Plasma Processing Equipment

Abstract

To efficiently remove a deposit in an exhaust space.SOLUTION: A chamber is provided with a stage inside which a substrate is placed, and an exhaust port connected to an exhaust system, which is provided around the stage. A baffle is provided around the stage and divides the space in the chamber into a processing space in which plasma processing is performed on the substrate and an exhaust space connected to the exhaust port. A switching mechanism switches the baffle between a shielding state for shielding plasma and a transmission state for allowing plasma to pass therethrough. A control unit controls the switching mechanism such that the baffle changes from the shielding state to the transmission state or from the transmission state to the shielding state.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a plasma processing apparatus and a cleaning method. [Background technology]

[0002] Patent Document 1 discloses a plasma processing chamber system that includes an exhaust port connected to a vacuum pump and a conductance control structure around a stage on which a substrate is placed in the chamber. The conductance control structure has a slit-shaped opening, and exhaust can be controlled by aligning or misaligning the exhaust port and the opening. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2015 / 0060404 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique for efficiently removing deposits from an exhaust space. [Means for solving the problem]

[0005] A plasma processing apparatus according to an aspect of the present disclosure includes a chamber, a baffle, a switching mechanism, and a controller. The chamber is provided with a stage on which a substrate is placed, and an exhaust port connected to an exhaust system is provided around the stage. The baffle is provided around the stage and divides the space within the chamber into a processing space where plasma processing is performed on the substrate, and an exhaust space connected to the exhaust port. The switching mechanism switches the baffle between a shielding state that blocks plasma and a transparent state that allows plasma to pass through. The controller controls the switching mechanism so that the baffle changes from the shielding state to the transparent state, or from the transparent state to the shielding state. Effect of the Invention

[0006] According to the present disclosure, deposits in the exhaust space can be efficiently removed. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing an example of a schematic configuration of a plasma processing system according to a first embodiment. [Diagram 2] FIG. 2 is a diagram illustrating accumulation of deposits in the exhaust space according to the first embodiment. [Diagram 3] FIG. 3 is a diagram illustrating an example of the configuration of the baffle plate according to the first embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of a blade according to the first embodiment. [Diagram 5] FIG. 5 is a diagram illustrating an example of a change in the slit according to the first embodiment. [Figure 6] FIG. 6 is a diagram for explaining the blocking state and the transmitting state of the baffle plate according to the first embodiment. [Figure 7] FIG. 7 is a diagram illustrating an example of a process order of the cleaning method according to the embodiment. [Figure 8] FIG. 8 is a diagram illustrating another example of the configuration of the baffle plate according to the first embodiment. [Figure 9] FIG. 9 is a diagram showing an example of switching of the region 18 to be in a transmissive state during plasma cleaning according to the first embodiment. [Figure 10] FIG. 10 is a diagram illustrating the configuration of a plasma processing apparatus 1 according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, embodiments of the plasma processing apparatus and cleaning method disclosed in the present application will be described in detail with reference to the drawings. Note that the plasma processing apparatus and cleaning method disclosed are not limited to the embodiments.

[0009] There is known a plasma processing apparatus that reduces the pressure inside a chamber and performs plasma processing such as plasma etching on a substrate. In a plasma processing apparatus, a stage on which a substrate is placed is provided in the center of the chamber, and an exhaust port is often formed near the edge of the bottom surface of the chamber in consideration of space limitations and ease of maintenance. In such a plasma processing apparatus, when the chamber is depressurized by exhausting air from the exhaust port, a bias in the exhaust characteristics occurs. For this reason, in the plasma processing apparatus, a baffle plate is provided around the stage to equalize the exhaust characteristics.

[0010] In plasma processing apparatuses, deposits accumulate in the chamber. For example, in the plasma processing apparatus, deposits accumulate in the processing space in the chamber where the plasma processing is performed, and also in the exhaust space in the chamber that is closer to the exhaust port than the baffle plate.

[0011] Therefore, a technology for efficiently removing deposits from the exhaust space is desired.

[0012] [First embodiment] [Device configuration] An example of a plasma processing apparatus according to the present disclosure will be described. In the embodiment described below, the plasma processing apparatus according to the present disclosure is used as a plasma processing system having a system configuration. Fig. 1 is a diagram showing an example of a schematic configuration of a plasma processing system according to a first embodiment.

[0013] An example of the configuration of a plasma processing system will be described below. The plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a control unit 2. The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas introduction unit. The gas introduction unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas introduction unit includes a shower head 13. The substrate support 11 is disposed in the plasma processing chamber 10. The shower head 13 is disposed above the substrate support 11. In one embodiment, the shower head 13 constitutes at least a part of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the shower head 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 has at least one gas supply port for supplying at least one processing gas to the plasma processing space 10s and at least one gas exhaust port for exhausting gas from the plasma processing space. The sidewall 10a is grounded. The shower head 13 and the substrate support 11 are electrically insulated from the plasma processing chamber 10 housing.

