KR101425268B1 - Substrate transfer method - Google Patents

Abstract

A substrate holding method capable of flatly mounting a substrate on a mount table and making it possible to prevent an abnormal discharge from occurring in the substrate when the substrate is lifted from the mount table by releasing the attraction by the electrostatic chuck Provide.
A substrate G supported by a first lift pin 8a and a second lift pin 8b located lower than the first lift pin 8a above the substrate mounting surface 4c, A substrate mounting step for mounting the substrate G on the substrate mounting surface 4c from the central portion of the substrate G by suctioning the substrate G mounted on the substrate mounting surface 4c by the electrostatic chuck 41, G of the substrate W is subjected to a plasma treatment after the plasma treatment is completed and the adsorption by the electrostatic chuck 41 is released so that the first lift pin 8a and the second lift pin 8b are set at the same height, And separating the substrate G from the substrate mounting surface 4c.

Description

[0001] SUBSTRATE TRANSFER METHOD [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a substrate receiving method for receiving a substrate on a mount table.

A plasma processing such as etching or film formation is performed on a large glass substrate in an FPD manufacturing apparatus or a solar cell manufacturing apparatus or the like. To this end, a transporting apparatus for carrying a glass substrate into a processing chamber and carrying it out from the processing chamber is provided have. This transport apparatus normally supports a glass substrate by an arm which can be moved forward and backward, and is capable of being carried in and out between the processing chamber and the processing chamber. The processing chamber is provided with a mounting table on which a glass substrate is mounted. The substrate between the arm and the mount table penetrated into the processing chamber is carried by a lift pin that can be retracted from the substrate mounting surface of the mounting table.

When the glass substrate received by the lift pins from the arm is mounted on the mount table and the lift pins are held at the same height in the peripheral portion and the center portion, the glass substrate is flexible, When the glass substrate is mounted on the mount table, a space is formed between the substrate mounting surface of the mount table and the glass substrate.

In order to suppress the formation of such a space and to mount the substrate uniformly in contact with the mount table, the height of the lift pin at the peripheral portion is higher than the lift pin at the center portion to support the glass substrate, Patent Document 1 discloses a technique in which the substrate is placed on the substrate mounting surface of the mount table while being convexly warped.

In addition, in Patent Document 1, the lift pins of the peripheral portion are projected first, and the glass substrate is lifted in a warped state so that the glass substrate is convex toward the substrate mounting surface. This is to suppress shaking of the glass substrate.

(Prior art document)

(Patent Literature)

(Patent Document 1) JP-A-2008-60285

However, while the glass substrate is mounted on the mounting table and subjected to the plasma treatment, the glass substrate is attracted by the electrostatic chuck provided on the mounting table, so that even after the plasma treatment, the electrostatic attraction is released, The glass substrate may be charged. Therefore, when lifting the glass substrate from the mounting table by releasing the attraction, the glass substrate is lifted in a convex shape toward the substrate mounting surface, and the glass substrate is moved to the portion where the charge on the entire glass substrate is still in contact There is a problem that an electric charge is concentrated on the central portion of the glass substrate which is finally reduced in contact area to form a large electric field between the glass substrate and the substrate mounting surface and an abnormal discharge may occur.

It is an object of the present invention to provide a flexible substrate capable of uniformly bringing a flexible substrate into contact with the stage and uniformly bringing the substrate into contact with the stage and releasing the attraction by the electrostatic chuck to lift the substrate from the stage, A method of receiving a substrate is provided.

A substrate conveying method according to an aspect of the present invention is a method of conveying a substrate to a table provided in a processing chamber for performing plasma processing on a flexible substrate and having an electrostatic chuck for sucking the substrate by electrostatic attraction, Wherein the mounting table has a substrate mounting surface on which the substrate is mounted, a first elevating pin capable of protruding from the substrate mounting surface and supporting an edge of the substrate, And a second lift pin which is rotatable with respect to a surface of the substrate and supports a central portion of the substrate, wherein the substrate is supported by the first lift pin and the second lift pin at a position lower than the first lift pin A substrate mounting step of mounting the substrate on the substrate mounting surface from a central portion of the substrate by lowering the substrate supported by the two lift pins; A step of holding the substrate by the electrostatic chuck after the plasma processing is completed; and a step of performing plasma treatment on the substrate by adsorbing the substrate with the electrostatic chuck, And a substrate removing step of supporting the substrate with the same height and separating the substrate from the substrate mounting surface.

According to the present invention, it is possible to mount the flexible substrate in a uniform contact with the mounting table, and also, when the substrate is lifted from the mounting table by releasing the attraction by the electrostatic chuck, It is possible to provide a substrate receiving method which can be difficult.

