JP7774651B2 - Plasma Processing Systems - Google Patents

Description

The present invention relates to a plasma processing system.

Plasma processing apparatuses are known that perform plasma processing by placing a substrate on a mounting table installed inside a processing chamber. Such plasma processing apparatuses contain consumable parts that gradually wear out as plasma processing is repeated (see, for example, Patent Document 1).

An example of a consumable part is the focus ring that is placed around the substrate on the top surface of the mounting table. The focus ring is worn away by exposure to plasma and therefore needs to be replaced periodically.

Conventionally, the processing chamber is periodically opened to the atmosphere and the operator manually replaces the focus ring.

Japanese Patent Application Laid-Open No. 2006-253541

However, when the processing chamber is opened to the atmosphere, replacing the focus ring takes a long time, and substrates cannot be processed inside the processing chamber while the focus ring is being replaced, resulting in reduced productivity.

This disclosure provides technology that can improve productivity.

A plasma processing system according to one aspect of the present disclosure includes a first transfer module, a first transfer device provided inside the first transfer module, a process module connected to the first transfer module, a first load lock module connected to the first transfer module, a second load lock module connected to the first transfer module, a second transfer module connected to the first load lock module and the second load lock module and to which a container for storing unused rings is connected, a second transfer device provided inside the second transfer module, and a controller, wherein the controller controls the first transfer device to (a) open the process module to the atmosphere, (b) transporting a used ring unloaded from the process module toward the first load lock module without opening the ring to the container; the control unit controls the second transport device to (b) transport the unused ring housed in the container connected to the second transport module into the second load lock module; the control unit controls the first transport device to (c) transport the unused ring unloaded from the second load lock module into the process module after (b) without opening the process module to the atmosphere; and the control unit controls the first transport device to (d) unload a substrate from the process module before (a) .

This disclosure can improve productivity.

1 is a schematic configuration diagram illustrating a plasma processing system according to an embodiment; 1 is a schematic cross-sectional view showing a plasma processing apparatus according to an embodiment; 1 is a flowchart illustrating a focus ring replacement method according to an embodiment. FIG. 2 is a diagram for explaining the processing unit side transport device of FIG. 1; 2 is a diagram showing a state in which the processing unit side transfer device of FIG. 1 holds a wafer. FIG. 2 is a diagram showing a state in which the processing unit side transport device of FIG. 1 holds a focus ring. FIG. 2 is a diagram for explaining the position detection sensor of FIG. 1 ; FIG. 10 is a diagram for explaining a method for correcting the position of a wafer. 5A and 5B are diagrams for explaining a method for correcting the position of a focus ring.

Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that in this specification and drawings, components having substantially the same functional configuration will be designated by the same reference numerals, and redundant description will be omitted.

In one embodiment of the focus ring replacement method, a transfer device removes the focus ring from a processing chamber without opening the processing chamber to the atmosphere, cleans the processing chamber, and then the transfer device returns the focus ring to the processing chamber. The focus ring is a component located inside the processing chamber and placed on the top surface of the mounting table on which the substrate is placed, surrounding the periphery of the substrate, and its purpose is to improve etching uniformity.

The focus ring replacement method of one embodiment of the present invention is applicable to various plasma processing apparatuses that use focus rings.

(Plasma Processing System)
First, a plasma processing system according to an embodiment of the present invention will be described below with reference to Fig. 1. Fig. 1 is a schematic diagram showing the configuration of a plasma processing system according to an embodiment of the present invention.

As shown in FIG. 1, the plasma processing system is a cluster tool having a processing unit PU and a transport unit TU.

The processing unit PU is a unit that performs predetermined processes such as film formation and etching on substrates such as semiconductor wafers (hereinafter referred to as "wafers W"). The processing unit PU has process modules PM1 to PM6, a transfer module TM, and load lock modules LL1 and LL2. Note that the number of process modules PM and load lock modules LL is not limited to the above.

Process modules PM1 to PM6 are connected to the periphery of transfer module TM and perform predetermined processes such as film formation and etching on wafers W. Note that process modules PM1 to PM6 may perform the same type of process or different types of processes.

Each of the process modules PM1 to PM6 is provided with a mounting table 3 on which a wafer W is placed. Although not shown, each of the process modules PM1 to PM6 is also equipped with a gas introduction system for introducing purge gas, a gas introduction system for introducing process gas, and an exhaust system capable of vacuum drawing.

In the process modules PM1 to PM6, predetermined processing is performed on the wafer W based on a recipe indicating processing steps that is stored in advance in the memory unit of the control unit CU. Furthermore, in the process modules PM1 to PM6, the focus ring is replaced at a predetermined timing that is stored in advance in the memory unit of the control unit CU. Details of the process modules PM and the focus ring replacement method will be described later.

The transfer module TM is shaped like a hexagon, with a pair of opposing sides longer than the other sides. The two shorter sides at the tip of the transfer module TM are connected to process modules PM3 and PM4 via gate valves G3 and G4, respectively. The two shorter sides at the base of the transfer module TM are connected to load lock modules LL1 and LL2 via gate valves G7 and G8, respectively. One long side of the transfer module TM is connected to process modules PM1 and PM2 via gate valves G1 and G2, respectively. The other long side of the transfer module TM is connected to process modules PM5 and PM6 via gate valves G5 and G6, respectively.