[0014] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a central region (substrate support surface) 111a for supporting a substrate (wafer) W, and an annular region (ring support surface) 111b for supporting the ring assembly 112. The annular region 111b of the main body 111 surrounds the central region 111a of the main body 111 in a plan view. The substrate W is disposed on the central region 111a of the main body 111, and the ring assembly 112 is disposed on the annular region 111b of the main body 111 so as to surround the substrate W on the central region 111a of the main body 111. In one embodiment, the main body 111 includes a base and an electrostatic chuck. The base includes a conductive member. The conductive member of the base functions as a lower electrode. The electrostatic chuck is disposed on the base. The upper surface of the electrostatic chuck has a substrate support surface 111a. The ring assembly 112 includes one or more annular members. At least one of the one or more annular members is an edge ring. Although not shown, the substrate support 11 may include a temperature adjustment module configured to adjust at least one of the electrostatic chuck, the ring assembly 112, and the substrate to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow path, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path. The substrate support 11 may also include a heat transfer gas supply unit configured to supply a heat transfer gas between the back surface of the substrate W and the substrate support surface 111a.

[0015] The shower head 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The shower head 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The processing gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c. The shower head 13 also includes a conductive member. The conductive member of the shower head 13 functions as an upper electrode. In addition to the shower head 13, the gas introduction unit may include one or more side gas injectors (SGIs) attached to one or more openings formed in the side wall 10a.

[0016] The gas supply 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply 20 is configured to supply at least one process gas from a respective gas source 21 through a respective flow controller 22 to the showerhead 13. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply 20 may include one or more flow modulation devices to modulate or pulse a flow rate of the at least one process gas.

[0017] The power source 30 includes an RF power source 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power source 31 is configured to supply at least one RF signal (RF power), such as a source RF signal and a bias RF signal, to a conductive member of the substrate support 11 and / or a conductive member of the showerhead 13. This causes a plasma to be formed from at least one processing gas supplied to the plasma processing space 10s. Thus, the RF power source 31 can function as at least a part of a plasma generating unit configured to generate a plasma from one or more processing gases in the plasma processing chamber 10. In addition, by supplying a bias RF signal to the conductive member of the substrate support 11, a bias potential is generated on the substrate W, and ion components in the formed plasma can be attracted to the substrate W.

[0018] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to the conductive member of the substrate support 11 and / or the conductive member of the shower head 13 via at least one impedance matching circuit, and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 13 MHz to 150 MHz. In one embodiment, the first RF generating unit 31a may be configured to generate a plurality of source RF signals having different frequencies. The generated one or more source RF signals are supplied to the conductive member of the substrate support 11 and / or the conductive member of the shower head 13. The second RF generating unit 31b is coupled to the conductive member of the substrate support 11 via at least one impedance matching circuit, and is configured to generate a bias RF signal (bias RF power). In one embodiment, the bias RF signal has a lower frequency than the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 400 kHz to 13.56 MHz. In one embodiment, the second RF generator 31b may be configured to generate multiple bias RF signals having different frequencies. The generated bias RF signal or signals are provided to the conductive members of the substrate support 11. Also, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0019] In addition, the power supply 30 may include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generation unit 32a and a second DC generation unit 32b. In one embodiment, the first DC generation unit 32a is connected to the conductive member of the substrate support 11 and is configured to generate a first DC signal. The generated first bias DC signal is applied to the conductive member of the substrate support 11. In one embodiment, the first DC signal may be applied to other electrodes such as the electrodes in the electrostatic chuck. In one embodiment, the second DC generation unit 32b is connected to the conductive member of the shower head 13 and is configured to generate a second DC signal. The generated second DC signal is applied to the conductive member of the shower head 13. In various embodiments, at least one of the first and second DC signals may be pulsed. Note that the first and second DC generation units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generation unit 32a may be provided in place of the second RF generation unit 31b.

[0020] The plasma processing chamber 10 is formed in a cylindrical shape with a space formed inside, and the above-described substrate support 11 is disposed at the center inside. The substrate support 11 is formed in a columnar shape, and the substrate W to be subjected to plasma processing is placed thereon. Further, the plasma processing chamber 10 is formed with a gas discharge port 10e for exhausting the inside at a position lower than the substrate support 11 around the substrate support 11. In the plasma processing apparatus 1 according to the first embodiment, the gas discharge port 10e is formed at the bottom of the plasma processing chamber 10.

[0021] The exhaust system 40 can be connected, for example, to the gas discharge port 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure in the plasma processing space 10s is adjusted by the pressure regulating valve. The vacuum pump may include a turbo molecular pump, a dry pump, or a combination thereof.

