KR100622201B1 - Plasma processing apparatus for lcd substrate - Google Patents

Abstract

The plasma processing apparatus for the substrate for liquid crystal display device uses the first and second conveyance assist mechanisms 11 and 12 to perform conveyance assist of loading and unloading of the substrate S to be mounted on the mounting table 2. Have The second conveyance assist mechanism 12 has four lifters 12A arranged around the outside of the mounting table 2. Each lifter 12A has a support shaft 13 which can be elevated relative to the mounting table 2, and a bracket 14A that protrudes laterally from the support shaft 13. The bracket 14A is movable between a protruding position that protrudes toward the mounting table 2 to support the substrate S to be processed when carrying assist and a retracted position that retracts from the mounting table 2 when generating plasma. Do. Corresponding to the retreat position of each bracket 14A, a case 15 for housing the bracket 14A is disposed. The upper end opening of the case 15 is closed by the lid 14B disposed on the upper side of the bracket 14A to move up and down together with the bracket 14A.

Description

Plasma processing apparatus for substrate for liquid crystal display device {PLASMA PROCESSING APPARATUS FOR LCD SUBSTRATE}             

1A is a cross-sectional view showing a processing chamber of a plasma processing apparatus according to an embodiment of the present invention;

1B is an enlarged cross-sectional view of a junction of a processing chamber of a plasma processing apparatus according to an embodiment of the present invention;

2 is a plan view showing the bottom surface of the processing chamber shown in FIG.

3A is a perspective view of the gas rectifying block shown in FIG. 1;

3B is a cross-sectional view showing a state of fixing a gas rectifying block;

3C is a sectional view showing a modification of the state of fixing the gas rectifying block.

4 is a partial perspective view showing a relationship between a second conveyance assist mechanism and a mounting table used in the plasma processing apparatus shown in FIG. 1;

5 is a cross-sectional view showing the second conveyance assist mechanism shown in FIG. 4;

6 is a plan view showing the inside of the upper electrode shown in FIG. 1 in an upward direction;

FIG. 7 is a perspective view illustrating a shield ring of the upper electrode illustrated in FIG. 1;

8 is a cross-sectional view showing a main part of a modification of the second conveyance assist mechanism;                 

9 is a perspective view showing a plasma processing apparatus of a multi-chamber type,

FIG. 10 is a perspective view showing a state in which the LCD substrate to be mounted is replaced by the transport apparatus in the plasma processing apparatus shown in FIG. 9;

11A is a perspective view illustrating a state in which the conveyance assist mechanism of FIG. 10 is not in operation;

FIG. 11B is a perspective view showing a state in which the transport assist mechanism of FIG. 10 is operating; FIG.

Explanation of symbols for the main parts of the drawings

1: processing chamber 2: mounting table

2A: lower electrode 3: upper electrode

4: process gas supply source 5: gas piping

5A: Flange 6: Exhaust Pipe

8: electrostatic chuck 9, 27: shield ring

10 gas rectifying block 11 first conveyance assist mechanism

11A: Lifter pin 12: Second conveyance assist mechanism

13: support shaft 14A: bracket

14B: Cover 15: Case

16: suspension 16A: bottom plate

16C: first sleeve 16D: second sleeve

16E: elastic member 16F: third sleeve                 

19: sleeve 20: sealing member

22: first baffle plate 23: second baffle plate

24: first boundary plate 25: second boundary plate

The present invention relates to an apparatus for performing a plasma treatment on a substrate for a liquid crystal display device (hereinafter referred to as "LCD substrate"). In particular, the present invention relates to an improvement of a mechanism for assisting loading and unloading of a substrate to be mounted on a mounting table.

9 is a perspective view showing a multi-chamber type plasma processing apparatus for performing plasma processing on an LCD substrate. The plasma processing apparatus shown in FIG. 9 includes three processing chambers 101, for example. These process chambers 101 are connected to the rectangular conveyance chamber 103 via the gate valve 102. The transfer chamber 103 is connected to the load lock chamber 105 via the gate valve 104.

The conveying apparatus 107 is arrange | positioned so that the load lock chamber 105 may adjoin through the gate valve 106. Indexers 108 are disposed on the left and right of the conveying apparatus 107. The indexer 108 is equipped with a cassette C in which 25 LCD substrates S are stored, for example. The substrate S inside the cassette is carried into the load lock chamber 105 by the transfer device 107, and the processed substrate S is carried out in the load lock chamber 105.

At the time of processing, the substrate S is loaded into the load lock chamber 105 to close the gate valve 106. Next, after depressurizing the inside of the load lock chamber 105 to a predetermined degree of vacuum, the gate valve 104 between the transfer chamber 103 and the load lock chamber 105 is opened. After the board | substrate S in the load lock chamber 105 is carried in into the conveyance chamber 103 via the conveying apparatus (not shown) in the conveyance chamber 103, the gate valve 104 is closed.

In the transfer chamber 103, the pressure is reduced to a higher degree of vacuum than in the load lock chamber 105. Thereafter, the gate valve 102 is opened and the unprocessed substrate S and the processed substrate S 'are exchanged between the mounting table in the processing chamber 101 (see FIG. 10). After the replacement, the plasma is generated between the lower electrode and the upper electrode in the processing chamber 101 to perform a predetermined plasma treatment on the substrate S. As shown in FIG. The three processing chambers 101 may perform the same process (for example, etching process), and may perform different processes (for example, etching process, ashing process, etc.).

