High power electrostatic chuck with feature to prevent helium hole ignition / arcing

Abstract

A spark suppression apparatus for a helium line in an electrostatic chuck within a plasma processing chamber is provided. The spark suppression device includes a dielectric multi-cavity plug in a helium line, where the dielectric multi-cavity plug has a plurality of cavities, where the number of the plurality of cavities is between 30 and 100,000 cavities, and the plurality of cavities has a width between 1 and 200 microns.

Description

This application is a divisional application of the application with application number 201980072982.6, application date October 29, 2019, and invention name “High-power electrostatic chuck with features for preventing helium hole ignition / arcing”. CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Application No. 62 / 754,308, filed on November 1, 2018, which is incorporated herein by reference for all purposes. Technical Field

[0002] The present disclosure relates to apparatus for processing a substrate. More particularly, the present disclosure relates to apparatus for plasma processing a substrate. Background Art

[0003] In many plasma processing chambers, helium (He) is flowed to the backside of a substrate on an electrostatic chuck (ESC) to provide temperature control. Due to the high voltages associated with plasma formation, the radio frequency (RF) power used to form the plasma can cause secondary plasma light-up in the ESC cavity. Light-up will cause arcing between any two surfaces if there is a high potential difference between the two surfaces. Such arcing will cause damage to the ESC. Summary of the invention

[0004] To achieve the foregoing objectives and in accordance with the objectives of the present disclosure, a spark suppression device for a helium line in an electrostatic chuck in a plasma processing chamber is provided. The spark suppression device includes a dielectric multi-cavity plug in the helium line, wherein the dielectric multi-cavity plug has a plurality of cavities, wherein the number of the plurality of cavities is between 30 and 100,000 cavities, and has a width between 1 micron and 200 microns.

[0005] These and other features of the present disclosure will be described in more detail below in the detailed description and in conjunction with the following figures. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The present disclosure is illustrated by way of example and not limitation in the accompanying figures and in which like reference numerals indicate similar elements and in which:

[0007] Figure 1 is a schematic cross-sectional view of a spark arresting device in a portion of an electrostatic chuck (ESC) that may be used in one embodiment.

[0008] Figure 2 is a schematic cross-sectional view of a spark arresting device in a portion of an ESC that may be used in another embodiment.

[0009] Figure 3 is a schematic cross-sectional view of a spark arresting device in a portion of an ESC that may be used in another embodiment.

[0010] Figure 4 is a schematic cross-sectional view of a spark arresting device in a portion of an ESC that may be used in another embodiment.

[0011] Figure 5 is a schematic cross-sectional view of a spark arresting device in a portion of an ESC that may be used in another embodiment.

[0012] Figure 6 is a schematic cross-sectional view of a spark arresting device in a portion of an ESC that may be used in another embodiment.

[0013] Figure 7 is a schematic cross-sectional view of a spark arresting device in a portion of an ESC that may be used in another embodiment.

[0014] Figure 8 is a schematic cross-sectional view of a spark arresting device in a portion of an ESC that may be used in another embodiment.

[0015] Fig. 9 is a schematic cross-sectional view of a spark arresting device in a portion of an ESC that may be used in another embodiment.

[0016] Fig.10 is a schematic diagram of a processing chamber that may be used in one embodiment. DETAILED DESCRIPTION

[0017] The present application will now be described in detail with reference to several non-exclusive embodiments shown in the accompanying drawings. In the following description, many specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure can be implemented without some or all of these specific details. In other cases, well-known process steps and / or structures are not described in detail to avoid making the present invention unclear unnecessarily.

[0018] New semiconductor production processes require plasmas with very high RF power. Increased RF power leads to an increase in the RF current and total voltage applied to the electrostatic chuck (ESC-wafer base). At the same time, new plasma etching processes require significantly lower RF frequencies (e.g., 2 MHz, 400 kHz, or lower) than those required in the past. Low RF frequencies lead to an additional increase in the RF voltage applied to the entire ESC ceramic. The high voltage applied to the entire ceramic can cause electrical discharges (arcing) between the wafer and the substrate or ignition (ignition) of a heat-conducting gas (e.g., He) in the gas supply hole. The arcing of the ESC usually causes catastrophic damage to the components, which is accompanied by wafer damage, possible damage to other components, and interruption of the production process. In the case of ignition of the heat-conducting gas, ESC damage may be catastrophic, or may be slowly developed to affect multiple wafers and damage semiconductor devices, and this damage can only be detected in the later steps of the production process. In both cases, ESC failure causes serious losses in wafer production and manufacturer revenue.

[0019] For low voltage applications, straight holes are usually used in the ceramic plate, and there is a ceramic bushing in the substrate that opposes the hole in the ceramic plate and prevents a direct line of sight. For low and medium voltage applications, the ceramic bushing in the substrate is replaced with a porous plug that provides a higher withstand voltage than the ceramic bushing. For medium voltage applications, a porous plug is inserted into the ceramic plate in addition to the bushing in the substrate. Further breakdown voltage improvements require new solutions.

[0020] One embodiment provides a solution to the ESC arcing and He ignition problems by introducing a plug (made of a ceramic material such as aluminum oxide Al2O3 or aluminum nitride AlN) with a small opening (0.1-100 microns in diameter) into the He hole. The plug partitions the He hole volume into smaller micro volumes, which limits the possibility of ignition by reducing the number of impacts of charged particles, and prevents a direct line of sight between the wafer and the metal parts of the chuck below the upper ceramic plate while ensuring the required He flow through the hole for wafer backside cooling.

