error when transporting the substrate. An object of the present invention is to provide a suction method, a substrate transfer device and a substrate transfer method using the same.

[0008]

The present inventors have conducted experiments and studies to solve the above-mentioned problems, and as a result, have found that
It has been clarified that even an insulating substrate such as a substrate can be attracted by electrostatic attraction during transport. In other words, LCD
An insulating substrate such as a substrate is insulative and cannot be electrostatically attracted by the same principle as a semiconductor wafer, which is a conductor. However, an insulating substrate such as an LCD substrate has a different principle from that of a conductor by electrostatic attraction. It has been found that the electrostatic attraction can be achieved.

That is, an insulating substrate such as an LCD substrate is placed on an electrostatic attraction member having an insulator and electrodes provided therein, similar to an electrostatic attraction device used for a semiconductor wafer. A predetermined DC voltage is applied from a DC power source to the substrate, and ions having a polarity opposite to the voltage applied to the electrodes are supplied onto the substrate, thereby causing a Coulomb force (electrostatic force) between the ions on the substrate and the electrodes. Is generated, whereby the substrate is adsorbed.

The present invention has been completed based on such knowledge, and a first invention is an electrostatic attraction device for adsorbing an insulating substrate, which is provided with an insulator and an interior thereof. An electrode, and an adsorption member for adsorbing the substrate; a DC voltage application unit for applying a DC voltage to the electrode; and ions having a polarity opposite to a voltage applied to the electrode by the DC voltage application unit. An ion supply means for supplying ions to the substrate, and applying a DC voltage to the electrodes while supplying ions to the substrate, whereby an electrostatic force generated between the ions on the substrate and the electrodes An electrostatic attraction device is provided, wherein the insulating substrate is attracted to the attraction member.

The second invention comprises a step of placing an insulating substrate on an adsorption member having an insulator and an electrode provided therein, a step of applying a DC voltage to the electrode, and a step of applying a DC voltage to the electrode.
A step of supplying ions having a polarity opposite to the voltage applied to the electrodes by the voltage applying means onto the substrate, wherein a voltage is applied between the electrodes and the ions supplied on the insulating substrate. Wherein the insulating substrate is attracted to the attracting member by electrostatic force generated in the electrostatic attracting member.

According to a third aspect of the present invention, there is provided a substrate transfer apparatus for transferring an insulating substrate, wherein the substrate transfer member is provided on the substrate transfer member for supporting and transferring the substrate. An adsorbing member for adsorbing the substrate, and a D for applying a DC voltage to the electrode.
C voltage applying means, an ion supply means for supplying ions of the opposite polarity to the voltage applied to the electrode by the DC voltage applying means on the substrate, and a driving means for driving the substrate transport member, By applying a DC voltage to the electrodes while supplying ions to the substrate, the insulating substrate is adsorbed to the adsorption member by an electrostatic force generated between the ions on the substrate and the electrodes. Provided is a substrate transfer device for transferring a substrate.

A fourth invention comprises a step of placing an insulating substrate on an adsorption member having an insulator and an electrode provided therein, a step of applying a DC voltage to the electrode, and a step of applying a DC voltage to the electrode.
A step of supplying ions having a polarity opposite to the voltage applied to the electrodes by the voltage applying means onto the substrate; And transporting the substrate, and the insulating substrate is adsorbed to the adsorption member by an electrostatic force generated between the electrode to which a voltage is applied and ions supplied on the insulating substrate. A substrate transfer method is provided, wherein the substrate is transferred in a state.

In the present invention, since the ions are supplied onto the substrate, even if the substrate is an insulating substrate, it can be adsorbed by electrostatic attraction. be able to. Therefore,
Even when a large substrate is transferred at high speed, a transfer error can be reliably prevented.

[0015]

Embodiments of the present invention will be specifically described below with reference to the accompanying drawings. Here, substrate transfer in a multi-chamber type vacuum processing apparatus for performing an etching process and an ashing process on a glass LCD substrate will be described.

