Pressure Control System for the Multi-Head Processing Chamber of a Plasma Processing Apparatus

Abstract

A pressure control system is provided. The pressure control system includes a member that is at least partially located within a pumping port, the pumping port being fluidly coupled between a multi-head processing chamber and a pump configured to extract gas from the multi-head processing chamber. The member is rotatable relative to the pumping port. The pressure control system includes a plurality of pressure sensors. Each of the pressure sensors is configured to obtain data indicative of the pressure of an airflow entering the multi-head processing chamber at a corresponding head of the multi-head processing chamber. The pressure control system includes an actuator configured to rotate the member to control the pressure of the airflow at a first processing head of the multi-head processing chamber.

Description

Technical Field

[0001] The present disclosure generally relates to a plasma processing apparatus having a multi-head processing chamber, and more particularly to a pressure control system for a multi-head processing chamber. Background Art

[0002] Plasma processing tools can be used to fabricate devices such as integrated circuits, microelectromechanical systems, flat panel displays, and other devices. Plasma processing tools for modern plasma etching applications may be required to provide high plasma uniformity and a variety of plasma controls, including independent plasma profiles, plasma density, and ion energy control. In some cases, plasma processing tools may be required to maintain a stable plasma in a variety of process gases and under a variety of different conditions (e.g., gas flow, gas pressure, etc.).

[0003] A plasma processing tool can include a processing chamber in which a workpiece (e.g., a semiconductor wafer) is processed. For example, the processing chamber can be a dual-head chamber that shares a common gas supply. The plasma processing tool can include a throttle valve fluidly coupled to the common gas supply. The throttle valve can move between a first position (e.g., a fully open position) and a second position (e.g., a fully closed position) to selectively deliver gas to each head of the dual-head chamber. In some instances, a pressure difference between a first head and a second head of the dual-head chamber may occur at least in part due to the throttle valve being in an intermediate third position. Such a pressure difference can cause non-uniformity, for example, when processing one or more workpieces being processed. Summary of the Invention

[0004] In the following description, some aspects and advantages of the present disclosure are set forth, or these aspects and advantages may be apparent from the description, or may be learned by practice of the embodiments.

[0005] In one aspect, a pressure control system is provided. The pressure control system includes a member at least partially located within a pumping port fluidly coupled between a multi-head processing chamber and a pump configured to extract gas from the multi-head processing chamber. The member is rotatable relative to the pumping port. The pressure control system includes a plurality of pressure sensors. Each pressure sensor of the pressure sensors is configured to obtain data indicative of a pressure of a gas flow entering the multi-head processing chamber at a corresponding head of the multi-head processing chamber. The pressure control system includes an actuator configured to rotate the member to control the pressure of the gas flow at a first processing head of the multi-head processing chamber.

[0006] In another aspect, an operation control method for a pressure control system of a multi-head processing chamber of a plasma processing apparatus is provided. The method includes: obtaining first data from a first pressure sensor of the pressure control system, the first data indicating the pressure of an air flow entering the multi-head processing chamber via a first head of the multi-head processing chamber. The method further includes: providing one or more control signals based at least in part on the first data, the one or more control signals being associated with a rotating member that is at least partially located within a pumping port that is fluidly coupled between the multi-head processing chamber and a pump configured to extract gas from the multi-head processing chamber.

[0007] In yet another aspect, a plasma processing apparatus is provided. The plasma processing apparatus includes a multi-head processing chamber. The plasma processing apparatus includes a pumping port fluidly coupled to the multi-head processing chamber. The plasma processing apparatus includes a pump fluidly coupled to the multi-head processing chamber via the pumping port. The pump is configured to extract gas from the multi-head processing chamber via the pumping port. The plasma processing apparatus includes a pressure control system. The pressure control system includes a member that is at least partially located within the pumping port. The member is rotatable relative to the pumping port. The pressure control system includes a plurality of pressure sensors. Each pressure sensor of the pressure sensors is configured to obtain data indicating the pressure of an air flow entering the multi-head processing chamber via a corresponding head of the multi-head processing chamber. The pressure control system includes an actuator configured to rotate the member to control the pressure of the air flow at a first head of the multi-head processing chamber.

[0008] These and other features, aspects, and advantages of the present disclosure will be better understood with reference to the following description and the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] A more complete and enabling disclosure to those of ordinary skill in the art is set forth in the remainder of the specification including reference to the accompanying drawings, in which

[0010] Figure 1 a plasma processing apparatus according to an example embodiment of the present disclosure is depicted.

[0011] Figure 2 a block diagram of components of a pressure control system for a multi-head processing chamber of a plasma processing apparatus according to an example embodiment of the present disclosure is depicted.

[0012] Figure 3 a pressure sensor of a pressure control system installed in a multi-head processing chamber according to an example embodiment of the present disclosure is depicted.

[0013] Figure 4 Depicts a pressure control system for a multi-head processing chamber of a plasma processing apparatus according to an exemplary embodiment of the present disclosure.

[0014] Figure 5A Depicts components of the pressure control system in a first position according to an exemplary embodiment of the present disclosure. Figure 4 of the pressure control system.

[0015] Figure 5B Depicts components of the pressure control system in an intermediate third position according to an exemplary embodiment of the present disclosure. Figure 4 of the pressure control system.

[0016] Figure 5C Depicts components of the pressure control system in a second position according to an exemplary embodiment of the present disclosure. Figure 4 of the pressure control system.

[0017] Figure 6 Depicts a flowchart of operating a pressure control system for a multi-head processing chamber of a plasma processing apparatus according to an exemplary embodiment of the present disclosure.