[0022] The plasma processing chamber 10 is provided with a baffle plate 14 around the substrate support portion 11. The baffle plate 14 is formed in a flat annular shape. The baffle plate 14 according to the first embodiment has flat planes formed on the inner peripheral side and the outer peripheral side, and a step is formed such that the outer peripheral side is higher than the inner peripheral side. Note that the baffle plate 14 may be formed in a flat plane without a step. The baffle plate 14 is arranged so as to surround the periphery of the substrate support portion 11. The inner peripheral side of the baffle plate 14 is fixed to the substrate support portion 11, and the outer peripheral side is fixed to the inner wall of the plasma processing chamber 10. The baffle plate 14 is formed to have conductivity. For example, the baffle plate 14 is formed of a conductive material such as a conductive metal. The baffle plate 14 is electrically connected to the side wall 10a of the plasma processing chamber 10 and is grounded through the side wall 10a. A number of slits are formed in the baffle plate 14, and gas is allowed to pass through. The inside of the plasma processing chamber 10 is divided by the baffle plate 14 into a plasma processing space 10s, which is a processing space for performing basic plasma processing on the substrate W, and an exhaust space 10t including a gas discharge port 10e. The plasma processing space 10s is a space upstream of the baffle plate 14 with respect to the exhaust flow to the gas discharge port 10e. The exhaust space 10t is a space downstream of the baffle plate 14 with respect to the exhaust flow to the gas discharge port 10e.

[0023] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various steps described in the present disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform various steps described herein. In one embodiment, a part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include, for example, a computer 2a. The computer 2a may include, for example, a processing unit (CPU: Central Processing Unit) 2a1, a storage unit 2a2, and a communication interface 2a3. The processing unit 2a1 may be configured to perform various control operations based on a program stored in the storage unit 2a2. The storage unit 2a2 may include a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0024] Next, a flow of performing plasma processing such as plasma etching on a substrate W by the plasma processing system according to the embodiment will be briefly described. The substrate W is placed on the substrate support 11 by a transport mechanism such as a transport arm (not shown). When performing plasma processing, the plasma processing apparatus 1 reduces the pressure inside the plasma processing chamber 10 by the exhaust system 40. The plasma processing apparatus 1 supplies a processing gas from the gas supply unit 20 and introduces the processing gas into the plasma processing chamber 10 from the shower head 13. Then, the plasma processing apparatus 1 supplies at least one RF signal from the RF power source 31 to generate plasma in the plasma processing space 10s, and performs plasma processing on the substrate W.

[0025] By the way, when plasma processing is performed, deposits accumulate inside the plasma processing chamber 10. The deposits accumulate in the plasma processing space 10s, but deposits are also likely to accumulate in the exhaust space 10t on the gas exhaust port 10e side of the baffle plate 14 in the plasma processing chamber 10. The deposits include products generated by the plasma processing, ash caused by heat, and the like.

[0026] When the plasma processing apparatus 1 performs plasma processing, deposits are deposited in the plasma processing space 10s and the exhaust space 10t. Therefore, the plasma processing apparatus 1 performs a cleaning process to remove the deposits. When performing the cleaning process, the plasma processing apparatus 1 reduces the pressure inside the plasma processing chamber 10 by the exhaust system 40. The plasma processing apparatus 1 supplies a cleaning gas from the gas supply unit 20 and introduces the cleaning gas into the plasma processing chamber 10 from the shower head 13. Then, the plasma processing apparatus 1 supplies at least one RF signal from the RF power supply 31 to generate plasma in the plasma processing space 10s and perform plasma cleaning. Dry cleaning may be performed by placing a dummy substrate on the substrate support 11 to protect the surface of the substrate support 11.

[0027] The cleaning gas may be any gas type that can remove the deposits. For example, when the deposits are organic products generated from an etching gas during an etching process of the substrate W, the cleaning gas may be O 2 , O 3 , CO, CO 2 In addition, when the deposit is an organic film containing metals such as W (tungsten) and Ti (titanium), the cleaning gas is O 2 , C.O., O 3 , CO 2 Oxygen-containing gases such as CF 4、 Cl 2 Gases containing halogen-containing gases such as F 2 Gas, ClF 3In addition, when the deposit is a deposit made by metal etching such as Ru (ruthenium), cobalt (Co), or iron (Fe), the cleaning gas may be methanol (CH 3 OH) gas. In addition, a plurality of types of gases may be switched and supplied as the cleaning gas. When the deposit is a laminated film of a plurality of products or organic films, the cleaning gas may be selected and supplied according to the film type exposed on the top surface of the laminated film. When a cleaning process is performed simultaneously with a plasma process in which a plurality of step processes in which different reaction products that become deposits are performed, the cleaning gas may be switched for each step process.

[0028] Here, in the conventional plasma processing apparatus 1, in order to improve the processing efficiency of the plasma processing and improve uniformity for the substrate W, the plasma generated in the plasma processing space 10s is shielded by a baffle plate 14 so that the plasma does not flow into the exhaust space 10t.

[0029] However, in the conventional plasma processing apparatus 1, the plasma of the cleaning gas during plasma cleaning is also blocked by the baffle plate 14, so the cleaning rate of deposits in the exhaust space 10t is low and the deposits cannot be completely removed.

