Conductive member for cleaning focus ring of plasma processing apparatus

Abstract

The present disclosure provides a base assembly. The susceptor assembly includes an electrostatic chuck configured to support a workpiece, the electrostatic chuck including a base plate defining one or more channels and a disk disposed on the base plate and configured to support the workpiece; a focus ring having a top surface and a bottom surface, the focus ring configured to surround a perimeter of the workpiece with the workpiece positioned on the disk; a plurality of insulating rings; and a conductive member configured to reduce an amount of particles associated with plasma processing of the workpiece aggregated on the focus ring.

Description

[0001] This application is a divisional application of the Chinese application entitled “Conductive component for cleaning the focusing ring of plasma processing equipment”, filed on September 8, 2021, and with application number 202111048934.9. Technical Field

[0002] The present disclosure generally relates to focus rings for use in processing equipment, such as for processing substrates, such as semiconductor substrates. Background Art

[0003] Plasma processing tools are used to manufacture devices such as integrated circuits, micromachined devices, flat panel displays, and other devices. Plasma processing tools used in modern plasma etching applications may need to provide high plasma uniformity and a variety of plasma controls, including independent control of plasma distribution, plasma density, and ion energy. In some cases, the plasma processing tool 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.).

[0004] A pedestal assembly can be used to support a substrate in plasma processing equipment and other processing tools (e.g., thermal processing tools). The pedestal assembly can include an electrostatic chuck and an insulating ring surrounding a portion of the electrostatic chuck. The pedestal assembly can also include a focus ring surrounding the periphery of a workpiece (e.g., a semiconductor wafer) supported by the electrostatic chuck. During processing of the workpiece, particles can accumulate on the focus ring due, at least in part, to a bias applied across the workpiece by the electrostatic chuck. Therefore, the focus ring must be periodically cleaned to remove particles that have accumulated thereon. Summary of the Invention

[0005] Aspects and advantages of the disclosure will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the embodiments.

[0006] In one aspect, a pedestal assembly is provided. The pedestal assembly includes an electrostatic chuck configured to support a workpiece, the electrostatic chuck including a base plate defining one or more channels and a disk disposed on the base plate and configured to support the workpiece; a focus ring having a top surface and a bottom surface, the focus ring configured to surround a periphery of the workpiece when the workpiece is positioned on the disk; a plurality of insulating rings; and a conductive member configured to reduce the amount of particle accumulation on the focus ring associated with plasma processing of the workpiece.

[0007] In another aspect, a plasma processing apparatus is provided. The plasma processing apparatus includes a processing chamber and a pedestal assembly disposed within the processing chamber, the pedestal assembly including an electrostatic chuck configured to support a workpiece, the electrostatic chuck including a base plate defining one or more channels and a disk disposed on the base plate and configured to support the workpiece; a focus ring having a top surface and a bottom surface, the focus ring configured to surround a periphery of the workpiece when the workpiece is positioned on the disk; a plurality of insulating rings; and a conductive member configured to reduce the amount of particle accumulation on the focus ring associated with plasma processing of the workpiece.

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

[0009] The remainder of this specification, including reference to the accompanying drawings, more particularly sets forth a complete and enabling disclosure for one of ordinary skill in the art, in which:

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

[0011] Figure 2 A base assembly according to an example embodiment of the present disclosure is depicted.

[0012] Figure 3 Depicts Figure 2 The base assembly of the electrostatic chuck.

[0013] Figure 4 Depicts Figure 2 Part of the base assembly.

[0014] Figure 5 A portion of a base assembly according to another example embodiment of the present disclosure is depicted.

[0015] Figure 6 A base assembly according to yet another example embodiment of the present disclosure is depicted.

[0016] Figure 7 Depicts Figure 6 Part of the base assembly.