[0018] Figure 7 Depicts another plasma processing apparatus according to an exemplary embodiment of the present disclosure. Detailed Description

[0019] Now, referring in detail to embodiments of the present invention, one or more examples of these embodiments are illustrated in the accompanying drawings. Each example is provided to explain the present invention and not to limit the present invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the scope or spirit of the present invention. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield yet another embodiment. Accordingly, the present invention is intended to cover such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0020] Exemplary aspects of the present disclosure relate to a plasma processing apparatus. The plasma processing apparatus can include a multi-head processing chamber. For example, the processing chamber can be divided into a plurality of processing regions. Each of the processing regions can include a susceptor assembly configured to support a workpiece. Further, gas can be provided to respective workspaces in the working space via separate gas feeds. For example, a first gas feed can provide gas to a first processing region of the multi-head processing chamber at a first head of the multi-head processing chamber. Conversely, a second gas feed can provide gas to a second processing region of the multi-head processing chamber at a second head of the multi-head processing chamber.

[0021] A plasma processing apparatus may include a throttle valve that is movable between at least a first position (e.g., fully open) and a second position (e.g., fully closed) to control the delivery of gas to each head of a multi-head processing chamber. For example, when the throttle valve is in the first position, gas may flow into each processing area in the processing region. Conversely, when the throttle valve is in the second position, gas cannot flow into the processing region. In some instances, the throttle valve may not be fully open or fully closed. When this occurs, a pressure difference is created because the pressure of the first gas flow entering the first processing area at the first head is different from (e.g., greater than, less than) the pressure of the second gas flow entering the second area at the second head. For example, this pressure difference may cause non-uniformity when processing one or more workpieces being processed in the corresponding processing chamber.

[0022] Example aspects of the present disclosure relate to a pressure control system for a plasma processing apparatus having a multi-head processing chamber. The pressure control system may include a pumping port located downstream of the heads of the multi-head processing chamber. For example, the pumping port may be coupled to the floor of the multi-head processing chamber, while each of the heads in the multi-head processing chamber may be located at the ceiling (e.g., top plate) of the multi-head processing chamber.

[0023] The pressure control system may include a member that is at least partially located within the pumping port. For example, in some implementations, the member may include a baffle that is rotatable relative to the pumping port. Further, in some implementations, the range of motion of the baffle may be approximately 180 degrees.

[0024] The pressure control system may include a plurality of pressure sensors. For example, the pressure control system may include a first pressure sensor configured to obtain data indicative of the pressure of a first gas flow entering a first processing area at a first head of the plasma processing apparatus. The pressure control system may also include a second pressure sensor configured to obtain data indicative of the pressure of a second gas flow entering a second processing area at a second head of the plasma processing apparatus. In some implementations, both the first pressure sensor and the second pressure sensor may include pressure gauges.

[0025] The pressure control system may include an actuator configured to move the member. For example, in some implementations, the actuator may be configured to rotate the member about a rotational axis in a first direction (e.g., clockwise) or a second direction (e.g., counterclockwise). The actuator may be configured to rotate the member in the first direction or the second direction based on at least one of the first data obtained from the first pressure sensor or the second data obtained from the second pressure sensor.

[0026] In some implementations, only one processing area in the processing area of the multi-head processing chamber may be occupied. For example, a workpiece may be disposed on a base assembly associated with a first processing area of the multi-head processing chamber, while every other processing area of the multi-head processing chamber may be vacant (i.e., not occupied by a workpiece). Further, since only the first processing area of the multi-head processing chamber is occupied, gas may be injected into the first processing area only at the first head of the first processing area. In such an implementation, the actuator may be configured to rotate the member in a first direction or a second direction based at least in part on data obtained from a first pressure sensor configured to obtain data indicative of the pressure of an airflow entering the processing area at the first head of the multi-head processing chamber.

[0027] In some implementations, multiple processing areas of the multi-head processing chamber may be occupied. For example, a first workpiece may be disposed on a base assembly associated with a first processing area, while a second workpiece may be disposed on a base assembly associated with a second processing area. In such an implementation, gas may be injected into the first processing area at the first head of the multi-head processing chamber. Additionally, gas may be injected into the second processing area at the second head of the multi-head processing chamber. As discussed below, the actuator may rotate the member about a rotation axis in a first direction or a second direction to control the pressure difference between the pressure of the airflow entering the first processing area at the first head of the multi-head processing chamber and the pressure of the airflow entering the second processing area at the second head of the multi-head processing chamber.

[0028] In some implementations, the actuator may rotate the member about a rotation axis in a first direction or a second direction to eliminate or reduce the pressure difference. For example, the actuator may be configured to rotate the member in a first direction or a second direction until first data obtained from a first pressure sensor and second data obtained from a second pressure sensor indicate that the pressure of the airflow entering the first processing area at the first head of the multi-head processing chamber matches the pressure of the airflow entering the second processing area at the second head of the multi-head processing chamber. In this way, the pressure control system may monitor the pressure difference in real time or near real time and operate the actuator accordingly to eliminate the pressure difference in order to prevent or reduce non-uniformities during the processing of workpieces (e.g., the first workpiece and the second workpiece) being processed in the multi-head processing chamber.

[0029] In some implementations, the actuator can rotate the member about the axis of rotation in a first direction or a second direction to create a desired pressure differential between the pressure at the first head of the gas flow entering the first processing region at the first head of the multi-head processing chamber and the pressure of the gas flow entering the second processing region at the second head of the multi-head processing chamber. For example, in some implementations, the actuator can be configured to rotate the member in a first direction or a second direction until the first data obtained from the first pressure sensor and the second data obtained from the second pressure sensor indicate that the pressure differential matches a predefined pressure differential greater than zero.

[0030] The pressure control system according to the example aspects of the present disclosure can have several technical effects and benefits. For example, pressure sensors located at each head of the multi-head processing chamber can obtain data that can be used to determine the pressure differential occurring between the two heads of the multi-head processing chamber. Further, a member at least partially within the pumping port downstream of the head of the multi-head processing chamber can be moved (e.g., rotated) as needed to control the pressure differential. In this way, since the pressure differential can be controlled in real time or near real time, non-uniformities caused at least in part by the pressure differential during processing of the workpiece can be reduced.