The transfer module TM has the function of transporting (loading and unloading) wafers W and focus rings between the process modules PM1-PM6, and between the process modules PM1-PM6 and the load lock modules LL1 and LL2. Although not shown, the transfer module TM is equipped with, for example, a gas introduction system for introducing purge gas and an exhaust system capable of vacuum drawing.

A processing unit-side transfer device TR1 is provided inside the transfer module TM to transfer wafers W and focus rings between the process modules PM1-PM6 and the load lock modules LL1 and LL2. Details of the processing unit-side transfer device TR1 will be described later.

Position detection sensors S11 and S12 are provided near the gate valve G1 of the transfer module TM on the transfer path of the wafer W and focus ring transferred from the transfer module TM to the process module PM1. The position detection sensors S11 and S12 are positioned so that the distance between them is smaller than the outer diameter of the wafer W and smaller than the inner diameter of the focus ring. This allows the positions of the wafer W and focus ring transferred to the process module PM1 to be corrected. Details of the position detection sensors S11 and S12 will be provided later.

Similar position detection sensors are also provided near the gate valves G2 to G6 of the transfer module TM, along the transfer path of the wafer W and focus ring transported from the transfer module TM to the process modules PM2 to PM6. That is, the transfer module TM is provided with position detection sensors S11, S12, S21, S22, S31, S32, S41, S42, S51, S52, S61, and S62.

Load lock modules LL1 and LL2 are connected to the transfer module LM via gate valves G9 and G10, respectively. Load lock modules LL1 and LL2 have the function of temporarily holding the wafer W transferred from the transfer module LM and transferring it to the transfer module TM after adjusting the pressure. Load lock modules LL1 and LL2 also have the function of temporarily holding the wafer W transferred from the transfer module TM and transferring it to the transfer module LM after adjusting the pressure.

Each of the load lock modules LL1 and LL2 is provided with a transfer table on which a wafer W can be placed. In addition, although not shown, each of the load lock modules LL1 and LL2 is equipped with an exhaust system capable of purging and exhausting particles such as residue.

In this processing unit PU, the gaps between the process modules PM1 to PM6 and the transfer module TM, and between the transfer module TM and the load lock modules LL1 and LL2, can be opened and closed airtight. Furthermore, the gaps between the transfer module LM and the load lock modules LL1 and LL2 can also be opened and closed airtight.

The transfer unit TU is a unit that transfers wafers W between a FOUP (Front Opening Unified Pod) (described below) and the processing unit PU, and has a transfer module LM.

The transfer module LM is rectangular. Multiple load ports LP1 to LP3 are arranged side by side on one long side of the transfer module LM. Each of the load ports LP1 to LP3 is capable of loading a FOUP. Note that FIG. 1 shows a case where FOUPs are loaded on all of the load ports LP1 to LP3. A FOUP is a container that can accommodate, for example, 25 wafers W, arranged in multiple stages at equal intervals. The FOUP has a sealed structure, with the interior filled with, for example, _N2 gas. The FOUP is connected to the transfer module LM via opening and closing doors D1 to D3. Note that the number of load ports LP is not limited to the above.

An aligner AU is provided on one short side of the transfer module LM. The aligner AU has a rotary stage on which the wafer W is placed, and an optical sensor that optically detects the outer periphery of the wafer W. The aligner AU detects, for example, the orientation flat, notch, etc. of the wafer W to align the wafer W.

The transfer module LM is provided with a transfer unit-side transfer device TR2 for transferring wafers W and focus rings between the load lock modules LL1 and LL2, the FOUP, and the aligner AU. The transfer unit-side transfer device TR2 has a transfer arm that is rotatably attached to a base 231 by a rotation mechanism, and is slidable along the longitudinal direction of the transfer module LM by a slide mechanism. The transfer arm of the transfer unit-side transfer device TR2 is a double-arm mechanism having a pair of articulated arms, as shown in FIG. 1, for example. The transfer arm shown in FIG. 1 includes a first arm 211 and a second arm 221, which are extendable articulated arms arranged side by side above and below.

The slide mechanism of the transport unit-side transport device TR2 has, for example, a linear motor. Specifically, a guide rail 232 is provided longitudinally inside the transport module LM, and a base 231 to which the transport arm is attached is slidable along the guide rail 232. The base 231 and guide rail 232 are each provided with a mover and stator of a linear motor, and a linear motor drive mechanism 233 for driving the linear motor is provided at the end of the guide rail 232. The control unit CU is connected to the linear motor drive mechanism 233. This drives the linear motor drive mechanism 233 based on a control signal from the control unit CU, and the transport unit-side transport device TR2 moves together with the base 231 along the guide rail 232 in the direction of the arrow. Note that the slide mechanism of the transport unit-side transport device TR2 is not limited to the above and may include other mechanisms.

The first arm 211 and second arm 221, which are the transfer arms of the transfer unit side transfer device TR2, each have a pick 212, 222 at their tip, and are capable of holding two wafers W or two focus rings at a time. This allows the wafer W and focus ring to be exchanged when transferring them to, for example, load lock modules LL1, LL2, a FOUP, or an aligner AU. Note that it is also possible to hold and transfer one wafer W and one focus ring at a time. Furthermore, the number of transfer arms of the transfer unit side transfer device TR2 is not limited to the above, and it may be, for example, a single-arm mechanism having only one arm.