1 is a schematic sectional view showing an example of a substrate processing apparatus provided with a substrate mounting mechanism according to an embodiment of the present invention.
Fig. 2 is a schematic sectional view of the substrate processing apparatus shown in Fig. 1 in a planar direction; Fig.
3 is a cross-sectional view schematically showing a substrate mounting mechanism;
4 is a schematic cross-sectional view showing an example of a method of delivering a substrate according to one embodiment;
5 is a schematic diagram schematically showing the warpage of the substrate G according to the reference example.
6 is a schematic diagram schematically showing warpage of a substrate G according to an embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. Like reference numerals are used for like parts throughout the drawings.

Fig. 1 is a schematic cross-sectional view showing an example of a substrate processing apparatus capable of carrying out a substrate carrying method according to an embodiment of the present invention, and Fig. 2 is a schematic cross-sectional view in plan view thereof. In this example, a plasma etching apparatus is shown as an example of the substrate processing apparatus.

As shown in Fig. 1, the plasma etching apparatus 1 is a flexible substrate, for example, a capacitive coupling type parallel flat plate plasma (hereinafter referred to as " substrate ") which etches a glass substrate And is configured as an etching apparatus. Examples of the FPD include a liquid crystal display (LCD), an electroluminescence (EL) display, a plasma display panel (PDP), and the like.

The plasma etching apparatus 1 is provided with a processing chamber (hereinafter referred to as a chamber) 2 as a processing vessel for containing a substrate G therein. The chamber 2 is made of, for example, aluminum whose surface has been subjected to an alumite treatment (anodizing treatment), and is formed into a square pillar shape corresponding to the shape of the substrate G.

At the bottom of the chamber 2, a susceptor 4 as a mounting table for mounting the substrate G is provided. The susceptor 4 is formed in a square plate or column shape corresponding to the shape of the substrate G and includes a base 4a made of a conductive material such as metal and a base 4b made of a material And an insulating member 4b provided between the bottoms. A feeder line 23 for feeding a high frequency power is connected to the base material 4a and a matching device 24 and a high frequency power source 25 are connected to the feeder line 23. [ From the high-frequency power supply 25, for example, a high-frequency power of 13.56 MHz is applied to the susceptor 4 so that the susceptor 4 functions as a lower electrode.

The susceptor 4 is provided with an electrostatic chuck 41 for sucking the mounted substrate G by electrostatic attraction. The electrostatic chuck 41 is provided on the upper side of the base material 4a and is composed of a dielectric and an internal electrode 42 provided inside the dielectric. A power source 43 for applying a voltage to the internal electrode 42 is connected to the internal electrode 42 through a switch 44 for turning on / off the application of voltage.

An upper or upper wall of the chamber 2 is provided so as to face the susceptor 4 with a showerhead 11 which supplies a processing gas into the chamber 2 and which functions as an upper electrode. The shower head 11 is provided with a gas diffusion space 12 for diffusing a process gas therein and a plurality of discharge holes 13 for discharging a process gas on a surface opposed to the under surface or the susceptor 4, Respectively. This showerhead 11 is grounded and forms a pair of parallel flat plate electrodes together with the susceptor 4. [

A gas introducing port 14 is provided on the upper surface of the shower head 11. A process gas supply pipe 15 is connected to the gas introducing port 14. The process gas supply pipe 15 is connected to a valve 16 And a mass flow controller 17, as shown in Fig. From the process gas supply source 18, a process gas for etching is supplied. As the process gas, a halogen-based gas, an O ₂ gas, an Ar gas, and the like can be used.

An exhaust pipe 19 is connected to the bottom of the chamber 2 and an exhaust device 20 is connected to the exhaust pipe 19. The exhaust device 20 is provided with a vacuum pump such as a turbo-molecular pump, whereby the inside of the chamber 2 can be vacuum-sucked up to a predetermined reduced-pressure atmosphere. An inlet / outlet port 21 (see FIG. 2) for loading / unloading the substrate G is formed on the side wall of the chamber 2 and a gate valve 22 for opening / closing the loading / When the outlet 21 is opened, the substrate G is conveyed through the inlet / outlet 21 and the gate valve 22 in a state in which the substrate G is supported from below by the conveyance arm 40 (see Figs. 2 and 4) And is conveyed between the adjacent load lock chambers (not shown).