Unlike the semiconductor wafer, the LCD substrate S has a large processing area, and since the plasma apparatus itself is larger than that for the semiconductor wafer, there are various problems that cannot be supported by the specifications of the plasma processing apparatus for semiconductor wafers. For example, the conveyance assist mechanism of the LCD substrate S with respect to the mounting table is also different from that of the semiconductor wafer as described below. Moreover, since the structural member in a process chamber is large compared with the case for a semiconductor wafer, and in recent years, the board | substrate S itself becomes large and large, there exists a unique difficulty of the plasma processing apparatus for liquid crystal display substrates. .

Here, the conveyance assist mechanism of the board | substrate S which is an independent mechanism of the plasma processing apparatus for liquid crystal display substrates is demonstrated with reference to FIG. 10, FIG. 11A, and FIG. In the processing chamber 101, as shown in FIG. 10, a mounting table 109 for mounting the LCD substrate S is disposed, and a lower electrode 109A is disposed as a part thereof. On the other hand, the articulated conveying apparatus (only the hand 110 is shown in FIG. 10) is arrange | positioned in the conveyance chamber 103, for example.

The first conveyance assist mechanism 111 and the second conveyance assist mechanism 112 are disposed on the mounting table 109. The exchange of the unprocessed board | substrate S and the processed board | substrate S 'is performed between the mounting base 109 and the hand 110 of a conveying apparatus via the 1st, 2nd conveyance assist mechanisms 111 and 112. FIG. The hand 110 has forks 110A and 110B in the upper and lower two stages as shown in FIG. 10, supports the unprocessed substrate S by the upper forks 110A, and the processed substrates by the lower forks 110B. S ').

In addition, the 1st, 2nd conveyance assist mechanisms 111 and 112 are demonstrated with reference to FIG. 10, FIG. 11A, and FIG. The first conveyance assist mechanism 111 has, for example, two pairs of first lifter pins 111A arranged before and after the left and right both peripheral portions of the mounting table 109, and the substrate ( Support S) horizontally.

The second conveyance assist mechanism 112 has, for example, two pairs of second lifter pins 112A arranged on the left and right sides of the frame-shaped shield ring 113 covering the periphery of the lower electrode 109A. For example, the second lifter pin 112A is formed by bending the upper end portion twice in the horizontal direction and the upper direction twice by 90 °, and at the position higher than the first lifter pin 111A at the tip of the “L” shape, the untreated substrate S ). In addition, since the second lifter pin 112A is rotatable in the forward and reverse directions, when the substrate S is replaced, as shown in FIG. 11B, the L-shaped portion is rotated 90 degrees counterclockwise to mount the mounting table. Toward the inside of 109. In other cases, the "L" shaped portion is rotated 90 degrees clockwise to retract into the recess 113A formed in the shield ring 113, and the recess 113A is closed by the lid 112B.

Therefore, the exchange of untreated and processed substrates S and S 'is performed as follows. First, in the second conveyance assist mechanism 112, after the cover 112B is opened from the state of FIG. 11A, as shown by the arrow of FIG. 11B, the second lifter pin 112A is a recess of the shield ring 113. At the same time as it rises at 113A, an "L" shaped portion faces the inside of the mounting table 109. Next, in the first conveyance assist mechanism 111, the first lifter pin 111A is raised to lift the processed substrate S 'horizontally.

And when the hand 110 of a conveying apparatus advances toward the mounting base 109, the unprocessed board | substrate S mounted in the upper fork 110A will be slightly upper part of the "L" shaped part of the 2nd lifter pin 112A. At the same time as the lower fork 110B is located slightly below the processed substrate (S '). Next, the second lifter pin 112A is raised to receive the unprocessed substrate S from the upper fork 110A, and the first lifter pin is lowered to bring the processed substrate S 'to the lower fork 110B. Guide.

Next, the hand 110 retreats from the mounting table 109, the first lifter pin 111A is slightly raised and the second lifter pin 112A is lowered to move the unprocessed substrate S to the second lifter. Leading from pin 112A to first lifter pin 111A. Further, when the first lifter pin 111A is lowered and retracted into the mounting table 109, the substrate S is mounted on the mounting table 109. After the second lifter pin 112A guides the unprocessed substrate S, the “L” shaped portion rotates 90 ° in the opposite direction, and further descends to retreat into the recess 113A of the shield ring 113. Thereafter, the lid 112B is closed to complete a series of substrate exchanges.

112A of 2nd lifter pins of the 2nd conveyance assist mechanism 112 are accommodated in the recessed part 113A of the shield ring 113, and since the cover 112B closes the recessed part 113A, the cover 112B is carried out. ) And the recess 113A need opening and closing gaps. Moreover, since the drive part of the 2nd lifter pin 112A is arrange | positioned in the cavity in the mounting table 109, abnormal discharge may generate | occur | produce through this clearance gap during a plasma process. In addition, there is a fear that the plasma by-products enter from this gap, and the by-products accumulate in the recess 113A, which may cause foreign matters. Moreover, since the 2nd conveyance assist mechanism 112 is provided in the shield ring 113 which adjoins the board | substrate S, there exists a possibility that the foreign material generate | occur | produced in the movable part may contaminate the board | substrate S. FIG.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and in particular, an object of the present invention is to provide a plasma processing apparatus for an LCD substrate which can prevent abnormal discharge during plasma processing and at the same time prevent generation of foreign matter in the vicinity of the LCD substrate. Doing.                         

