CN1736830A - Substrate transfer device and cleaning method thereof and substrate processing system and cleaning method thereof - Google Patents

Abstract

Provided is a substrate conveying device capable of sufficiently removing accumulated particles without reducing the actual operating rate of a substrate processing system. The substrate conveying device (10) consists of a box-shaped chamber (11) and a conveying arm (12) equipped in the chamber (11), an exhaust pipeline (15) responsible for exhausting the chamber (11), and a The _N2 gas enters the gas introduction line (18) in the chamber (11) and so on. A pickup (24) with an electrode layer (25) applied with a high voltage is moved to a desired position in the chamber (11) by means of a transport arm (12). The gas introduction pipeline (18) introduces _N gas into the chamber (11), and the chamber (11) is exhausted by the exhaust pipeline (15), so that viscous flow is generated in the chamber (11), and then moved to The electrode layer (25) of the pick-up (24) of desired position adds high voltage, thereby makes the electrostatic field between chamber (11) inner face and pick-up (24), like this, electrostatic stress will act on the cavity of particle accumulation Chamber (11) inner surface.

Description

Substrate conveying device and cleaning method thereof, substrate processing system and cleaning method thereof

technical field

The present invention relates to a substrate conveying device and a cleaning method thereof, a substrate processing system and a cleaning method thereof, and in particular, to a substrate conveying device for cleaning the inside of the substrate conveying device in a state not open to the atmosphere, a cleaning method thereof, a substrate processing system and its cleaning method.

Background technique

As we all know, at present, as a substrate processing system that performs various plasma treatments such as ion doping, film formation, and etching on a substrate, it is known that a plurality of substrate processing devices are arranged radially to bundle substrates through a common substrate transfer chamber. processing system.

This clustered substrate processing system is shown in Fig. 6 (a), and it comprises: by processing wafer, for example 2 substrate processing apparatuses 61; The assembly 62 includes two wafer loading and unloading chambers 63 for loading and unloading wafers; and a substrate transfer chamber 64 as a vacuum chamber interposed between the substrate processing apparatus 61 and the wafer loading and unloading chamber 63 (see Patent Document 1).

As shown in FIG. 6(b), the substrate transfer chamber 64 has a gas introduction part 65 for flushing the inside with _N2 or the like, and a pump part 66 for evacuating the inside. In addition, there is a loading and unloading device 67 for transporting wafers inside. On the side wall adjacent to the substrate processing apparatus 61 and the wafer loading/unloading chamber 63 , there is a gate valve 68 which can be freely opened and closed. The loading and unloading device 67 is an articulated arm type device having several wrist members and a turntable, and transfers wafers to the substrate processing device 61 and the wafer loading and unloading chamber 63 through the gate valve 68 .

In such a clustered substrate processing system, when wafers are continuously processed, fine particles adhering to the wafers and brought into the substrate transfer chamber 64 and particles of cutting powder generated when the loading and unloading device 67 operates are accumulated in the substrate transfer chamber. Within 64. These accumulated particles adhere to the wafer due to the flushing of N ₂ gas in the substrate transport chamber 64 or the air flow generated when the substrate transport chamber 64 is evacuated, thereby reducing the yield of the wafer. Therefore, it is necessary to remove the particles accumulated in the substrate transfer chamber 64 . Usually, when removing particles accumulated in the substrate transfer chamber 64 , the operator cleans the inside of the substrate transfer chamber 64 with a scrubbing member or the like impregnated with ordinary alcohol.

[Patent Document 1] Japanese Unexamined Patent Publication No. 10-154739 (FIG. 1)

When the operator cleans the inside of the substrate transfer chamber 64 with scrubbing components, etc., since the maintenance window (not shown) communicates with the external environment (maintenance area), like this, the dust in the atmosphere will invade into the substrate transfer chamber 64 as particles, This makes it difficult to completely remove the particles accumulated in the substrate transfer chamber 64 . In addition, after the operator cleans and returns to the normal state, the substrate transfer chamber 64 needs to be evacuated and dried, and the wafer cannot be transferred immediately. In this way, the actual operation rate of the substrate processing system will also decrease.

Contents of the invention

The object of the present invention is to provide a substrate conveying device, a cleaning method, a substrate processing system and a cleaning method that can sufficiently remove accumulated particles without reducing the actual operating rate of the substrate processing system.

In order to achieve the above object, the technical solution 1 is characterized in that the substrate conveying device is provided with: a storage chamber for accommodating the substrate; a substrate conveying part arranged in the storage chamber for conveying the above-mentioned substrate; a gas part; and a gas introduction part for introducing gas into the storage chamber, in the substrate transfer device, the substrate transfer part is provided with a mounting part on which the substrate is placed; one end is connected to the mounting part and the mounting part a wrist part that moves; and an electrode that is placed on the mounting part and that applies a voltage. A high voltage is applied to the electrodes when gas is introduced and discharged into the storage chamber.

In the substrate transfer device according to Claim 2, in the substrate transfer device described in Claim 1, the electrodes are disposed so as to face the substrate placed on the mounting section.

