Process chamber improvement

Abstract

A process chamber is provided including: a chamber body disposed around an interior volume; a substrate support in the interior volume, the substrate support having a substrate supporting surface; a gas delivery assembly positioned over the substrate support. A central vertical axis extends through the gas delivery assembly and through a center of the substrate support, and the substrate support includes an inner portion and an outer portion, the outer portion located further from the central vertical axis than the inner portion is to the central vertical axis. The process chamber further includes an electrode in the substrate support, the electrode located in the outer portion of the substrate support without extending into the inner portion of the substrate support.

Description

PROCESS CHAMBER IMPROVEMENT BACKGROUNDField

[0001] Embodiments of the present disclosure generally relate to process chambers having improvements relating to the gas supply and substrate support as well as related methods.Description of the Related Art

[0002] The edge region of substrates (e.g., semiconductor substrates) is often processed differently than the remainder of the substrate during various processes performed on substrates, such as plasma processing (e.g., plasma enhanced chemical vapor deposition). Depending on the particular process, this difference in processing of the edge region of the substrate may be unintentional or intentional.

[0003] Plasma processing of substrates (e.g., plasma etching or plasma deposition) is one example of a process where the edge region of the substrate is often unintentionally processed differently than the remainder of the substrate. Attempts are often made to make the plasma processing more uniform from the center to the edge of the substrate. Despite these attempts at achieving higher levels of uniformity in plasma processing, the edge region of the substrate can often still unintentionally be processed significantly different than the remainder of the substrate, such as a deposition thickness in the edge region that is significantly different than the remainder of the substrate. Thus, there is an ongoing need to improve the uniformity of plasma processing on substrates from the center to the edge of the substrates.

[0004] For other processes, there may be an intentional difference for the process results on the edge region of the substrate compared to the remainder of the substrate. For example, many substrates have a bevel at the edge of the substrate, which improves the mechanical strength of the substrate leading to less chipping and cracking during handling of the substrate. Although the edge region with the bevel can improve the mechanical strength of the substrate, the edge region can often become a region with increased occurrences of defects,such as defects leading to deposited films flaking off. These defects can lead to the generation of particles in the process chamber, which can damage that substrate or subsequent substrates processed in the same process chamber. These defects can also cause problems with subsequent processing of the substrate having the defect. For example, wafer bonding can be more challenging when the substrates being bonded have high levels of defects near the edge of the substrates. Thus, there is an ongoing need to reduce the occurrences of defects in the edge regions of substrates during processing of substrates, such as plasma processing.SUMMARY

[0005] Embodiments of the present disclosure generally relate to process chambers having improvements relating to the gas supply and substrate support as well as related methods.

[0006] In one embodiment, a process chamber is provided comprising: a chamber body disposed around an interior volume; a substrate support in the interior volume, the substrate support having a substrate supporting surface; a gas delivery assembly positioned over the substrate support, wherein a central vertical axis extends through the gas delivery assembly and through a center of the substrate support, and the substrate support includes an inner portion and an outer portion, the outer portion located further from the central vertical axis than the inner portion is to the central vertical axis; and an electrode in the substrate support, the electrode located in the outer portion of the substrate support without extending into the inner portion of the substrate support.

[0007] In another embodiment, a process chamber is provided comprising: a chamber body disposed around an interior volume; a substrate support in the interior volume, the substrate support having a substrate supporting surface; and a gas delivery assembly positioned over the substrate support, wherein a central vertical axis extends through the gas delivery assembly and through a center of the substrate support, and the gas delivery assembly includes an electrically insulating inner portion and an electrically conductive outer portiondisposed around the inner portion, the outer portion located further from the central vertical axis than the inner portion is to the central vertical axis.