The transport unit side transport device TR2 also has a rotation motor, an extension motor, and an elevation motor (not shown) for rotating, extending, and raising and lowering the transport arm. Each motor is connected to the control unit CU, and can control the transport arm of the transport unit side transport device TR2 based on control signals from the control unit CU.

The plasma processing system is equipped with a control unit CU that controls various parts of the plasma processing system, such as the processing unit side transfer device TR1, the transfer unit side transfer device TR2, the gate valves G1-G10, the opening and closing doors D1-D3, and the aligner AU.

(Plasma processing apparatus)
Next, a plasma processing apparatus according to one embodiment of the present invention will be described with reference to Fig. 2. Fig. 2 is a schematic cross-sectional view showing the plasma processing apparatus according to one embodiment. The plasma processing apparatus shown in Fig. 2 is an apparatus that can be used as process modules PM1 to PM6 in the plasma processing system described above.

As shown in FIG. 2, the plasma processing apparatus has a substantially cylindrical processing chamber 10. The inner wall surface of the processing chamber 10 is formed of, for example, anodized aluminum. The processing chamber 10 is grounded.

The processing chamber 10 is equipped with a gas shower head 2 for introducing processing gas. The gas shower head 2 functions as an upper electrode. Inside the processing chamber 10, a mounting table 3 is provided facing the gas shower head 2. The mounting table 3 functions as a lower electrode.

The underside of the gas shower head 2 (upper electrode) is formed with multiple gas discharge ports 22 that communicate via the gas supply channel 21 and buffer chamber 21a. The multiple gas discharge ports 22 discharge processing gas toward the wafer W placed on the mounting table 3. The base end of the gas supply channel 21 is connected to a gas introduction system 23.

The gas introduction system 23 has a supply source of process gas used for film formation processing on the wafer W, and a supply source of process gas used for etching processing on the wafer W. The gas introduction system 23 also has a supply source of process gas used for cleaning processing of the processing chamber 10, and a supply source of process gas used for seasoning processing of the processing chamber 10. The gas introduction system 23 has supply control devices such as valves and flow rate adjusters, and can supply process gas into the processing chamber 10 at a predetermined flow rate.

A high-frequency power supply unit 26 is connected to the upper electrode via a matching unit 25 to supply high-frequency power. The upper electrode is insulated from the sidewall of the processing chamber 10 by an insulating member 27.

The mounting table 3 has a main body 30 and an electrostatic chuck 31.

The main body 30 is formed from a conductive material such as aluminum. A coolant flow path (not shown) that functions as a temperature control mechanism is provided inside the main body 30. The temperature of the wafer W held by the electrostatic chuck 31 is controlled by adjusting the temperature of the coolant supplied to the coolant flow path.

An electrostatic chuck 31 capable of attracting both the wafer W and the focus ring FR arranged to surround the wafer W is provided on the main body 30. A convex substrate mounting portion 32 is formed in the upper center of the electrostatic chuck 31, and the upper surface of the substrate mounting portion 32 forms a substrate mounting surface 33 on which the wafer W is mounted. The upper surface of the lower portion around the periphery of the substrate mounting surface 33 forms a focus ring mounting surface 34 on which the focus ring FR is mounted.

The electrostatic chuck 31 has an electrode 35 sandwiched between insulating materials. The electrode 35 extends not only below the substrate mounting surface 33 but also below the focus ring mounting surface 34 so that it can attract both the wafer W and the focus ring FR.

A predetermined DC voltage is applied to the electrostatic chuck 31 from a DC power supply 37 connected to the electrode 35 via a switch 36. This causes the wafer W and focus ring FR to be electrostatically attracted to the electrostatic chuck 31. Note that, as shown in FIG. 2, the substrate mounting portion 32 is formed with a diameter smaller than that of the wafer W so that the edge of the wafer W extends beyond the substrate mounting portion 32 when the wafer W is mounted thereon.

The mounting table 3 is provided with a heat transfer gas supply unit 38 that supplies a heat transfer gas (e.g., helium (He) gas) separately to the backside of the wafer W and the backside of the focus ring FR.

The heat transfer gas supply unit 38 includes a first heat transfer gas supply unit 38a that supplies a first heat transfer gas to the back surface of the wafer W placed on the substrate mounting surface 33, and a second heat transfer gas supply unit 38b that supplies a second heat transfer gas to the back surface of the focus ring FR placed on the focus ring mounting surface 34.

The focus ring FR is placed on the electrostatic chuck 31. A step is formed on the top surface of the focus ring FR, with the outer periphery being higher than the inner periphery. The inner periphery of the focus ring FR is also formed to fit under the outer periphery of the wafer W, which protrudes outward beyond the mounting table 3. In other words, the inner diameter of the focus ring FR is smaller than the outer diameter of the wafer W. This protects the electrostatic chuck 31 from plasma when etching the wafer W.

A high-frequency power supply unit 40 that applies bias power via a matching box 39 is connected to the mounting table 3. Also, inside the mounting table 3, lift pins (not shown) are provided that can transfer the wafer W and focus ring FR to and from the processing unit side transfer device TR1 shown in FIG. 1. When the processing unit side transfer device TR1 transfers the focus ring FR, the lift pins are raised to separate the focus ring FR from the mounting table 3.