In the substrate transfer device according to claim 3, in the substrate transfer device according to claim 1 or 2, the absolute value of the high voltage ranges from 1 to 5 kV.

A substrate transfer device according to claim 4 is characterized in that, in the substrate transfer device according to any one of claims 1 to 3, high voltages of different polarities are alternately applied to the electrodes.

In the substrate transfer device according to claim 5, in the substrate cleaning device according to any one of claims 1 to 4, the exhaust unit keeps the pressure in the storage chamber at 133 Pa or higher.

In order to achieve the above object, a method of cleaning a substrate transfer device according to claim 6 is a method of cleaning a substrate transfer device for removing foreign matter accumulated on the inner surface of a substrate storage chamber of the substrate transfer device. The method is characterized in that the method has: a moving step of moving the mounting part on which the substrate is mounted to a desired position in the storage chamber; A high voltage application step in which a high voltage is applied to the electrodes on the part.

In order to achieve the above object, technical solution 7 relates to a substrate processing system, which includes: a substrate conveying device having a first storage chamber for storing substrates and a substrate conveying part disposed in the first storage chamber and transporting substrates; and The substrate transfer device is connected to a substrate processing apparatus having a second storage chamber for storing the substrate, and the substrate processing system is characterized in that it further includes an exhaust system for exhausting at least one of the first and second storage chambers. An air part and a gas introduction part for introducing gas into the exhausted storage chamber, the above-mentioned substrate conveying part has: a mounting part for mounting the above-mentioned substrate; and the electrodes arranged on the mounting portion and to which a voltage is applied, in the first and second storage chambers, when gas is introduced into the storage chamber in which the mounting portion has been moved and the storage chamber is exhausted , apply a high voltage to the above electrodes.

In order to achieve the above object, the technical solution 8 relates to a cleaning method of a substrate processing system, which is characterized in that: removing the substrate accumulated on the surface of the substrate storage chamber in at least one of the substrate conveying device and the substrate processing device included in the substrate processing system Foreign matter, the method includes: a moving step of moving a mounting part on which the substrate is placed to a desired position in a substrate storage chamber of at least one of the substrate transfer device and the substrate processing device; and a high voltage application step of applying a high voltage to an electrode disposed on the moving mounting portion when gas is introduced and the storage chamber is exhausted.

According to the substrate transfer device according to Claim 1, since the substrate transfer unit has a mounting portion on which the substrate is placed, and an arm portion connected to the mounting portion at one end to move the mounting portion, the mounting portion can be moved. Go to the desired location within the containment chamber. In addition, when gas is introduced into and exhausted from the storage chamber, since a high voltage is applied to the electrodes arranged on the mounting portion, an airflow is generated in the storage chamber, and electrostatic stress acts near a desired position in the storage chamber. The inner surface of the container is used to shed the foreign objects accumulated on the surface of the container, and the detached foreign objects are discharged from the container along with the above-mentioned air flow. Therefore, the accumulated foreign matter can be removed without opening the storage chamber to the outside environment, that is, the substrate processing system with the substrate conveying device can fully remove the accumulated foreign matter without reducing the actual operation rate.

As in the substrate conveying device according to technical solution 2, since the electrodes are arranged so as to face the substrate placed on the mounting portion, electrostatic stress acts on the substrate, causing the foreign matter adhering to the substrate to fall off, and the fallen foreign matter is carried along with the airflow. Educted from the containment chamber, so that the substrate can be cleaned.

In the substrate conveying device according to claim 3, since the absolute value of the high voltage is in the range of 1 to 5 kV, the electrostatic stress acting on the inside of the storage chamber can be increased, and the foreign matter can be reliably dropped off.

According to the substrate transfer device according to claim 4, since high voltages with different polarities are applied alternately, it is possible to prevent the inside of the storage chamber from being charged. If the surface of the storage chamber is charged, the electrostatic stress acting on the surface of the storage chamber will be reduced. Therefore, by preventing the surface of the storage chamber from being charged, it is possible to avoid reducing the removal efficiency of foreign objects accumulated in the storage chamber.

According to the substrate conveying device described in technical solution 5, since the pressure in the storage chamber is kept above 133Pa, a viscous flow with a strong gas viscosity can indeed be generated in the storage chamber, and the foreign matter falling off from the inside of the storage chamber will be swept away by the viscous flow. Evacuate from containment chamber. Therefore, the foreign objects accumulated inside the containment chamber can indeed be removed.

According to the cleaning method of the substrate transfer device described in claim 6, when introducing gas into the storage chamber and exhausting the storage chamber, since a high The voltage generates an airflow in the storage chamber, and electrostatic stress acts on the vicinity of the desired position in the storage chamber, and the foreign objects accumulated on the surface of the storage chamber will fall off, and the fallen foreign objects are discharged from the above-mentioned storage chamber by the air flow. In this way, the accumulated foreign matter can be removed without opening the storage chamber to the outside environment. In other words, the accumulated foreign matter can be sufficiently removed without reducing the operating rate of the substrate processing system having the substrate transfer device.