[0031] For purposes of illustration and discussion, aspects of the present disclosure are discussed with reference to a "substrate" or "wafer". Those of ordinary skill in the art using the present disclosure provided herein should understand that the example aspects of the present disclosure can be used in association with any semiconductor substrate or other suitable substrate or workpiece. Further, as used herein, the terms "substantially" and "about" refer to a range of values within ten percent of the specified value.

[0032] Now, referring to the drawings, Figure 1 a plasma processing apparatus 100 according to an example embodiment of the present disclosure is depicted. For purposes of illustration and discussion, the present disclosure is discussed with reference to Figure 1 the depicted plasma processing apparatus 100. Those of ordinary skill in the art using the present disclosure provided herein should understand that, without departing from the scope of the present disclosure, the example aspects of the present disclosure can be used with other processing tools and / or apparatuses such as plasma strip tools, heat treatment tools, and the like.

[0033] The plasma processing apparatus 100 includes a multi-head processing chamber 101. The interior of the multi-head processing chamber 101 may at least include a first processing region 102 and a second processing region 103. In some implementations, the plasma processing apparatus 100 may include a first susceptor assembly 104 and a second susceptor assembly 106. The first susceptor assembly 104 may be configured to support a first workpiece 108 (e.g., a semiconductor wafer) for processing within the first processing region 102. The second susceptor assembly 106 may be configured to support a second workpiece 109 (e.g., a semiconductor wafer) for processing within the second processing region 103. In an alternative implementation, the plasma processing apparatus 100 may include a common susceptor assembly to support both the first workpiece 108 and the second workpiece 109.

[0034] The plasma processing apparatus 100 may include a first dielectric window 110 and a second dielectric window 112. The first dielectric window 110 may define the top of the first processing region 102. The second dielectric window 112 may define the top of the second processing region 103. In some implementations, the first dielectric window 110 and the second dielectric window 112 may each include a relatively flat central portion 114 and an angled peripheral portion 116. Alternatively or additionally, the first dielectric window 110 and the second dielectric window 112 may include a dielectric material, such as a quartz material.

[0035] The plasma processing apparatus 100 may include a first showerhead 120 and a second showerhead 122. The first showerhead 120 and the second showerhead 122 may each be in fluid communication with a gas supply 124. The first showerhead 120 may extend into a first opening 117 defined by the central portion 114 of the first dielectric window 110. In this way, the first showerhead 120 may supply process gas into the first processing region 102. The second showerhead 122 may extend into a second opening 118 defined by the central portion 114 of the second dielectric window 112. In this way, the second showerhead 122 may supply process gas into the second processing region 103.

[0036] The plasma processing apparatus 100 may include a throttle valve 126. The throttle valve 126 may be fluidly coupled between the gas supply unit 124 and the first showerhead 120. Additionally, the throttle valve 126 may be fluidly coupled between the gas supply unit 124 and the second showerhead 122. Further, the throttle valve 126 may move between at least a first position (e.g., fully open) and a second position (e.g., fully closed) to control the gas flow from the gas supply unit to the first showerhead 120 and the second showerhead 122. For example, when the throttle valve 126 is in the first position (e.g., fully open), gas may flow from the gas supply unit 124 to each of the first showerhead 120 and the second showerhead 122. Conversely, when the throttle valve 126 is in the second position (e.g., fully closed), gas cannot flow from the gas supply unit 124 to each of the first showerhead 120 and the second showerhead 122.

[0037] The plasma processing apparatus 100 further includes one or more inductive elements, such as a primary inductive element 130 and an optional secondary inductive element 140, for generating inductive plasma in the first processing region 102 and the second processing region 103. The inductive elements 130, 140 may include coils or antenna elements that, when supplied with RF power, induct a plasma in the process gas in the first processing region 102 and the second processing region 103. For example, the first RF generator 160 may be configured to provide electromagnetic energy to the primary inductive element 130 through a matching network 162. The second RF generator 170 may be configured to provide electromagnetic energy to the secondary inductive element 140 through a matching network 172.

[0038] Although the present disclosure refers to a primary inductive element and a secondary inductive element, those of ordinary skill in the art should appreciate that the terms primary and secondary are for convenience only. The secondary coil may operate independently of the primary coil. The primary coil may operate independently of the secondary coil. Additionally, in some embodiments, the plasma processing apparatus may have only a single inductive coupling element.

[0039] In accordance with aspects of the present disclosure, the plasma processing apparatus 100 may include a metal shielding portion 152 disposed around the secondary inductive element 140. The metal shielding portion 152 separates the primary inductive element 130 and the secondary inductive element 140 to reduce crosstalk between the inductive elements 130, 140. The plasma processing apparatus 100 may further include a first Faraday shield 154 disposed between the primary inductive element 130 and the dielectric windows (e.g., the first dielectric window 110 and the second dielectric window 112). The first Faraday shield 154 may be a slotted metal shield that reduces capacitive coupling between the primary inductive element 130 and the multi-head processing chamber 101 (e.g., the first processing region 102, the second processing region 103). As illustrated, the first Faraday shield 154 may be mounted on the angled portions of the dielectric windows 110, 112.

[0040] In some implementations, the metal shielding portion 152 and the first Faraday shield 154 may form an integrated metal shield / Faraday shield 150 for ease of manufacturing and other purposes. The multi-turn coil of the primary inductive element 130 may be positioned adjacent to the first Faraday shield 154 of the integrated metal shield / Faraday shield 150. The secondary inductive element 140 may be positioned adjacent to the metal shielding portion 152 of the metal shield / Faraday shield unitary body 150, such as between the metal shielding portion 152 and the dielectric windows 110, 112.

[0041] The arrangement of the primary inductive element 130 and the secondary inductive element 140 on opposite sides of the metal shielding portion 152 allows the primary inductive element 130 and the secondary inductive element 140 to have different structural configurations and perform different functions. For example, the primary inductive element 130 may include a multi-turn coil that is positioned adjacent to the peripheral portion of the multi-head processing chamber 101. The primary inductive element 130 may be used for basic plasma generation and reliable startup during the inherent transient ignition phase. The primary inductive element 130 may be coupled to a powerful RF generator and an expensive automatic tuning matching network, and may operate at an increasing RF frequency (such as about 13.56 MHz).