An opening 13 with a gate valve G1 that can be opened and closed is formed in the sidewall of the processing chamber 10. The wafer W and focus ring FR are transferred through the opening 13.

A deposit shield 41 is detachably provided along the inner wall of the processing chamber 10. The deposit shield 41 is also provided on the outer periphery of the mounting table 3. The deposit shield 41 prevents reaction products generated by etching from adhering to the inner wall surface of the processing chamber 10, and is formed by coating aluminum with ceramics such as _{Y2O3 ,} for example.

A baffle plate 42 having a large number of exhaust holes is provided around the mounting table 3 to uniformly exhaust the inside of the processing chamber 10. The baffle plate 42 is formed, for example, by coating aluminum with a ceramic such as _{Y2O3 .} A vacuum pump 12 such as a turbo molecular pump or a dry pump is connected below the baffle plate 42 via an exhaust pipe 11.

The plasma processing apparatus has a control unit 50 that controls each component. The control unit 50 is, for example, a computer having a CPU and a program. The program contains a set of steps (commands) for controlling, for example, the supply of gases from the gas introduction system 23 and the supply of power from the high-frequency power supplies 26 and 40 to perform film formation and etching processes on the wafer W using the plasma processing apparatus. The program is stored on a storage medium, such as a hard disk, compact disc, or memory card, and is installed on the computer from the storage medium.

(How to replace the focus ring)
Next, a focus ring replacement method according to one embodiment of the present invention will be described with reference to Fig. 3. Fig. 3 is a flowchart illustrating the focus ring replacement method according to one embodiment.

The following describes an example of replacing the focus ring FR mounted on the mounting table 3 of the aforementioned process module PM1. Specifically, the description will cover the case where the focus ring used in process module PM1 is stored in a FOUP and replaced with an unused focus ring previously stored in the FOUP. Note that the focus rings FR mounted on the mounting tables 3 of process modules PM2 to PM6 other than process module PM1 can also be replaced using a similar method. Furthermore, the focus ring replacement method of one embodiment of the present invention is performed by the control unit CU controlling each component of the plasma processing system.

As shown in FIG. 3, one embodiment of the focus ring replacement method includes a wear level determination step S10, a replacement feasibility determination step S20, a first cleaning step S30, a removal step S40, a second cleaning step S50, a load step S60, and a seasoning step S70. Each step is described below.

The wear level determination step S10 is a step for determining whether the focus ring FR placed on the mounting table 3 of the process module PM1 needs to be replaced. In the wear level determination step S10, the control unit CU determines whether the focus ring FR placed on the mounting table 3 of the process module PM1 needs to be replaced. Specifically, the control unit CU determines whether the focus ring FR needs to be replaced based on, for example, the RF cumulative time, the RF cumulative power, and the cumulative value of a specific step of the recipe. The RF cumulative time is the cumulative value of the time over which high-frequency power is supplied in the process module PM1 during a specified plasma process. The RF cumulative power is the cumulative value of the high-frequency power supplied in the process module PM1 during a specified plasma process. The cumulative value of a specific step of the recipe is the cumulative value of the time over which high-frequency power is supplied or the cumulative value of the high-frequency power in a step of the process performed in the process module PM1 in which the focus ring FR is removed. The RF cumulative time, RF cumulative power, and cumulative values for specific recipe steps are values calculated from the point in time when the focus ring FR was replaced, such as when the device was installed or when maintenance was performed.

When determining whether or not the focus ring FR needs to be replaced based on the RF integrated time, the control unit CU determines that the focus ring FR needs to be replaced if the RF integrated time reaches a threshold value. Conversely, the control unit CU determines that the focus ring FR does not need to be replaced if the RF integrated time does not reach the threshold value. The threshold value is a value determined based on the type of material, etc., of the focus ring FR through preliminary experiments, etc.

When determining whether or not the focus ring FR needs to be replaced based on the RF integrated power, the control unit CU determines that the focus ring FR needs to be replaced if the RF integrated power reaches a threshold value. Conversely, the control unit CU determines that the focus ring FR does not need to be replaced if the RF integrated power does not reach the threshold value. The threshold value is a value determined based on the type of material, etc., of the focus ring FR through preliminary experiments, etc.

When determining whether or not the focus ring FR needs to be replaced based on the integrated value of a specific step in the recipe, the control unit CU determines that the focus ring FR needs to be replaced if the RF integrated time or RF integrated power in the specific step reaches a threshold. In contrast, the control unit CU determines that the focus ring FR does not need to be replaced if the RF integrated time or RF integrated power in the specific step does not reach the threshold. When determining whether or not the focus ring FR needs to be replaced based on the integrated value of a specific step in the recipe, the timing for replacing the focus ring FR can be calculated based on the step in which high-frequency power is applied and the focus ring FR is scraped. This makes it possible to calculate the timing for replacing the focus ring FR with particularly high accuracy. The threshold is a value determined based on the type of material, etc., of the focus ring FR through preliminary experiments, etc.