[0021] To facilitate understanding, Figure 11 is a schematic cross-sectional view of a spark suppression device in a portion of an electrostatic chuck (ESC) 100 that can be used in one embodiment. In this embodiment, the ESC 100 includes a substrate 104 bonded to a ceramic plate 108 by a bonding layer 112. In this embodiment, the substrate 104 is a conductive metal substrate 104, such as aluminum. The substrate 104 has a He supply line hole 116. At the output end of the He supply line hole 116 is a porous plug 120. The He supply line hole 116 is on the first side of the porous plug 120. In this embodiment, the porous plug 120 is a porous dielectric plug of ceramic aluminum oxide or aluminum nitride with a porosity of 30-50%. In this embodiment, the porous plug 120 has a diameter of 3 to 10 mm, which is more than 3 times the characteristic size (diameter or width) of the supply line hole 116. In this example, the porous plug 120 extends to the top surface of the substrate 104. The porous plug 120 may have various shapes: for example, Figure 1 The straight shape shown in Figure 6 , Figure 7 , Figure 8 ,or Fig. 9 The one shown in FIG. 1 has a T-shaped housing.

[0022] On the second side of the porous plug 120 opposite to the first side of the porous plug is a first plenum 124. The porous plug 120 is on the first side of the first plenum 124. The first plenum 124 is formed in the bonding layer 112. On the second side of the first plenum 124 (opposite to the first side) is a ceramic plate 108 and a dielectric multi-cavity plug 128 formed of aluminum oxide or aluminum nitride having a plurality of small through holes. In this embodiment, the dielectric multi-cavity plug 128 is bonded to the ceramic plate 108. In this example, the dielectric multi-cavity plug 128 is a dielectric plug having 50 to 100,000 cavities, wherein each cavity has a diameter between 1 micron and 200 microns. The cavities extend from a first side of the dielectric multi-cavity plug 128 adjacent to the first plenum 124 to a second side of the dielectric multi-cavity plug 128 opposite to the first side. The ceramic plate 108 has a thickness between 0.5 mm and 3 mm. The dielectric multi-cavity plug 128 has a height between 0.1 mm and 2.5 mm. In this embodiment, the cavities are straight circular tubes forming a honeycomb cross-section. Since the cavities are straight and extend across the height of the dielectric multi-cavity plug 128, the cavities have a length between 0.1 mm and 2.5 mm. In this embodiment, the dielectric multi-cavity plug 128 has a diameter of 3 to 5 mm. In this embodiment, the dielectric multi-cavity plug 128 is made of aluminum oxide.

[0023] The second plenum 132 is on the second side of the dielectric multi-cavity plug 128. At least one He hole 136 extends from the second plenum 132 to the surface of the ceramic plate 108. In this example, the at least one He hole 136 has a diameter between 0.02 and 0.3 mm. In this embodiment, the other parts of the ESC 100 have other He supply line holes 116, porous plugs 120, first plenum 124, dielectric multi-cavity plugs 128, second plenum 132, and He holes 136. The at least one He hole 136 at the top surface of the ceramic plate 108 is shown as wider because the wider portion may be a part of a channel or groove connected between multiple He holes 136 at the top surface of the ceramic plate 108. The He supply line hole 116 and the at least one He hole 136 form a helium line, wherein the He supply line hole 116 is a first part of the He line, and the at least one He hole 136 is a second part of the He line. The second plenum has a width 148. The first plenum 124 has a width. The width of the first plenum 124 is approximately the same as the diameter of the porous portion of the porous plug 120, while the width 148 of the second plenum 132 is approximately 80% of the diameter of the dielectric multi-cavity plug 128 and is at least twice the width of the He supply line hole 116.

[0024] This embodiment has been found to reduce arcing. Thus, damage to the wafer has been reduced. In addition, the life time / factor has been improved. Without being limited by theory, it is believed that providing a large number of thin cavities can significantly reduce arcing and allow for adequate He flow. In addition, the porous plug 120 increases the path length that the power must travel to reach the conductive material. This further reduces arcing.

[0025] Figure 2 2 is a schematic cross-sectional view of a spark arresting device in a portion of an ESC 200 that may be used in another embodiment. In this embodiment, the ESC 200 includes a substrate 204 bonded to a ceramic plate 208 by a bonding layer 212. In this embodiment, the substrate 204 is a conductive metal substrate 204, such as aluminum. The substrate 204 has a He supply line hole 216. At the output end of the He supply line hole 216 is a porous plug 220. The He supply line hole 216 is on a first side of the porous plug 220. In this embodiment, the porous plug 220 is a ceramic aluminum oxide or aluminum nitride having a porosity of 30-50%. In this embodiment, the porous plug 220 has a diameter of 3 to 10 millimeters. In this example, the porous plug 220 extends to the top surface of the substrate 204.

[0026] On the second side of the porous plug 220 opposite to the first side of the porous plug 220 is a first plenum 224. The porous plug 220 is on the first side of the first plenum 224. The first plenum 224 is formed in the bonding layer 212. On the second side of the first plenum 224 (opposite to the first side) is a ceramic plate 208 and a dielectric multi-cavity plug 228 formed of aluminum oxide or aluminum nitride having a plurality of small through holes. In this embodiment, the dielectric multi-cavity plug 228 has a solid core 230 at the center. The dielectric multi-cavity plug 228 is bonded to the ceramic plate 208. In this example, the dielectric multi-cavity plug 228 has 30 to 100,000 cavities, wherein each cavity has a diameter between 1 micron and 200 microns. These cavities extend from a first side of the dielectric multi-cavity plug 228 adjacent to the first plenum 224 to a second side of the dielectric multi-cavity plug 228 opposite to the first side.