[0042] The secondary inductive element 140 can be used for correction and support functions and for enhancing the stability of the plasma during steady-state operation. Since the secondary inductive element 140 can be primarily used for correction and support functions and for enhancing the stability of the plasma during steady-state operation, the secondary inductive element 140 does not have to be coupled to an RF generator as powerful as the primary inductive element 130 and can be designed in a different and cost-effective manner to overcome the difficulties associated with prior designs. As discussed in detail below, the secondary inductive element 140 can also operate at a lower frequency (such as about 2 MHz), thereby allowing the secondary inductive element 140 to be very compact and fit into the limited space at the top of the dielectric window.

[0043] The primary inductive element 130 and the secondary inductive element 140 can operate at different frequencies. The frequencies can be sufficiently different to reduce crosstalk in the plasma between the primary inductive element 130 and the secondary inductive element 140. For example, the frequency applied to the primary inductive element 130 can be at least about 1.5 times the frequency applied to the secondary inductive element 140. In some implementations, the frequency applied to the primary inductive element 130 can be about 13.56 MHz, while the frequency applied to the secondary inductive element 140 can be in the range of about 1.75 MHz to about 2.15 MHz. Other suitable frequencies can also be used, such as about 400 kHz, about 4 MHz, and about 27 MHz. Although the present disclosure is discussed with reference to the primary inductive element 130 operating at a higher frequency relative to the secondary inductive element 140, those of ordinary skill in the art using the present disclosure provided herein should understand that the secondary inductive element 140 can operate at a higher frequency without departing from the scope of the present disclosure.

[0044] The secondary inductive element 140 can include a planar coil 142 and a flux concentrator 144. The flux concentrator 144 can be made of a ferrite material. Using a flux concentrator with an appropriate coil can provide high plasma coupling and good energy transfer efficiency for the secondary inductive element 140 and can significantly reduce its coupling to the metal shield 150. Using a lower frequency, such as about 2 MHz, can increase the skin layer on the secondary inductive element 140, which also improves the plasma heating efficiency.

[0045] According to aspects of the present disclosure, different inductive elements 130, 140 can carry out different functions. Specifically, the primary inductive element 130 can be used for the basic function of plasma generation during ignition and provide sufficient loading to the secondary inductive element 140. The primary inductive element 130 can be coupled to both the plasma and the ground shield to stabilize the plasma potential. The first Faraday shield 154 associated with the primary inductive element 130 prevents window sputtering and can be used for the coupling to the ground.

[0046] Additional coils can operate in the presence of good plasma startup provided by the primary inductive element 130 and thus preferably have good plasma coupling and good energy transfer efficiency to the plasma. The secondary inductive element 140 including the flux concentrator 144 provides good transfer of magnetic flux to the plasma volume while providing good decoupling of the secondary inductive element 140 from the surrounding metal shield 150. Using the flux concentrator 144 and symmetrically driving the secondary conductive element 140 further reduces the voltage amplitude between the coil ends and the surrounding grounded elements. This can reduce dome sputtering but at the same time provides some small capacitive coupling to the plasma which can be used to assist ignition. In some implementations, a second Faraday shield can be used in combination with the secondary inductive element 140 to reduce the capacitive coupling of the secondary inductive element 140.

[0047] The plasma processing apparatus 100 can include a pump assembly 200. The pump assembly 200 can include a pump 210 and a pumping port 220. The pump 210 can be fluidly coupled to the multi-head processing chamber 101 through the pumping port 220. In this way, the pump 210 can be configured to draw gas from the multi-head processing chamber 101 via the pumping port 220. For example, the pump can be operated to draw gas from the first processing region 102, the second processing region 103, or both.

[0048] In some implementations, the pump 210 can be a turbomolecular pump having multiple stages. Each stage of the multiple stages can include rotor blades and fixed stator blades. The turbomolecular pump can draw in gas at the uppermost stage (e.g., from the multi-head processing chamber 101) and push the gas through the successive stages of the turbomolecular pump.

[0049] In some implementations, the pump assembly 200 may include a pressure sensor (e.g., a pressure gauge) located at the inlet of the pumping port 220. In this way, the pressure sensor 230 may be configured to measure the pressure of the combined gas flow (e.g., the gas withdrawn from the first processing area 102 and the gas withdrawn from the second processing area 103). In some implementations, the throttle valve 125 may be controlled at least in part based on data obtained from the pressure sensor. However, since the pressure sensor is located at the inlet of the pumping port 220 downstream of both the first head and the second head, the data obtained from the pressure sensor 230 does not indicate the pressure difference between the pressure of the gas flow entering the first processing area 102 via the first showerhead 120 and the pressure of the gas flow entering the second processing area 103 via the second showerhead 122, at least in part due to the throttle valve 125 being in the intermediate third position. As discussed below, various example aspects of the present disclosure relate to a pressure control system for controlling the pressure difference to reduce or eliminate non-uniformities caused at least in part by the pressure difference when processing a workpiece (e.g., the first workpiece 108 and the second workpiece 109).

[0050] Now, referring to Figure 2 and Figure 3 , there is provided a pressure control system 300 for a multi-head processing chamber 302 according to an example embodiment of the present disclosure. In some implementations, the multi-head processing chamber 302 may include a top plate 304 that defines a first head 306 and a second head 308. In alternative implementations, the top plate 304 may define more than two heads (e.g., a first head 306 and a second head 308). It should be understood that gas may be injected into the multi-head processing chamber 302 at the first head 306 and the second head 308. For example, gas may be injected into the multi-head processing chamber 302 at the first head 306 via a first gas delivery device (e.g., the first showerhead 120). Conversely, gas may be injected into the multi-head processing chamber 302 at the second head 308 via a second gas delivery device (e.g., the second showerhead).