[0017] Figure 8 A portion of a base assembly according to yet another example embodiment of the present disclosure is depicted. DETAILED DESCRIPTION

[0018] Reference will now be made in detail to embodiments of the present invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided to illustrate the present invention, not to limit the present invention. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made to the present invention without departing from the scope or spirit of the present invention. For example, features shown or described as part of one embodiment may be used together with another embodiment to produce yet another embodiment. Therefore, the present invention is intended to encompass such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0019] Example aspects of the present disclosure relate to a pedestal assembly for use in conjunction with a processing apparatus, such as a plasma processing apparatus (e.g., a plasma etcher). The plasma processing apparatus may include a processing chamber defining a processing chamber. The pedestal assembly may be located within the processing chamber. The pedestal assembly may include an electrostatic chuck configured to support a workpiece (e.g., a semiconductor wafer). The electrostatic chuck may be coupled to a radio frequency (RF) source. In this manner, the electrostatic chuck may receive an RF input from the RF source. When the electrostatic chuck receives the RF input, the electrostatic chuck may apply a self-bias across the workpiece to facilitate plasma processing (e.g., etching) of the workpiece.

[0020] The base assembly may include multiple insulators. For example, the base assembly may include an inner insulating ring and an outer insulating ring. The inner insulating ring may surround a portion of the periphery of the electrostatic chuck. The outer insulating ring may surround the periphery of the inner insulating ring. The inner and outer insulating rings may each comprise a dielectric material (e.g., alumina, yttrium oxide, quartz).

[0021] The pedestal assembly can include a focus ring that surrounds the periphery of a workpiece on an electrostatic chuck. In this manner, the focus ring can be used, for example, to reduce non-uniformities in a plasma process (e.g., etch rate) at or near the periphery of the workpiece. However, byproducts or particles generated in part by plasma processing of the workpiece (e.g., etching) can accumulate on the focus ring. In particular, particles can accumulate at or near the periphery of the focus ring. Because particles can shorten the useful life of the focus ring, conventional plasma processing equipment must be taken offline periodically to clean the focus ring. In particular, particles that accumulate on the focus ring can be removed therefrom.

[0022] Example aspects relate to a pedestal assembly having a conductive member configured to reduce the amount of particles that accumulate on a focus ring. For example, the conductive member can be positioned between a bottom surface of the focus ring and at least a portion of one of the insulators (e.g., an inner insulating ring, an outer insulating ring, a top ring, or a cover ring). Furthermore, in some embodiments, the conductive member can be positioned closer to the periphery of the focus ring relative to the center of the focus ring. In this manner, the conductive member can be positioned to reduce the amount of particles that accumulate on the focus ring. For example, the conductive member can be positioned to reduce the amount of particles that accumulate at the periphery of the focus ring.

[0023] In some embodiments, the conductive member can be spaced apart from the electrostatic chuck by a first distance along a first axis. For example, the first distance can be between about 2 mm and about 5 mm. In some embodiments, the first distance can be no greater than about 3 mm. Alternatively or additionally, the conductive member can be spaced apart from the electrostatic chuck by a second distance along a second axis to control the electrical coupling between the electrostatic chuck and the conductive member. The second axis can be substantially perpendicular (e.g., less than 15 degrees, less than 10 degrees, less than 5 degrees, less than 1 degree, etc.) to 90 degrees) with respect to the first axis. It will be appreciated that the wear of the focus ring is a function of the second distance. For example, decreasing the second distance can increase the wear of the focus ring, thereby reducing the useful life of the focus ring.

[0024] In some embodiments, the conductive member may comprise a semiconductor material. In alternative embodiments, the conductive member may comprise a metal. For example, in some embodiments, the conductive member may comprise aluminum. Furthermore, in some embodiments, the surface of the conductive member may be anodized.

[0025] In some embodiments, the conductive member can be a conductive ring. It should be understood that the conductive member can have any suitable shape. It should also be understood that in some embodiments, the base assembly according to example aspects of the present disclosure can include multiple conductive members.

[0026] The susceptor assembly according to example aspects of the present disclosure can have a variety of technical effects and benefits. For example, the conductive member reduces the rate at which particles associated with plasma processing of a workpiece (e.g., plasma etching) accumulate on the focus ring. In this way, the conductive member can allow the plasma processing equipment to operate for a longer period of time before needing to be offline to allow the focus ring to be cleaned. Therefore, compared to conventional plasma processing equipment, a plasma processing equipment having a susceptor assembly according to example aspects of the present disclosure can have a higher throughput.

[0027] For purposes of illustration and discussion, various aspects of the present disclosure are discussed with reference to a "substrate" or "wafer." One of ordinary skill in the art, using the disclosure provided herein, will understand that the exemplary aspects of the present disclosure can be used in conjunction with any semiconductor substrate or other suitable substrate or workpiece. Furthermore, the use of the term "about" in conjunction with a numerical value is intended to refer to within 10% of the stated value.