Through holes 7a and 7b penetrating through the bottom of the chamber 2 and the susceptor 4 are formed at the edge position and the center position (inside or near the edge position) of the susceptor 4, respectively . The through holes 7a are formed in eight parts in total, for example, two portions at predetermined intervals on the respective sides, and the through holes 7b are formed, for example, in parallel with a pair of opposing sides of the susceptor 4 Two portions are formed at predetermined intervals so as to be arranged. Lifter pins 8a (first elevating pins) and 8b (second elevating pins) supporting and elevating the substrate G from below are respectively inserted into the through holes 7a and 7b from the substrate mounting surface 4c of the susceptor 4, The lifter pins 8a and 8b are provided so as to be in contact with the edge and the central portion of the substrate G at the time of protrusion, respectively, and the lifter pins 8a and 8b are arranged in the radial direction or the width direction by a positioning bush And is inserted into the through holes 7a and 7b.

3 is a cross-sectional view schematically showing a substrate mounting mechanism.

As shown in Fig. 3, the lifter pins 8a and 8b each have a lower portion projecting outwardly of the chamber 2 and a lower end portion connected to the drive portions 9a and 9b, And is configured to be projected and immersed in the substrate mounting surface 4c of the susceptor 4 by being raised and lowered by driving. The driving units 9a and 9b are each constructed using, for example, a step motor.

A flange 26 is formed under each of the lifter pins 8a and 8b and one of the expandable bellows 27 provided to surround the lifter pins 8a and 8b And the other end (upper end) of the bellows 27 is connected to the bottom of the chamber 2. The other end The bellows 27 is expanded and contracted as the lifter pins 8a and 8b move up and down and the gap between the through holes 7a and 7b and the lifter pins 8a and 8b is sealed.

The driving of the driving units 9a and 9b is controlled separately by the controller 31 having a microprocessor (computer). Thereby, the lifter pin 8a and the lifter pin 8b are independently controlled And can be raised and lowered. The controller 31 is provided with a keyboard for performing a command input operation or the like for managing the driving of the driving units 9a and 9b by the process manager or a user for displaying the driving conditions of the driving units 9a and 9b, An interface 32 and a storage unit 33 in which a recipe recording control programs and driving condition data for realizing driving of the driving units 9a and 9b under the control of the controller 31 is stored. If necessary, an arbitrary recipe is retrieved from the storage unit 33 by an instruction from the user interface 32 and executed by the controller 31, whereby the driving units 9a and 9b Is driven and stopped. The recipe may be stored in a computer-readable storage medium such as a CD-ROM, a hard disk, a flash memory, or the like, or may be transferred from another apparatus, for example, through a dedicated line .

The controller 31, the user interface 32 and the storage section 33 constitute a control section for controlling the lifting and lowering of the lifter pins 8a and 8b by the drive sections 9a and 9b, and the susceptor 4, The pins 8a and 8b driving parts 9a and 9b and the control part constitute a substrate mounting mechanism.

Next, a substrate passing method according to one embodiment will be described.

4 (a) to 4 (f) are schematic sectional views showing an example of a method of transporting a substrate according to one embodiment.

First, the loading / unloading port 21 is opened by the gate valve 22 shown in Fig. 2, the substrate G is carried by the carrying arm 40 from the loading / unloading port 21, and transported to the upper side of the susceptor 4 do. Then, the lifter pins 8a and 8b are raised so as to protrude higher than the transport arm 40. [ Thereby, the substrate G is transferred from the transfer arm 40 onto the lifter pins 8a, 8b. The lifter pins 8a and 8b are arranged so as not to be in contact with the carrier arm 40. [

At this time, the position of the tip of the lifter pin 8b supporting the center of the substrate G is made lower than the position of the tip of the lifter pin 8a supporting the edge of the substrate G. For example, the height, from 4 in the example shown in (a), the lifter pin (8b) state-of-the-art substrate with the surface (4c) the height H _C, the lifter pin (8a) a substrate-mounting surface (4c) of the top of the from of H _E. In this manner, the substrate G is supported by the lifter pins 8a and 8b in a state in which the substrate G is bent in a downward convex shape above the substrate mounting surface 4c.

Next, the lifter pins 8a and 8b are lowered without changing the positional relationship of the tips of the lifter pins 8a and 8b, and the lifter pins 8b and the lifter pins 8a, And is immersed in the substrate mounting surface 4c. Thus, as shown in FIG. 4 (b) to FIG. 4 (c), the substrate G is mounted on the substrate mounting surface 4c from the central portion of the substrate G toward the edge of the substrate G. At this time, since the load of the substrate G is balancedly distributed to the respective lifter pins 8a and 8b, the substrate G is deformed by the supporting reaction force of the lifter pins 8a and 8b, Deformation of the susceptor 4 can be suppressed and contact with the substrate mounting surface 4c of the susceptor 4 over the front surface or almost entire surface.