Plasma processing apparatus for a liquid crystal display substrate of the present invention

A confidential processing room,

A mounting table having a mounting surface for mounting a substrate to be processed in the processing chamber;

A processing gas supply system for supplying a processing gas into the processing chamber;

An exhaust system for evacuating the processing chamber and setting the processing chamber to a vacuum;

An excitation system for generating a plasma by exciting the processing gas by generating a discharge in the processing chamber;

A plurality of lifters disposed around the outside of the mounting table for carrying out load assisting of the substrate and the unloading of the substrate to the mounting surface by the conveying device, each of the lifters being a support shaft that can be lifted with respect to the mounting table. And a bracket which protrudes laterally from the support shaft, wherein the bracket protrudes toward the mounting table side when the conveying assist is executed to support the substrate to be processed, and the mounting table when generating the plasma. The lifter, which is movable between a retracted position to retract from and

And a plurality of cases for accommodating the brackets disposed corresponding to the retreat positions of each of the brackets.

EMBODIMENT OF THE INVENTION Below, the Example of this invention is described with reference to drawings. In addition, in the following description, the same code | symbol is attached | subjected about the component which has substantially the same function and structure, and the duplicate description shall be made only when necessary.

1A is a cross-sectional view showing a processing chamber of a plasma processing apparatus for an LCD substrate according to an embodiment of the present invention. The plasma processing apparatus is basically provided with a processing chamber for performing plasma processing on the LCD substrate S as in the prior art, and a transfer chamber having a transfer apparatus connected to the processing chamber. As shown in FIG. 1A, the gate valve G is mounted on the side wall of the processing chamber 1, and the processing chamber 1 and the transfer chamber (not shown) can communicate with each other via the gate valve G. As shown in FIG. In the processing chamber 1, a mounting table 2 for mounting the substrate S for processing is disposed, and a lower electrode 2A is disposed as a part thereof.

Above the lower electrode 2A, an upper electrode 3 serving as a supply portion of the processing gas is disposed to face each other. The upper electrode 3 is connected to the RF (high frequency) power supply 3B via the matching circuit 3A, and RF power of 13.56 MHz is applied to the upper electrode 3 from the RF power supply 3B. The processing gas is supplied into the processing chamber 1 through the upper electrode 3 from the processing gas supply source 4 disposed outside the processing chamber 1. When RF power is applied to the upper electrode 3, a discharge occurs between the lower electrode 2A and the upper electrode 3 to excite the process gas to generate a plasma. Using this plasma, plasma processing such as etching or ashing is performed.

As shown in FIG. 1A, the processing gas supply source 4 is connected to the upper electrode 3 via the mass flow controller 4A, the opening / closing valve 4B, and the gas pipe 5. The gas pipe 5 near the processing chamber 1 passes through a through hole 1A formed in the side wall of the processing chamber 1. The processing chamber 1 is divided up and down in the vicinity of the upper end portion so that the internal maintenance can be easily performed, and the upper portion of the processing chamber 1 can be opened and closed, whereby the gas pipe 5 is also divided.

As shown in an enlarged view in FIG. 1B, flanges 5A and 5A are attached to the divided ends of each of the gas pipes 5. The periphery of the flange 5A is housed in a ring-shaped recess 1B provided in a dividing surface of the side wall of the processing chamber 1. Sealing members 5B and 5C are fitted between the abutting surfaces of the flanges 5A and 5A, and between the flanges 5A and the adjacent surfaces of the ring recess 1B, respectively. The sealing member 1C is also sandwiched between the divided surfaces of the side walls, and the airtight in the processing chamber 1 is maintained by these sealing members. Thus, when opening and closing the process chamber 1 by accommodating the gas piping 5 in the wall surface of the process chamber 1, the gas piping 5 does not interfere. When the upper electrode 3 is cooled, the refrigerant pipe can be passed through the through hole 1A on the side wall.

As shown in FIG. 1A and FIG. 2, the exhaust port 1E is formed in the bottom surface of the process chamber 1 by disperse | distributing substantially equally to five places. A vacuum pump (not shown) is arranged in the exhaust port 1E, and the inside of the processing chamber 1 is set to vacuum while the inside of the processing chamber 1 is exhausted by the vacuum pump. Since the exhaust port 1E is also formed in the lower direction of the mounting table 2 in addition to the periphery of the mounting table 2, the exhaust port 1E is accelerated by passing the exhaust pipe 6 connected to the exhaust port 1E and in the processing chamber 1. The exhaust stream can be made uniform. Therefore, it is possible to realize uniformity of plasma processing such as etching treatment.