[0027] The second plenum 232 is on the second side of the dielectric multi-cavity plug 228. At least one He hole 236 extends from the second plenum 232 to the surface of the ceramic plate 208. In this example, the at least one He hole 236 has a diameter between 0.05 and 0.3 mm. In this embodiment, the solid core 230 has a diameter larger than the diameter of the at least one He hole 236, such as a group of He holes (1-6 holes per position). The solid core 230 has a certain width and is placed to prevent a direct line of sight path from the He supply line hole 216 through the cavity of the dielectric multi-cavity plug 228 to the at least one He hole 236. In this embodiment, further reducing the direct line of sight of the He flow will further reduce arcing. The He supply line hole 216 and the at least one He hole 236 form a helium pipeline, wherein the He supply line hole 216 is the first part of the He pipeline, and the at least one He hole 236 is the second part of the He pipeline.

[0028] Figure 33 is a schematic cross-sectional view of a spark suppression device in a portion of an ESC 300 that may be used in another embodiment. In this embodiment, the ESC 300 includes a substrate 304 bonded to a ceramic plate 308 by a bonding layer 312. In this embodiment, the substrate 304 is a conductive metal substrate 304, such as aluminum. The substrate 304 has a He supply line hole 316. At the output end of the He supply line hole 316 is a first plenum 318. The He supply line hole 316 is on a first side of the first plenum 318. On a second side of the first plenum 318 is a first side of a first dielectric multi-cavity plug 320 formed of aluminum oxide or aluminum nitride having a plurality of small through holes. In this embodiment, the first dielectric multi-cavity plug 320 has a solid core 322 at the center. The first dielectric multi-cavity plug 320 is bonded to the substrate 304. In this example, the first dielectric multi-cavity plug 320 has 30 to 100,000 cavities, wherein each cavity has a diameter between 1 micron and 200 microns. The cavities extend from a first side of the first dielectric multi-cavity plug 320 adjacent to the first plenum 318 to a second side of the first dielectric multi-cavity plug 320 opposite the first side. In this example, the first dielectric multi-cavity plug 320 extends to the top surface of the substrate 304.

[0029] On the second side of the first dielectric multi-cavity plug 320 opposite to the first side of the first dielectric multi-cavity plug 320 is a second plenum 324. The first dielectric multi-cavity plug 320 is on the first side of the second plenum 324. The second plenum 324 is formed in the bonding layer 312. On the second side of the second plenum 324 (opposite to the first side) is the ceramic plate 308 and a second dielectric multi-cavity plug 328 formed of aluminum oxide or aluminum nitride having a plurality of small through holes. In this embodiment, the second dielectric multi-cavity plug 328 has a solid core 330 at the center. The second dielectric multi-cavity plug 328 is bonded to the ceramic plate 308. In this example, the second dielectric multi-cavity plug 328 has 30 to 100,000 cavities, wherein each cavity has a diameter between 1 micron and 200 microns. The cavities extend from a first side of the second dielectric multi-cavity plug 328 adjacent to the second plenum 324 to a second side of the second dielectric multi-cavity plug 328 opposite the first side.

[0030] The third plenum 332 is on the second side of the second dielectric multi-cavity plug 328. At least one He hole 336 extends from the third plenum 332 to the surface of the ceramic plate 308. In this example, the at least one He hole 336 has a diameter between 0.05 and 0.3 mm. The solid core 330 of the second dielectric multi-cavity plug 328 has a larger diameter than the diameter of the at least one He hole 336. The solid core 322 of the first dielectric multi-cavity plug 320 has a larger diameter than the solid core 330 of the second dielectric multi-cavity plug 328 and larger than the diameter of the He supply line hole 316. The solid core 322 of the first dielectric multi-cavity plug 320 and the solid core 330 of the second dielectric multi-cavity plug 328 each have a certain width and are configured to prevent a direct line of sight path from the He supply line hole 316 through the cavities of the first dielectric multi-cavity plug 320 and the second dielectric multi-cavity plug 328 to the at least one He hole 336. These cavities allow for increased He flow. The He supply line hole 316 and the at least one He hole 336 form a helium line, wherein the He supply line hole 316 is a first portion of the He line, and the at least one He hole 336 is a second portion of the He line.

[0031] In other embodiments, the solid core 322 of the first dielectric multi-cavity plug 320 and / or the solid core 330 of the second dielectric multi-cavity plug 328 can be replaced by multiple cavities. Four combinations can be provided. The width of the solid core can also be varied to add additional embodiments.

[0032] Figure 4 4 is a schematic cross-sectional view of a spark suppression device in a portion of an ESC 400 that can be used in another embodiment. In this embodiment, the ESC 400 includes a substrate 404 bonded to a ceramic plate 408 by a bonding layer 412. In this embodiment, the substrate 404 is a conductive metal substrate 404. The substrate 404 has a He supply line hole 416. At the output end of the He supply line hole 416 is a first plenum 418. The He supply line hole 416 is on a first side of the first plenum 418. On a second side of the first plenum 418 is a first side of a dielectric multi-cavity plug 420. In this embodiment, the dielectric multi-cavity plug 420 has a solid core 422 at the center. The dielectric multi-cavity plug 420 is bonded to the substrate 404. In this example, the dielectric multi-cavity plug 420 has 30 to 100,000 cavities, wherein each cavity has a width between 1 micron and 200 microns. The cavities extend from a first side of the dielectric multi-cavity plug 420 adjacent the first plenum 418 to a second side of the dielectric multi-cavity plug 420 opposite the first side. In this example, the dielectric multi-cavity plug 420 extends to the surface of the substrate 404.

[0033] On a second side of the dielectric multi-cavity plug 420 opposite the first side of the dielectric multi-cavity plug 420 is a second plenum 424 located in the bonding layer 412. The dielectric multi-cavity plug 420 is on a first side of the second plenum 424.