Next, when the substrate G is mounted on the susceptor 4 with the gate valve 22 closed, the switch 44 of the electrostatic chuck 41 is turned on and the DC power is supplied from the power source 43 A voltage is applied to the internal electrode 42, and the substrate G is attracted to the susceptor 4. In addition, the inside of the chamber 2 is evacuated to a predetermined degree of vacuum by the evacuation device 20. The processing gas is supplied from the processing gas supply source 18 to the chamber 2 through the processing gas supply pipe 15, the gas inlet 14 and the showerhead 11 while adjusting the flow rate by the mass flow controller 17. [ . Subsequently, high-frequency electric power is applied from the high-frequency power source 25 to the susceptor 4 through the matching device 24, and a high frequency electric field is applied between the susceptor 4 as a lower electrode and the showerhead 11 as an upper electrode Thereby causing the process gas in the chamber 2 to be plasmaized. The substrate G is etched, for example, by the plasma of the process gas (see Fig. 4 (d)).

Next, when the etching process of the substrate G is completed, the switch 44 is turned off, the application of the DC voltage to the internal electrode 42 is stopped, and the attraction by the electrostatic chuck 41 is released e)).

Next, the height H _E of the lifter pin 8a from the substrate mounting surface 4c at the tip end is made equal to the height H _C from the substrate mounting surface 4c at the tip of the lifter pin 8b, (7a, 7b) so as to support the substrate G and detach it from the substrate mounting surface 4c. Thereafter, although not specifically shown, the transfer arm 40 is inserted below the substrate G, and the lifter pins 8a and 8b are lowered. Thus, the transfer of the substrate G is completed by transferring the substrate G from the lifter pins 8a, 8b to the transfer arm 40. [

When the substrate G is transferred from the lifter pins 8a and 8b to the substrate mounting surface 4c, the height H of the tip of the lifter pin 8b supporting the center of the substrate G _C lower than the height H _E of the tip of the lifter pin 8a supporting the edge of the substrate G. By doing so, the substrate G is supported by the lifter pins 8a and 8b while being bent so as to be convex toward the substrate mounting surface 4c by gravity. The substrate G is mounted from the central portion of the substrate mounting surface 4c toward the edge portion so that the groove at the central portion of the substrate formed by the lifter pin 8b for supporting the central portion of the substrate remains and the substrate G and the substrate mounting surface It is possible to prevent a portion where the substrate G and the substrate mounting surface 4c from coming into contact with each other due to the occurrence of a space between the substrates G and C on the substrate mounting surface 4c And can be transferred to the substrate mounting surface 4c in a uniform contact state.

When the substrate G is transferred from the substrate mounting surface 4c to the lifter pins 8a and 8b by releasing the attraction by the electrostatic chuck 41, the tip end of the lifter pin 8b supporting the center portion of the substrate G It is a and of the height H _C, H the height of the cutting edge _E of the lifter pin (8a) for supporting the edge of the substrate G at the same height. By doing so, the substrate G can evenly or completely remove the entire surface or the entire surface of the substrate G from the substrate mounting surface 4c. Therefore, as compared with the case where the lifter pin 8a is moved away from the substrate mounting surface 4c toward the center portion from the edge portion of the substrate G, the final contact area with the substrate mounting surface 4c is locally Can be suppressed from becoming small. As a result, it is possible to prevent the final contact area from being reduced locally. As a result, it is possible to prevent the occurrence of abnormal discharge in the substrate G by collecting the electric charge charged on the substrate G at the contact portion, It is possible to suppress the occurrence of an abnormal discharge in the central portion of the substrate G in which the charged charge moves and is concentrated.

Therefore, according to the method of transporting a substrate according to the embodiment, it is possible to mount the flexible substrate G so as to be uniformly in contact with the electrostatic chuck 41 of the susceptor 4, It is possible to obtain a substrate receiving method capable of making it difficult for an abnormal discharge to occur in the substrate G when the substrate G is lifted from the electrostatic chuck 41 of the susceptor 4 by releasing the adsorption by the substrate W. [

Further, the possibility of an abnormal discharge occurring when the substrate G is lifted after the electrostatic attraction is released increases as the size of the substrate G increases. This is because as the size of the substrate G becomes larger, the absolute amount of charges existing on the back surface of the substrate G which can not be completely eliminated increases, and the electric field generated when charges are concentrated on the final contact portion increases.

For example, when the substrate G is lifted from the edge portion as shown in the schematic view schematically showing the deflection of the substrate G according to the reference example of Fig. 5, a portion of the central portion of the outermost recess of the substrate G becomes the final contact portion C . Therefore, if residual charges e and h remaining on the surface of the substrate G are not completely eliminated, these residual charges e and h move to the final contact portion C and gather. It is expected that if the absolute amount of the residual charge collected in the final contact portion C is large and is sufficient to discharge, the discharge is almost certainly caused.