[0030] FIG. 2 is a diagram for explaining the deposition of deposits in the exhaust space 10t according to the first embodiment. In FIG. 2, the vicinity of the side surface of the substrate support 11 of the plasma processing chamber 10 is shown in an enlarged manner. In FIG. 2, the plasma is shielded by the baffle plate 14. For this reason, in the conventional plasma processing apparatus 1, when the cumulative time of plasma processing becomes long, for example, deposits 50 are deposited on the substrate support 11 under the baffle plate 14 or on the wall surface of the side wall 10a. When deposits 50 are deposited in the exhaust space 10t, for example, the following problems occur. The deposits 50 in the exhaust space 10t become a source of dust generation of particles. In addition, the deposits 50 in the exhaust space 10t may fall into the pressure regulation valve of the exhaust system 40, changing the opening degree of the pressure regulation valve and changing the pressure in the plasma processing chamber 10. In the conventional plasma processing apparatus 1, the deposits 50 must be manually removed for each maintenance cycle, which takes time for maintenance.

[0031] Therefore, in the plasma processing apparatus 1 according to the embodiment, the baffle plate 14 is configured to be switchable between a shielding state that shields the plasma and a transparent state that allows the plasma to pass through. For example, the baffle plate 14 according to the first embodiment has a plurality of slits formed therein, and is switchable between the shielding state and the transparent state by changing the width of the plurality of slits. The baffle plate 14 has openings formed along the circumferential direction of the substrate support portion 11. The baffle plate 14 according to the first embodiment has openings formed on a flat surface on the inner circumferential side. Note that the baffle plate 14 may have openings 14b and blades 15, which will be described later, on a flat surface or a stepped surface on the outer circumferential side.

[0032] FIG. 3 is a diagram for explaining an example of the configuration of the baffle plate 14 according to the first embodiment. In FIG. 3, a flat plane 14a on the inner periphery side of the baffle plate 14 is shown. An opening 14b is formed in the plane 14a along the circumferential direction of the baffle plate 14. A plurality of blades 15 are arranged in the opening 14b. Each blade 15 is fixed to a rod-shaped shaft 15a and is rotatable around the shaft 15a as a rotation axis. A gap functioning as a slit 16 is formed between each blade 15. The shaft 15a of each blade 15 is rotatably supported on the plane 14a sandwiching the opening 14b of the baffle plate 14. The shaft 15a of each blade 15 is rotated by a switching mechanism. A shaft 17 is provided on the plane 14a of the baffle plate 14 as a switching mechanism. A worm gear is provided on the shaft 15a of each blade 15, and the rotation is transmitted to the shaft 17 via the worm gear to rotate the shaft 15a. The shaft 17 rotates by the driving force of a power source such as a servo motor (not shown). The control unit 2 controls the power source to control the rotation of the shaft 17, thereby controlling the rotation angle of each blade 15. Note that the switching mechanism according to the first embodiment may have any configuration as long as it is capable of rotating each blade 15 around the shaft 15a as the rotation axis.

[0033] FIG. 4 is a diagram for explaining an example of the blade 15 according to the first embodiment. As described above, each blade 15 is rotatable about the shaft 15a as a rotation axis. In the baffle plate 14, the width of the slit 16 (gap) between the blades 15 changes by changing the rotation angle of each blade 15. FIG. 5 is a diagram for explaining an example of the change in the slit 16 according to the first embodiment. For example, in the baffle plate 14, the width of the slit 16 becomes narrower by making the plane of each blade 15 horizontal, and the width of the slit 16 becomes wider by making the plane of each blade 15 vertical.

[0034] The baffle plate 14 according to the first embodiment can be switched between a shielding state in which the plasma is shielded and a transmitting state in which the plasma can pass by controlling the rotation angle of each blade 15 to change the width of the slits 16. FIG. 6 is a diagram for explaining the shielding state and transmitting state of the baffle plate 14 according to the first embodiment. When the width of the slits 16 of the baffle plate 14 is smaller than twice the plasma sheath width, the plasma cannot pass through the slits 16 and the baffle plate 14 shields the plasma. When the width of the slits 16 of the baffle plate 14 is greater than or equal to twice the plasma sheath width, the plasma can pass through the slits 16 and the plasma is transmitted. When the plane of each blade 15 of the baffle plate 14 is horizontal, the width d of the slits 16 1 is the plasma sheath width d sh When the plane of each blade 15 is made vertical, the width d of the slit 16 is smaller than twice the 2 is the sheath width d sh It is configured to be more than twice as large as the

[0035] The controller 2 controls the baffle plate 14 to the blocking state when performing plasma processing on the substrate W, and controls the baffle plate 14 to the transmitting state when performing plasma cleaning inside the plasma processing chamber 10.

[0036] For example, the control unit 2 controls the rotation angle of each blade 15 by controlling the power source, thereby controlling the width of the slit 16 of the baffle plate 14. When performing plasma processing, the control unit 2 sets the width of the slit 16 of the baffle plate 14 to be smaller than twice the sheath width of the plasma, thereby putting the baffle plate 14 in a shielding state. For example, when performing plasma processing, the control unit 2 controls the rotation angle so that the plane of each blade 15 is in a horizontal state, thereby putting the baffle plate 14 in a shielding state. As a result, in the plasma processing apparatus 1, the plasma generated in the plasma processing space 10s during the plasma processing of the substrate W is shielded by the baffle plate 14 and remains in the plasma processing space 10s, thereby improving the processing efficiency of the plasma processing. In addition, the plasma processing apparatus 1 can perform plasma processing on the substrate W with good uniformity.