If it is determined in wear level determination step S10 that the focus ring FR placed on the mounting table 3 of the process module PM1 needs to be replaced, the control unit CU performs replacement feasibility determination step S20. If it is determined in wear level determination step S10 that the focus ring FR placed on the mounting table 3 of the process module PM1 does not need to be replaced, the control unit CU repeats wear level determination step S10.

The replacement feasibility determination step S20 is a step for determining whether the state of the plasma processing system allows replacement of the focus ring FR. In the replacement feasibility determination step S20, the control unit CU determines whether the state of the plasma processing system allows replacement of the focus ring FR. Specifically, for example, when no wafer W is being processed in the process module PM1 in which the focus ring FR is to be replaced, the control unit CU determines that the focus ring FR is replaceable. In contrast, when a wafer W is being processed in the process module PM1, the control unit CU determines that the focus ring FR is not replaceable. Alternatively, the control unit CU may determine that the focus ring FR is replaceable when, for example, processing of a wafer W from the same lot as the wafer W being processed in the process module PM1 in which the focus ring FR is to be replaced has finished. In this case, the control unit CU determines that the focus ring FR is not replaceable until processing of a wafer W from the same lot as the wafer W being processed in the process module PM1 has finished.

If the control unit CU determines in replacement feasibility determination step S20 that the state of the plasma processing system is such that replacement of the focus ring FR is possible, the control unit CU performs the first cleaning step S30. If the control unit CU determines in replacement feasibility determination step S20 that the state of the plasma processing system is such that replacement of the focus ring FR is not possible, the control unit CU repeats replacement feasibility determination step S20.

The first cleaning step S30 is a step for cleaning the process module PM1. In the first cleaning step S30, the control unit CU controls the gas supply system, exhaust system, power supply system, etc. to perform the cleaning process of the process module PM1. The cleaning process is a process for removing deposits generated in the process module PM1 by using plasma of a processing gas or the like to stabilize the inside of the process module PM1 in a clean state. By performing the first cleaning step S30, it is possible to prevent deposits from being blown up in the processing chamber 10 when the focus ring FR is unloaded from the mounting table 3 in the unloading step S40. Examples of the processing gas that can be used include oxygen (O ₂ ) gas, fluorocarbon (CF )-based gas, nitrogen (N ₂ ) gas, argon (Ar) gas, He gas, and a mixture of two or more of these gases. Furthermore, when cleaning the process module PM1, depending on the processing conditions, the cleaning may be performed with a wafer W, such as a dummy wafer, placed on the top surface of the electrostatic chuck of the mounting table 3 to protect the electrostatic chuck. Note that the first cleaning step S30 does not need to be performed if there is no deposit in the processing chamber 10, or if there is no possibility of deposits being rolled up. Furthermore, if the focus ring FR is attached to the mounting table 3 by the electrostatic chuck, a neutralization process is performed before the next unloading step S40.

In the unloading step S40, the focus ring FR is unloaded from the process module PM1 without opening the process module PM1 to the atmosphere. In the unloading step S40, the control unit CU controls the various components of the plasma processing system to unload the focus ring FR from the process module PM1 without opening the process module PM1 to the atmosphere. Specifically, the gate valve G1 is opened, and the processing unit-side transfer device TR1 unloads the focus ring FR mounted on the mounting table 3 inside the process module PM1 from the process module PM1. Next, the gate valve G8 is opened, and the processing unit-side transfer device TR1 places the focus ring FR unloaded from the process module PM1 on the transfer table of the load lock module LL2. Next, the gate valve G8 is closed, and after adjusting the pressure inside the load lock module LL2, the gate valve G10 is opened, and the transfer unit-side transfer device TR2 transfers the focus ring FR mounted on the transfer table to the transfer module TM. Next, the door D3 is opened, and the transport unit side transport device TR2 places the focus ring FR into the FOUP placed on the load port LP3.

The second cleaning step S50 is a step of cleaning the surface (focus ring mounting surface 34) of the mounting table 3 of the process module PM1 on which the focus ring FR is mounted. In the second cleaning step S50, the control unit CU controls the gas supply system, exhaust system, power supply system, etc. to clean the surface of the mounting table 3 of the process module PM1 on which the focus ring FR is mounted. The cleaning process in the second cleaning step S50 can be performed, for example, in the same manner as the first cleaning step S30. That is, the process gas can be, for example, O ₂ gas, CF-based gas, N ₂ gas, Ar gas, He gas, or a mixture of two or more of these gases. Depending on the process conditions, the cleaning process of the process module PM1 may be performed with a wafer W, such as a dummy wafer, mounted on the electrostatic chuck of the mounting table 3 to protect the electrostatic chuck.

In the loading step S60, the focus ring FR is loaded into the process module PM1 and placed on the mounting table 3 without opening the process module PM1 to the atmosphere. In the loading step S60, the control unit CU controls each component of the plasma processing system to load the focus ring FR into the process module PM1 without opening the process module PM1 to the atmosphere. Specifically, for example, the opening/closing door D3 is opened, and the transport unit-side transport device TR2 unloads the unused focus ring FR housed in the FOUP placed on the load port LP3. Next, the gate valve G9 is opened, and the transport unit-side transport device TR2 places the unused focus ring FR on the transfer table of the load lock module LL1. Next, gate valves G7 and G1 are opened, and the processing unit side transfer device TR1 removes the unused focus ring FR placed on the transfer table of load lock module LL1, loads it into process module PM1, and places it on the mounting table 3.