The mounting table 2 is disposed at the center of the bottom surface of the processing chamber 1, and is supported in a state of being raised from the bottom surface by, for example, four hollow pillars 7. As shown in FIG. 2, the support | pillar 7 is flange-bonded with respect to the through-hole 1F of the bottom surface of the process chamber 1, and also serves as utility storage piping. A coolant flow path 2D is formed on an inner surface of the mounting table 2, and the coolant flow path 2D is connected to a coolant pipe 2B connected to a coolant supply source (not shown). Cooling control of the mounting table 2 to predetermined temperature can be performed by the refrigerant | coolant which circulates through the refrigerant | coolant flow path 2D via the refrigerant | coolant piping 2B. An electrostatic chuck 8 is disposed on the surface of the mounting table 2, and the LCD substrate S is electrostatically adsorbed through the electrostatic chuck 8. The electrostatic chuck 8 is connected to the power supply 8B via a wiring 8A. Utility-related piping and wiring such as the refrigerant pipe 2B, the wiring 5A, and the ground wiring 2C of the mounting table 2 are stored in the support post 7.

As shown in FIG. 1A, in the mounting table 2, the outer peripheral portion of the lower electrode 2A is covered with a shield ring 9 formed in a frame shape by a plasma resistant material such as ceramic. The shield ring 9 prevents damage due to sputtering of the outer periphery of the lower electrode 2A, and at the same time, the lower electrode 2A of the plasma generated between the lower electrode 2A and the upper electrode 3 Expansion to the outside can be prevented. The shield ring 9 is composed of a ring-shaped frame 9A covering the outer periphery of the lower electrode 2A, and a cylindrical body 9B covering the outer circumferential surface of the lower electrode 2A. These ring-shaped frames 9A and the cylindrical body 9B may be divided or integrated as shown in FIG. 1A.

As shown in FIG. 1A, the electrostatic chuck 8 is surrounded by a ring-shaped frame 9A disposed at the periphery of the mounting table 2 and the gas rectifying block 10 on the upper surface thereof. The gas rectifying block 10 rises toward the upper electrode 3 when the LCD substrate S is carried in or out. As shown in Figs. 3A and 3B, the gas rectifying block 10 is formed into a frame shape having a cross-section "L" shape by a plasma resistant material such as ceramic. By the gas rectifying block 10, the processing gas supplied from the upper electrode 3 to the downstream is spread at a uniform flow rate over the entire surface of the substrate S. FIG.

That is, the processing gas is supplied from the upper electrode 2 to the down stream, and the used gas is exhausted from the exhaust port 1E. At this time, the exhaust stream has a faster peripheral edge than the central portion of the substrate S. By providing the gas rectifying block 10, the gas flow is blocked by the gas rectifying block 10, and the gas flow rate of the peripheral edge of the substrate S is slowed. As a result, the density of the processing gas on the entire surface of the substrate S inside the gas rectifying block 10 is made uniform, so that the plasma processing can be made uniform. In order to acquire these results more reliably, it is preferable to set the height from the surface of the board | substrate S of the gas rectifying block 10 about 25 mm, for example.

As shown in FIGS. 3A and 3B, the gas rectifying block 10 is mounted via a rectangular base frame 10A and a plurality of fixing pins 10B to be detachable to the inner circumference of the base frame 10A. Has a rectified frame 10C. A fixture 10D such as a cam is arranged to press the rectifying frame 10C from the side in a state where the rectifying frame 10C is attached to the base frame 10A, whereby the rectifying frame 10C is fixed with a pin ( It is fixed on the base frame 10A via 10B).

The fixing pin 10B is mounted vertically downward over the entire circumference at a lower end portion of the rectifying frame 10C at predetermined intervals, and is fitted into a pin hole formed in the base frame 10A. For example, as shown in FIG. 3A, a fastener 10D such as a cam is attached to each side of the base frame 10A. Therefore, during maintenance, the rectifying frame 10C can be easily detached from the base frame 10A by manually operating the fixture 10D. For this reason, when the plasma by-products adhere and deposit on the rectifying frame 10C, cleaning can be performed simply.

The positioning and mounting of the rectifying frame 10C with respect to the base frame 10A may adopt a configuration other than the fixing pin 10B. For example, as shown in FIG. 3C, the stepped portion 10E may be formed at the lower end of the rectifying frame 10C, and the stepped portion 10E may be coupled to the convex portion 10F of the base frame 10A.

In order to perform the load and unload assist of the board | substrate S with respect to the mounting surface of the mounting table 2, the 1st conveyance assist mechanism 11 is arrange | positioned inside the mounting table 2, and the mounting table 2 The second conveyance assist mechanism 12 is disposed around the outer side of the. The 1st conveyance assist mechanism 11 forms the 1st support level above the mounting surface of the mounting table 2, and the 2nd conveyance assist mechanism 12 raises a 2nd support level above the said 1st support level. It is set to form.

As shown in FIG. 4, the 1st conveyance assist mechanism 11 has four lifter pin 11A arrange | positioned along the inner periphery of 2 A of lower electrodes like conventionally. Although not shown, these lifter pins 11A may be pins having a constant thickness (outer diameter), and may also be pins whose upper end portion is thick and reduced downward and is uniformly tapered. A bush (not shown) formed of an insulating material is attached to the hole of the lower electrode 2A on which the lifter pin 11A is projected, and the lifter pin 11A is raised and lowered along the bush. The bush is mounted on the back side of an electrode plate (not shown) forming the lower electrode 2A so that the bush itself is not exposed to the electrode surface and prevents discharge in the hole of the lower electrode 2A. .