In the substrate processing system according to claim 7, since the substrate transfer unit has a mounting portion on which the substrate is placed and an arm portion connected at one end to the mounting portion to move the mounting portion, the mounting portion can be moved. Go to any desired location in the primary or secondary containment chamber. In addition, when introducing gas into and exhausting the storage chamber in which the mounting part has been moved, a high voltage is applied to the electrodes provided on the mounting part, so that an airflow is generated in the storage chamber where the mounting part has moved, And, electrostatic stress acts on the surface of the storage chamber near the desired position in the storage chamber, and the foreign objects accumulated on the surface of the storage chamber will fall off, and the detached foreign objects will be discharged from the storage chamber along with the above-mentioned air flow. Therefore, the accumulated foreign matter can be removed without opening the first and second storage chambers to the outside, in other words, the accumulated foreign matter can be sufficiently removed without lowering the operating rate of the substrate processing system.

According to the cleaning method of the substrate processing system described in claim 8, when gas is introduced into and exhausted from the accommodation chamber in which the placement unit is moved, a high voltage is applied to the electrodes provided on the placement unit, thus, An airflow will be generated in the storage room where the loading part is moved, and the electrostatic stress acts on the storage room surface near the desired position in the storage room, and the foreign matter accumulated on the storage room surface will fall off, and the fallen foreign matter will With the above-mentioned air flow, it is discharged from the containing chamber. Therefore, the accumulated foreign matter can be removed without opening any storage chamber of the substrate conveying device and the substrate processing device to the external environment. In other words, the accumulated foreign matter can be sufficiently removed without reducing the operating rate of the substrate processing system.

Description of drawings

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

2 is a perspective view showing a schematic configuration of a transfer arm included in the substrate transfer device of FIG. 1 .

3 is a cross-sectional view showing a schematic configuration of a substrate processing system according to an embodiment of the present invention.

FIG. 4 is a flowchart showing the evaluation procedure of particle removal processing performed as an embodiment of the present invention.

FIG. 5 is a graph showing the transition of PWP measured when the method of cleaning the substrate transfer device according to the embodiment of the present invention is repeated a plurality of times.

FIG. 6 is a diagram showing a schematic configuration of a conventional clustered substrate processing system equipped with an articulated arm handling device. Fig. 6(a) is a horizontal cross-sectional view of the clustered substrate processing system; Fig. 6(b) is a cross-sectional view along line V1-V1 in Fig. 6(a).

Explanation of symbols: 10 substrate conveying device; 11, 32 chamber; 12 conveying arm; 13, 41 loading and unloading outlet; 14 gate valve; 15 exhaust pipeline; 16, 37 exhaust pipe; 17, 36 DP; 18 gas introduction pipeline; 19 gas supply device; 20 gas introduction pipe; 21 rotary table; 22 first wrist part; 23 second wrist part; 24 pickup; 25 electrode layer; 26 electric wire; 27 DC power supply; 33 base; 34 APC; 35TMP; 38 high frequency power supply; 39 electrode plate; 40 heat transfer gas supply hole;

Detailed ways

Embodiments of the present invention will be described below using the drawings.

First, the substrate transfer device according to the embodiment of the present invention will be described in detail.

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

In FIG. 1 , a substrate transfer device 10 has a box-shaped chamber (storage chamber, first storage chamber) 11 made of metal, such as aluminum or stainless steel, with protective grounding. A transfer arm (substrate transfer unit) 12 .

On the side wall of the chamber 11, there is provided a loading/unloading port 13 through which the wafer W passes when the transfer arm 12 carries the wafer W into/out of the chamber 11, and the loading/unloading port 13 is sealed by a freely openable gate valve 14. At the bottom of the chamber 11, an exhaust line (exhaust portion) 15 is connected. The exhaust pipeline 15 has an exhaust pipe 16 with a diameter of, for example, 25 mm, a valve V1 provided in the middle of the exhaust pipe, and a dry exhaust pump (hereinafter referred to as "DP") 17 as a pump connected to the exhaust pipe 16, It is responsible for the exhaust and decompression in the chamber 11, and the valve V1 can isolate the chamber 11 from the DP17. A gas introduction line (gas introduction part) 18 is connected to the top of the chamber 11 . This gas introduction line 18 includes a gas supply device 19 for supplying N ₂ gas, for example, and a gas introduction pipe 20 for introducing N ₂ gas into the chamber 11 from the gas supply device 19 . A valve V2 is provided in the middle of the gas introduction pipe 20 , and the valve V2 can block the chamber 11 from the gas supply device 19 .

The substrate transfer device 10 is arranged in a cluster type or a parallel type substrate processing system, and is connected to a plasma processing device included in the substrate processing system through a gate valve 14 .

FIG. 2 is a perspective view showing a schematic structural view of a transfer arm of the substrate transfer device in FIG. 1 .