[0028] Referring now to the accompanying drawings, Figure 1 A plasma processing apparatus 100 is depicted in accordance with an example embodiment of the present disclosure. For purposes of illustration and discussion, reference is made to Figure 1The present disclosure is discussed with reference to the plasma processing apparatus 100 depicted in FIG. A person of ordinary skill in the art, using the disclosure provided herein, will appreciate that example aspects of the present disclosure may be used with other processing tools and / or apparatus, such as plasma stripping tools, thermal processing tools, etc., without departing from the scope of the present disclosure.

[0029] Plasma processing apparatus 100 includes a process chamber 101 defining a process chamber 102. A susceptor assembly 104 is used to support a workpiece 106, such as a semiconductor wafer, within process chamber 102. A dielectric window 110 is positioned above susceptor assembly 104 and serves as a ceiling for process chamber 102. Dielectric window 110 includes a relatively flat central portion 112 and an inclined peripheral portion 114. Dielectric window 110 includes space within central portion 112 for a showerhead 120 that delivers process gas into process chamber 102.

[0030] The plasma processing apparatus 100 further includes a plurality of inductive elements, such as a primary inductive element 130 and a secondary inductive element 140, for generating an inductive plasma in the process chamber 102. The inductive elements 130 and 140 may include coils or antenna elements that, when supplied with RF power, induce plasma in a process gas in the process chamber 102 of the plasma processing apparatus 100. For example, a first RF generator 160 may be configured to provide electromagnetic energy to the primary inductive element 130 via a matching network 162. A second RF generator 170 may be configured to provide electromagnetic energy to the secondary inductive element 140 via a matching network 172.

[0031] Although this disclosure refers to a primary inductive element and a secondary inductive element, one of ordinary skill in the art will understand that the terms primary and secondary are used for convenience only. The secondary coil can operate independently of the primary coil. The primary coil can operate independently of the secondary coil. Furthermore, in some embodiments, a plasma processing apparatus may have only a single inductive coupling element.

[0032] According to aspects of the present disclosure, the plasma processing apparatus 100 may include a metal shield portion 152 disposed around the secondary inductive element 140. The metal shield portion 152 separates the primary inductive element 130 from 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 window 110. The first Faraday shield 154 may be a slotted metal shield that reduces capacitive coupling between the primary inductive element 130 and the process chamber 101. As shown, the first Faraday shield 154 may be mounted on an angled portion of the dielectric window 110.

[0033] In some embodiments, the metal shield portion 152 and the first Faraday shield 154 can form a single piece of metal shield / Faraday shield 150 for ease of manufacturing and other purposes. The multi-turn coil of the primary inductive element 130 can be located adjacent to the first Faraday shield 154 of the single piece of metal shield / Faraday shield 150. The secondary inductive element 140 can be located adjacent to the metal shield portion 152 of the metal shield / Faraday shield monolith 150, for example, between the metal shield portion 152 and the dielectric window 110.

[0034] The arrangement of the primary inductive element 130 and the secondary inductive element 140 on opposite sides of the metal shield 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 located near the periphery of the process chamber 101. The primary inductive element 130 may be used for basic plasma generation and reliable startup during the inherently transient ignition phase. The primary inductive element 130 may be coupled to a powerful RF generator and an expensive auto-tuning matching network and may operate at increased RF frequencies (e.g., approximately 13.56 MHz).

[0035] The secondary inductive element 140 can be used for calibration and support functions, as well as for improving plasma stability during steady-state operation. Because the secondary inductive element 140 can be used primarily for calibration and support functions, as well as for improving plasma stability during steady-state operation, the secondary inductive element 140 does not need to be coupled to a powerful RF generator like the primary inductive element 130, allowing for different and cost-effective designs that overcome difficulties associated with previous designs. As discussed in detail below, the secondary inductive element 140 can also operate at a lower frequency (e.g., approximately 2 MHz), allowing the secondary inductive element 140 to be very compact and fit within the limited space atop the dielectric window.