[0037] Furthermore, when performing plasma cleaning, the control unit 2 makes the width of the slits 16 in the baffle plate 14 larger than twice the plasma sheath width to put the baffle plate 14 in a transparent state. For example, when performing plasma processing, the control unit 2 controls the rotation angle so that the plane of each blade 15 is vertical to put the baffle plate 14 in a transparent state. As a result, the plasma processing apparatus 1 can efficiently remove deposits in the exhaust space 10t because the plasma generated in the plasma processing space 10s by plasma cleaning passes through the baffle plate 14 and flows into the exhaust space 10t.

[0038] Next, a process flow of the cleaning method performed by the plasma processing apparatus 1 according to the embodiment will be described. Fig. 7 is a diagram illustrating an example of a process sequence of the cleaning method according to the embodiment. The process of the cleaning method shown in Fig. 7 is performed when performing plasma processing or plasma cleaning on the substrate W.

[0039] The control unit 2 determines whether the process to be performed is plasma processing (S10). If the process to be performed is plasma processing (S10: Yes), the control unit 2 controls the baffle plate 14 to a shielding state (S11) and ends the process. For example, the control unit 2 controls the power source to control the rotation angle of each blade 15, and makes the width of the slits 16 of the baffle plate 14 smaller than twice the plasma sheath width to put the baffle plate 14 in the shielding state.

[0040] On the other hand, if the process to be performed is plasma cleaning and not plasma processing (S10: No), the control unit 2 controls the baffle plate 14 to the transmitting state (S12) and ends the process. For example, the control unit 2 controls the power source to control the rotation angle of each blade 15, and increases the width of the slits 16 in the baffle plate 14 to at least twice the sheath width of the plasma to set the baffle plate 14 to the transmitting state.

[0041] In the above first embodiment, the baffle plate 14 is configured to be uniformly switched between a shielding state and a transmitting state around the entire circumference, but the present invention is not limited to this. The baffle plate 14 may be divided into a plurality of regions along the circumferential direction of the substrate support portion 11, and each of the plurality of regions may be individually switched between a shielding state and a transmitting state. FIG. 8 is a diagram for explaining another example of the configuration of the baffle plate 14 according to the first embodiment. The baffle plate 14 is flat and annular. The baffle plate 14 is divided into, for example, four regions 18 (18a-18d) along the circumferential direction. An opening 19 is formed in each of the four regions 18, and a plurality of blades 15 are arranged in the openings 19. The baffle plate 14 is configured such that the rotation angle of the blade 15 can be controlled for each region 18 by a switching mechanism.

[0042] The control unit 2 controls all the regions 18 of the baffle plate 14 to be in a shielded state when performing plasma processing on the substrate W, and controls some or all of the regions 18 of the baffle plate 14 to be in a transparent state when performing plasma cleaning in the plasma processing chamber 10. For example, the control unit 2 controls the four regions 18 of the baffle plate 14 to be in a transparent state in sequence when performing plasma cleaning in the plasma processing chamber 10. FIG. 9 is a diagram showing an example of switching of the regions 18 to be in a transparent state during plasma cleaning according to the first embodiment. In FIG. 9, the regions 18 in the shielded state are marked with a diagonal line pattern, and the regions 18 in the transparent state are marked with a dot pattern. In FIG. 9(A), the regions 18a-18d are all in a shielded state. In FIG. 9(B), the regions 18b-18d are in a shielded state, and the shielding of the region 18a is turned off and the region 18 is in a transparent state. In FIG. 9C, the regions 18 are sequentially controlled to the transparent state, and in FIG. 9B, the region 18b is switched to the shielding state, and the region 18c is switched to the transparent state. This allows the plasma processing apparatus 1 to locally concentrate and flow the plasma of the cleaning gas into the exhaust space 10t of the region 18 in the transparent state during plasma cleaning. This allows the plasma processing apparatus 1 to efficiently remove deposits in the exhaust space 10t of the region 18 in the transparent state at a high rate. In addition, the plasma processing apparatus 1 sequentially controls the regions 18 of the baffle plate 14 to the transparent state, so that the regions 18 in the transparent state are sequentially switched, and the entire exhaust space 10t can be cleaned.

[0043] In addition, the plasma processing apparatus 1 can be used for partial pressure adjustment in the plasma processing chamber 10 by adjusting the inclination of the blades 15 in each region 18 by configuring the baffle plate 14 as shown in Fig. 8. For example, the pressure on the surface of the substrate W can be partially adjusted in the circumferential direction during plasma processing, which can be used to eliminate bias in the etching rate. In addition, the plasma density on the baffle plate 14 can be reduced by making it partially transparent during plasma processing, so that the plasma density on the surface of the substrate W can be partially adjusted in the circumferential direction, which can be used to eliminate bias in the etching rate.