In Fig. 2, the conveying arm 12 as the articulated arm (scalar arm) type loading and unloading device comprises: the rotary table 21 that is arranged on the bottom surface of the chamber 11 and can rotate freely around the vertical axis relative to the bottom surface (hereinafter referred to as the chamber vertical axis), A rod-shaped first arm 22 connected to the turntable, a rod-shaped second arm 23 connected to the first arm 22, and a picker (loader) on which a wafer W is placed connected to one end of the second arm 23 is connected. home) 24.

In the delivery arm 12, the other end of the second wrist part 23 is connected with one end of the first wrist part 22 which can freely rotate around the vertical axis of the chamber, and the pick-up 24 is connected with the second wrist part 22 which can freely rotate around the vertical axis of the chamber. One end of the wrist member 23 is connected. In this way, the turntable 21, the first wrist member 22, the second wrist member 23 and the picker 24 can cooperate to perform rotational motion. Therefore, the picker 24 and the wafer W placed on the picker 24 can be moved to a desired position in the chamber 11 or transferred to an adjacent plasma processing apparatus or the like through the loading/unloading port 13 .

The picker 24 is in the shape of a tuning fork, and the two forks are responsible for holding the wafer W, and the end opposite to the two forks is connected to one end of the second wrist member 23 . The pickup 24 has a three-layer structure, starting from the bottom surface side of the chamber 11, as follows: a lower insulating layer made of an insulator such as ceramics; Electrode layer 25 ; an upper insulating layer made of a heat-resistant resin such as polyimide laminated on the electrode layer 25 . The electrode layer 25 is electrically connected to a DC power source 27 through the wires 26 disposed inside the second arm member 23 , the first arm member 22 and the turntable 21 , and can be pressurized and energized. Here, the electrode layer 25 is not only sandwiched by two insulating layers, but also covered with an insulating material around the pick-up 24, and will not be exposed to the ambient atmosphere in the chamber 11. Therefore, even if a voltage is applied to the electrode layer 25, No electricity leakage.

In the substrate transfer device 10, when _N gas enters the chamber 11 from the gas introduction line 18 and is exhausted from the chamber 11 from the exhaust line 15, the picker 24 moved to a desired position such as near the inner surface of the chamber 11 A high voltage is applied to the electrode layer 25 of the chamber 11 to generate an electrostatic field between the inner surface of the chamber 11 and the pick-up 24 , so that electrostatic stress such as Maxwell (Maxwell) stress acts on the inner surface of the chamber 11 . In this way, the adhesive force of the particles deposited on the inner surface of the chamber 11 is weakened, and the particles fall off. That is, the substrate transfer apparatus 10 can peel off the particles accumulated at a desired position on the inner surface of the chamber 11 by moving the picker 24 to a desired position.

In addition, the closer the picker 24 is to the inner surface of the chamber 11, the greater the electrostatic stress acting on the inner surface of the chamber, so when moving the picker 24, it is best to be as close to the inner surface of the chamber 11 as possible.

When the picker 24 is in charge of carrying the wafer W, an electrostatic field is also generated between the wafer W and the picker 24, so that electrostatic stress acts on the wafer W, so that the particles attached to the wafer W will fall off. At this time, in order for electrostatic stress to effectively act on the wafer W, the electrode layer 25 is preferably provided so as to face the wafer W held by the pickup 24 . These particles detached from the inner surface of the chamber 11 and the wafer W are discharged to the outside of the chamber 11 along with the viscous flow described later.

However, in the conventional substrate conveying device, the pick-up of the conveying arm is only made of insulating materials such as ceramics, and there is no electrode equivalent to the electrode layer 25, so the electrostatic stress will not act on the surface where the particles accumulate, and the accumulation on the inner surface of the chamber 11 Particles and particles adhering to the wafer W cannot be removed either.

The voltage applied to the electrode layer 25 of the pickup 24 is preferably several hundred V or more in absolute value, and more preferably in the range of 1 to 5 kV in absolute value, in order to generate sufficiently large electrostatic stress. However, when the applied voltage is large, if the thickness of the upper insulating layer and the dielectric coefficient are not set properly, leakage will occur, resulting in insulation damage to the upper insulating layer. The thickness and permittivity of the upper insulating layer will be set according to the magnitude of the voltage applied to the electrode layer 25, and the voltage applied to the electrode layer 25 can also be set according to the thickness and permittivity of the upper insulating layer.

The cleaning method of the substrate transfer device implemented in the substrate transfer device 10 to remove particles deposited on the inner surface of the chamber 11 will be described below. The preconditions for carrying out the cleaning treatment corresponding to this method are: no voltage is applied to the electrode layer 25, the chamber 11 is exhausted and decompressed through the exhaust pipeline 15, and the on-off valve V2 is in a closed state.

First, the picker 24 is moved to a desired position in the chamber 11 by the rotary motion of the rotary table 21 and the like, then V2 is turned on, and N ₂ gas is introduced into the chamber 11 from the gas introduction line 18 . Since the introduced N ₂ gas is discharged to the outside of the chamber 11 through the exhaust line 15 , at this moment, a viscous flow of N ₂ gas is generated in the chamber 11 from top to bottom.