[0036] 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 greater than the frequency applied to the secondary inductive element 140. In some embodiments, the frequency applied to the primary inductive element 130 can be about 13.56 MHz and 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, a person of ordinary skill in the art, using the disclosure provided herein, will understand that the secondary inductive element 140 can operate at a higher frequency without departing from the scope of the present disclosure.

[0037] The secondary inductive element 140 may include a planar coil 142 and a magnetic flux concentrator 144. The magnetic flux concentrator 144 may be made of a ferrite material. Using a magnetic 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 with the metal shield 150. Using a lower frequency (e.g., about 2 MHz) on the secondary inductive element 140 can increase the surface area, which also improves the plasma heating efficiency.

[0038] According to aspects of the present disclosure, different inductive elements 130 and 140 can carry different functions. Specifically, the primary inductive element 130 can be used to perform the basic function of plasma generation during ignition and provide sufficient startup for 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. A first Faraday shield 154 associated with the primary inductive element 130 prevents window sputtering and can be used to provide coupling to ground.

[0039] The additional coil can operate in the presence of a good plasma start provided by the primary inductive element 130 and therefore preferably has good plasma coupling and good plasma energy transfer efficiency. The secondary inductive element 140, including the flux concentrator 144, provides good magnetic flux transfer to the plasma stack while providing good decoupling of the secondary inductive element 140 from the surrounding metal shield 150. The use of the flux concentrator 144 and the symmetrical driving of the secondary inductive element 140 further reduce the voltage amplitude between the coil ends and the surrounding ground elements. This can reduce sputtering of the dome while providing some small capacitive coupling to the plasma that can be used to assist ignition. In some embodiments, a second Faraday shield can be used in conjunction with the secondary inductive element 140 to reduce the capacitive coupling of the secondary inductive element 140.

[0040] Now refer to Figure 2 , a susceptor assembly 200 is provided according to an example embodiment of the present disclosure. As shown, the susceptor assembly 200 may include an electrostatic chuck 210. In some embodiments, the electrostatic chuck 210 may include one or more clamping electrodes. The one or more electrodes may be configured to hold the workpiece 106. For example, when a radio frequency (RF) input is provided to the electrostatic chuck 210, a self-bias voltage may be applied across the workpiece 106. In this way, the electrostatic chuck 210 may absorb iron associated with the plasma and bombard the workpiece 106 to facilitate a plasma machining process (e.g., plasma etching). Alternatively or additionally, the electrostatic chuck 210 may include a temperature regulation system (e.g., a fluid channel, an electric heater, etc.) that may be used to control the temperature distribution on the workpiece 106.

[0041] The pedestal assembly 200 may include a focus ring 220. The focus ring 220 may be arranged relative to the electrostatic chuck 210 such that the focus ring 220 surrounds the periphery of the workpiece 106 when the workpiece 106 is positioned on the electrostatic chuck 210. In some embodiments, the focus ring 220 may include a dielectric material. For example, in some embodiments, the dielectric material may include aluminum oxide (Al2O3) or yttrium oxide (Y2O3). In alternative embodiments, the dielectric material may include quartz. However, it should be understood that the focus ring 220 may include any suitable dielectric material.

[0042] The base assembly 200 may include one or more insulators. For example, in some embodiments, the base assembly 200 may include an inner insulating ring 230 and an outer insulating ring 240. As shown, the inner insulating ring 230 may surround the periphery 216 ( Figure 3). The outer insulating ring 240 may surround the periphery 232 of the inner insulating ring 230. In some embodiments, the inner insulating ring 230 and the outer insulating ring 240 may comprise a dielectric material. For example, in some embodiments, the dielectric material may comprise aluminum oxide (Al2O3) or yttrium oxide (Y2O3). In alternative embodiments, the dielectric material may comprise quartz. However, it should be understood that the inner insulating ring 230 and the outer insulating ring 240 may comprise any suitable dielectric material.

[0043] The pedestal assembly 200 can include a conductive member 250 configured to reduce the amount of particles that accumulate on the focus ring 220 associated with plasma processing of the workpiece 106. As shown, the conductive member 250 can be positioned between a bottom surface of the focus ring 220 and at least a portion of the inner insulating ring 230. In this manner, the conductive member 250 can be positioned to reduce the amount of particles that accumulate on the focus ring 220. For example, the conductive member 250 can reduce the amount of particles that accumulate at or near the perimeter of the focus ring 220.