The seasoning step S70 is a step in which the process module PM1 is seasoned. In the seasoning step S70, the control unit CU performs seasoning on the process module PM1 by controlling the gas introduction system, exhaust system, power introduction system, etc. The seasoning process is a process for stabilizing the temperature and state of deposits within the process module PM1 by performing a specified plasma process. In addition, in the seasoning step S70, after the seasoning process on the process module PM1, quality control wafers may be loaded into the process module PM1 and a specified process may be performed on the quality control wafers. This makes it possible to check whether the state of the process module PM1 is normal.

By following the above steps, you can replace the focus ring FR.

As described above, in the focus ring replacement method of one embodiment of the present invention, the processing unit-side transfer device TR1 removes the focus ring FR from the processing chamber 10 without opening the processing chamber 10 to the atmosphere, the processing chamber 10 is cleaned, and the processing unit-side transfer device TR1 loads the focus ring FR into the processing chamber 10. This eliminates the need for an operator to manually replace the focus ring FR. This reduces the time required for focus ring FR replacement and improves productivity. Furthermore, cleaning the focus ring mounting surface 34 before loading the focus ring FR reduces the presence of deposits between the focus ring FR and the focus ring mounting surface 34. As a result, good contact between the two is achieved, allowing the temperature controllability of the focus ring FR to be maintained.

(Processing unit side transport device)
Next, an example of the processing unit side transport device TR1 will be described with reference to Fig. 4. Fig. 4 is a diagram for explaining the processing unit side transport device of Fig. 1.

First, an example of the slide mechanism of the processing unit side transport device TR1 will be described. The transport arms (first arm 111, second arm 121) of the processing unit side transport device TR1 are attached to a base 131, as shown in FIG. 4(a), for example. The base 131 is slidable on guide rails 132a and 132b in the direction of the Y axis (the longitudinal direction of the transfer module TM), which serves as the slide axis. Then, for example, a ball screw 134 driven by a Y axis motor 133 is threaded into the base 131, and the slide drive of the transport arms of the processing unit side transport device TR1 can be controlled by controlling the drive of the Y axis motor 133.

Next, an example of the rotation mechanism of the processing unit side transport device TR1 will be described. The transport arms (first arm 111, second arm 121) of the processing unit side transport device TR1 are attached to a base 131 via a rotating plate 135 that is rotatable in the direction of the θ axis, which is the rotation axis, as shown in FIG. 4, for example. The rotating plate 135 is driven by a θ axis motor 136 that is mounted on the base 131, for example. As a result, by controlling the drive of the θ axis motor 136, the rotation drive of the transport arms of the processing unit side transport device TR1 can be controlled.

The first arm 111 and second arm 121, which are the transfer arms of the processing unit side transfer device TR1, are equipped with picks 112 and 122 at their tips, respectively, and are capable of holding two wafers W or two focus rings FR at a time. This allows the wafers W or focus rings FR to be exchanged when transferring them to, for example, the process modules PM1 to PM6 or the load lock modules LL1 and LL2. The number of transfer arms of the processing unit side transfer device TR1 is not limited to the above, and may be, for example, a single-arm mechanism having only one arm.

The processing unit side transport device TR1 also has an extension motor (not shown) for extending and retracting the transport arm. The extension motor is attached, for example, below the θ-axis motor 136, and can be controlled independently of the θ-axis motor 136. In addition to the motors mentioned above, an elevation motor (not shown) for raising and lowering the transport arm may also be provided as a motor for driving the processing unit side transport device TR1.

The θ-axis motor 136, Y-axis motor 133, and other motors used to drive the processing unit-side transport device TR1 are each connected to the control unit CU and are controlled and driven based on commands from the control unit CU.

In addition, as shown in FIG. 1, a flexible arm 137 is connected to the base 131 of the processing unit side transport device TR1, for example, to pass wiring for the θ-axis motor 136 and the like. The flexible arm 137 is, for example, a cylindrical arm mechanism. The flexible arm 137 is connected airtight, and its interior is connected to the atmosphere via a hole formed in the bottom of the transfer module TM. As a result, even if the inside of the transfer module TM is in a vacuum state, the inside of the flexible arm 137 is at atmospheric pressure, preventing damage to the wiring, etc.

In this way, the processing unit side transfer device TR1 can slide along the guide rails 132a and 132b and extend and retract the transfer arm. This allows wafers W and focus rings FR to be transferred between the process modules PM1 to PM6 and the load lock modules LL1 and LL2.

Next, an example of the pick 112 of the processing unit side transfer device TR1 will be described. Figure 5 is a diagram showing the processing unit side transfer device of Figure 1 holding a wafer. Figure 5(a) is a side view of the pick 112 holding a wafer W, and Figure 5(b) is a top view of the pick 112 holding a wafer W. Figure 6 is a diagram showing the processing unit side transfer device of Figure 1 holding a focus ring. Figure 6(a) is a side view of the pick 112 holding a focus ring FR, and Figure 6(b) is a top view of the pick 112 holding a focus ring FR. Note that while Figures 5 and 6 use the pick 112 as an example for explanation, the same can be said for the pick 122.