At this time, if the pressure inside the chamber 11 is equal to or higher than a predetermined pressure, viscous flow is likely to occur. Therefore, the exhaust line 15 is discharged from the chamber so that the pressure in the chamber 11 is not lower than a predetermined pressure, for example, 133 Pa (1 Torr), preferably, the pressure in the chamber 11 is not lower than tens of thousands of Pa (hundreds of Torr). _N gas in 11, like this, in the chamber 11, the viscous flow with high gas viscosity will indeed be produced.

In addition, the flow rate of the _N2 gas introduced into the chamber 11 should be set according to the discharge capacity of the exhaust pipeline 15, specifically, it can be above several SLM (L/min at 0°C, 101.3kPa). Of course, it is preferred Above tens of SLMs. The gas introduced into the chamber 11 is not limited to _N2 gas, as long as it is an inert gas, such as helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn) Other gases and _O2 gas can be used.

In order to smoothly introduce _N2 gas into the chamber 11, it is preferable to provide an orifice structure such as a flow control device (mass flow controller) or a deceleration valve downstream of the valve V2 in the gas introduction line 18.

Next, the DC power supply 27 alternately applies high voltages with different polarities, such as +1 kV and −1 kV, to the electrode layer 25 . At this time, because an electrostatic field is generated by applying a high voltage to the electrode layer 25, the electrostatic stress acts on the inner surface of the chamber 11, and the particles fall off from the inner surface of the chamber 11, and the fallen particles flow to the chamber 11 with the above-mentioned viscosity. external discharge.

The electrostatic stress described above effectively acts on the inner surface of the chamber 11 when the high voltage is applied to the electrode layer 25 and when it is stopped. Since the substrate conveying device 10 repeatedly applies a high voltage to the electrode layer 25 , the electrostatic stress also effectively acts on the inner surface of the chamber 11 repeatedly. Particle buildup on the inner surface of the chamber 11 can thus be removed particularly cleanly.

If a high voltage of the same polarity is repeatedly applied to the electrode layer 25, the inner surface of the chamber 11 will be charged (charged). As a result, the electrostatic stress acting on the inner surface of the chamber 11 will be reduced, and the accumulated The efficiency of the particles will decrease. In the substrate conveying device 10 , it is precisely because high voltages of different polarities are alternately applied to the electrode layer 25 that the inner surface of the chamber 11 is not charged and the efficiency of removing particles accumulated on the inner surface of the chamber 11 is prevented from being reduced.

In addition, as mentioned above, the effect of the above-mentioned electrostatic stress is related to the number of times the high voltage is applied to the electrode layer 25, but has little to do with the time of applying the high voltage to the electrode layer 25. Therefore, applying a high voltage to the electrode layer 25 The duration of the voltage can be set to be less than 1 second, for example.

Then, _N2 gas is introduced into the chamber 11 from the gas introduction line 18, and high voltages of different polarities are alternately applied to the electrode layer 25 according to a predetermined number of times, then the valve V2 of the gas introduction line 18 is closed, and the valve V2 of the exhaust line 15 is closed. Valve V1, end of processing job.

For example, according to the wafer cleaning method of the above-mentioned substrate transfer device, when N _gas is introduced into the chamber 11 and the chamber 11 is exhausted, the electrode layer arranged on the pickup 24 moved to the desired position in the chamber will be damaged. 25 Alternately apply high voltages of different polarities to generate viscous flow in the chamber 11, and generate an electrostatic field at the desired position in the chamber 11. The electrostatic stress acts on the inner surface of the chamber 11 near the desired position and accumulates in the chamber. The particles on the inner surface of the chamber 11 will fall off, and these fallen particles will be discharged from the chamber 11 along with the above-mentioned viscous flow. Therefore, the particles deposited on the inner surface of the chamber 11 can be removed without opening the chamber 11 to the outside environment. That is to say, the substrate processing system provided with the substrate conveying device 10 can sufficiently remove accumulated particles without lowering the actual operation rate.

In the above-mentioned substrate transfer device 10, the electrode layer 25 to which a high voltage is applied is arranged on the picker 24, but the place where the electrode is installed is not limited to the picker 24, as long as it is desired to be able to move into the chamber 11 by using the transfer arm 12. The place of the position is just fine, for example, also can be set near the end portion of the second wrist member 23. However, since the electrode layer 25 is arranged on the picker 24, the wafer W can be adsorbed on the picker 24 by electrostatic adsorption force during the conveyance of the wafer W, so that the conveying speed of the wafer W can be accelerated and the production capacity can be improved.

In addition, when removing particles adhering to the wafer W, before placing the wafer W on the picker 24 and performing the cleaning method of the above-mentioned substrate transfer device, the above-mentioned substrate transfer device may be carried out without placing the wafer W on the pickup 24. The cleaning method is to remove the particles accumulated on the inner surface of the chamber 11, so that the efficiency of removing particles attached to the wafer W can be improved.

The substrate processing system according to the embodiment of the present invention will be described in detail below.