On the other hand, the 2nd conveyance assist mechanism 12 has four lifter 12A arrange | positioned around the outer side of the mounting table 2. As shown in FIG. For example, as shown in FIG. 4 and FIG. 5, each lifter 12A has a support shaft 13 that can be reversely rotated and can be elevated. In order to support the board | substrate S in the upper end part of the support shaft 13, the elliptical bracket 14A which protrudes in the horizontal direction is arrange | positioned. The bracket 14A is raised and rotated by the support shaft 13 to protrude to the mounting table 2 side when carrying assist is performed, and to support the substrate S, and the mounting table 2 when generating plasma. It becomes possible to move between retreat positions which retreat from).

Four cases 15 for accommodating the bracket 14A are disposed corresponding to the retreat positions of the brackets 14A. In order to reduce the influence on the generation of plasma, the upper end of each case 15 is disposed below the mounting surface of the mounting table 2 by 10 mm to 50 mm. Each case 15 has an elliptical shape similar to that of the bracket 14A, and accepts the bracket 14A at its upper opening. Each case 15 is supported by the suspension 16 elastically receiving the load in the vertical direction, which is installed from the bottom of the processing chamber 1, and is disposed parallel to the side surface of the mounting table 2. In addition, a cover 14B for closing the opening of the case 15 is disposed above the bracket 14A and is fixed to the bracket 14A. In addition, the bracket 14A and the case 15 are basically formed from anodized aluminum on the surface, while the lid 14B is formed from a plasma resistant material such as ceramic.

As shown in FIG. 5, the support shaft 13 penetrates through holes 1G formed in the bottom surface of the processing chamber 1 and is connected to the drive shaft 17 arranged in the lower direction of the bottom surface. Connection via 13A). The drive shaft 17 is capable of forward and reverse rotation through a rotation drive mechanism and a lift drive mechanism (both not shown) disposed in the lower direction of the bottom surface. Thus, the support shaft 13 is capable of forward and reverse rotation through the drive shaft 17 and can be separated from the drive shaft 17 through the connecting member 13A.

Further, bellows 18 is mounted to the rear of the through hole 1G on the bottom surface via the flange 18A, and the drive shaft 17 is accommodated in the bellows 18. The support shaft 13 is accommodated in the sleeve 19 in a lower portion than the case 15. A flange 19A is formed at the lower end of the sleeve 19 and fixed to one end of the bottom plate 16A of the suspension 16 via the flange 19A. A bush 19B is attached to the upper end opening of the sleeve 19 to block the inside of the processing chamber 1 from the space in the sleeve 19 and further from the bottom side of the bottom surface. By such a configuration, foreign matters generated by the drive mechanism in the lower direction of the bottom surface do not enter the processing chamber 1. In addition, the bush 19B also has a function of a lifting guide of the support shaft 13.

As shown in FIG. 5, the bracket 14A is formed to have a shape similar to the case 15 so as to enter the case 15, and is connected to the upper end of the support shaft 13 at its proximal end. The bracket 14A is formed at the tip side as a thin receiving portion and at the same time as the base end is thick, and receives the substrate S at the receiving portion. On the surface of the bracket 14A, a brace 14C made of a heat resistant and corrosion resistant material having a large coefficient of friction, such as a fluorine resin, is disposed. The brace 14C prevents the substrate S from slipping off the bracket 14A.

The lid 14B has a flat outline slightly larger than the case 15, and is fixed to the thick portion of the bracket 14A. When the bracket 14A reaches the lower end through the support shaft 13, the lid 14B closes the top opening of the case 15. The sealing member 20 is attached to the opening end surface of the case 15 over the whole periphery, and the inside of the case 15 is cut off from the process chamber 1 through the sealing member 20. For this reason, the plasma by-products do not enter the case 15 during the plasma treatment, and do not adhere and deposit, and the bracket 14A for supporting the substrate S is kept clean.

As shown in FIG. 5, the bottom surface of the case 15 is provided with a hole 15A for loosely fitting the support shaft 13 to the proximal end. Further, two holes are formed in the bottom surface at predetermined intervals along the long axis, and the suspension 16 is connected through these holes. As shown in FIG. 5, each suspension 16 has two core shafts 16B and 16B which vertically penetrate two holes of the case 15, respectively.

On the upper side of the core shaft 16B, a first sleeve 16C having a flange fixed to the case 15 is mounted. Below the core shaft 16B, the second sleeve 16D is mounted at a predetermined distance from the first sleeve 16C. An elastic member (for example, a coil spring) 16E is mounted between the first and second sleeves 16C and 16D. The third sleeve 16F is mounted to cover the elastic member 16E, and this flange is fixed to the lower surface of the case 15.

The two core shafts 16B and 16B project from the flange of the upper end of the first sleeve 16C and are connected to each other via the connecting plate 16G at the protruding end. The first sleeve 16C is fixed to the bottom surface of the case 15 via a flange located in the case 15. Thus, by the elasticity of the spring 16E of the suspension 16, the lid 14B elastically contacts the opening end face of the case 15 at the lower end, and the case 15 through the sealing member 20. It seals me well. In addition, since the cover 14B elastically contacts the opening end surface of the case 15, the sealing member 20 can also be abbreviate | omitted.

On the other hand, as shown in FIG. 1A, the upper electrode 3 is formed in hollow shape, and is attached to the center hole of the upper surface of the process chamber 1 via the frame 21 which consists of an insulating member. On the entire surface of the lower surface of the upper electrode 3 (the surface facing the lower electrode 2A), a plurality of ejection holes 3C are equally distributed and disposed from the respective ejection holes 3C to the entire process chamber 1. Gas is supplied to the down stream.