FIG. 1 is a perspective view showing an outline of the vacuum processing apparatus, and FIG. 2 is a horizontal sectional view showing the inside thereof. In the vacuum processing apparatus 100, a transfer chamber 20 and a load lock chamber 30 are connected to each other at the center. Around the transfer chamber 20, first, second, and third vacuum processing chambers 2, 4, and 6 are provided. These openings are provided between the transfer chamber 20 and the load lock chamber 30, between the transfer chamber 20 and each of the processing chambers 2, 4, and 6, and between the load lock chamber 30 and the outside atmosphere. A gate valve 22 that hermetically seals the space and that can be opened and closed is interposed.

Outside the load lock chamber 30, two cassette indexers 41 are provided, on which are mounted cassettes 40 for accommodating LCD substrates, respectively. One of the cassettes 40 stores unprocessed substrates, and the other stores processed substrates. These cassettes 40 can be raised and lowered by a lifting mechanism 42.

Between these two cassettes 40, a substrate transfer member 50 is provided on a support table 51, and the transfer member 50 is provided with arms 52, 53 provided in two upper and lower stages.
And a base 54 for integrally supporting them so as to advance, retract and rotate.

4 supports the substrate on the arms 52 and 53.
One projection 55 is formed. The protrusion 55 is made of an elastic body made of synthetic rubber having a high coefficient of friction, and prevents the substrate from shifting or dropping during substrate support.

The transfer member 50 can transfer two substrates at a time by the arms 52 and 53, that is,
Two substrates can be taken out or loaded into the cassette 40 at one time. The height of each cassette 40 is adjusted by an elevating mechanism 42, and the positions where substrates are taken out or loaded by the arms 52 and 53 are set. The interval between the two arms 52 and 53 is set to be larger than the maximum value of the substrate support interval of various cassettes.
For this reason, it can correspond to various cassettes.

Incidentally, only one cassette can be installed. In this case, the processed substrates are returned to the empty space in the same cassette.

The vacuum processing chambers 2, 4, and 6 can be maintained in a predetermined reduced-pressure atmosphere. Two of them perform the same etching processing, and the other performs an ashing processing. Is performed. A mounting table 10 is provided in each of the processing chambers, and the mounting table 10 is provided with four support pins 11 for supporting the substrate S. The mounting table 10 functions as a lower electrode for forming plasma.

The transfer chamber 20 can be maintained at a predetermined reduced pressure atmosphere, similarly to the vacuum processing chamber, and a transfer mechanism 60 is provided therein, as shown in FIG. The transfer mechanism 60 transfers the substrate between the load lock chamber 30 and the vacuum processing chambers 2, 4, and 6.

As shown in FIG. 3, the transport mechanism 60 is provided at one end of a base 64 and has a first arm 61 rotatably provided on the base 64, and a distal end of the first arm 61. A second arm 62 rotatably provided on the second arm 62
And a fork-shaped substrate support plate 63 rotatably provided on the first arm 61 and the second arm 62 by a drive mechanism built in the base 64.
By driving the substrate support plate 63,
The substrate S can be transported. The base 64 can be moved up and down by a cylinder mechanism 65 provided thereunder, and can be rotated around a cylinder.

The substrate holding plate 63 is provided with an electrostatic attraction device 70. The electrostatic attraction device 70 is provided on the entire upper surface of the substrate support plate 63 and has an attraction member 71 having an insulating layer 72 made of polyimide or ceramic and an electrode 73 made of copper or the like embedded in the insulating layer 72.
And a DC power supply 76 for applying a C voltage.
The electrode 73 and the DC power supply 76 are connected by a cable 74. The cable 74 is provided with a switch 75, which can be switched between the power supply side and the ground side by this switch 75. When connected to the power supply side, power is supplied to the electrode 73 and connected to the ground side. To eliminate the charge. On the other hand, a plurality of ionizers 7 for supplying ions onto the substrate are provided at the upper corner of the transfer chamber 20.
7 are arranged. The ionizer 77 can also be used for static elimination at the time of releasing electrostatic attraction. The cable 74 has a sufficient length so as to follow the movement of the substrate support plate 63. An ionizer is also provided in each vacuum processing chamber.