As shown in FIG. 5, the pick 112 is formed with multiple (e.g., three) protrusions 113 that hold the outer peripheral edge of the wafer W. The protrusions 113 are, for example, frustoconical in shape and are arranged along the outer peripheral edge of the wafer W. The protrusions 113 abut against the outer peripheral edge of the wafer W at the tapered portions 114 of the frustoconical shape, thereby preventing the wafer W from shifting relative to the pick 112. The protrusions 113 are formed, for example, from an elastomer.

Also, as shown in FIG. 6, the protrusion 113 is able to hold the focus ring FR by abutting the truncated cone-shaped upper surface 115 against the lower surface of the focus ring FR. This is because, as mentioned above, the inner diameter of the focus ring FR is smaller than the outer diameter of the wafer W. In this way, the processing unit side transfer device TR1 is able to hold the wafer W and the focus ring FR with a single pick 112.

As described above, the pick 112 holds the wafer W at the tapered portion 114 of the protrusion 113, and holds the focus ring FR at the upper surface 115 of the protrusion 113, so the focus ring FR can be held without increasing the length of the pick 112. This prevents the tip of the pick 112 from coming into contact with other parts (e.g., the inner wall surface of a FOUP) when transporting the wafer W or focus ring FR with the pick 112. Note that while Figures 5 and 6 show an example in which there are three protrusions 113, the number of protrusions 113 is not limited to this.

Furthermore, when the processing unit side transport device TR1 rotates while holding the focus ring FR, it is preferable that the rotation radius be minimized. This prevents the focus ring FR held by the pick 112 from coming into contact with other parts. Furthermore, when the two picks 112, 122 rotate on approximately the same plane, even if one pick 112 holds the wafer W and the other pick 122 holds the focus ring FR, it is possible to prevent the wafer W and the focus ring FR from coming into contact with each other.

(position detection sensor)
Next, an example of a position detection sensor will be described with reference to Fig. 7. Fig. 7 is a diagram for explaining the position detection sensor of Fig. 1, showing a part of a cross section taken along dashed line 1A-1B in Fig. 1.

As shown in FIG. 7, the position detection sensor S11 has a light-emitting unit 310 and a light-receiving unit 320. The light-emitting unit 310 is provided on the upper wall 330 of the transfer module TM, and the light-receiving unit 320 is provided on the lower wall 340 of the transfer module TM. The light-emitting unit 310 irradiates laser light L toward the light-receiving unit 320. The light-receiving unit 320 detects whether or not the laser light L irradiated from the light-emitting unit 310 is received. Note that while FIG. 7 illustrates the light-emitting unit 310 and light-receiving unit 320 of the position detection sensor S11, the position detection sensor S12 also has a light-emitting unit and a light-receiving unit, similar to the position detection sensor S11. As a result, the laser light L irradiated from the light-emitting unit 310 of the position detection sensor S11 to the light-receiving unit 320 is blocked for a predetermined period of time by the wafer W or focus ring FR being transported from the transfer module TM to the process module PM1. In addition, the laser light L irradiated from the light-emitting portion of the position detection sensor S12 to the light-receiving portion is blocked for a predetermined period of time by the wafer W or focus ring FR being transported from the transfer module TM to the process module PM1.

Next, we will explain how to correct the positions of the wafer W and focus ring FR.

In a method for correcting the positions of the wafer W and focus ring FR according to one embodiment of the present invention, the control unit CU corrects the position of the wafer W and the focus ring FR using the same position detection sensor. This is described in detail below.

First, the transfer of a wafer W from transfer module TM to process module PM1 will be described with reference to FIG. 8. FIG. 8 is a diagram for explaining a method of correcting the wafer position. FIG. 8(a) shows the relationship between the position of the wafer W and the position of the position detection sensor. FIG. 8(b) shows the change in sensor output of position detection sensors S11 and S12 when the wafer W is transferred from position P11 in FIG. 8(a) as a starting point to position P14. Note that in FIG. 8(b), the time at position P11 is indicated as t11, the time at position P12 as t12, the time at position P13 as t13, and the time at position P14 as t14.

The control unit CU calculates the amount of deviation of the wafer W held on the pick 112 from the reference position based on the position of the wafer W detected by the position detection sensors S11 and S12 and a predetermined reference position. The control unit CU then uses the processing unit side transfer device TR1 to place the wafer W on the mounting table 3 of the process module PM1 so as to correct for the calculated amount of deviation. This allows the wafer W to be placed at a predetermined position on the mounting table 3 of the process module PM1 even if the position of the wafer W held on the pick 112 is deviated from the reference position.

The position of the wafer W held by the pick 112 can be calculated based on changes in the sensor output of the position detection sensors S11 and S12 that occur when the outer periphery of the wafer W passes through them. For example, as shown in FIG. 8(a), when the wafer W is transported from position P11 to position P14, the position detection sensors S11 and S12 can be calculated based on the time T1 from position P12, at which they are shaded by the wafer W, to position P13. Specifically, as shown in FIG. 8(b), T1 can be calculated using time t12 at position P12 and time t13 at position P13, as T1 = t13 - t12. Note that while FIG. 8 shows a case where the position when the position detection sensor S11 is shaded by the wafer W is the same as the position when the position detection sensor S12 is shaded, these positions may be different.