According to this embodiment, as shown in the schematic diagram of Fig. 6, the height of the tips of the lifter pins 8a and 8b is equalized, and the substrate G is raised. Therefore, the substrate G is bent between the lifter pins 8a and 8b by the support reaction force of the lifter pins 8a and 8b. In other words, in one embodiment, rather than bending one portion of the substrate G, it bends a plurality of portions of the substrate G. As a result of bending a plurality of portions of the substrate G, the final contact portion C can be dispersed into a plurality of portions. Therefore, even if there is residual charge remaining because the charge can not be completely eliminated, the residual charge is dispersed and gathered in the plurality of final contact portions C. It is possible to distribute a plurality of portions where the residual charges are collected so that the absolute amount of residual charge collected in the final contact portion C can be reduced as compared with the case where the final contact portion C is a single portion. Therefore, according to the embodiment, the absolute amount of residual charge collected in the final contact portion C can be reduced, and the probability that the amount of residual charge reaches a sufficient amount to discharge can be suppressed to a low level.

As described above, in the embodiment in which the residual charge can be dispersed in the plurality of final contact portions C even when the residual charge is present, the larger the size of the substrate G, the higher the effect of suppressing the abnormal discharge can be. As long as the size of the substrate G is 1320 mm x 1500 mm or more, a sufficient effect can be expected. The upper limit of the size does not particularly exist in view of the essence of the present invention, but is determined by other factors such as the manufacturing technology of the substrate G in the present period and the plasma processing technique as the upper limit of the embodiment.

As described above, even when lifting the substrate G in the prior art, since the substrate G is prevented from being shaken by being bent and supported so as to be convex downward, the substrate G is lifted by the lifter pins 8a and 8b, When the substrate G is lifted up from the substrate mounting surface 4c as compared with the case where the height of the peak of the lifter pin 8a is raised higher than the lifter pin 8b, There is a possibility that the shake of the substrate G becomes large.

The possibility that the shaking of the substrate G becomes large can be solved by suppressing the rising speed of the lifter pins 8a and 8b to be late.

While the present invention has been described with reference to the preferred embodiments thereof, the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the invention. Further, the embodiment of the present invention is not the only embodiment.

For example, in the above-described embodiment, a plurality of lifter pins 8b for supporting the central portion of the substrate G are provided as shown in Fig. 2, but one lifter pin 8b may be provided.

In the above embodiment, the present invention is applied to an RIE-type capacitively coupled parallel flat plate plasma etching apparatus for applying a high frequency power to a lower electrode. However, the present invention is not limited to this, and other plasma processing such as ashing, The present invention is also applicable to a substrate processing apparatus other than the plasma processing apparatus in which the substrate is mounted on a mount table.

Further, in the above-described embodiment, an example in which the present invention is applied to a glass substrate for an FPD has been described. However, the present invention is applicable to a substrate having flexibility other than a glass substrate for an FPD.

In addition, various modifications are possible.

G: substrate
2: Processing chamber
4: susceptor
4c: substrate mounting surface
8a: lifter pin supporting edge
8b: lifter pin for supporting the center portion
41: electrostatic chuck

Claims (2)

A substrate transfer method for transferring a substrate to a mounting table provided in a processing chamber for performing a plasma process on a flexible substrate and having an electrostatic chuck for sucking the substrate by electrostatic attraction,
Wherein the mounting table includes a first mounting pin which can be projected onto a substrate mounting surface on which the substrate is mounted and a mounting surface of the mounting table and supports an edge of the substrate, And a second lift pin for supporting a central portion of the substrate,
Lowering the substrate supported by the first lift pin and the second lift pin lower in position than the first lift pin at a position above the substrate mounting surface of the substrate, A substrate mounting step of mounting the substrate on the substrate mounting surface,
A step of causing the substrate mounted on the substrate mounting surface to be attracted by the electrostatic chuck to perform plasma processing on the substrate;
The first lift pin and the second lift pin are held at the same height to support the substrate and the substrate is separated from the substrate mounting surface by releasing the attraction by the electrostatic chuck after the completion of the plasma treatment, fair
Wherein the substrate is a substrate.
The method according to claim 1,
The substrate lifting step may be performed such that the first lift pin and the second lift pin are made flush with each other and the substrate having flexibility is bent at a plurality of portions in a downward convex shape to separate the substrate from the substrate mounting surface Wherein the substrate is a substrate.

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