[0008] In another embodiment, .a system for process a substrate comprising: a chamber body disposed around an interior volume; a substrate support in the interior volume, the substrate support having a substrate supporting surface; a gas delivery assembly positioned over the substrate support, wherein a central vertical axis extends through the gas delivery assembly and through a center of the substrate support, and the gas delivery assembly includes an electrically insulating inner portion and an electrically conductive outer portion disposed around the inner portion, the outer portion of the gas delivery assembly located further from the central vertical axis than the inner portion is to the central vertical axis, the substrate support includes an inner portion and an outer portion, the outer portion of the substrate support located further from the central vertical axis than the inner portion is to the central vertical axis, and a radio frequency power source electrically connected to the conductive outer portion of the gas delivery assembly.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, may admit to other equally effective embodiments.

[0010] Figure 1 A shows a side cross-sectional view of a processing system 100, according to one embodiment.

[0011] Figure 1B shows a side cross-sectional view of the gas delivery assembly from Figure 1A, according to one embodiment.

[0012] Figure 1C is a close-up view of a portion of the right side of Figure 1A to show additional detail for processing the edge region of the substrate, according to one embodiment.

[0013] Figure 2 is a process flow diagram of a method for performing a process on the outer region of a substrate in the process chamber using the processing system of Figure 1 A and then performing an optional wafer bonding processing using the substrate and another substrate, according to one embodiment.

[0014] Figures 3A, 3B, and 3C show partial cross-sectional views of two substrates during different portions of the method described in reference to Figure 2, according to one embodiment.

[0015] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.DETAILED DESCRIPTION

[0016] Embodiments of the present disclosure generally relate to process chambers having improvements relating to the gas supply and substrate support as well as related methods. These improvements relating to the gas supply and the substrate support allow a process to be performed only on an outer region of the substrate without the process being performed on the inner region of the substrate. In some embodiments, the outer region of the substrate can be a small portion of the substrate, such as less than 20%, less than 10%, or less than 5% of the substrate, such as from about 1 % to about 5% of the substrate. For example, in one embodiment, a process is performed on the outer 145-150 mm radial portion of a 300 mm substrate without being performed on the inner 145 mm radial portion of the substrate.

[0017] The gas supply equipment is improved (1 ) by orienting the gas to flow in a radially outward direction in the interior volume of the process chamber, and (2) by arranging the gas flow outlets of the gas supply equipment to causethe gas flowing through the independent channels of the gas supply equipment to mix over edge region of the substrate while substantially preventing mixing of the different gases over the inner regions of the substrate. For plasma processes, the gas supply equipment is improved by having the gas delivery assembly formed of an electrically insulating inner portion and an electrically conductive outer portion. Radio Frequency (RF) power can be coupled to the electrically conductive outer portion, so that a plasma can be generated in regions of the interior volume directly underlying the conductive outer portion of the gas delivery assembly while not being generated in the regions underlying the electrically insulating inner portion.

[0018] The substrate support is improved by including an electrode that is positioned in an outer portion of the substrate support while the inner portion of the substrate support does not include an electrode for the plasma process. This electrode can be positioned to underlie the outer portion of the substrate during processing, such as the outer 145-150 mm portion of a 150 mm substrate. The electrode can be grounded and can serve as the ground connection for the RF power that is provided to the electrically conductive outer portion of the gas delivery assembly. The location of the electrode in the outer portion of the substrate support also assists in only forming the plasma over an edge region of the substrate without forming the plasma over the remaining inner portion of the substrate.

[0019] Performing a process (e.g., a plasma process) on only part of the substrate (e.g., portion near the outer edge) can be used to improve nonuniformities at the outer edge (e.g., thickness non-uniformities) or can be used to address problems occurring near outer edge of the substrate, such as flaking of deposited films near a beveled edge of the substrate.

[0020] Although the following disclosure is mainly directed to embodiments configured to perform a plasma process on a substrate, the benefits of this disclosure can also be applied to processes other than plasma processes, such as depositions that are unassisted by plasma. For example, the gas flow channels of the gas delivery channels as described in further detail below can be configured to only allow mixing of one or more reactant gases over the outeredge region of the substrate, so that the intended deposition does not occur on the inner region of the substrate.

[0021] Figure 1 A shows a side cross-sectional view of a processing system 100, according to one embodiment. The processing system 100 includes a process chamber 101, a gas supply system 140, a vacuum pump 155, a radio frequency (RF) power source 160, and a controller 185.