[0044] In some embodiments, the conductive member 250 may comprise a metal. For example, the conductive member 250 may comprise aluminum. Furthermore, in such embodiments, the surface of the conductive member 250 may be anodized. In alternative embodiments, the conductive member 250 may comprise a semiconductor material. It should be understood that the conductive member 250 may have any suitable shape. For example, in some embodiments, the conductive member 250 may be a conductive ring.

[0045] Now refer to Figure 3 The electrostatic chuck 210 can extend along a first axis 202 (e.g., a vertical axis) between a top 212 of the electrostatic chuck 210 and a bottom 214 of the electrostatic chuck 210. Additionally, the electrostatic chuck 210 can extend along a second axis 204 (e.g., a horizontal axis) that is substantially perpendicular (e.g., less than 15 degrees, less than 10 degrees, less than 5 degrees, less than 1 degree, etc.) to the first axis 202 to a perimeter 216 of the electrostatic chuck 210. In some embodiments, the perimeter 216 of the electrostatic chuck 210 can define a plurality of stepped surfaces 218. For example, in some embodiments, the perimeter 216 of the electrostatic chuck 210 can define two stepped surfaces (e.g., a first stepped surface and a second stepped surface). In alternative embodiments, the perimeter 216 of the electrostatic chuck 210 can define more than two stepped surfaces. Alternatively or additionally, each of the plurality of stepped surfaces 218 can have a different depth 219. For example, a first stepped surface of the plurality of stepped surfaces 218 may have a first depth, while a second stepped surface of the plurality of stepped surfaces 218 may have a second depth that is different (eg, deeper, shallower) than the first depth.

[0046] Now refer to Figure 4 In some embodiments, the inner insulating ring 230 may be positioned around the periphery 216 of the electrostatic chuck 210 ( Figure 3 For example, a first portion of inner insulating ring 230 may be positioned on a first step surface of the plurality of step surfaces 218 defined by perimeter 216 of electrostatic chuck 210. Additionally, a second portion of inner insulating ring 230 may be positioned on a second step surface of the plurality of step surfaces 218 defined by perimeter 216 of electrostatic chuck 210.

[0047] In some embodiments, the inner insulating ring 230 can define a stepped surface 234. As shown, the conductive member 250 can be positioned on the stepped surface 234 defined by the inner insulating ring 230 such that the conductive member 250 is positioned between the focus ring 220 and the stepped surface 234 along the first axis 202. Additionally, the conductive member 250 can be positioned between the outer insulating ring 240 and a portion of the inner insulating ring 230 along the second axis 204.

[0048] The conductive member 250 can be spaced a first distance 260 from the electrostatic chuck 210 along the first axis 202. For example, in some embodiments, the first distance 260 can be about 2 mm to about 5 mm. In alternative embodiments, the first distance 260 can be no greater than about 15 mm.

[0049] The conductive member 250 can also be spaced a second distance 262 from the electrostatic chuck 210 along the second axis 204 to control the electrical coupling between the electrostatic chuck 210 and the conductive member 250. It should be understood that the wear of the focus ring 220 can be a function of the second distance 262. For example, decreasing the second distance 262 can increase the wear of the focus ring 220, thereby reducing the useful life of the focus ring 220. In some embodiments, the second distance 262 can be between about 2 mm and about 10 mm. In alternative embodiments, the second distance 262 can be zero, such that the conductive member 250 contacts a portion of the electrostatic chuck 210.

[0050] In some embodiments, the thickness 264 of the conductive member 250 can be no greater than 1 mm. It should be understood that the conductive member 250 can have any suitable thickness 264. For example, in some embodiments, the thickness 264 of the conductive member 250 can be greater than 1 mm.

[0051] Now refer to Figure 5, a portion of a pedestal assembly 300 according to another example embodiment of the present disclosure is provided. The pedestal assembly 300 can include an electrostatic chuck 310. The electrostatic chuck 310 can include a base plate 312. The base plate can extend along a first axis 302 (e.g., a vertical axis) and a second axis 304 (e.g., a horizontal axis) that is substantially perpendicular (e.g., less than 15 degrees, less than 10 degrees, less than 5 degrees, less than 1 degree, etc.) to the first axis 302. In some embodiments, the base plate 312 can define one or more channels through which a fluid (e.g., water) flows to reduce (e.g., cool) the temperature of the base plate.