Behind the base member 64, a plurality of LCs
A buffer frame 80 configured to hold the D substrate is provided, and the buffer frame 80 temporarily holds an unprocessed substrate or a processed substrate. By temporarily holding the substrate as described above, the throughput is improved.

The buffer frame 80 is, as shown in FIG.
The other end of the base 64 is installed so as to be able to move up and down with respect to the base 64. The frame body 80 has four buffers 82, 8
4, 86, 88, which form four horizontal levels of substrate support. These buffers are provided with protrusions 89 for supporting the substrate. The projection 89 is made of synthetic rubber having a high coefficient of friction, and prevents the substrate from shifting or dropping during substrate support.

The load lock chamber 30 can be maintained at a predetermined reduced pressure atmosphere similarly to the processing chamber and the transfer chamber 20, and includes a buffer having a pair of stands 91 for supporting the LCD substrate. A rack 90 is provided. The buffer rack 90 is configured to hold two LCD substrates at one time in the load lock chamber 30, thereby improving the efficiency of vacuuming and purging.

As shown in FIG. 5, the buffer rack 90 includes two buffers 92 and 94, which are two horizontal stages corresponding to the two arms 52 and 53 of the transport member 50 on the atmosphere side. Forming a substrate support level. The interval between the levels of the rack 90 is set to be larger than the substrate support interval of the cassette 40. Each level of the rack 90 is provided with a projection 93 for supporting a substrate. Protrusion 9
Numeral 3 is made of synthetic rubber having a high coefficient of friction, thereby preventing the substrate from shifting and falling. The stand 91 of the buffer rack 90 can be moved up and down integrally. The transfer mechanism 6 in the transfer chamber 20 is moved up and down by the buffer rack 90.
It is possible to selectively take out one of the two substrates without raising / lowering 0.

The load lock chamber 30 also includes a pair of positioners 9 for aligning two substrates at a time.
6 and an optical sensor 95 for confirming the completion of the alignment of the substrate.

The pair of positioners 96 are arranged so as to face each other on an extension of a diagonal line of the substrate.
Each positioner 96 includes a base 98 that can be activated in the direction of arrow A in the figure, and a pair of rollers 100 supported on the base 98 so as to be freely rotatable. The positioner 96
The alignment of the substrates is performed in such a manner that the two substrates supported by the rack 90 are sandwiched diagonally. Roller 10
Since 0 is positioned by pressing the side surface of the substrate S at four points, it is particularly suitable for positioning a substantially rectangular substrate. Rollers 100 are removably mounted on base 98 and are replaced according to the dimensions of the LCD substrate being processed.

Next, the operation of the apparatus configured as described above will be described. First, the two arms 52 and 53 of the transport member 50 are driven forward and backward to transfer the two substrates S from the one cassette 40 (the cassette on the left side in FIG. 1) containing the unprocessed substrates at a time to the load lock chamber 30. Carry in.

In the load lock chamber 30, two substrates S are provided by the buffers 92 and 94 of the buffer rack 90.
After the arms 52 and 53 are retracted, the gate valve on the atmosphere side of the load lock chamber 30 is closed. After that, the inside of the load lock chamber 30 is evacuated, and the inside of the
For example, the pressure is reduced to about 10 ^-1 Torr. After the evacuation, the substrate S is aligned by pressing the substrate with the four rollers 100 of the pair of positioners 96.

After the alignment as described above, the gate valve 22 between the transfer chamber 20 and the load lock chamber 30 is opened, and then the transfer mechanism 60 transfers the substrate S from the lower buffer 94 from the viewpoint of preventing contamination. Carried into the room 20,
It is held in the uppermost buffer 72. In this case, the substrate S
Are supported on the buffer rack 80 at predetermined intervals, so that the operation of the transport mechanism is controlled by the cassette 40.
Can be performed without depending on the substrate support interval. That is, there is no need for complicated control means for changing the operation amount and the like of the transport mechanism 60 for each support interval of different substrates. Therefore, contamination in the device can be reduced.