[0022] The gas supply system 140 includes a first gas source 141 and a second gas source 142. In one embodiment, which can be combined with other embodiments, the first gas source 141 stores a first reactant (e.g., oxygen (O2) or nitrous oxide (N2O)) or a non-reactive purge gas (e.g., argon or helium), and the second gas source 142 stores one or more reactant gases (e.g., silane (SiF ) or tetraethoxysilane (TEOS)) As described in fuller detail below, the gases from the gas sources flow in a radially outward direction towards the interior walls of the process chamber 101 upon entering the interior volume of the process chamber 101. The direction of these gas flows allows the gases to be combined in a space overlying the outer edge of the substrate, so that the intended process (e.g., a deposition) can be performed over the outer edge of the substrate without being performed over the remainder of the substrate. Although much of the disclosure describes supplying process gases to the process chamber 101 for performing a process on a substrate in the process chamber 101, the gas delivery assembly 120 described below is also useful for directing cleaning gases (e.g., NF3) in a radially outward direction inside the process chamber 101, so that the cleaning gases flow along a similar path as the process gases used to perform the process on the substrate in the process chamber 101.

[0023] The process chamber 101 includes a chamber body 102 disposed around an interior volume 109. The chamber body 102 includes a top 103, a bottom 104, and one or more sidewalls 105 connecting the top 103 with the bottom 104. The process chamber 101 can include one or more ports (not shown) that are configured to open to allow the transferring of one or more substrates 50 into and out of the interior volume 109 of the process chamber 101.

[0024] The process chamber 101 further includes a substrate support assembly 110 that includes a substrate support 112 positioned in the interior volume 109. The substrate support assembly 110 further includes a shaft 111 coupled to the substrate support 112. The substate support 112 can further include a heater (not shown), such as a resistive heater. The substrate support 112 can be formed of an electrically insulating material with high thermal conductivity, such as aluminum nitride.

[0025] The substrate support 112 can include a substrate supporting surface 113. A substrate 50A can be positioned on the substrate supporting surface 113 of the substrate support 112. The substrate 50A can include a top surface 51 , a back surface 52, and a beveled outer edge 55. As described in further detail below, the substrate 50A can include a first layer 60A deposited over the top surface 51 of the substrate 50A.

[0026] In some embodiments, the shaft 111 can be coupled to an actuator (not shown), which can rotate the shaft 111 and substrate support 112 during processing. In embodiments including an actuator for rotation, the rotation of the shaft 111 can be used to rotate the substrate support 112 and the substrate 50A positioned on the substrate support 112 during processing. The rotation of the substrate 50A can improve process uniformity for the process (e.g., deposition) being performed on the substrate 50A.

[0027] The substrate support assembly 110 can further include one or more conductors 115 and an electrode 116. The electrode 116 is positioned inside the substrate support 112. The electrode 116 can be connected to electrical ground through the one or more conductors 115. RF power from the RF power source 160 can be coupled to the electrode 116 during processing. The electrode 116 can have an annular shape when viewed from above. In some embodiments, which can be combined with other embodiments, the electrode 116 can be formed of a conductive mesh. Furthermore, in some embodiments, which can be combined with other embodiments, the electrode 116 is the only electrode in the substrate support 112 or the only electrically grounded electrode in the substrate support 112. In these embodiments, the electrode 116 is the only electrode used for the generation of the plasma P, but there maybe another electrode, such as another electrode used for electrostatic chucking of the substrate. If a separate electrode is used for electrostatic chucking, then a direct current voltage is typically applied to this separate electrode. This separate electrode is electrically isolated from the electrode 116 to ensure the RF power provided to the electrode 116 does not leak over to this separate electrode. By having the electrode 116 be the only electrode used for plasma generation, the plasma P is confined to the intended region over the outer portion of the substrate 50A.