[0051] As shown, the pressure control system 300 may include a member 310 that is at least partially located within the pumping port 220. Further, the member 310 may be movable relative to the pumping port 220. The pressure control system 300 may also include a plurality of pressure sensors 320. For example, the pressure control system 300 may include a first pressure sensor 322 that is configured to obtain an indication of the pressure at the first head 306 of the multi-head processing chamber 302 entering the first processing area .................. Figure 1) the data of the pressure of the airflow. The pressure control system 300 may further include a second pressure sensor 324 configured to obtain data indicating the pressure of the airflow entering the second processing area 103 at the second head 308 of the multi-head processing chamber 302 ( Figure 1 ) the data of the pressure of the airflow. It should be understood that the first pressure sensor 322 and the second pressure sensor 324 may include any suitable type of pressure sensor. For example, in some implementations, the first pressure sensor 322 and the second pressure sensor 324 may each include a pressure gauge.

[0052] In some implementations, the pressure control system 300 may include a third pressure sensor 326. For example, the third pressure sensor 326 may be located at the inlet of the pumping port 220. In this way, the third pressure sensor 326 may be configured to measure the pressure of the airflow drawn out of the multi-head processing chamber 302.

[0053] As shown, the pressure control system 300 may include an actuator 330 configured to move the member 310. The actuator 330 may be configured to rotate the member 310 about a rotation axis in a first direction (e.g., clockwise) or a second direction (e.g., counterclockwise). For example, the actuator 330 may be configured to rotate the member 310 in the first direction or the second direction based at least in part on the first data obtained from the first pressure sensor 322, the second data obtained from the second pressure sensor 324, or both. As discussed below, the actuator 330 may rotate the member 310 in the first direction or the second direction to control the pressure difference between the pressure of the airflow entering the first processing area of the multi-head processing chamber 302 and the pressure of the airflow entering the second processing area of the multi-head processing chamber 302.

[0054] In some implementations, the actuator 330 may rotate the member 310 in the first direction or the second direction to eliminate or reduce the pressure difference. For example, the actuator 330 may be configured to rotate the member 310 in the first direction or the second direction until the first data obtained from the first pressure sensor 322 and the second data obtained from the second pressure sensor 324 indicate that the pressure of the airflow entering the multi-head processing chamber 302 at the first head 306 of the multi-head processing chamber 302 matches the pressure of the airflow entering the multi-head processing chamber 302 at its second head 308. In this way, the pressure control system 300 can monitor the pressure difference in real time or near real time, and operate the actuator 330 as needed to move the member 310 to reduce or eliminate the pressure difference, thereby preventing or reducing non-uniformity during the processing of the workpiece being processed in the multi-head processing chamber 302.

[0055] In some implementations, the actuator 330 may rotate the member 310 in a first direction or a second direction to generate a pressure difference between the pressure of the gas flow entering the multi-head processing chamber 302 at the first head 306 of the multi-head processing chamber 302 and the pressure of the gas flow entering the multi-head processing chamber 302 at the second head 308 of the multi-head processing chamber 302. For example, in some implementations, the actuator 330 may be configured to rotate the member 310 in a first direction or a second direction until the first data obtained from the first pressure sensor 322 and the second data obtained from the second pressure sensor 324 indicate that the pressure difference matches a predefined pressure difference.

[0056] In some implementations, the pressure control system 300 may include one or more control devices 350. As shown, the one or more control devices 350 may include one or more processors 352 configured to perform various computer-implemented functions (e.g., execute the methods, steps, calculations, etc. disclosed herein). As used herein, the term "processor" refers not only to integrated circuits known in the art as being included in a computer, but also to controllers, microcontrollers, microcomputers, programmable logic controllers (PLCs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), and other programmable circuits.

[0057] In some implementations, the one or more control devices 350 may include one or more memory devices 354. Examples of the one or more memory devices 354 may include computer-readable media, which include but are not limited to non-transitory computer-readable media, such as RAM, ROM, hard disk drives, flash drives, or other suitable memory devices. The one or more memory devices 354 may store information accessible by the one or more processors 352, which includes computer-readable instructions executable by the one or more processors 352. The computer-readable instructions may be any set of instructions that, when executed by the one or more processors 352, cause the one or more processors 352 to perform operations, such as controlling the operation of the actuator 330 at least partially based on data obtained from one or more of the pressure sensors 320. The computer-readable instructions may be software written in any suitable programming language or may be implemented in hardware.

[0058] In some implementations, one or more control devices 350 may include a communication module 356 to facilitate communication between the one or more control devices 350 and various components of the pressure control system 300. For example, the one or more control devices 350 may send control signals to control the operation of the actuator 330 of the pressure control system 300. Further, the control signals may be at least partially based on the first data obtained from the first pressure sensor 322, the second data obtained from the second pressure sensor 324, or both.

[0059] In some implementations, the communication module 356 may include a sensor interface 358 to permit conversion of signals transmitted from the pressure sensor 320 into signals that can be understood and processed by the one or more control devices 350. For example, the pressure sensor 320 may be communicatively coupled to the sensor interface 358 via a wired communication link or a wireless communication link. In this manner, the one or more control devices 350 may receive data associated with the pressure sensor 320.

[0060] Now, referring Figure 4 , in some implementations, the member 310 may include a shaft 312 that extends along a rotational axis A between a first end 314 and a second end 316 of the shaft 312. As shown, the first end 314 of the shaft 312 may be located within a first protrusion 222 of the pumping port 220, while the second end 316 of the shaft 312 may extend through a second protrusion 224 of the pumping port 220. As shown, the first protrusion 222 and the second protrusion 224 may be circumferentially spaced from each other. In some implementations, the first protrusion 222 may be capped to prevent the first end 314 of the shaft 312 from extending therethrough. In contrast, in some implementations, the second protrusion 224 may be open (i.e., uncapped) to allow the second end 316 of the shaft 312 to extend therethrough. In an alternative implementation, the actuator 330 may include a cap 360 that is configured to seal an open end of the second protrusion 224 on the pumping port 220. In this manner, the interior of the pumping port 220 may be sealed from the external environment via the cap 360.