3 is a cross-sectional view of a schematic configuration of a substrate processing system according to an embodiment of the present invention.

In FIG. 3 , a substrate processing system 30 includes the aforementioned substrate transfer device 10 and a plasma processing device 31 connected to the substrate transfer device 10 through a gate valve 14 .

A plasma processing apparatus 31 configured as an etching processing apparatus for etching a wafer W has a metal cylindrical chamber (second storage chamber) 32 . In the chamber 32, a cylindrical susceptor 33 on which the wafer W is placed is provided.

In the chamber 32, the lower part of the chamber 32 communicates with an automatic pressure control valve (hereinafter referred to as "APC") 34. The APC 34 is connected to a turbomolecular pump (hereinafter referred to as “TMP”) 35 , and further connected to DP36 via TMP35 . The APC34 is responsible for the pressure control in the chamber 32, while the TMP35 and DP36 are responsible for the decompression, so that the chamber 32 is depressurized to a near vacuum state.

In addition, in the chamber 32 , a rough discharge line is connected to the lower inner wall of the chamber 32 . This rough exhaust line has an exhaust pipe 37 that communicates the chamber 32 with the DP 36 , and a valve V3 provided in the middle of the exhaust pipe 37 . The valve V3 can isolate the chamber 32 from the DP36. The coarse exhaust line exhausts the gas in the chamber 32 .

The susceptor 33 is electrically connected to a high-frequency power source 38, and thus, the susceptor 33 functions as a lower electrode for applying high-frequency power.

Above the susceptor 33, an electrode plate 39 for attracting the wafer W by electrostatic attraction is provided. The wafer W is attracted and held on the susceptor 33 by Coulomb force or Johnson-Rahbek force generated by a DC voltage applied to the electrode plate 39 .

A plurality of heat transfer gas supply holes 40 are opened on the portion where the wafer W is adsorbed on the susceptor 33 . These heat transfer gas supply holes 40 supply heat transfer gas from a heat transfer gas supply device (not shown) to between the upper surface of the susceptor 33 and the back surface of the wafer W through a heat transfer gas supply line provided inside the susceptor 33 . the gap between.

A wafer W loading and unloading port 41 is opened on the side wall of the chamber 32 , and the loading and unloading port 41 is sealed by the gate valve 14 . When the gate valve 14 is opened, the inside of the chamber 11 of the substrate transfer device 10 communicates with the inside of the chamber 32 of the plasma processing device 31 .

In addition, on the chamber ceiling of the chamber 32, a shower head 43 serving as an upper electrode at a ground potential is provided. In this way, a high-frequency voltage from the high-frequency power supply 38 is applied between the susceptor 33 and the shower head 43 . The pouring head 43 on the top is connected to the processing gas introduction pipe 42 from the processing gas supply device (not shown), and a gate valve V4 is set in the middle of the processing gas introduction pipe 42, and the gate valve V4 can isolate the buffer chamber 47 from the processing gas supply device .

In the plasma processing apparatus 31 , when performing the etching process, the gate valve 42 is first set to an open state, and then the wafer W to be processed is transported into the chamber 32 by the transport arm 12 and placed on the susceptor 33 . Next, process gas (such as a mixture of C ₄ F ₈ gas, O ₂ gas, and Ar gas at a specified flow ratio) is introduced into the chamber 32 from the pouring head 43 according to the specified flow rate and flow ratio, and the chamber is turned on by the APC34. The pressure in 32 is adjusted to the specified value. Then, the high-frequency power supply 38 supplies high-frequency power to the susceptor 33 , and the DC voltage is applied to the electrode plate 39 to attract the wafer W on the susceptor 33 . On the other hand, the process gas ejected from the shower head 43 is plasmaized by the RF electric field formed between the susceptor 33 and the shower head 43 . Radicals and ions generated by the plasma etch the surface of the wafer W.

In the plasma processing apparatus 31 described above, the portion of the generated plasma that is not focused on the surface of the wafer W collides with the inner wall of the chamber 32 to generate particles, and the residual deposit of the reaction product by the plasma also becomes particle. Among these particles, some cannot be discharged with the main discharge line and the rough discharge line, and are still accumulated on the inner surface of the chamber 32, etc., so it is necessary to remove these particles.

In the substrate processing system 30, the chamber 11 of the substrate transfer device 10 communicates with the chamber 32 of the plasma processing device 31 through the loading and unloading port 13, the gate valve 14, and the loading and unloading port 41. Therefore, the transfer arm 12 is The picker 24 can be moved to a desired position in the chamber 32 through the loading/unloading port 13 , the gate valve 14 , and the loading/unloading port 41 .

In the plasma processing device 31, when the _N2 gas is introduced into the chamber 32 through the shower head 43 and the chamber 32 is exhausted through the rough discharge pipeline, due to the movement to the desired position in the chamber 32— For example, a high voltage is applied to the electrode layer 25 on the pickup 24 near the inner surface of the chamber 32 , so that electrostatic stress acts on the inner surface of the chamber 32 . In this way, the adhesion of the particles accumulated on the inner surface of the chamber 32 is weakened, and the particles fall off. Therefore, in the substrate processing system 30, by moving the pickup 24 to a desired position, not only the particles on the inner surface of the chamber 11 of the substrate transfer device 10 can be dropped, but also the particles on the inner surface of the chamber 32 of the plasma processing device 31 can be removed. The accumulated particles are peeled off.