[0028] The electrode 116 is positioned to underlie the outer edge region of the substrate 50A while not underlying a central portion of the substrate 50A as described in more detail below. The position of the electrode 116 in the outer portion of the substrate support 112 can be used to generate a plasma P only over an outer edge region of the substrate 50A while not generating the plasma P over a central region of the substrate 50A as described in further detail below.

[0029] The process chamber 101 further includes a gas delivery assembly 120 positioned over the substrate support 112. In some embodiments, which can be combined with other embodiments, the gas delivery assembly 120 can form a portion or all of the top 103 of the process chamber 101. In some embodiments, which can be combined with other embodiments, the gas delivery assembly 120, can be configured to have a showerhead arrangement of orifices that are configured to direct gases into the interior volume 109 of the process chamber 101.

[0030] The gas delivery assembly 120 can include an inner portion 121 and an outer portion 130 disposed around the inner portion 121. The inner portion 121 can be formed of an electrically insulating material, such as an electrically insulating ceramic or plastic material. The outer portion 130 can be formed of an electrically conductive material, such as aluminum.

[0031] The inner portion 121 of the gas delivery assembly 120 includes a first gas flow channel 122 for supplying one or more gases from the first gas source 141 to the interior volume 109 of the process chamber 101. The processing system 100 further includes a first conduit 145 positioned over thegas delivery assembly 120. The first gas flow channel 122 of the gas delivery assembly 120 is fluidly coupled to the first gas source 141 of the gas supply system 140 through the first conduit 145.

[0032] The first gas flow channel 122 includes an inlet portion 123 and one or more outlet portions 124. The gas from the first gas source 141 flows through the first conduit 145, into the inlet portion 123 of the first gas flow channel 122, and then through the one or more outlet portions 124 to the interior volume 109. Each outlet portion 124 includes one or more outlets 125 for directing the one or more gases from the first gas source 141 into the interior volume 109. In some embodiments, which can be combined with other embodiments, the outlets125 can be arranged in a showerhead arrangement. In some embodiments, which can be combined with other embodiments, the outlet portion 124 is a single annular channel for most of the length of the outlet portion 124 with multiple outlets 125 spaced apart from each other in an angular direction in a showerhead arrangement around a central vertical axis C extending through the center 112C of the substrate support 112.

[0033] Figure 1B shows a side cross-sectional view of the gas delivery assembly 120 from Figure 1A, according to one embodiment. With reference to Figure 1 B, each outlet portion 124 includes an inlet 224. Each outlet portion 124 is angled relative to a vertical line extending through the inlet 224 of the outlet portion 124 at an angle from about 10 degrees to about 60 degrees, such as about 30 degrees. This angle at which the outlet portion 124 is oriented directs the gas in a radially outward direction towards the outer edge 55 of the substrate 50A. Used herein, radially outward refers to a horizontal direction away from the central vertical axis C extending through the center 51 C of the top surface 51 of the substrate 50A, which is the same as the horizontal direction away from the center 112C of the top surface 113 of the substrate support 112. The angle of the one or more outlet portions 124 can assist in providing high-velocity vectors for the gases to move in the radially outward direction. The outlets 125 of the one or more outlet portions 124 can also be oriented at a same or similar angle as the one or more outlet portion 124.

[0034] With reference to Figure 1 A, the inner portion 121 of the gas delivery assembly 120 further includes a second gas flow channel 126 for supplying one or more gases from the second gas source 142 to the interior volume 109 of the process chamber 101. The processing system 100 further includes a second conduit 146 positioned over the gas delivery assembly 120. In some embodiments, which can be combined with other embodiments, the second conduit 146 can be disposed around the first conduit 145. The second conduit 146 can have an annular shape in these embodiments. The second gas flow channel 126 of the gas delivery assembly 120 is fluidly coupled to the second gas source 142 of the gas supply system 140 through the second conduit 146.