With the substrate loaded in the transfer chamber 20, the chamber is further evacuated to about 10 ^-4 Torr. Thereby, contamination in the device can be reduced. Next, the substrate S carried into the transfer chamber 20 and held in the buffer 72 is received on the suction member 71 on the substrate support plate 63. Then, a predetermined DC voltage (for example, 0 to 5 Kv) is applied to the electrode 73 from the DC power supply 76 through the cable 74 by turning the switch 75 on the power supply side, and the electrode is positively charged. Supply ions. As a result, as shown in FIG. 6, negative ions are adsorbed on the substrate S, and the insulating LCD substrate S is adsorbed on the adsorption member 11 by Coulomb force generated between the negative ions and the positively charged electrode 73. Is done.

After holding the substrate S in this way, the arms 61 and 62 and the substrate support plate 6 are driven by a driving mechanism.
3 is driven to transfer the substrate S to a predetermined vacuum processing chamber, for example, the first vacuum processing chamber 2. The substrate S is transferred to the first vacuum processing chamber 2
First, the electrostatic chuck 7 is mounted on the mounting table 10.
The switch 75 of 0 is set to the ground side to remove electricity, and the suction of the substrate S is released. Then, after placing the substrate S on the support pins 11 with the support pins 11 of the mounting table 10 protruding,
The pin 11 is lowered. Then, the substrate support arm 63
Retreats from the vacuum processing chamber, closes the gate valve 22, and performs a predetermined etching process on the substrate S. After this process is completed, the substrate S is transported to another vacuum processing chamber by the transport mechanism 60 in the same manner as necessary, and a predetermined process is performed.

After the predetermined processing for one substrate is completed,
The processed substrate S is raised by the support pins 11 from the mounting table 10 in the final vacuum processing chamber, the gate valve 22 is opened, and the substrate support plate 63 of the transport mechanism 60 is inserted into the processing chamber, and the suction member The substrate is placed on 71. In this state, ions are supplied onto the substrate S from an ionizer provided in the processing chamber while applying a positive voltage to the electrode 73, and the substrate S is electrostatically attracted by the same principle as described above. Then, the substrate support plate 63 supporting the substrate S is returned to the transfer chamber 20 and further transferred to the load lock chamber 30. The substrate S transported to the load lock chamber 30 is placed in the processed substrate cassette 40 (the right cassette in FIG. 1) by the arms 52 and 53 of the transport member 50. As a result, a series of processing operations on one substrate is completed. This processing operation is repeated by the number of substrates mounted in the cassette 40 for unprocessed substrates, and all the processing is completed.

According to the present embodiment, since the voltage is applied from the DC power source 76 to the electrode 72 and the ions are supplied onto the substrate S as described above, the LCD substrate S is attracted to the attracting member 71 by electrostatic attraction. Is done. Therefore, the LCD substrate S can be securely held by suction, and it is possible to reliably prevent the substrate S from shifting and causing a transport error when the substrate S is transported. This makes it possible to handle high-speed conveyance,
High-speed conveyance of about 1.5 times that of the related art is realized. Also, a large substrate can be transported reliably. Furthermore, since the substrate is sucked by the entire suction member 71 provided on the entire surface of the substrate support plate 63 without using an O-ring as in the related art, the deflection of the substrate in a large-sized substrate can be reduced. Furthermore, in the case of such electrostatic attraction, the generation of particles can be avoided since there is no operating member such as a mechanical clamp.

As described above, even an insulating substrate can be reliably attracted by electrostatic attraction.
This is particularly effective for a CD substrate processing apparatus.

In the above-described apparatus, continuous processing of etching and ashing can be performed, and the efficiency is also high in this respect. Further, by changing the program, it is possible to perform various processes corresponding to the needs of the user, such as etching, continuous etching, and single etching, which is extremely versatile.