Next, a substrate processing system cleaning method for removing particles deposited on the inner surface of the chamber 11 of the substrate transfer apparatus 10 and the inner surface of the plasma processing apparatus 31 implemented in the substrate processing system 30 will be described. Wherein, the cleaning method when the picker 24 is moved to the desired position in the chamber 11 of the substrate conveying device 10 has been described above, so it is omitted here, and the picker 24 is moved to the chamber 32 of the plasma processing device 31 below. The cleaning method at the desired location will be explained.

The preconditions for carrying out the cleaning treatment corresponding to this cleaning method are: no voltage is applied to the electrode layer 25, the chamber 32 is exhausted and decompressed through the rough discharge pipeline, and the gate valve V4 is in a closed state.

First, the picker 24 is moved to a desired position in the chamber 32 by rotating the turntable 21 and the like, and then V4 is turned on to introduce N ₂ gas from the shower head 43 into the chamber 32 . Since the introduced N ₂ gas is discharged to the outside of the chamber 32 through the rough discharge pipeline, a viscous flow of N ₂ gas is generated in the chamber 32 from the top to the bottom. At this time, in the same way as the cleaning method of the above-mentioned substrate transfer device, the rough discharge line discharges the N ₂ gas and the like in the chamber 32 so that the pressure in the chamber 32 does not fall below a predetermined pressure.

In addition, the flow rate and type of N ₂ gas introduced into the chamber 32 are also the same as the cleaning method of the aforementioned substrate transfer device.

Next, the DC power supply 27 alternately applies high voltages of different polarities to the electrode layer 25, such as voltages of +3kV and -3kV. Shedding, the shedding particles are discharged to the outside of the chamber 32 along with the above-mentioned viscous flow. The absolute value of the high voltage applied to the electrode plate 39 can be in the range of 1-5kV, for example, and the time for applying the high voltage can be, for example, less than 1 second, which is the same as the cleaning method of the aforementioned substrate transfer device.

Then, in the state where _N gas is introduced into the chamber 32 from the shower head 43, high voltages with different polarities are alternately applied to the electrode layer 25 for a predetermined number of times, then the valve V4 of the shower head 43 is closed, and the coarse discharge is closed at the same time. The valve V3 of the pipeline is now processed.

According to the cleaning method of the substrate processing system described above, _N2 gas is introduced into the chamber (hereinafter referred to as "pickup moving chamber") in which the picker 24 is moved into the chamber 11 and the chamber 32, and the pickup moving chamber is exhausted. When the air is in the air, due to the alternate application of high voltages of different polarities to the electrode plates 25 arranged on the pick-up 24, a viscous flow is generated in the pick-up moving chamber, and an electrostatic field is generated at a desired position in the pick-up moving chamber, thereby The electrostatic force acts on the inside of the pickup moving chamber near the desired position, and the particles accumulated inside the pickup moving chamber will fall off, and the fallen particles will be discharged from the pickup moving chamber by the above-mentioned viscous flow. In this way, the accumulated particles can be removed without opening the chamber 11 and the chamber 32 to the external environment, that is, the accumulated particles can be sufficiently removed without lowering the operating rate of the substrate processing system 30 .

In the substrate processing system 30 described above, each of the substrate transfer device 10 and the plasma processing device 31 has its own exhaust device (exhaust line 15, rough discharge line). In fact, the substrate conveying device 10 and the plasma conveying device 31 may also share an exhaust device, for example, the exhaust pipeline 15 and the DP36 are connected together.

Although in the above substrate processing system 30, the plasma processing device 31 is connected to the substrate conveying device 10, of course, the structural device of the substrate processing system connected to the substrate conveying device 10 is not limited thereto, as long as the constituent device includes the following parts: A chamber for accommodating a wafer W (hereinafter referred to as "other chambers"); a gas introduction line for introducing _N2 gas or the like into the other chamber; an exhaust line for exhausting the other chambers; and other chambers and chambers 11 openings. For example, a plasma processing apparatus configured as a CVD apparatus and an ashing apparatus, or a substrate transfer chamber 63 in FIG. 6 may be used. The structural device connected to the substrate conveying device 10 can remove accumulated particles without opening other chambers to the outside environment according to the above cleaning method of the substrate processing system.

In addition, there is no particular limitation on the arrangement form of the substrate conveying device 10 and the plasma processing device 31 in the substrate processing system 30 , and both cluster type and parallel type can be used.

In the aforementioned substrate transfer device 10 and substrate processing system 30, the transfer arm is an articulated arm loading and unloading device, but the actual transfer arm is not limited to this, and a frog loading and unloading device is also acceptable.

[Example]

Embodiments of the present invention will be specifically described below.