[0035] The second gas flow channel 126 includes an inlet portion 127 and one or more outlet portions 128. The gas from the second gas source 142 flows through the second conduit 146, into the inlet portion 127 of the second gas flow channel 126, and then through the one or more outlet portions 128 to the interior volume 109. The inlet portion 127 can have an annular shape. Each outlet portion 128 includes one or more outlets 129 fluidly coupling the second gas flow channel 126 to the interior volume 109. In some embodiments, which can be combined with other embodiments, the outlets 129 can be arranged in a showerhead arrangement. In some embodiments, which can be combined with other embodiments, the outlet portion 128 is a single annular channel for most of the length of the outlet portion 128 with multiple outlets 129 spaced apart from each other in an angular direction in a showerhead arrangement around the central vertical axis C extending through the center 112C of the substrate support 112.

[0036] With reference to Figure 1 B, each outlet portion 128 includes an inlet 228. Each outlet portion 128 is angled relative to a vertical line extending through the inlet 228 of the outlet portion 128 at an angle from about 10 degrees to about 60 degrees, such as about 30 degrees. This angle at which the outlet portion 128 is oriented directs the gas from the second gas source 142 in a radially outward direction towards the outer edge 55 of the substrate 50A. The angle of the one or more outlet portions 128 can assist in providing high-velocity vectors for the gases to move in the radially outward direction. The outlets 129of the one or more outlet portions 128 can also be oriented at a same or similar angle as the one or more outlet portions 128.

[0037] With reference to Figure 1A, although the first gas flow channel 122 and the second gas flow channel 126 are shown entirely in the inner portion 121 of the gas delivery assembly 120, in some embodiments, which can be combined with other embodiments, portions or all of the gas flow channels 122, 126 can be located in the outer portion 130 of the gas delivery assembly. Although the gas delivery assembly 120 described includes two channels, the benefits of this disclosure can be applied to similar gas delivery assemblies having one gas flow channel or three or more separate gas flow channels that are configured to direct the corresponding gas in a radially outward direction. The first gas flow channel 122 is independent of the second gas flow channel 126, so that there is no mixing of the gases flowing through the separate channels 122, 126 until the gases reach the interior volume 109.

[0038] RF power from the RF power source 160 can be provided to the electrically conductive outer portion 130 of the gas delivery assembly 120. The RF energy provided to the outer portion 130 can be coupled through the interior volume 109 to the electrode 116. The RF energy generates a plasma P from the gases provided to the interior volume 109 from the gas supply system 140 as the RF energy is coupled from the outer portion 130 of the gas delivery assembly 120 to the electrode 116 in the substrate support 112 through the interior volume 109. The generated plasma P can have an annular shape due to the annular shapes of the outer portion 130 and the electrode 116.

[0039] The outer portion 130 of the gas delivery assembly 120 includes a lower surface 131 facing the substrate support 112. The conductive lower surface 131 can have an annular shape when viewed from below. The annular shape of the lower surface 131 can be similar to the annular shape of the electrode 116 in the substrate support 112. For example, portions of the lower surface 131 can directly overlie portions of the electrode 116. Used herein, directly overlie refers to locations that share the same horizontal positions in the X and Y-directions and only differ in the vertical positions (i.e. , Z-direction). In some embodiments, which can be combined with other embodiments, thelower surface 131 is the only surface of the outer portion 130 exposed to the interior volume 109. For example, in some of these embodiments, the outer portion 130 can be positioned on and / or against an insulator 135 that shields other surfaces of the outer portion 130 from the interior volume 109. The non-conductive, inner portion 121 of the gas delivery assembly 120 can also shield surfaces of the outer portion 130 of the gas delivery assembly 120 from the interior volume 109.

[0040] Figure 1C is a close-up view of a portion of the right side of Figure 1A to show additional detail for processing the edge region of the substrate 50A, according to one embodiment. With reference to Figures 1A and 1 C, the additional detail for the processing the edge region of the substrate 50A is described.