The present invention can be variously modified without being limited to the above embodiment. For example, the insulating substrate of the object to be processed is not limited to the LCD substrate, but may be another insulating substrate. In addition, although ions are supplied using an ionizer, the present invention is not limited to this, and any device that can supply ions having a polarity opposite to the voltage applied to the electrodes may be used. However, since the ionizer has both a positive ion and a negative ion and thus has a charge eliminating function, the ionizer is preferable. Further, in the above-described embodiment, the case where the present invention is applied to the transfer of the substrate in the etching apparatus has been described. Also,
In the above-described embodiment, the application of the voltage to the electrode 73 of the adsorption member 71 and the supply of the ions are performed at the same time.

[0042]

As described above, according to the present invention,
Since the ions are supplied onto the substrate, even an insulated substrate can be adsorbed by electrostatic attraction, and can be reliably adsorbed to the substrate support plate of the transport member even when the substrate is transported. Therefore, even when a large substrate is transferred at high speed, a transfer error can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an overview of a vacuum processing apparatus to which the present invention is applied.

FIG. 2 is a horizontal sectional view showing a vacuum processing apparatus to which the present invention is applied.

FIG. 3 is a cross-sectional view showing a substrate transfer mechanism according to one embodiment of the present invention applied to the vacuum processing apparatus of FIGS. 1 and 2;

FIG. 4 is a perspective view showing a buffer frame provided behind the substrate transport mechanism.

FIG. 5 is a perspective view showing a buffer rack and a positioner provided in a load lock chamber of the vacuum processing apparatus shown in FIGS. 1 and 2;

FIG. 6 is a diagram for explaining the principle of suction of an insulating substrate in the substrate transport mechanism.

[Explanation of symbols]

 20 transfer chamber 60 transfer mechanism 63 substrate support plate 70 electrostatic suction device 71 suction member 73 electrode 76 DC power supply 77 ionizer S substrate

Claims (4)

[Claims] 1. An electrostatic attraction device for adsorbing an insulating substrate, comprising: an insulator and an electrode provided therein; an adsorbing member for adsorbing the substrate; DC voltage applying means for applying a DC voltage, and ion supplying means for supplying ions having a polarity opposite to the voltage applied to the electrode by the DC voltage applying means on the substrate, comprising: Applying a DC voltage to the electrode while supplying the same, the insulating substrate is attracted to the attracting member by an electrostatic force generated between ions on the substrate and the electrode. apparatus. A step of placing an insulating substrate on an adsorption member having an insulator and an electrode provided therein; a step of applying a DC voltage to the electrode; and a step of applying a DC voltage to the electrode. Supplying ions having a polarity opposite to the voltage applied to the electrode onto the substrate, and applying an electrostatic force generated between the electrode applied with the voltage and the ions supplied on the insulating substrate. An electrostatic attraction method, wherein the insulating substrate is attracted to the attraction member. 3. A substrate transport device for transporting an insulating substrate, comprising: a substrate transport member for supporting and transporting the substrate; a substrate transport member provided on the substrate transport member; and an insulator provided inside the insulator. An adsorbing member for adsorbing the substrate, a DC voltage applying means for applying a DC voltage to the electrode, and an ion having a polarity opposite to a voltage applied to the electrode by the DC voltage applying means. An ion supply unit for supplying the substrate with the substrate; and a driving unit for driving the substrate transport member. By applying a DC voltage to the electrode while supplying the ion to the substrate, ions on the substrate are provided. A substrate transporting device that transports the substrate in a state where the insulating substrate is attracted to the attraction member by an electrostatic force generated between the substrate and the electrode. 4. A step of placing an insulating substrate on an adsorption member having an insulator and an electrode provided therein, a step of applying a DC voltage to the electrode, and a step of applying a DC voltage to the electrode. A step of supplying ions having a polarity opposite to the voltage applied to the electrodes onto the substrate; and transporting the substrate by moving the substrate transport member in a state where the substrate suction member is provided on a transport member that supports and transports the substrate. Transporting the substrate in a state where the insulating substrate is adsorbed by the adsorption member by an electrostatic force generated between the electrode to which a voltage is applied and the ions supplied on the insulating substrate. A substrate transfer method.