[0052] Electrostatic chuck 310 may further include disk 314. Disk 314 may be disposed on base plate 312. Disk 314 may be configured to support workpiece 106. In some embodiments, disk 314 may include one or more clamping electrodes configured to hold workpiece 106 via an electrostatic charge.

[0053] The base assembly 300 can include a focus ring 320. The focus ring 320 can be configured to surround the periphery of the workpiece 106 when the workpiece 106 is positioned on the disk 314. The focus ring 320 can include a first portion (e.g., a horizontal portion) and a second portion (e.g., a vertical portion). The first portion of the focus ring 320 can extend along the first axis 302. The second portion of the focus ring 320 can extend from the first portion thereof and along the second axis 304.

[0054] In some embodiments, the focus ring 320 can include a dielectric material. For example, in some embodiments, the dielectric material can include aluminum oxide (Al2O3) or yttrium oxide (Y2O3). In alternative embodiments, the dielectric material can include quartz. However, it should be understood that the focus ring 320 can include any suitable dielectric material.

[0055] The base assembly 300 can include one or more insulating rings. For example, in some embodiments, the one or more insulating rings can include an inner insulating ring 330 and an outer insulating ring 340. The inner insulating ring 330 can surround a portion of the perimeter of the substrate 312. The outer insulating ring 340 can surround a perimeter 332 of the inner insulating ring 330. In some embodiments, the outer insulating ring 340 can define a stepped surface 342, and the second portion (e.g., the vertical portion) of the focus ring 320 can be positioned on the stepped surface 342.

[0056] Inner and outer insulating rings 330 and 340 may comprise a dielectric material. For example, in some embodiments, the dielectric material may comprise aluminum oxide (Al2O3) or yttrium oxide (Y2O3). In alternative embodiments, the dielectric material may comprise quartz. However, it should be understood that inner and outer insulating rings 230 and 240 may comprise any suitable dielectric material.

[0057] The pedestal assembly 300 may include a conductive member 350 configured to reduce the amount of particles that accumulate on the focus ring 320 associated with plasma processing of the workpiece 106. As shown, the conductive member 350 may be positioned between the focus ring 320 and a stepped surface 344 defined by the inner insulating ring 330. Additionally, the conductive member 350 may be positioned between the outer insulating ring 340 and a first portion (e.g., a horizontal portion) of the focus ring 320. Additionally, a second portion (e.g., a vertical portion) of the focus ring 320 may surround a perimeter 352 of the conductive member 350. In this manner, the focus ring 320 and the insulating rings (i.e., the inner insulating ring 330 and the outer insulating ring 340) may shield the conductive member 350 from the plasma generated within the processing chamber 102. Figure 1 ).

[0058] In some embodiments, the conductive member 350 may comprise a metal. For example, the conductive member 350 may comprise aluminum. Furthermore, in such embodiments, the surface of the conductive member 350 may be anodized. In alternative embodiments, the conductive member 350 may comprise a semiconductor material. In some embodiments, the conductive member 350 may be a conductive ring. In alternative embodiments, the conductive member 350 may have a different shape.

[0059] The conductive member 350 can be spaced a first distance 360 ​​from the substrate 312 along the first axis 302. For example, in some embodiments, the first distance 360 ​​can be about 2 mm to about 5 mm. In alternative embodiments, the first distance 260 can be no greater than about 3 mm.

[0060] The conductive member 350 can also be spaced apart from the substrate along the second axis 304 by a second distance 362 to control the electrical coupling between the electrostatic chuck 310 and the conductive member 350. It should be understood that the wear of the focus ring 320 can be a function of the second distance 362. For example, decreasing the second distance 362 can increase the wear of the focus ring 320, thereby reducing the useful life of the focus ring 320. In some embodiments, the second distance 362 can be between about 2 mm and about 10 mm.

[0061] In some embodiments, the thickness 364 of the conductive member 350 can be no greater than about 1 mm. It should be understood that the conductive member 350 can have any suitable thickness 364. For example, in some embodiments, the thickness 364 of the conductive member 350 can be greater than 1 mm.