[0041] The lower surface 131 of the outer portion 130 of the gas delivery assembly 120 directly overlies the electrode 116 in the substrate support 112. The lower surface 131 and the electrode 116 can each have an annular shape. The annular shapes of the electrode 116 in the substrate support 112 and the lower surface 131 of the outer portion 130 of the gas delivery assembly 120 along with the overlying arrangement of the lower surface 131 relative to the electrode 116 enables the process chamber 101 to generate the plasma P to have an annular shape over the outer region of the substrate 50A. This annular plasma P enables a plasma process (e.g., deposition or etch) to be performed only over the outer region of the substrate 50A without performing the process to any significant degree over the remainder of the substrate 50A.

[0042] A vertical dividing line DL is used to describe different portions of (1 ) the interior volume 109, (2) the substrate 50A, and (3) the substrate support 112. The dividing line DL can extend through a radially inner edge of the plasma P as shown in Figure 1C. In some embodiments, which can be combined with other embodiments, the dividing line DL can also extend through an inner edge of the lower surface 131 of the outer portion 130 of the gas delivery assembly 120 as well as an inner edge of the electrode 116.

[0043] The plasma P is generated in an outer region 107 of the interior volume 109 on a radially outward side of the dividing line DL while not being generated in an inner region 108 of the interior volume 109 on a radially inward side of the dividing line DL. The substrate 50A includes an outer region 56 on the radially outward side of the dividing line DL and an inner region 57 on the radially inward side of the dividing line DL. Because the plasma P is only in the outer region 107 on the radially outward side of the dividing line DL, the process to be performed on the substrate (e.g., a plasma etch or deposition) is only performed on the outer region 56 of the substrate 50A on the radially outward side of the dividing line DL while not being performed on the inner region 57 of the substrate 50A on the radially inward side of the dividing line DL.

[0044] The substrate support 112 includes an outer portion 117 on the radially outward side of the dividing line DL and an inner portion 118 on the radially inward side of the dividing line DL. The electrode 116 is located entirely in the outer portion 117 of the dividing line DL. The electrode 116 in the substrate support 112 and the lower surface 131 of the outer portion 130 of the gas delivery assembly 120 are each located entirely on the radially outward side of the dividing line DL, which causes the plasma P to be generated in the outer region 107 of the interior volume 109.

[0045] The inner portion 118 of the substrate support 112 can be substantially larger than the outer portion 117 of the substrate support 112. For example, in some embodiments, which can be combined with other embodiments, greater than 80%, greater than 90%, or greater than 95% of the substrate supporting surface 113 of the substrate support 112 is part of the inner portion 118 of the substrate support 112.

[0046] With reference to Figures 1A and 1C, the process chamber 101 further includes an exhaust ring 150 that fluidly couples the interior volume 109 to the vacuum pump 155. In some embodiments, which can be combined with other embodiments, the exhaust ring 150 can have an annular shape extending 360 degrees around the substrate support 112. The annular shape of the exhaust ring 150 causes the gases from the gas sources 141, 142 to move in a radially outward direction in the interior volume 109 away from the centralvertical axis C. The radially outward flow of the gases limits the mixing of the gases to the outer region 107 of the interior volume 109 and prevents the mixing of the gases in the inner region 108 of the interior volume 109.

[0047] The processing system 100 also includes the controller 185 for controlling processes performed by the processing system 100. The controller 185 can be any type of controller used in an industrial setting, such as a programmable logic controller (PLC). The controller 185 includes a processor 187, a memory 186, and input / output (I / O) circuits 188. The controller 185 can further include one or more of the following components (not shown), such as one or more power supplies, clocks, communication components (e.g., network interface card), and user interfaces typically found in controllers for semiconductor equipment.

[0048] The memory 186 can include non-transitory memory. The non-transitory memory can be used to store the programs and settings described below. The memory 186 can include one or more readily available types of memory, such as read only memory (ROM) (e.g., electrically erasable programmable read-only memory (EEPROM), flash memory, floppy disk, hard disk, or random access memory (RAM) (e.g., non-volatile random access memory (NVRAM).