[0034] At least one He hole 436 extending from the second plenum 424 to the surface of the ceramic plate 408 is on a second side (opposite the first side) of the second plenum 424. In this example, the at least one He hole 436 has a diameter between 0.03 and 0.3 mm. The solid core 422 of the dielectric multi-cavity plug 420 has a certain width and is positioned to prevent a direct line of sight from the He supply line hole 416 through the cavity of the dielectric multi-cavity plug 420 to the at least one He hole 436 (such as a group of smaller He holes).

[0035] This embodiment uses only a single plug. By joining the dielectric multi-cavity plug 420 to the substrate 404, the dielectric multi-cavity plug 420 can be larger, thereby allowing a single plug. In this embodiment, the ceramic plate 408 has a thickness between 0.5 mm and 1.5 mm. The dielectric multi-cavity plug 420 has a thickness much greater than 1 mm. For example, the dielectric multi-cavity plug 420 has a thickness or height 421 between 2 mm and 10 mm. In this example, the solid core 422 has a diameter of 1 to 2 mm. The He supply line hole 416 and the at least one He hole 436 form a helium line, wherein the He supply line hole 416 is a first portion of the He line, and the at least one He hole 436 is a second portion of the He line.

[0036] Figure 55 is a schematic cross-sectional view of a spark suppression device in a portion of an ESC 500 that can be used in another embodiment. In this embodiment, the ESC 500 includes a substrate 504 bonded to a ceramic plate 508 by a bonding layer 512. In this embodiment, the substrate 504 is a conductive metal substrate 504, such as aluminum. The substrate 504 has a He supply line hole 516. At the output end of the He supply line hole 516 is a first plenum 518. The He supply line hole 516 is on a first side of the first plenum 518. The first side of the first dielectric multi-cavity plug 520 is on a second side of the first plenum 518. In this embodiment, the first dielectric multi-cavity plug 520 has a solid core 522 at the center. The first dielectric multi-cavity plug 520 is bonded to the substrate 504. In this example, the first dielectric multi-cavity plug 520 has 30 to 100,000 cavities, each of which has a diameter between 1 micron and 200 microns. The cavities extend from a first side of the first dielectric multi-cavity plug 520 adjacent to the first plenum 518 to a second side of the first dielectric multi-cavity plug 520 opposite the first side. In this example, the first dielectric multi-cavity plug 520 extends to the surface of the substrate 504.

[0037] The second plenum 524 is on a second side of the first dielectric multi-cavity plug 520 opposite to the first side of the first dielectric multi-cavity plug 520. The first dielectric multi-cavity plug 520 is on the first side of the second plenum 524. The second plenum 524 is formed in the bonding layer 512. The ceramic plate 508 and the second dielectric multi-cavity plug 528 formed of aluminum oxide or aluminum nitride having a plurality of small through holes are on the second side (opposite to the first side) of the second plenum 524. In this embodiment, the second dielectric multi-cavity plug 528 has a solid core 530 at the center. The second dielectric multi-cavity plug 528 is bonded to the ceramic plate 508. In this example, the second dielectric multi-cavity plug 528 has 30 to 100,000 cavities, wherein each cavity has a diameter between 1 micron and 200 microns. The cavities extend from a first side of the second dielectric multi-cavity plug 528 adjacent to the second plenum 524 to a second side of the second dielectric multi-cavity plug 528 opposite the first side. In this embodiment, the second dielectric multi-cavity plug 528 extends into the second plenum 524. The first side of the second dielectric multi-cavity plug 528 extends through the surface of the ceramic plate 508 into the area or layer defined by the bonding layer 512. In this embodiment, the second dielectric multi-cavity plug 528 extends into the second plenum 524 to form an overhang of approximately 50 to 80% of the gap distance, which in this particular example is between 0.01 mm and 0.25 mm. In this example, the gap distance is the thickness of the bonding layer 512.

[0038] The third plenum 532 is on the second side of the second dielectric multi-cavity plug 528. At least one He hole 536 extends from the third plenum 532 to the surface of the ceramic plate 508. In this example, the at least one He hole 536 has a diameter between 0.2 and 0.3 mm. The solid core 522 of the first dielectric multi-cavity plug 520 and the solid core 530 of the second dielectric multi-cavity plug 528 each have a width and are arranged to prevent a direct line of sight path from the He supply line hole 516 through the cavities of the first dielectric multi-cavity plug 520 and the second dielectric multi-cavity plug 528 to the at least one He hole 536. These cavities allow for increased He flow. By extending the second dielectric multi-cavity plug 528 into the second plenum 524, the height of the second plenum 524 is reduced and arcing is further reduced.

[0039] Figure 66 is a schematic cross-sectional view of a spark suppression device in a portion of an ESC 600 that may be used in another embodiment. In this embodiment, the ESC 600 includes a substrate 604 bonded to a ceramic plate 608 by a bonding layer 612. In this embodiment, the substrate 604 is a conductive metal substrate 604, such as aluminum. The substrate 604 has a He supply line hole 616. At the output end of the He supply line hole 616 is a cavity 618. In this embodiment, the cavity 618 is T-shaped. Partially filling the T-shaped cavity 618 is a dielectric multi-cavity plug 620. In this embodiment, the dielectric multi-cavity plug 620 has a central through hole 622 extending partially through the center of the dielectric multi-cavity plug 620, the central through hole 622 having a diameter of 2 to 10 mm. A plurality of He through holes 623 extend from the central through hole 622 to a first plenum 624 within the dielectric multi-cavity plug 620. In this embodiment, the first plenum 624 has a diameter between 1 mm and 10 mm and a height of 0.01 mm to 0.5 mm. In this embodiment, there are between 1 and 300 He through holes 623, and the He through holes 623 have a diameter from 30 microns to 1 mm. A plurality of cavities 628 extend from the first plenum 624 to a second plenum 632 adjacent to the surface of the dielectric multi-cavity plug 620. In this example, the dielectric multi-cavity plug 620 has 30 to 500 cavities 628, wherein each cavity 628 has a diameter between 30 microns and 150 microns. The plurality of cavities 628 can be placed to form concentric circles. At least one He hole 636 is on the second side (opposite to the first side) of the second plenum 632, and the at least one He hole 636 extends from the second plenum 632 to the surface of the ceramic plate 608. In this example, the at least one He hole 636 has a diameter between 0.2 and 0.3 mm. The He supply line hole 616 and the at least one He hole 636 form a helium line, wherein the He supply line hole 616 is a first portion of the He line and the at least one He hole 636 is a second portion of the He line.