[0062] Now refer to Figure 6 and Figure 7According to another exemplary embodiment of the present disclosure, a pedestal assembly 400 is provided. As shown, the pedestal assembly 400 can include an electrostatic chuck 410. The electrostatic chuck 410 can include a base plate 412. The base plate can extend along a first axis 402 (e.g., a vertical axis) and a second axis 404 (e.g., a horizontal axis) that is substantially perpendicular (e.g., less than 15 degrees, less than 10 degrees, less than 5 degrees, less than 1 degree, etc.) to the first axis 402. In some embodiments, the base plate 412 can define one or more channels through which a fluid (e.g., water) flows to reduce (e.g., cool) the temperature of the base plate.

[0063] Electrostatic chuck 410 may further include disk 414. Disk 414 may be disposed on base plate 412. Disk 414 may be configured to support workpiece 106. In some embodiments, disk 414 may include one or more clamping electrodes configured to hold workpiece 106 via an electrostatic charge.

[0064] The pedestal assembly 400 may include a focus ring 420. The focus ring 420 may be arranged relative to the electrostatic chuck 410 such that the focus ring 420 surrounds the periphery of the workpiece 106 when the workpiece 106 is positioned on the electrostatic chuck 410. In some embodiments, the focus ring 420 may include a dielectric material. For example, in some embodiments, the dielectric material may include aluminum oxide (Al2O3) or yttrium oxide (Y2O3). In alternative embodiments, the dielectric material may include quartz. However, it should be understood that the focus ring 420 may include any suitable dielectric material.

[0065] The base assembly 400 may include a plurality of insulators. For example, in some embodiments, the plurality of insulators may include a first insulator 430 (e.g., an upper ring), a second insulator 432 (e.g., a cover ring), and a third insulator 434 (e.g., a clamp ring). In alternative embodiments, the base assembly 400 may include more or fewer insulators. It will be appreciated that the plurality of insulators may include any suitable dielectric material. For example, in some embodiments, the first insulator 430 and the second insulator 432 may each include a quartz material. Alternatively or additionally, the third insulator 434 may include aluminum with an yttrium oxide coating.

[0066] The pedestal assembly 400 may include a conductive member 440 positioned between a bottom surface of the focus ring 420 and one of the plurality of insulators. For example, the conductive member 440 may be positioned between the bottom surface of the focus ring 420 and a first insulator 430 (e.g., an upper ring). In this manner, the conductive member 440 may be positioned to reduce the amount of particles that accumulate on the focus ring 420 associated with plasma processing of the workpiece 106.

[0067] In some embodiments, the conductive member 440 may comprise a metal. For example, the conductive member 440 may comprise aluminum. Furthermore, in such embodiments, the surface of the conductive member 440 may be anodized. In alternative embodiments, the conductive member 440 may comprise a semiconductor material. In some embodiments, the conductive member 440 may be a conductive ring. In alternative embodiments, the conductive member 440 may have a different shape.

[0068] Now refer to Figure 8 According to another exemplary embodiment of the present disclosure, another base assembly 500 is provided. The base assembly 500 can be used in conjunction with the base assembly 500 of the embodiment of the present disclosure. Figure 6 and Figure 7 The base assembly 400 discussed above is configured in substantially the same manner. For example, the base assembly 500 may include the electrostatic chuck 410 and the focus ring 420. However, the base assembly 500 does not include a first insulator 430 ( Figure 6 ) between the conductive member 440 ( Figure 7 ). In contrast, the base assembly 500 replaces the first insulator 430 with a conductive member 510. In this way, Figure 8 The base assembly 500 includes Figure 6 and Figure 7 The base assembly 400 has fewer insulators. More specifically, Figure 8 The base assembly 500 includes a first insulator 520 (eg, a cover ring) and a second insulator 522 (eg, a clamp ring).

[0069] As shown, the conductive member 510 is positioned between the bottom surface of the focus ring 420 and the first insulator 520 (e.g., a cover ring). In some embodiments, the conductive member 510 can include silicon carbide (SiC). However, it should be understood that the conductive member 510 can include any suitable conductive material. In some embodiments, the conductive member 510 can be a conductive ring. In alternative embodiments, the conductive member 510 can have a different shape.