As shown in FIG. 1A, inside the upper electrode 3, first and second baffle plates 22 and 23 are arranged at two upper and lower stages at predetermined intervals. In each of the baffle plates 22 and 23, the dispersion holes 22A and 23A are evenly formed over the entire surface, and the dispersion holes 22A and 23A are shifted from each other. In addition, the inner surface of the upper wall of the upper electrode 3 and the first baffle plate 22 are connected by the first and second boundary plates 24 and 25, for example, as shown in FIG. The space between the wall and the first baffle plate 22 is divided into three sub chambers 3D, 3E, and 3F. The first boundary plate 24 is formed as a frame body similar in shape to the planar upper electrode 3, and the second boundary plate 25 is formed on both sides of the first boundary plate 24 and the upper electrode 3. It is formed as a rectangular plate connecting the inner wall surface of the.

Branch pipes 5D, 5E, and 5F of the gas pipe 5 are connected to each of the sub-chambers 3D, 3E, and 3F, as shown in Fig. 1A. The control valves 26, 26, 26 are attached to these branch pipes 5D, 5E, and 5F, and the flow volume of the processing gas to each sub chamber 3D, 3E, 3F can be individually controlled. In this way, by individually controlling the gas flow rates to the respective sub chambers 3D, 3E, and 3F, even if the substrate S becomes large, the gas flow rates in the entire area of the substrate S can be equalized, and further, the plasma processing. Can be made uniform.

As shown in FIG. 1A, a frame-shaped shield ring 27 is mounted on the periphery of the lower surface of the upper electrode 3. The shield ring 27 basically has the same function as the shield ring 9 of the mounting table 2, and is formed of a plasma resistant material. Since the shield ring 27 is enlarged as the area of the substrate S is enlarged, it is difficult to handle it with an integrated body, and as shown in FIG. 7, the shield ring 27 is divided into four and closely adhered to each other without a gap. Furthermore, as shown in Fig. 7, each joint 27A has a step in the horizontal direction and the vertical direction, and the joints overlap so that abnormal discharge can be prevented and the plasma by-product enters from the joint. I never do that. The shield ring 9 on the side of the mounting table 2 shown in FIG. 1A is also formed by dividing in the same manner as the shield ring 27 of the upper electrode 3.                     

Next, the operation of the plasma processing apparatus shown in FIG. 1A will be described.

When the plasma processing of the preceding substrate S 'is finished in the processing chamber 1, the gate valve G is opened. Accordingly, as shown in FIG. 4, after the support shaft 13 of the second conveyance assist mechanism 12 rises from the state shown in FIG. 5, the bracket 14A and the cover ( 14B) faces the inside of the mounting table 2. Next, the 1st and 2nd conveyance assist mechanisms 11 and 12 and the conveying apparatus (not shown) in a conveyance chamber operate | move, and the board | substrate 2 is replaced with the board | substrate S and S '. . At this time, the conveying apparatus and the 1st conveyance assist mechanism 11 operate | move as usual, while the 2nd conveyance assist mechanism 12 performs an operation in the form mentioned later.

First, the lifter pin 11A of the 1st conveyance assist mechanism 11 raises the processed board | substrate S 'horizontally to a 1st support level above a mounting surface. At this time, the bracket 14A and the lid 14B of the lifter 12A of the second conveyance assist mechanism 12 are arranged to protrude above the first support level. In this state, the unprocessed board | substrate S is carried in by a conveying apparatus, and the periphery of the board | substrate S is inserted in the clearance gap of 14 A of brackets and the lid 14B. Next, the support shaft 13 is raised to receive the unprocessed substrate S from the conveying apparatus with the bracket 14A, and the lifter pin of the first conveying assist mechanism 11 is lowered to process the processed substrate S '. To the conveying device. Next, after the conveying apparatus carries out the processed board | substrate S 'from the process chamber 1 like conventionally, the gate valve G is closed.

On the other hand, in the processing chamber 1, the lifter pin of the 1st conveyance assist mechanism 11 rises slightly, and the support shaft 13 of the 2nd conveyance assist mechanism 12 falls, and the unprocessed board | substrate S is bracketed. It guides from 14A to the 1st conveyance assist mechanism 11. Next, the bracket 14A is rotated 90 degrees counterclockwise through the support shaft 13, and the bracket 14A is lowered through the support shaft 13 while retreating from the mounting table 2. In the retracted position where the bracket 14A is lowered, the bracket 14A is accommodated in the case 15 and the lid 14B elastically lands on the opening end face of the case 15 to seal the case 15. do. In the meantime, the lifter pin of the 1st conveyance assist mechanism 11 descend | falls, it retracts into the mounting table 2, and guides the board | substrate S on the mounting table 2, and of a series of board | substrates S and S 'is carried out. End the exchange. The substrate S on the mounting table 2 is securely fixed by the electrostatic chuck 8.