[0040] The He through-hole 623 and the plurality of cavities 628 are placed in a manner that there is no direct line of sight from the top of the dielectric multi-cavity plug 620 to the bottom thereof. For example, if placed in a circle, the diameter of the circle formed by the He through-hole 623 is significantly different from the diameter of the circle formed by the plurality of cavities 628. In this embodiment, the multi-cavity core 640 is attached to the outer plug 644 by bonding or ceramic lamination or any other process to form the dielectric multi-cavity plug 620. As shown, the plurality of cavities 628 are formed through the multi-cavity core 640. The bottom of the multi-cavity core 640 is separated from the top of the central cavity in the outer plug 644 to provide space for forming the first plenum 624. Such an arrangement enables the dielectric multi-cavity plug 620 to be formed more easily. The dielectric multi-cavity plug 620 is T-shaped. In this embodiment, the top of the T-shaped dielectric multi-cavity plug 620 is bonded to the top of the T-shaped cavity 618 of the substrate 604. A gap 652 is between the bottom of the T-shaped dielectric multi-cavity plug 620 and the T-shaped cavity 618. In this embodiment, the gap is between 0.1 mm and 1 mm.

[0041] Charge can travel along the surface of the T-shaped dielectric multi-cavity plug 620 and reach the conductive substrate 604. The gap 652 creates a longer surface length from the at least one He hole 636 through the second plenum 632, multiple cavities 628, the first plenum 624, multiple He through holes 623, the central through hole 622, and the outer surface of the bottom of the outer plug 644 to the substrate 604. The increase in surface length reduces arcing. Since the top of the T-shaped dielectric multi-cavity plug 620 is engaged with the top of the T-shaped cavity 618 of the substrate 604 with an air seal, the gap 652 is airtight, so that He passing from the He supply pipeline hole 616 flows through the central through hole 622, multiple He through holes 623, the first plenum 624, the cavity 628, the second plenum 632 and reaches the He hole 636. It has been found that this embodiment prevents arcing in excess of 50kW.

[0042] Figure 77 is a schematic cross-sectional view of a spark suppression device in a portion of an ESC 700 that may be used in another embodiment. In this embodiment, the ESC 700 includes a substrate 704 bonded to a ceramic plate 708 by a bonding layer 712. In this embodiment, the substrate 704 is a conductive metal substrate 704. The substrate 704 has a He supply line hole 716. At the output end of the He supply line hole 716 is a cavity 718. In this embodiment, the cavity 718 is T-shaped. Partially filling the cavity 718 is a dielectric multi-cavity plug 720. In this embodiment, the dielectric multi-cavity plug 720 has a central core 740 having a central through hole 722 with a diameter of 2 to 10 mm, and the central core 740 extends partially through the center of the dielectric multi-cavity plug 720 to a first plenum 724 within the dielectric multi-cavity plug 720. A plurality of cavities 728 extend from the first plenum 724 to a second plenum 732 adjacent to the surface of the dielectric multi-cavity plug 720. In this example, the dielectric multi-cavity plug 720 has 30 to 500 cavities 728, wherein each cavity 728 has a diameter between 1 micron and 150 microns. The plurality of cavities 728 may be placed to form concentric circles. All cavities 728 must be spaced from the central through hole 722 to avoid a direct line of sight from the top of the dielectric multi-cavity plug 720 to its bottom. At least one He hole 736 is on a second side (opposite to the first side) of the second plenum 732, the at least one He hole 736 extending from the second plenum 732 to the surface of the ceramic plate 708. In this example, the at least one He hole 736 has a diameter between 0.02 and 0.3 mm. The He supply line hole 716 and the at least one He hole 736 form a helium line, wherein the He supply line hole 716 is a first portion of the He line and the at least one He hole 736 is a second portion of the He line.

[0043] The plurality of cavities 728 are placed in a manner that there is no direct line of sight from the top of the dielectric multi-cavity plug 720 to the bottom of the dielectric multi-cavity plug 720. In this embodiment, the central core 740 is joined in the outer plug 744 to form the dielectric multi-cavity plug 720. As shown, the cavities 728 are formed through the outer plug 744. The top surface of the central core 740 is separated from the surface of the central cavity in the outer plug 744 to provide space to form the first plenum 724. Such an arrangement allows the dielectric multi-cavity plug 720 to become easier to form. The dielectric multi-cavity plug 720 is T-shaped. In this embodiment, the top of the T-shaped dielectric multi-cavity plug 720 is joined to the top of the T-shaped cavity 718 of the substrate 704. As explained in the previous embodiment, a gap is between the bottom of the T-shaped dielectric multi-cavity plug 720 and the T-shaped cavity 718 to reduce arcing. In this embodiment, the gap is between 0.1 mm and 1 mm.