[0044] 8, the area is divided into four areas, but is not limited to this. For example, it is sufficient to divide the area into two or more areas, and by dividing the area into eight areas, twelve areas, or more, deposits in the exhaust space 10t in the area 18 in the transparent state can be removed more efficiently and at a higher rate. In addition, the pressure or plasma density during plasma processing can be adjusted more finely and partially in the circumferential direction, and this can also be used to better eliminate bias in the etching rate.

[0045] As described above, the plasma processing apparatus 1 according to the first embodiment includes the plasma processing chamber 10 (chamber), the baffle plate 14, a switching mechanism (shaft 17, a motor for rotating the shaft 17, etc.), and the controller 2. The plasma processing chamber 10 is provided with a substrate support 11 (stage) for placing the substrate W therein, and a gas exhaust port 10e (exhaust port) connected to an exhaust system is provided around the substrate support 11. The baffle plate 14 is provided around the substrate support 11 and divides the space in the plasma processing chamber 10 into a plasma processing space 10s where the plasma processing is performed on the substrate W, and an exhaust space 10t connected to the gas exhaust port 10e. The switching mechanism switches the baffle plate 14 between a shielding state that blocks plasma and a transmitting state that allows plasma to pass through. When plasma is generated in the plasma processing chamber 10 and plasma processing is performed on the substrate W, the controller 2 controls the switching mechanism so that the baffle plate 14 is in the shielding state. Furthermore, when performing plasma cleaning inside the plasma processing chamber 10, the control unit 2 controls the switching mechanism so that the baffle plate 14 is in the transparent state. This allows the plasma processing apparatus 1 to efficiently remove deposits in the exhaust space 10t.

[0046] Further, the baffle plate 14 is formed with a plurality of slits 16. The switching mechanism switches between the blocking state and the transmitting state by changing the width of the plurality of slits 16. In this manner, the plasma processing apparatus 1 can switch the baffle plate 14 between the blocking state and the transmitting state by changing the width of the slits 16 of the baffle plate 14.

[0047] Further, in the baffle plate 14, an opening 14b is formed along the periphery of the substrate support portion 11, a plurality of blades 15 respectively fixed to the shafts 15a are arranged side by side in the opening 14b, and slits 16 are formed between the respective blades 15. The switching mechanism switches the baffle plate 14 between a shielding state and a transmitting state by rotating the shafts 15a of the plurality of blades 15 to change the width of the slits 16. Thereby, the plasma processing apparatus 1 can switch the baffle plate 14 between a shielding state and a transmitting state by rotating the plurality of blades 15 arranged in the opening 14b.

[0048] Further, the switching mechanism sets the baffle plate 14 in a shielding state by making the width of the slit 16 smaller than twice the sheath width of the plasma, and sets the baffle plate 14 in a transmitting state by making the width of the slit 16 larger than twice the sheath width. Thereby, the plasma processing apparatus 1 can switch the baffle plate 14 between a shielding state and a transmitting state.

[0049] Further, the baffle plate 14 is divided into a plurality of regions 18 along the circumferential direction of the substrate support portion 11, and the plurality of regions 18 can be individually switched between a shielding state and a transmitting state. The switching mechanism individually switches between a shielding state and a transmitting state in each of the plurality of regions 18. Thereby, the plasma processing apparatus 1 can locally concentrate and flow the plasma of the cleaning gas into the exhaust space 10t and perform local cleaning.

[0050] Further, when performing plasma processing on the substrate W, the control unit 2 controls the switching mechanism so that the plurality of regions 18 of the baffle plate 14 are in a shielding state. Further, when performing plasma cleaning in the plasma processing chamber 10, the control unit 2 controls the switching mechanism so that some or all of the plurality of regions 18 of the baffle plate 14 are in a transmitting state. Thereby, the plasma processing apparatus 1 can flow the plasma of the cleaning gas into the exhaust space 10t of the region 18 in the transmitting state, and can locally or entirely clean a part of the exhaust space 10t.

[0051] Furthermore, when performing plasma cleaning in the plasma processing chamber 10, the control unit 2 controls the switching mechanism to sequentially set the multiple regions 18 of the baffle plate 14 to the transparent state. This allows the plasma processing device 1 to locally concentrate the plasma of the cleaning gas into the exhaust space 10t of the region 18 that is in the transparent state, thereby efficiently removing deposits in the exhaust space 10t of the region 18 that is in the transparent state at a high rate. Furthermore, by sequentially controlling the regions 18 of the baffle plate 14 to the transparent state, the plasma processing device 1 sequentially switches the regions 18 in the transparent state, thereby cleaning the entire exhaust space 10t.

[0052] [Second embodiment] Next, a second embodiment will be described. Since the plasma processing system, the plasma processing apparatus 1, and the control unit 2 according to the second embodiment have the same configuration as those of the first embodiment, the description of the same parts will be omitted and differences will be mainly described.