Next, in the processing chamber 1, RF power is applied to the upper electrode 3 to perform plasma processing. At this time, the processing gas is distributed and supplied to each of the sub chambers 3D, 3E, and 3F of the upper electrode 3 through the branch pipes 5D, 5E, and 5F of the gas pipe 5. The processing gas supplied to each sub chamber 3D, 3E, 3F is lowered in the processing chamber 1 through the holes 22A, 23A, 3C of the first and second baffle plates 22, 23 and the upper electrode 3. Is supplied in the At this point, since RF power is applied to the upper electrode 3, discharge occurs between the lower electrode 2A and the upper electrode 3, and the processing gas is excited to generate plasma.

At this time, since the surface of the shield ring 9 (more specifically, the ring-shaped frame 9A) of the mounting table 2 does not have a gap (gap) due to the conveyance assist mechanism as in the related art, the upper electrode 3 and Abnormal discharge does not occur between. Moreover, the plasma does not extend to the outside of each electrode by the action of the shield rings 9 and 27 around each of the lower electrode 2A and the upper electrode 3.

The processing gas from the upper electrode 3 reaches the surface of the substrate S in the downward flow, and the gas flow rate at the center of the substrate S and the gas flow rate at the peripheral edge thereof are approximately uniform by the action of the gas rectifying block 10. do. Moreover, the exhaust gas can be exhausted at high speed and evenly from the entire processing chamber 1 through the exhaust port 1E distributed in all areas on the bottom surface of the processing chamber 1. Therefore, uneven distribution of the processing gas can be prevented, and the uniform plasma treatment can be performed on the substrate S. FIG.

By-products are generated during the plasma treatment to enter the gaps in the processing chamber 1. However, in this embodiment, since the shield ring 9 of the mounting table 2 has no gap caused by the second conveyance assist mechanism, the by-product does not enter the shield ring 9. In addition, although there are seams 27A in the shield ring 27 of the upper electrode 3, the seams 27 are joined by overlapping with different steps so that the by-products do not enter the inside of the seams 27A. In addition, since the case 15 of the second conveyance assist mechanism 12 is sealed by the lid 14B, the by-product does not enter the case 15.

When the plasma processing ends, the application of the RF power to the upper electrode 3 is stopped, and the processed substrate S 'and the unprocessed substrate S are exchanged in the above-described manner. Then, when the predetermined number of substrates S have been processed and the cleaning in the processing chamber 1 is performed or the maintenance is performed, the inside of the processing chamber 1 is opened and the internal cleaning and maintenance are performed. Can be. At this time, since the gas piping 5 is accommodated in the wall surface of the process chamber 1, the gas piping 5 etc. are not obstructed.                     

In addition, in description of the operation | movement of the said plasma processing apparatus, the case where the conveying apparatus by the side of a conveyance chamber has the fork of two stages of upper and lower as shown in FIG. 10 is assumed, but the 1st and the above-mentioned demonstrated with reference to FIGS. The structure of the 2nd conveyance assist mechanisms 11 and 12 is applicable also when the conveying apparatus has only one fork. In this case, the forks of the conveying apparatus are reciprocated between the processing chamber 1 and the conveying chamber in the following manner, whereby the substrates S and S 'can be replaced.

That is, first, the unprocessed board | substrate S is carried into the process chamber 1 by the fork of a conveying apparatus, and it is arrange | positioned above the mounting table 2. In this state, the bracket 14A of the lifter 12A of the second conveyance assist mechanism 12 is raised to receive the unprocessed substrate S from the forks. When the bracket 14A receives the unprocessed substrate S, the forks retreat into the transfer chamber. Next, the lifter pin 11A of the first transport assist mechanism 11 lifts the processed substrate S 'from the mounting table 2. Then, the fork of the conveying apparatus enters into the processing chamber 1 again and enters the processed substrate S 'lower portion. In this state, the lifter pin 11A is lowered, leading the processed substrate S 'to the upper portion of the fork. When the forks receive the processed substrate S ', they are taken out from the processing chamber 1. The subsequent steps are the same as those described above in the description of the operation of the plasma processing apparatus.

As mentioned above, according to this embodiment, the 2nd conveyance assist mechanism 12 is arrange | positioned in the vicinity of the outer periphery of the mounting base 2, and the mounting base 2 does not have a clearance like the conventional one. For this reason, abnormal discharge does not generate | occur | produce during a plasma process, and uniform and stable plasma process can be performed. In addition, the second conveyance assist mechanism 12 is spaced apart from the mounting table 2, and the movable portion is spaced far from the processing chamber 1 by the sleeve 19. Therefore, even if foreign matters are generated in the movable portion, the foreign matters are directed to the exhaust port, so that the substrate S on the mounting table 2 can be prevented from contamination. In addition, since the support shaft 13 is detachable from the drive shaft 17, the support shaft 13 can be properly replaced or separated and cleaned.

The upper opening of the case 15 is closed by the lid 14B upon receipt of the bracket 14A. For this reason, by-products can be prevented from accumulating in the case 15 during a plasma process, and the source of a foreign material can be reduced. Moreover, the sealing member 20 is attached to the upper end surface of the case 15, and the inside of the case 15 can be sealed more reliably. In addition, the case 15 is supported by the suspension 16 which is elastically subjected to the load in the vertical direction. For this reason, since 14A of brackets can be accommodated in the case 15 smoothly, the inside of the case 15 can be sealed reliably.