[0044] Figure 8 8 is a schematic cross-sectional view of a spark suppression device in a portion of an ESC 800 that can be used in another embodiment. In this embodiment, the ESC 800 includes a substrate 804 bonded to a ceramic plate 808 by a bonding layer 812. In this embodiment, the substrate 804 is a conductive metal substrate 804. The substrate 804 has a He supply line hole 816. At the output end of the He supply line hole 816 is a cavity 818. In this embodiment, the cavity 818 is T-shaped. Partially filling the cavity 818 is a dielectric multi-cavity plug 820. In this embodiment, the dielectric multi-cavity plug 820 includes a central core 840 and an outer plug 844. A cylindrical gap 822 is between the central core 840 and the outer plug. The central core has an upside-down T-shape with a flange attached to the outer plug 844. In order to facilitate He entry into the cylindrical gap 822, there are multiple openings or cutouts in the flange of the central core 840. The cylindrical gap 822 extends to the first plenum 824. As shown, these cavities 828 are formed through the external plug 844. The top surface of the central core 840 is separated from the surface of the central cavity in the external plug 844 to provide a space for forming the first plenum 824. A plurality of cavities 828 extend from the first plenum 824 to the second plenum 832 adjacent to the surface of the dielectric multi-cavity plug 820. In this example, the dielectric multi-cavity plug 820 has 30 to 500 cavities 828, wherein each cavity 828 has a diameter between 1 micron and 150 microns. A plurality of cavities 828 can be placed to form concentric circles. At least one He hole 836 is on the second side (opposite to the first side) of the second plenum 832, and the at least one He hole 836 extends from the second plenum 832 to the surface of the ceramic plate 808. In this example, the at least one He hole 836 has a diameter between 0.2 and 0.3 mm. A slit 848 at the bottom of the central core 840 allows gas to pass from the He supply line hole 816 to the cylindrical gap 822.

[0045] The dielectric multi-cavity plug 820 is T-shaped. In this embodiment, the top of the T-shaped dielectric multi-cavity plug 820 engages the top of the T-shaped cavity 818 of the substrate 804. A gap is between the bottom of the T-shaped dielectric multi-cavity plug 820 and the T-shaped cavity 818 to reduce arcing. In this embodiment, the gap is between 0.1 mm and 1 mm. The cavity 828 is placed away from the cylindrical gap 822 to avoid a direct line of sight from the top of the dielectric multi-cavity plug 820 to its bottom.

[0046] Fig. 99 is a schematic cross-sectional view of a spark suppression device in a portion of an ESC 900 that may be used in another embodiment. In this embodiment, the ESC 900 includes a substrate 904 bonded to a ceramic plate 908 by a bonding layer 912. In this embodiment, the substrate 904 is a conductive metal substrate 904. The substrate 904 has a He supply line hole 916. At the output end of the He supply line hole 916 is a cavity 918. In this embodiment, the cavity 918 is T-shaped. Partially filling the cavity 918 is a dielectric multi-cavity plug 920. A cylindrical groove 922 is formed in the dielectric multi-cavity plug 920, extending from the bottom of the dielectric multi-cavity plug 920 toward the top of the dielectric multi-cavity plug 920. The cylindrical groove 922 forms a first plenum. The cavity 928 is formed as a second plenum 932 extending from the cylindrical groove 922 to the top of the dielectric multi-cavity plug 920 and adjacent to the surface of the dielectric multi-cavity plug 920. In this example, the dielectric multi-cavity plug 920 has 30 to 500 cavities 928, wherein each cavity 928 has a diameter between 1 micron and 150 microns. The plurality of cavities 928 may be placed to form concentric circles. At least one He hole 936 is on a second side (opposite to the first side) of the second plenum 932, the at least one He hole 936 extending from the second plenum 932 to the surface of the ceramic plate 908. In this example, the at least one He hole 936 has a diameter between 0.02 and 0.3 mm. The He supply line hole 916 and the at least one He hole 936 form a helium line, wherein the He supply line hole 916 is a first portion of the He line, and the at least one He hole 936 is a second portion of the He line.

[0047] The dielectric multi-cavity plug 920 is T-shaped. In this embodiment, the top of the T-shaped dielectric multi-cavity plug 920 engages the top of the T-shaped cavity 918 of the substrate 904. A gap is between the bottom of the T-shaped dielectric multi-cavity plug 920 and the T-shaped cavity 918 to reduce arcing. In this embodiment, the gap is between 0.1 mm and 1 mm.

[0048] Other embodiments may have different combinations of the various features of these different embodiments. Figure 5 A dielectric multi-cavity plug such as the second dielectric multi-cavity plug 528 of the embodiment shown in FIG. 1 and a third plenum 532 may be provided in the embodiment shown in FIG. Figure 6 , Figure 7 , Figure 8 and Fig. 9 The ceramic plates 608, 708, 808 and 908 of the embodiment shown in FIG.

[0049] Fig.101 is a schematic diagram of an embodiment of a semiconductor processing chamber 1000 that can be used to process semiconductor wafers. In one or more embodiments, the semiconductor processing chamber 1000 includes a gas distribution plate 1006 that provides a gas inlet and an electrostatic chuck (ESC) 1008, which is within an etching chamber 1049 surrounded by a chamber wall 1052. Within the etching chamber 1049, a wafer 1003 is placed above the ESC 1008. The ESC 1008 is a wafer support. An edge ring 1009 surrounds the ESC 1008. The ESC source 1048 can supply a bias voltage to the ESC 1008. A gas source 1010 is connected to the etching chamber 1049 through the gas distribution plate 1006. An ESC He source 1050 is connected to the ESC 1008.

[0050] Radio frequency (RF) source 1030 supplies RF power to the lower electrode, the upper outer electrode 1016, and the upper inner electrode. In this embodiment, ESC 1008 is the lower electrode and gas distribution plate 1006 is the upper inner electrode. In an exemplary embodiment, 400 kilohertz (kHz), 60 megahertz (MHz), 2MHz, 13.56MHz, and / or 27MHz power sources constitute RF source 1030 and ESC source 1048. In this embodiment, a generator is provided for each frequency. In other embodiments, these generators can be separate RF sources, or separate RF generators can be connected to different electrodes. Other configurations of RF source and electrode can be used in other embodiments. In other embodiments, the electrode can be an induction coil.