[0061] In some implementations, the actuator 330 may include a magnet assembly. For example, the actuator 330 may include a first magnetic coupler 332 and a second magnetic coupler 334. The first magnetic coupler 332 and the second magnetic coupler 334 may each have an annular body 333, 335. Further, the first magnetic coupler 332 and the second magnetic coupler 334 may each include a plurality of magnets 336. As shown, each of the plurality of magnets 336 may be located within a corresponding recess of the plurality of recesses defined by the annular bodies 333, 335. In some implementations, the annular bodies 333, 335 may be magnetic shields.

[0062] The size of the first magnetic coupler 332 may be designed such that the first magnetic coupler 332 can be located within the second protrusion 224 of the pumping port 220. In contrast, the size of the second magnetic coupler 334 may be designed such that the second magnetic coupler 334 slides on the outer surface of the second protrusion 224. It should be understood that each of the plurality of magnets 336 associated with the second magnetic coupler 334 may be magnetically coupled to a corresponding magnet 336 of the plurality of magnets 336 associated with the first magnetic coupler 332. In this way, the magnets 336 can drive the member 310 to rotate about the rotation axis A in a first direction (e.g., clockwise) or a second direction (e.g., counterclockwise).

[0063] Now, referring Figure 5A , Figure 5B and Figure 5C , the member 310 may rotate relative to the partition wall 225 of the pumping port 220 that divides the inlet of the pumping port 220 into a first inlet 226 and a second inlet 228. When the member 310 rotates about the rotation axis A in a first direction D1 (e.g., clockwise) to a first position P1, the member 310 may block the first inlet 226. In this way, gas cannot flow through the pumping port 220 via its first inlet 226. In contrast, when the member 310 rotates about the rotation axis A in a second direction D2 (e.g., counterclockwise) to a second position P2, the member 310 may block the second inlet 228. Further, the member 310 may rotate about the rotation axis A in a first direction D1 or a second direction D2 to an intermediate third position P3, in which the member 310 blocks neither the first inlet 226 nor the second inlet 228.

[0064] Now, referring Figure 6 , a flowchart of a control method 400 for operating a pressure control system of a multi-head processing chamber of a plasma processing apparatus according to an exemplary embodiment of the present disclosure is provided. It should be appreciated that the method 400 may be implemented using the pressure control system 300 discussed above with reference to Figure 2 and Figure 3 .Figure 6 Illustrates steps performed in a particular order for purposes of illustration and discussion. A person of ordinary skill in the art using the present disclosure provided herein should understand that the various steps of method 400 can be adopted, modified, rearranged, performed simultaneously, or otherwise modified without departing from the scope of the present disclosure.

[0065] At (402), method 400 can include: obtaining first data from a first pressure sensor of a pressure control system via one or more control devices. For example, the first data can indicate the pressure of a first gas flow at a first head of a multi-head processing chamber. In some implementations, the first pressure sensor can be a pressure gauge.

[0066] At (404), method 400 can include: obtaining second data from a second pressure sensor via one or more control devices. For example, the second data can indicate a second gas flow at a second head of the multi-head processing chamber. In some implementations, the second pressure sensor can be a pressure gauge.

[0067] At (406), method 400 can include: providing one or more control signals via one or more control devices based on the first data obtained at (402), the second data obtained at (404), or both. For example, the one or more control signals can be associated with a rotating member (e.g., a baffle) that is at least partially located within a pumping port that is fluidly coupled between the multi-head processing chamber and a pump configured to draw gas from the multi-head processing chamber.

[0068] In some implementations, only one of the processing areas in the processing area of the multi-head processing chamber can be occupied. For example, a workpiece can be disposed on a base assembly associated with a first processing area of the multi-head processing chamber, while every other processing area of the multi-head processing chamber can be vacant (i.e., not occupied by a workpiece). Further, since only the first processing area of the multi-head processing chamber is occupied, gas can be injected into the first processing area at the first head of the multi-head processing chamber. In such an implementation, providing the one or more control signals can include: providing the one or more control signals to an actuator configured to rotate the member in a first direction or a second direction at least partially based on the one or more control signals to adjust the pressure of the gas flow entering the multi-head processing chamber at the first head of the multi-head processing chamber.

[0069] In some implementations, multiple processing regions of a multi-head processing chamber can be occupied. For example, a first workpiece can be disposed on a pedestal assembly associated with a first processing region, while a second workpiece can be disposed on a pedestal assembly associated with a second processing region. In such an implementation, gas can be injected into the first processing region at a first head of the multi-head processing chamber. Additionally, gas can be injected into the second processing region at a second head of the multi-head processing chamber. As discussed below, providing one or more control signals at (406) can include: providing one or more control signals to an actuator configured to rotate a member about a rotational axis in a first direction or a second direction at least partially based on the one or more control signals to control a pressure difference between an airflow entering the first processing region at the first head of the multi-head processing chamber and an airflow entering the second processing region at the second head of the multi-head processing chamber.

[0070] In some implementations, the actuator can rotate the member about the rotational axis in a first direction or a second direction to eliminate or reduce the pressure difference. For example, the actuator can be configured to rotate the member in a first direction or a second direction until first data obtained from a first pressure sensor and second data obtained from a second pressure sensor indicate that the pressure of the airflow entering the first processing region matches the pressure of the airflow entering the second processing region. In this way, the pressure control system can monitor the pressure difference in real time or near real time and accordingly operate the actuator to eliminate the pressure difference in order to prevent or reduce non-uniformities during processing of workpieces (e.g., the first workpiece and the second workpiece) being processed in the multi-head processing chamber.

[0071] In some implementations, the actuator can rotate the member about the rotational axis in a first direction or a second direction to cause a desired pressure difference between the pressure of the airflow entering the first processing region and the pressure of the airflow entering the second processing region. For example, in some implementations, the actuator can be configured to rotate the member in a first direction or a second direction until first data obtained from a first pressure sensor and second data obtained from a second pressure sensor indicate that the pressure difference matches a predefined pressure difference greater than zero.