The following embodiments have been implemented in the substrate transfer apparatus 10 described above.

FIG. 4 is a flowchart showing the evaluation procedure of particle removal processing implemented as an embodiment of the present invention.

First, the wafer W is sent into the chamber 11 of the substrate transfer device 10, and the initial PWP (Particle per Wafer Pass) is measured by counting the number of particles attached to the transferred wafer W (step S41). Next, the maintenance window of the substrate transfer device 10 is opened to allow dust in the atmosphere to enter the chamber 11 (step S42). Then, close the maintenance window of the substrate conveying device 10, set the counter of the control device (not shown) of the substrate conveying device 10 to "1" (step S43), implement the cleaning method of the above-mentioned substrate conveying device as NPPC (NonPlasma Particle Cleaning: non-plasma particle cleaning) (step S44), then in the chamber 11 of the substrate transport device 10 cleaned by NPPC, the wafer W is transported, and the number of particles attached to the transported wafer W is measured after cleaning. PWP (step S45).

Then, judge whether the value N of the counter is larger than the setting number of times (step S46), when the value N of the counter is below the setting number of times ("No" in step S46), the counter just increases (step S47), and returns to the step S44. When the value N of the counter is greater than the set number of times (YES in step S46), the process ends.

At this point, the measured PWP is plotted as shown in Figure 5.

In FIG. 5 , the horizontal axis represents the number of measurements, and the vertical axis represents the value of PWP. In addition, PWP at the right end of the horizontal axis represents the number of particles (hereinafter referred to as " base").

It can be seen from FIG. 5 that the value of PWP can be greatly reduced by performing NPPC once, that is, the particles accumulated in the chamber 11 of the substrate transfer device 10 can be fully removed. If NPPC is carried out more than 4 times, the value of PWP can be reduced to the base number, that is, the particles accumulated on the inner surface of the chamber 11 are almost completely removed. When NPPC is repeatedly performed, the maintenance window of the substrate conveying device 10 is in a closed state. Therefore, by using the cleaning method of the substrate conveying device described above, the accumulation on the inner surface of the chamber 11 can be removed without opening the chamber 11 to the outside environment. particle of. That is, the accumulated particles can be sufficiently removed without lowering the operating rate of the substrate processing system 30 including the substrate transfer device 10 .

Claims (8)

1. A substrate conveying device, characterized in that, the substrate conveying device is provided with: A containment chamber for containing substrates; a substrate conveying unit arranged in the storage chamber and conveying the substrate; an exhaust for exhausting the containment chamber; and a gas introduction part for introducing gas into the storage chamber, The substrate transfer unit includes: a placement unit on which the substrate is placed; an arm unit connected to the placement unit at one end to move the placement unit; and an electrode arranged on the placement unit and applying a voltage. , When the gas is introduced into the storage chamber and the storage chamber is exhausted, a high voltage is applied to the electrodes. 2. The substrate transfer apparatus according to claim 1, wherein: The electrodes are arranged to face the substrate placed on the placement unit. 3. The substrate transfer apparatus according to claim 1 or 2, wherein: The absolute value of the high voltage is in the range of 1-5kV. 4 . The substrate transfer device according to claim 1 , wherein high voltages with different polarities are alternately applied to the electrodes. 5. The substrate cleaning apparatus according to any one of claims 1 to 4, wherein the exhaust unit maintains the pressure in the storage chamber at 133 Pa or higher. 6. A method for cleaning a substrate conveying device, which removes foreign matter accumulated in a substrate containing chamber in the substrate conveying device, characterized in that the method has: a moving step of moving a mounting portion on which the substrate is mounted to a desired position in the storage chamber; and A high voltage application step of applying a high voltage to electrodes disposed on the moved mounting portion when introducing gas into the storage chamber and exhausting the storage chamber. 7. A substrate processing system, comprising: a substrate transfer device having a first storage chamber for storing substrates and a substrate transfer unit arranged in the first storage chamber to transfer the substrate; and a substrate processing apparatus connected to the substrate conveying apparatus and having a second storage chamber for accommodating the substrate, The substrate handling system also features: an exhaust unit for exhausting at least one of the first and second storage chambers; and a gas introduction part that introduces gas into said degassed containment chamber, The substrate transfer unit has: a placement unit on which the substrate is placed; an arm unit connected to the placement unit at one end to move the placement unit; the electrode, In the first and second storage chambers, a high voltage is applied to the electrodes when gas is introduced into the storage chamber in which the mounting portion is moved and when the storage chamber is exhausted. 8. A cleaning method for a substrate processing system, which removes foreign matter accumulated in a substrate storage chamber of at least one of the substrate conveying device and the substrate processing device included in the substrate processing system, characterized in that the method comprises: a moving step of moving a mounting portion on which the substrate is mounted to a desired position in a substrate storage chamber of at least one of the substrate transfer apparatus and the substrate processing apparatus; and A high voltage application step of applying a high voltage to an electrode arranged on the moving mounting portion when gas is introduced into the storage chamber and the storage chamber is exhausted.

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