[0051] The controller 1035 is controllably connected to the RF source 1030, the ESC source 1048, the exhaust pump 1020, and the gas source 1010. The high flow liner 1004 is a liner within the etching chamber 1049. The high flow liner 1004 in this embodiment is a C-shaped shield and confines the gas from the gas source, and has a groove 1002. The high flow liner 1004 allows a controlled gas flow to flow from the gas source 1010 to the exhaust pump 1020.

[0052] During processing, He gas may be supplied from the ESC He source 1050 to the back of the ESC 1008 to provide heat conduction. The RF source 1030 provides power to form a plasma. The plasma may cause arcing. The arcing may be transmitted toward the He source and damage the ESC 1008. The above-described embodiments reduce arcing and thus reduce damage to the ESC 1008.

[0053] Although the present disclosure has been described according to several embodiments, there are changes, modifications, permutations, and various alternative equivalents that fall within the scope of the present disclosure. It should also be noted that there are many alternatives to the methods and devices of the present disclosure. Therefore, the following appended claims are intended to be interpreted as including all such changes, modifications, permutations, and various alternative equivalents that fall within the true spirit and scope of the present disclosure.

Claims

1. A spark suppression device for a wafer backside cooling line, the wafer backside cooling line being in an electrostatic chuck within a plasma processing chamber, the spark suppression device comprising a dielectric multi-cavity plug in the wafer backside cooling line, wherein the dielectric multi-cavity plug has a plurality of cavities, wherein the wafer backside cooling line has a first portion on a first side of the dielectric multi-cavity plug and a second portion on a second side of the dielectric multi-cavity plug, and wherein cavities of the plurality of cavities are not positioned along a straight line between the first portion of the wafer backside cooling line and the second portion of the wafer backside cooling line, wherein the dielectric multi-cavity plug is T-shaped, and wherein the dielectric multi-cavity plug is mounted in a T-shaped cavity, and wherein the dielectric multi-cavity plug does not extend to a bottom of the T-shaped cavity.

2. The spark suppression device according to claim 1, further comprising: A first plenum on the first side of the dielectric multi-cavity plug and a second plenum on the second side of the dielectric multi-cavity plug, the second side being opposite the first side, wherein the plurality of cavities extend from the first plenum to the second plenum.

3. The spark suppression device of claim 1 , wherein the dielectric multi-cavity plug further comprises a solid core between the first portion of the wafer back side cooling line and the second portion of the wafer back side cooling line, and wherein the plurality of cavities surround the solid core. 4 . The spark suppression device of claim 2 , wherein the dielectric multi-cavity plug extends into at least one of the first plenum and the second plenum.

5. The spark suppression device of claim 1, wherein the dielectric multi-cavity plug is a dielectric ceramic plug.

6. The spark suppression device of claim 1, wherein the dielectric multi-cavity plug is engaged with the electrostatic chuck.

7. The spark suppression device of claim 1, wherein the dielectric multi-cavity plug further comprises a first plenum chamber within the dielectric multi-cavity plug, and wherein the plurality of cavities extend from the first plenum chamber to a surface of the dielectric multi-cavity plug.

8. The spark suppression device of claim 7 further comprising a second plenum adjacent to the surface of the dielectric multi-cavity plug to which the plurality of cavities extend.

9. The spark suppression device of claim 1, wherein a top portion of the dielectric multi-cavity plug engages a top portion of the T-shaped cavity, and further comprising a gap between the T-shaped cavity and the dielectric multi-cavity plug below the top portion of the T-shaped cavity.

10. The spark suppression device of claim 1, wherein the electrostatic chuck comprises a base plate, a ceramic plate, a bonding layer between the base plate and the ceramic plate, wherein the spark suppression device further comprises a first plenum between the base plate and the ceramic plate, wherein the first plenum is adjacent to the dielectric multi-cavity plug, and wherein the plurality of cavities extend to the first plenum.

11. The spark suppression device of claim 10, wherein the dielectric multi-cavity plug is engaged with the substrate or the ceramic plate.

12. The spark suppression device of claim 10, wherein the dielectric multi-cavity plug is engaged with the ceramic plate, wherein the spark suppression device further comprises a second plenum on a side of the dielectric multi-cavity plug opposite the first plenum, and wherein the plurality of cavities extend from the first plenum to the second plenum.

13. The spark suppression device according to claim 1, wherein: The plurality of cavities ranges in number from 30 to 100,000 cavities, inclusive, and has a width between 1 micron and 200 microns, inclusive.

14. A spark suppression device for a wafer backside cooling line in an electrostatic chuck within a plasma processing chamber, the spark suppression device comprising: A dielectric multi-cavity plug in the wafer back side cooling line, wherein the dielectric multi-cavity plug has a plurality of cavities, wherein the wafer back side cooling line has a first portion on a first side of the dielectric multi-cavity plug, and a second portion on a second side of the dielectric multi-cavity plug, and wherein cavities of the plurality of cavities are not positioned along a straight line between the first portion of the wafer back side cooling line and the second portion of the wafer back side cooling line, a first plenum on the first side of the dielectric multi-cavity plug, and a second plenum on the second side of the dielectric multi-cavity plug, the second side being an opposite side to the first side, wherein the plurality of cavities extend from the first plenum to the second plenum, a dielectric plug adjacent to the second plenum, the dielectric plug being spaced apart on a side of the second plenum opposite to the dielectric multi-cavity plug.

15. The spark suppression device of claim 14, wherein the dielectric plug is a porous dielectric plug or includes a second plurality of cavities extending through the dielectric plug.