[0072] Figure 7 A plasma processing apparatus 500 in accordance with another exemplary embodiment of the present disclosure is depicted. The plasma processing apparatus 500 includes a processing chamber 510 and a first plasma chamber 520 (e.g., a first plasma head) separate from the processing chamber 510. The plasma processing apparatus 500 can include a second plasma chamber 540 (e.g., a second plasma head) that can be substantially the same as the first plasma chamber 520. A top plate 524 can be disposed above the first plasma chamber 520 and the second plasma chamber 540.

[0073] The first plasma chamber 520 may include a dielectric sidewall 521. The top plate 524 and the dielectric sidewall 521 may form the interior 525 of the first plasma chamber. The dielectric sidewall 521 may be formed of any suitable dielectric material such as quartz.

[0074] The plasma processing apparatus 500 may include a first inductively coupled plasma source 535 configured to generate a plasma in a process gas supplied to the interior 525 of the first plasma chamber. The first inductively coupled plasma source 535 may include an inductive coil 530 disposed around the dielectric sidewall 521. The inductive coil 530 may be coupled to an RF power generator 534 through a suitable matching network 532. Reactants and / or carrier gas may be supplied to the chamber interior from a gas supply (not shown). When the inductive coil 530 is excited with RF power from the RF power generator 534, a substantially inductive plasma is induced in the interior 525 of the first plasma chamber. In some embodiments, the first plasma chamber 520 may include a grounded Faraday shield to reduce capacitive coupling between the inductive coil 530 and the plasma.

[0075] The second plasma chamber 540 may include a dielectric sidewall 542. The top plate 524 and the dielectric sidewall 542 may form the interior 545 of the second plasma chamber. The dielectric sidewall 542 may be formed of any suitable dielectric material such as quartz.

[0076] The plasma processing apparatus 500 may include a second inductively coupled plasma source 555 configured to generate a plasma in a process gas supplied to the interior 545 of the second plasma chamber. The second inductively coupled plasma source 555 may include an inductive coil 550 disposed around the dielectric sidewall 542. The inductive coil 550 may be coupled to an RF power generator 554 through a suitable matching network 552. Reactants and / or carrier gas may be supplied to the interior 545 of the second plasma chamber from a gas supply (not shown). When the inductive coil 550 is excited with RF power from the RF power generator 554, a substantially inductive plasma is induced in the interior 545 of the second plasma chamber. In some embodiments, the second plasma chamber 540 may include a grounded Faraday shield to reduce capacitive coupling between the inductive coil 550 and the plasma.

[0077] The first separation grid 516 can separate the first plasma chamber 520 from the processing chamber 510. The first separation grid 516 can be used to perform ion filtering on the particles generated by the plasma in the first plasma chamber 520. The particles passing through the first separation grid 516 can be exposed to a workpiece (e.g., a semiconductor wafer) in the processing chamber for surface treatment of the workpiece (e.g., photoresist removal).

[0078] More specifically, in some embodiments, the first separation grid 516 can be transparent to neutral substances but opaque to charged particles from the plasma. For example, charged particles or ions can recombine on the walls of the first separation grid 516. The first separation grid 516 can include one or more grid plates of a material, and the holes of the grid plates are distributed according to the hole pattern of each piece of material. The hole patterns of the respective grid plates can be the same or different.

[0079] For example, the holes can be distributed on a plurality of grid plates arranged in a substantially parallel configuration according to a plurality of hole patterns such that no hole can be directly seen between the plasma chamber and the processing chamber, for example, to reduce or block UV rays. Depending on the process, some or all of the grids in the grid can be made of a conductive material (e.g., Al, Si, SiC, etc.) and / or a non-conductive material (e.g., quartz, etc.). In some embodiments, if a portion of the grid (e.g., a grid plate) is made of a conductive material, that portion of the grid can be grounded.

[0080] The second separation grid 566 can separate the second plasma chamber 540 from the processing chamber 510. The second separation grid 566 can be used to perform ion filtering on the particles generated by the plasma in the second plasma chamber 540. The particles passing through the second separation grid 566 can be exposed to a workpiece (e.g., a semiconductor wafer) in the processing chamber for surface treatment of the workpiece (e.g., photoresist removal).

[0081] More specifically, in some embodiments, the second separation grid 566 can be transparent to neutral substances but opaque to charged particles from the plasma. For example, charged particles or ions can recombine on the walls of the second separation grid 566. The second separation grid 566 can include one or more grid plates of a material, and the holes of the grid plates are distributed according to the hole pattern of each piece of material. The hole patterns of the respective grid plates can be the same or different.

[0082] For example, the holes may be distributed among a plurality of grid plates arranged in a substantially parallel configuration such that no hole is in direct line of sight between the plasma chamber and the processing chamber to, for example, reduce or block UV rays. Depending on the process, some or all of the grids may be made of a conductive material (e.g., Al, Si, SiC, etc.) and / or a non-conductive material (e.g., quartz, etc.). In some embodiments, if a portion of the grid (e.g., a grid plate) is made of a conductive material, that portion of the grid may be grounded.

[0083] To improve azimuthal uniformity, the plasma processing apparatus 500 may include a first susceptor 512 (e.g., a heated susceptor) that defines a first processing station for supporting a first workpiece 514 below a first plasma chamber 520 to process the first workpiece 514. The plasma processing apparatus 500 may also include a second susceptor 522 (e.g., a heated susceptor) that defines a second processing station for supporting a second workpiece 523 below a second plasma chamber 540 to process the second workpiece 254 at the second processing station. The first susceptor 512 is separated from the second susceptor 522 such that no solid material connects the first susceptor 512 and the second susceptor 522.

[0084] In some embodiments, an optional wall 541 may divide the processing chamber 510 into a first processing region 511 and a second processing region 513. In this way, the wall 541 may separate the first susceptor 512 and the second susceptor 522 such that the first susceptor 512 is disposed within the first processing region 511 and the second susceptor 522 is disposed within the second processing region 513. The wall 541 may include a wall temperature regulation system 543. The wall temperature regulation system 543 may include one or more heating elements. Alternatively or additionally, the wall temperature regulation system 543 may include one or more cooling channels that are operable to circulate a fluid through the wall.