[0070] These and other modifications and variations of the present invention may be implemented by those skilled in the art without departing from the spirit and scope of the present invention as more particularly set forth in the appended claims. Furthermore, it should be understood that aspects of the various embodiments may be interchangeable in whole or in part. Furthermore, it will be understood by those skilled in the art that the foregoing description is by way of example only and is not intended to limit the present invention as further described in such appended claims.

Claims

1. A base assembly comprising: an electrostatic chuck configured to support a workpiece, the electrostatic chuck comprising a base plate defining one or more channels and a disk disposed on the base plate and configured to support the workpiece; a focus ring having a top surface and a bottom surface, the focus ring being configured to surround a periphery of the workpiece when the workpiece is positioned on the disk; Multiple insulating rings; as well as An electrically conductive member is configured to reduce an amount of particle accumulation on the focus ring associated with plasma processing of the workpiece.

2. The base assembly according to claim 1, wherein The puck includes one or more clamping electrodes configured to hold the workpiece via an electrostatic charge.

3. The base assembly according to claim 1, wherein: The focus ring includes a dielectric material.

4. The base assembly according to claim 1, wherein The plurality of insulating rings include: an inner insulating ring configured to surround a portion of a periphery of the electrostatic chuck, the inner insulating ring defining a stepped surface; and An outer insulating ring is configured to surround the inner insulating ring and the circumference of the conductive member.

5. The base assembly according to claim 4, wherein: The inner insulating ring and the outer insulating ring include a dielectric material.

6. The base assembly of claim 1, wherein: The conductive member is positioned between the stepped surface defined by the inner insulating ring and at least a portion of the bottom surface of the focus ring.

7. The base assembly according to claim 1, wherein: The focus ring includes a first portion and a second portion, the conductive member is positioned between the outer insulating ring and the first portion of the focus ring, and the second portion of the focus ring surrounds a periphery of the conductive member.

8. The base assembly according to claim 7, wherein: The focus ring, the inner insulating ring, and the outer insulating ring are configured to shield the conductive member from plasma generated within a process chamber.

9. The base assembly of claim 1, wherein: The conductive member is spaced a first distance from a perimeter of the electrostatic chuck along a first axis; and The conductive member is spaced a second distance from a perimeter of the electrostatic chuck along a second axis that is substantially perpendicular to the first axis.

10. The base assembly of claim 9, wherein: The first distance is different from the second distance.

11. The base assembly of claim 9, wherein: The first distance is about 2 mm to about 5 mm.

12. The base assembly of claim 1, wherein: The conductive member includes metal.

13. The base assembly of claim 1, wherein: The conductive member is also positioned between the outer insulating ring and at least a portion of the bottom surface of the focus ring.

14. A plasma processing apparatus comprising: processing room; as well as A base assembly is disposed in the processing chamber, and the base assembly includes: An electrostatic chuck configured to support a workpiece, the electrostatic chuck comprising a base plate defining one or more channels and a disk disposed on the base plate, and configured to support the workpiece; a focus ring having a top surface and a bottom surface, the focus ring being configured to surround a periphery of the workpiece when the workpiece is positioned on the disk; a plurality of insulating rings; and An electrically conductive member is configured to reduce an amount of particle accumulation on the focus ring associated with plasma processing of the workpiece.

15. The plasma processing apparatus according to claim 14, wherein: The puck includes one or more clamping electrodes configured to hold the workpiece via an electrostatic charge.

16. The plasma processing apparatus according to claim 14, wherein: The plurality of insulating rings include: an inner insulating ring configured to surround a portion of a periphery of the electrostatic chuck, the inner insulating ring defining a stepped surface; and An outer insulating ring is configured to surround the inner insulating ring and the circumference of the conductive member.

17. The plasma processing apparatus according to claim 14, wherein: The conductive member is spaced a first distance from a perimeter of the electrostatic chuck along a first axis; and The conductive member is spaced a second distance from a perimeter of the electrostatic chuck along a second axis that is substantially perpendicular to the first axis.

18. The plasma processing apparatus according to claim 14, wherein: The conductive member is positioned between the stepped surface defined by the inner insulating ring and at least a portion of the bottom surface of the focus ring.

19. The plasma processing apparatus according to claim 14, wherein: The conductive member is also positioned between the outer insulating ring and at least a portion of the bottom surface of the focus ring.

20. The plasma processing apparatus according to claim 14, wherein The conductive member includes a conductive ring.

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