16. A spark suppression device for a wafer backside cooling line in an electrostatic chuck within a plasma processing chamber, the spark suppression device comprising: a dielectric multi-cavity plug in the wafer backside cooling line, wherein the dielectric multi-cavity plug has a plurality of cavities, wherein the wafer backside cooling line has a first portion on a first side of the dielectric multi-cavity plug and a second portion on a second side of the dielectric multi-cavity plug, and wherein cavities of the plurality of cavities are not positioned along a straight line between the first portion of the wafer backside cooling line and the second portion of the wafer backside cooling line, wherein the electrostatic chuck comprises a substrate, a ceramic plate, a bonding layer between the substrate and the ceramic plate, wherein the spark suppression device further comprises a first plenum between the substrate and the ceramic plate, wherein the first plenum is adjacent to the dielectric multi-cavity plug, and wherein the plurality of cavities extend to the first plenum, wherein the dielectric multi-cavity plug is bonded to the ceramic plate, wherein the spark suppression device further comprises a second plenum on a side of the dielectric multi-cavity plug opposite the first plenum, and wherein the plurality of cavities extend from the first plenum to the second plenum, and the spark suppression device further comprises: a dielectric plug on an opposite side of the first plenum from the dielectric multi-cavity plug; and A third plenum is on an opposite side of the dielectric plug from the first plenum, wherein the dielectric plug includes a plurality of cavities extending from the first plenum to the third plenum.

17. A spark suppression device for a wafer backside cooling line in an electrostatic chuck within a plasma processing chamber, the spark suppression device comprising: A dielectric multi-cavity plug in the wafer backside cooling line, wherein the dielectric multi-cavity plug has a plurality of cavities, wherein the wafer backside cooling line has a first portion on a first side of the dielectric multi-cavity plug and a second portion on a second side of the dielectric multi-cavity plug, and wherein cavities of the plurality of cavities are not positioned along a straight line between the first portion of the wafer backside cooling line and the second portion of the wafer backside cooling line, a first plenum on the first side of the dielectric multi-cavity plug, and a second plenum on the second side of the dielectric multi-cavity plug, the second side being an opposite side to the first side, wherein the plurality of cavities extend from the first plenum to the second plenum, a dielectric plug adjacent to the second plenum, the dielectric plug being spaced apart on a side of the second plenum opposite to the dielectric multi-cavity plug, wherein the dielectric plug is a porous dielectric plug or includes a plurality of cavities extending through the dielectric plug, the dielectric multi-cavity plug extending into the first plenum such that the dielectric multi-cavity plug forms an overhang.

18. The spark suppression device according to claim 17, wherein: The end of the dielectric multi-cavity plug extends to the first plenum chamber such that a gap in the range of 0.01 mm to 0.25 mm is formed between the end of the dielectric multi-cavity plug and the dielectric plug.

19. A spark suppression device for a wafer backside cooling line in an electrostatic chuck within a plasma processing chamber, the spark suppression device comprising: A dielectric multi-cavity plug in the wafer back side cooling line, wherein the dielectric multi-cavity plug has a plurality of cavities, wherein the wafer back side cooling line has a first portion on a first side of the dielectric multi-cavity plug and a second portion on a second side of the dielectric multi-cavity plug, and wherein cavities of the plurality of cavities are not located along a straight line between the first portion of the wafer back side cooling line and the second portion of the wafer back side cooling line, a first plenum on the first side of the dielectric multi-cavity plug, and a second plenum on the second side of the dielectric multi-cavity plug, the second side being opposite to the first side, wherein the plurality of cavities extend from the first plenum to the second plenum, a dielectric plug adjacent to the second plenum, the dielectric plug being spaced apart on a side of the second plenum opposite to the dielectric multi-cavity plug, wherein the dielectric plug includes a second plurality of cavities, wherein the cavities of the second plurality of cavities are not located along a straight line between the first portion of the wafer back side cooling line and the second portion of the wafer back side cooling line.

20. The spark suppression device of claim 19, wherein the dielectric multi-cavity plug further comprises a solid core between the first portion of the wafer back side cooling line and the second portion of the wafer back side cooling line, and wherein the plurality of cavities surround the solid core.

21. A spark suppression device for a wafer backside cooling line in an electrostatic chuck within a plasma processing chamber, the spark suppression device comprising a T-shaped dielectric multi-cavity plug in the wafer backside cooling line, wherein the T-shaped dielectric multi-cavity plug has a plurality of cavities, wherein: The T-shaped dielectric multi-cavity plug is installed in the T-shaped cavity.

22. The spark suppression device of claim 21, wherein the electrostatic chuck comprises a base plate, a ceramic plate, a bonding layer between the base plate and the ceramic plate, wherein the T-shaped dielectric multi-cavity plug extends from the bonding layer into the base plate, wherein the T-shaped dielectric multi-cavity plug has a first end adjacent to the bonding layer and a second end spaced apart from the first end, wherein the second end does not contact the base plate.

23. The spark suppression device according to claim 22, wherein: The bonding layer covers a region where the first end of the T-shaped dielectric multi-cavity plug contacts the substrate.

24. The spark suppression device according to claim 21, wherein: The wafer back side cooling line has a first portion on a first side of the T-shaped dielectric multi-cavity plug and a second portion on a second side of the T-shaped dielectric multi-cavity plug, and wherein the plurality of cavities are not positioned along a straight line between the first portion of the wafer back side cooling line and the second portion of the wafer back side cooling line.

25. The spark suppression device according to claim 21, wherein: The plurality of cavities ranges in number from 30 to 100,000 cavities, inclusive, and has a width between 1 micron and 200 microns, inclusive.

26. The spark suppression device of claim 21, wherein a top portion of the T-shaped dielectric multi-cavity plug engages a top portion of the T-shaped cavity, and further comprising a gap between the T-shaped cavity and the T-shaped dielectric multi-cavity plug below the top portion of the T-shaped cavity.

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