[0053] FIG. 10 is a diagram illustrating the configuration of a plasma processing apparatus 1 according to the second embodiment. 1 shows an enlarged view of the vicinity of a side surface of a substrate support 11 of a plasma processing chamber 10.

[0054] As in the second embodiment, a baffle plate 14 is provided around the substrate support 11. The baffle plate 14 has a large number of slits formed therein to allow gas to pass through. Each slit is formed with a width smaller than twice the plasma sheath width.

[0055] The baffle plate 14 is configured to be switchable between a shielding state that shields plasma and a transparent state that allows plasma to pass through. For example, the baffle plate 14 according to the second embodiment is switchable between a ground potential and a floating state. The baffle plate 14 is provided with an insulating member such as a dielectric on the inner peripheral portion that contacts the substrate support portion 11 and the outer peripheral portion that contacts the side wall 10a, and is insulated from the substrate support portion 11 and the side wall 10a. In addition, a switch 60 (60a, 60b) that switches the substrate support portion 11, the side wall 10a, and the baffle plate 14 between a conductive state and a non-conductive state is provided at one or more locations along the circumferential direction of the baffle plate 14. The control unit 2 controls the on / off of the switch 60 to switch between a ground potential and a floating state.

[0056] The baffle plate 14 is in a blocking state when the switch 60 is turned on and is electrically connected to the side wall 10a, which is at ground potential, and is at ground potential, and is in a transmitting state when the switch 60 is turned off and is in a floating state.

[0057] The control unit 2 controls the baffle plate 14 to a shielding state when performing plasma processing on the substrate W, and controls the baffle plate 14 to a transparent state when performing plasma cleaning in the plasma processing chamber 10. For example, the control unit 2 controls the switch 60 to be on to set the baffle plate 14 to a shielding state. As a result, in the plasma processing apparatus 1, the plasma generated in the plasma processing space 10s by the plasma processing on the substrate W is shielded by the baffle plate 14 and remains in the plasma processing space 10s, improving the processing efficiency of the plasma processing. In addition, the plasma processing apparatus 1 can perform plasma processing on the substrate W with good uniformity. In addition, in the case of performing plasma cleaning, the control unit 2 controls the switch 60 to be off to set the baffle plate 14 to a transparent state. As a result, in the plasma processing apparatus 1, the plasma generated in the plasma processing space 10s by the plasma cleaning passes through the baffle plate 14 and flows into the exhaust space 10t, so that the deposits in the exhaust space 10t can be efficiently removed.

[0058] In the above second embodiment, an example has been described in which the entire circumference of the baffle plate 14 is configured to be switchable between a shielding state and a transmitting state uniformly, but the present invention is not limited to this. In the second embodiment, the baffle plate 14 may also be configured to be divided into a plurality of regions along the circumferential direction of the substrate support portion 11, and each of the plurality of regions may be individually switched between a shielding state and a transmitting state. The baffle plate 14 is divided into a plurality of regions along the circumferential direction of the substrate support portion 11, and each of the plurality of regions may be individually switched between a ground potential and a floating state, thereby making it possible to individually switch each of the plurality of regions between a shielding state and a transmitting state.

[0059] The switch 60 includes two switches, a switch 60a between the substrate support 11 and the baffle plate 14, and a switch 60b between the side wall 10a and the baffle plate 14, but is not limited to this. For example, only one of the switches 60a and 60b may be used, and the other switch may be fixed by an insulator. Alternatively, the space between the substrate support 11 and the baffle plate 14 and the space between the side wall 10a and the baffle plate 14 may both be fixed by an insulator, and the baffle plate 14 may be connected by a lead wire to another location at ground potential via another switch, and the baffle plate 14 may be switched between a shielding state and a transmitting state by turning on / off the switch.

[0060] As described above, the plasma processing apparatus 1 according to the second embodiment has a switching mechanism. The switching mechanism can switch the baffle plate 14 between a ground potential and a floating state. The switching mechanism sets the baffle plate 14 to a shielding state by setting the baffle plate 14 to a ground potential, and sets the baffle plate 14 to a floating state by setting the baffle plate 14 to a transparent state. In this way, the plasma processing apparatus 1 can switch the baffle plate 14 between a shielding state and a transparent state by switching the baffle plate 14 between a ground potential and a floating state.

[0061] The switching mechanism is a switch 60 that is provided at a connection point between the conductive member at ground potential and the baffle plate 14 and switches between a conductive state and a non-conductive state between the conductive member and the baffle plate 14. This allows the plasma processing apparatus 1 to easily switch the baffle plate 14 between the ground potential and a floating state using the switch 60.

[0062] Although the embodiments have been described above, the disclosed embodiments should be considered to be illustrative and not restrictive in all respects. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the claims.

[0063] For example, in the above embodiment, the plasma processing is performed on a semiconductor wafer as the substrate W, but the present invention is not limited to this.