It is sectional drawing which shows the principal part of the modification of a 2nd conveyance assist mechanism. In this modification, the lid 14B is designed to move up and down with the bracket 14A, but not to rotate with the bracket 14A. Specifically, two guide shafts 32 are fixed to the lid 14B so as to extend vertically downward. Two guide sleeves 34 are disposed at the bottom of the case 15 in correspondence with the guide shafts 32, and the guide shafts 32 penetrate the guide sleeves 34. A tube cap 35 is arranged at the bottom of the case 15 to seal the penetration of the guide shaft 32. In addition, a short shaft 36 is fixed to the lid 14B in the same axial form as the support shaft 13 so as to extend in the vertical lower direction. The shaft 36 is supported by the thrust bearing 38A and the radial bearing 38B disposed on the upper side of the base portion of the bracket 14A so as to be coaxial with the support shaft 13. In addition, although it abbreviate | omits in FIG. 8, also in this modification, the suspension 16, the sleeve 19, etc. are arrange | positioned in the form similar to the mechanism shown in FIG.

In the modified example shown in FIG. 8, the cover 14B is guided to the guide sleeve 34 by the coupling of the guide shaft 32 and the guide sleeve 34, and ascends and lifts up, the horizontal surface of the cover 34 by the sleeve 34. The motion in the direction of rotation within is constrained. For this reason, while the bracket 14A moves between the protruding position and the retracted position by rotating in and out of the horizontal plane with respect to the case 15, the lid 14B only performs raising and lowering. That is, even if the bracket 14A protrudes to the protruding position, the lid 14B remains above the case 15 and does not protrude above the mounting surface of the bracket 14A or the mounting table 2. For this reason, the possibility that the by-product deposited on the upper surface of the lid 14B during the plasma processing may fall onto the substrate S supported by the bracket 14A at the time of the conveyance assist may cause foreign matter contamination.

As mentioned above, although preferred embodiment of this invention was described with reference to an accompanying drawing, this invention is not limited to this structure. Various modifications and modifications can be considered by those skilled in the art in the scope of the technical idea described in the claims, and it is understood that the modifications and modifications also belong to the technical scope of the present invention. For example, in the above embodiment, a parallel plate type plasma processing apparatus is exemplified, but the present invention can also be applied to an inductively coupled type or an ECR (electron cyclotron resonance) type plasma processing apparatus.

According to the present invention, since the second conveyance assist mechanism is arranged near the outer periphery of the mounting table, and the mounting table does not have a gap as in the prior art, abnormal discharge does not occur during the plasma processing, and uniform and stable plasma processing can be performed. . Further, since the second conveyance assist mechanism is spaced apart from the mounting table and the movable part is spaced far away from the processing chamber by the sleeve, even if foreign matter occurs in the movable part, the foreign matter is directed to the exhaust port, thereby preventing the substrate to be mounted from contamination. Can be.

Claims (8)

In the plasma processing apparatus for a liquid crystal display substrate, A confidential processing room, A mounting table having a mounting surface for mounting a substrate to be processed in the processing chamber; A processing gas supply system for supplying a processing gas into the processing chamber; An exhaust system for evacuating the processing chamber and setting the processing chamber to a vacuum; An excitation system for generating a plasma by exciting the processing gas by generating a discharge in the processing chamber; A plurality of lifters spaced apart from the mounting table and arranged around the mounting table for carrying out load assist and unloading of the substrate to be processed by the conveying device, each of which is lifted with respect to the mounting table. Possible support shafts, and brackets protruding laterally from the support shafts, wherein the brackets protrude to the mount side to support the substrate to be processed when performing the conveyance assist, and when generating the plasma; The lifter, which is movable between a retracted position retracting from the mount, A plurality of cases for receiving the brackets disposed corresponding to the retracted positions of each of the brackets; Plasma processing apparatus for a substrate for liquid crystal display devices. The method of claim 1, The upper end of the case is disposed below the mounting surface by 10mm to 50mm Plasma processing apparatus for a substrate for liquid crystal display devices. The method of claim 1, And a lid disposed on each upper side of the bracket to move up and down with the support shaft and the bracket to close the opening of the case when the bracket is received in the case. Plasma processing apparatus for a substrate for liquid crystal display devices. The method of claim 3, wherein Further provided with a restricting member for restricting the cover from protruding above the bracket and above the mounting surface when the bracket protrudes into the protruding position. Plasma processing apparatus for a substrate for liquid crystal display devices. The method of claim 4, wherein Between the protruding position and the retracted position, the bracket is raised and lowered relative to the case in a horizontal plane, during which the lid only performs lifting and lowering. Plasma processing apparatus for a substrate for liquid crystal display devices. The method of claim 5, wherein The regulating member has a guide disposed in the case, and the lid is guided to the guide to move up and down, and the movement of the rotational direction in the horizontal plane is constrained by the guide. Plasma processing apparatus for a substrate for liquid crystal display devices. The method according to any one of claims 3 to 6, Each of the cases is supported by a suspension that is elastically loaded in the vertical direction Plasma processing apparatus for a substrate for liquid crystal display devices. The method of claim 7, wherein The suspension includes a vertical core shaft, a first sleeve mounted on the upper side of the core shaft and fixed to the case, and a second sleeve mounted on the lower side of the core shaft at a predetermined distance from the first sleeve. And an elastic member mounted between the first and second sleeves, and a third sleeve mounted to cover the elastic member. Plasma processing apparatus for a substrate for liquid crystal display devices.

Images