[0085] As shown, the plasma processing apparatus 500 may include the pumping assembly discussed above with reference to Figure 1 For example, the pump 210 may be fluidly coupled to the processing chamber 510 via a pumping port 220. In this way, the pump 210 may be configured to pump gas out of the processing chamber 510.

[0086] Without departing from the spirit and scope of the present invention, those of ordinary skill in the art may implement these and other modifications and variations of the present invention, which are more particularly set forth in the appended claims. Additionally, it should be understood that aspects of the various embodiments may be interchanged in whole or in part. Further still, those of ordinary skill in the art should appreciate that the foregoing description is by way of example only and is not intended to limit the present invention as further described in the appended claims.

Claims

1. A pressure control system, comprising: a member, at least partially located within a pumping port, the pumping port being fluidly coupled between a multi-head processing chamber and a pump, the pump being configured to extract gas from the multi-head processing chamber, the member being rotatable relative to the pumping port, the member including a shaft having a first end extending through a first protrusion of the pumping port and a second end extending through a second protrusion of the pumping port; a plurality of pressure sensors, each of the pressure sensors being configured to obtain data indicative of the pressure of an airflow entering the multi-head processing chamber at a corresponding head of the multi-head processing chamber; and an actuator, configured to rotate the member to control the pressure of the airflow at a first head of the multi-head processing chamber, the actuator being positioned adjacent the second end of the shaft, the actuator including a first magnetic coupler, a cover, and a second magnetic coupler.

2. The pressure control system according to claim 1, wherein the actuator is configured to rotate the member in a first direction or a second direction to control the pressure of the airflow at the first head of the multi-head processing chamber.

3. The pressure control system according to claim 1, wherein the actuator is configured to rotate the member to control a pressure difference between the pressure of the airflow at the first head of the multi-head processing chamber and the pressure of the airflow at a second head of the multi-head processing chamber.

4. The pressure control system according to claim 3, wherein the actuator is configured to rotate the member in a first direction or a second direction to reduce the pressure difference from a first value to a second value, the second value being greater than zero.

5. The pressure control system according to claim 3, wherein the actuator is configured to rotate the member in a first direction or a second direction to increase the pressure difference from a first value to a second value.

6. The pressure control system according to claim 1, wherein each of the pressure sensors includes a pressure gauge.

7. The pressure control system according to claim 1, wherein the first magnetic coupler is located within the second protrusion, and the second magnetic coupler surrounds an outer surface of the second protrusion.

8. The pressure control system according to claim 7, wherein both the first magnetic coupler and the second magnetic coupler include a magnetic shield and a plurality of magnets, each of the magnets being located within a corresponding one of a plurality of recesses defined by the magnetic shield.

9. An operation control method for a pressure control system of a multi-head processing chamber of a plasma processing apparatus, the method comprising: obtaining first data from a first pressure sensor of the pressure control system by one or more control devices, the first data indicative of the pressure of an airflow entering the multi-head processing chamber via a first head of the multi-head processing chamber; and One or more control signals are provided to an actuator by the one or more control devices at least partially based on the first data, the actuator being configured to rotate a member at least partially located within a pumping port, the pumping port being fluidly coupled between the multi-head processing chamber and a pump, the pump being configured to extract gas from the multi-head processing chamber, the member including a shaft having a first end extending through a first protrusion of the pumping port and a second end extending through a second protrusion of the pumping port, the actuator being positioned near the second end of the shaft, the actuator including a first magnetic coupler, a cover, and a second magnetic coupler.

10. The method according to claim 9, further comprising: Obtaining second data from a second pressure sensor of the pressure control system by the one or more control devices, the second data indicating the pressure of the airflow entering the multi-head processing chamber via a second head of the multi-head processing chamber.

11. The method according to claim 10, wherein providing one or more control signals comprises: Providing the one or more control signals by the one or more control devices at least partially based on the first data and the second data to control a pressure difference between the airflow entering the multi-head processing chamber via the first head and the airflow entering the multi-head processing chamber via the second head.

12. The method according to claim 11, wherein providing one or more control signals comprises: Providing the one or more control signals by the one or more control devices to rotate the member so as to eliminate the pressure difference.

13. The method according to claim 11, wherein providing one or more control signals comprises: Providing the one or more control signals by the one or more control devices to rotate the member so as to increase the pressure difference from a first value to a second value.

14. A plasma processing apparatus, comprising: A multi-head processing chamber; A pumping port fluidly coupled to the multi-head processing chamber; A pump fluidly coupled to the multi-head processing chamber via the pumping port, the pump being configured to extract gas from the multi-head processing chamber via the pumping port; And A pressure control system, comprising: A member at least partially located within the pumping port, the member being rotatable relative to the pumping port, the member including a shaft having a first end extending through a first protrusion of the pumping port and a second end extending through a second protrusion of the pumping port; A plurality of pressure sensors, each of the pressure sensors being configured to obtain data indicating the pressure of the airflow entering the multi-head processing chamber via a corresponding head of the multi-head processing chamber; and An actuator configured to rotate the member to control the pressure of the airflow at a first head of the multi-head processing chamber, the actuator being positioned near the second end of the shaft, the actuator including a first magnetic coupler, a cover, and a second magnetic coupler.

15. The plasma processing apparatus according to claim 14, wherein the actuator is configured to rotate the member to control a pressure difference between the pressure of the airflow at the first head of the multi-head processing chamber and the pressure of the airflow at a second head of the multi-head processing chamber.

16. The plasma processing apparatus according to claim 14, wherein the pump includes a turbomolecular pump.

17. The plasma processing apparatus according to claim 14, wherein the member includes a baffle.

18. The plasma processing apparatus according to claim 17, wherein the movement range of the baffle is about 180 degrees.

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