[0064] In addition, the control unit 2 controls the switching mechanism so that the baffle plate 14 is in the shielding state during plasma processing and in the transmitting state during cleaning processing, but the present invention is not limited to this. For example, even during the same cleaning processing, the baffle plate 14 may be in the shielding state when mainly cleaning the deposits 50 on the substrate W, the substrate support 11, and the wall surface of the side wall 10a of the plasma processing space 10s. That is, the control unit 2 may control the switching mechanism so that the baffle plate 14 is in the transmitting state during cleaning processing. Even during plasma processing, for example, during ashing to remove a mask on the substrate W, the baffle plate 14 can be in the transmitting state to simultaneously clean the wall surface of the side wall 10a of the exhaust space, thereby improving throughput. In addition, if the baffle plate 14 is partially in the transmitting state during plasma processing, the plasma density on the baffle plate 14 decreases, so that the plasma density on the substrate W surface can be partially adjusted in the circumferential direction, and can also be used to eliminate unevenness in the etching rate. That is, the control unit 2 may control the switching mechanism so that the baffle plate 14 is in the transmitting state during plasma processing.

[0065] In the above embodiment, the plasma processing apparatus is described as performing plasma etching as the plasma processing, but the present invention is not limited to this. The plasma processing apparatus may be any apparatus that performs plasma processing on the substrate W. For example, the plasma processing apparatus may be a film forming apparatus that generates plasma to form a film.

[0066] It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be construed as limiting. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0067] 1. Plasma processing equipment 2. Control section 10 Plasma Processing Chamber 10a side wall 10e Gas exhaust port 10s Plasma treatment space 10t exhaust space 11 Substrate support 14 Baffle plate 14a plane 14b opening 15 Blades 15a axis 16 Slit 17 Shaft 18 areas 50 Sediment 60, 60a, 60b Switch

Claims

1. a chamber having a stage therein for placing a substrate and an exhaust port connected to an exhaust system provided around the stage; a baffle provided around the stage and dividing a space within the chamber into a processing space in which plasma processing is performed on the substrate and an exhaust space connected to the exhaust port; a switching mechanism for switching the baffle between a shielding state for blocking plasma and a transmitting state for allowing plasma to pass therethrough; A control unit that controls the switching mechanism so that the baffle changes from a blocking state to a transmitting state, or from a transmitting state to a blocking state; having The baffle has a plurality of slits formed therein, The switching mechanism switches the baffle between the blocking state and the transmitting state by changing the width of the plurality of slits. Plasma processing equipment.

2. The control unit controls the switching mechanism so that the baffle is in the blocking state when plasma is generated in the chamber to perform plasma processing on the substrate, and so that the baffle is in the transmitting state when plasma cleaning is performed in the chamber. The plasma processing apparatus according to claim 1 .

3. The baffle has an opening formed along the periphery of the stage, a plurality of blades each fixed to a shaft are arranged in the opening, and slits are formed between each blade; The switching mechanism switches between the blocking state and the transmitting state by rotating the shafts of the plurality of blades to change the width of the slit.

3. The plasma processing apparatus according to claim 1 or 2.

4. the switching mechanism sets the baffle in the blocking state by making the width of the slit smaller than twice the sheath width of the plasma, and sets the baffle in the transmitting state by making the width of the slit larger than twice the sheath width. The plasma processing apparatus according to claim 1 .

5. a chamber having a stage therein for placing a substrate and an exhaust port connected to an exhaust system provided around the stage; a baffle provided around the stage and dividing a space within the chamber into a processing space in which plasma processing is performed on the substrate and an exhaust space connected to the exhaust port; a switching mechanism for switching the baffle between a shielding state for blocking plasma and a transmitting state for allowing plasma to pass therethrough; A control unit that controls the switching mechanism so that the baffle changes from a blocking state to a transmitting state, or from a transmitting state to a blocking state; having the switching mechanism is capable of switching the baffle between a ground potential and a floating state, and sets the baffle to the shielding state by setting the baffle to the ground potential, and sets the baffle to the transmitting state by setting the baffle to the floating state. Plasma processing equipment.

6. The switching mechanism is provided at a connection point between the conductive member at ground potential and the baffle, and serves as a switch for switching between a conductive state and a non-conductive state between the conductive member and the baffle. The plasma processing apparatus according to claim 5 .

7. The baffle is divided into a plurality of regions along a circumferential direction of the stage, and the plurality of regions can be individually switched between a blocking state and a transmitting state; The switching mechanism switches the plurality of regions individually between a blocking state and a transmitting state.

7. The plasma processing apparatus according to claim 1,

8. the control unit controls the switching mechanism so that the plurality of regions of the baffle are in the shielding state when the plasma processing is performed on the substrate, and so that a part or all of the plurality of regions of the baffle are in the transmitting state when the plasma cleaning in the chamber is performed. The plasma processing apparatus according to claim 7 .

9. When performing plasma cleaning inside the chamber, the control unit controls the switching mechanism so that the plurality of regions of the baffle are sequentially brought into the transmitting state. The plasma processing apparatus according to claim 8 .

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