The reference position can be calculated, for example, based on the encoder positions of the rotation motor and extension motor of the first arm 111 of the processing unit side transport device TR1. Note that the method for calculating the reference position is not limited to this, and various existing methods can be used.

Next, the transport of the focus ring FR from the transfer module TM to the process module PM1 will be described with reference to FIG. 9. FIG. 9 is a diagram illustrating a method for correcting the position of the focus ring. FIG. 9(a) shows the relationship between the position of the focus ring FR and the position of the position detection sensors. FIG. 9(b) shows the change in sensor output of the position detection sensors S11 and S12 when the focus ring FR is transported from position P21 in FIG. 9(b) as a starting point to position P24. Note that in FIG. 9(b), the time at position P21 is indicated as t21, the time at position P22 as t22, the time at position P23 as t23, and the time at position P24 as t24.

The control unit CU calculates the amount of deviation of the focus ring FR from the reference position based on the position of the focus ring FR detected by the position detection sensors S11 and S12 and a predetermined reference position. The control unit CU then uses the processing unit-side transport device TR1 to place the focus ring FR on the mounting table 3 of the process module PM1 so as to correct the calculated amount of deviation. This allows the focus ring FR to be placed at a predetermined position on the mounting table 3 of the process module PM1, even if the position of the focus ring FR held by the pick 112 is deviated from the reference position.

The position of the focus ring FR held by the pick 112 can be calculated based on the change in output of the position detection sensors S11 and S12 that occurs when the inner periphery of the focus ring FR passes through them. For example, as shown in FIG. 9(a), when the focus ring FR is transported from position P21 to position P24, the position can be calculated based on the time T2 it takes for the focus ring FR to move from position P22 to position P23. Position P22 is the position where the sensor output of the position detection sensors S11 and S12 changes from low (L) to high (H), and position P23 is the position where the sensor output of the position detection sensors S11 and S12 changes from high (H) to low (L). Specifically, as shown in FIG. 9(b), T2 can be calculated using time t22 at position P22 and time t23 at position P23 as T2 = t23 - t22. Note that while Figure 9 shows a case where the position detection sensor S11 and the position detection sensor S12 are shielded from light by the focus ring FR are the same, these positions may be different.

Furthermore, if the focus ring FR is damaged or falls during transport, the waveform shown in Figure 9 cannot be detected. In this case, it is determined that there is an abnormality in the focus ring transport, and the transport process is interrupted.

The reference position can be calculated, for example, based on the encoder positions of the rotation motor and extension motor of the first arm 111 of the processing unit side transport device TR1. Note that the method for calculating the reference position is not limited to this, and various existing methods can be used.

The above describes a preferred embodiment of the present invention, but the present invention is not limited to this specific embodiment, and various modifications and variations are possible within the scope of the gist of the present invention as set forth in the claims.

In the above embodiment, the first cleaning step S30 and the second cleaning step S50 are described as cleaning processes using plasma, but this is not limiting. For example, non-plasma particle cleaning (NPPC) processes may be used, which do not use plasma but instead use gas impact force, gas viscous force, and electromagnetic stress to remove particles from components inside the processing chamber and then discharge them from the processing chamber (see Japanese Patent Application Laid-Open No. 2005-101539).

3 Mounting table 10 Processing chamber 112 Pick 113 Protrusion FR Focus ring PM Process module TM Transfer module TR1 Processing unit side transfer device TR2 Transfer unit side transfer device W Wafer

Claims (7)

a first transfer module;
a first transfer device provided inside the first transfer module;
a process module connected to the first transfer module;
a first load lock module connected to the first transfer module;
a second load lock module connected to the first transfer module;
a second transfer module connected to the first load lock module and the second load lock module, the second transfer module being connected to a container for storing unused rings;
a second transfer device provided inside the second transfer module;
A control unit;
Equipped with
The control unit controls the first conveying device,
(a) transporting a used ring, which has been unloaded from the process module, toward the first load lock module without opening the process module to the atmosphere;
The control unit controls the second conveying device,
(b) carrying the unused ring housed in the container connected to the second transfer module into the second load lock module;
The control unit controls the first conveying device,
(c) after (b), carrying the unused ring carried out from the second load lock module into the process module without opening the process module to the atmosphere ;
The control unit controls the first conveying device,
(d) before (a), unloading the substrate from the process module;
Plasma treatment system. The control unit controls the first conveying device,
(e) after (c), loading the substrate into the process module;
10. The plasma processing system of claim 1 . a position detection sensor provided on a transport path of the unused ring transported by the first transport device at a position where the unused ring can be detected;
the position detection sensor detects the position of the unused ring based on an output generated when the unused ring passes through the position detection sensor during transport of the unused ring from the first transport module to the process module.
3. The plasma processing system according to claim 1. The used ring is stored in the container in which the unused ring is stored.
The plasma processing system of claim 1 . the first transport device and the second transport device are configured to be able to transport a substrate;
The plasma processing system of claim 1 . The container is a FOUP (Front Opening Unified Pod),
The plasma processing system of claim 1 . The second transport device is configured to be able to hold two substrates or two rings at a time.
The plasma processing system of claim 1 .