[0049] The processor 187 is configured to execute various programs stored in the memory 186, such as programs for performing a process on the outer region 56 of the substrate 50A in the interior volume 109 of the process chamber 101, such as plasma etch or deposition. During execution of these programs, the controller 185 can communicate to I / O devices through the I / O circuits 188. For example, during execution of these programs and communication through the I / O circuits 188, the controller 185 can control outputs, such as energizing the RF power from the RF power source 160 and changing the position of valves (not shown) to send different gases to the interior volume 109 of the process chamber 101, and the controller 185 can monitor measurements from various sensors, such as temperature and pressure sensors (not shown) to control the process. The memory 186 can further include various operational settings used to control the processingsystem 100. For example, the settings can include one or more pressures at which the controller 185 can maintain the interior volume 109 when the plasma P is generated to perform the process on the outer region 56 of the substrate 50A as well as durations (e.g., five minutes) for how long to perform the process on the outer region 56 of the substrate 50A.

[0050] Figure 2 is a process flow diagram of a method 2000 for performing a process on the outer region 56 of a substrate 50A in the process chamber 101 using the processing system 100 of Figure 1A and then performing an optional wafer bonding processing using the substrate 50A and another substrate 50B, according to one embodiment. Many portions of the method 2000 can be performed by the controller 185. Figures 3A, 3B, and 3C show partial cross-sectional views of the substrates 50A, 50B during different portions of the method 2000, according to one embodiment. With reference to Figures 1 A,-1 C, 2, and 3A-3C the method 2000 is described.

[0051] The method begins at block 2002. At block 2002, an optional initial process is performed on the substrate 50A. This process is typically a process that results in some non-uniform ity or defect on the outer region 56 of the substrate 50A. For example, with reference to Figure 3A, the initial process can be a deposition in which a first layer 60A is deposited over the top surface 51 of the substrate 50A. A thickness of the deposited first layer 60A is substantially uniform on the inner region 57 of the substrate 50A but non-uniform and / or absent on the outer region 56 of the substrate 50A.

[0052] As another example, the substrate 50A can have the beveled outer edge 55, which can result in the outer region 56 of the substrate 50A having a high concentration of defects compared to the inner region 57 of the substrate 50A after a process (e.g., deposition) is performed. These defects can lead to increased particle generation, which can damage that substrate 50A or subsequent substrates processed in the same process chamber. As shown in Figure 3B, the substrate 50A includes four defects D1-D4. In some embodiments, which can be combined with other embodiments, the defects D1 -D4 can include particles that landed on the substrate 50A, fragmented or cracked portions of the first layer 60A, cracked portions of the substrate 50, orother defects. In some embodiments, a substrate, such as substrate 50A, can include hundreds or thousands of defects like the defects D1-D4 shown in Figure 3A. In some embodiments, the defects D1-D4 can lead to the formation of additional defects, such as polymer particle defects that can become entrapped on or near the existing defects D1 -D4 when a wafer bonding process is performed using that polymer.

[0053] At block 2004, the substrate 50A with the defects D1 -D4 is positioned on the substrate support 112 in the interior volume 109 of the process chamber 101. The initial process performed at block 2002 can be performed in a same or different process chamber.

[0054] At block 2006, one or more gases from the gas supply system 140 are supplied to the interior volume 109 of the process chamber 101. For example, one or more gases can be provided to the interior volume 109 through the first gas flow channel 122 of the gas delivery assembly 120, and one or more other gases can be provided to the interior volume 109 through the second gas flow channel 126 of the gas delivery assembly 120. The orientation of the outlet portions 124, 128 of the respective channels 122, 126 directs the gases in a radially outward direction as the gases enter the interior volume 109. The vacuum pressure provided by the vacuum pump 155 and the exhaust ring 150 that is disposed around the substrate support 112 cause the gases to continue to flow in a radially outward direction after entering the interior volume 109. The position of the outlets 129 for the second gas flow channel 126 as well as the radially outward flow for all of the gases after entering the interior volume 109 prevents significant mixing of the gases from the separate gas flow channels 122, 126 before the gases reach the outer region 107 of the interior volume 109. The flow of the one or more gases from the first gas flow channel 122 can be configured to act as shield to prevent any flow of the one or more gases from the second gas flow channel 126 in a radially inward direction.

[0055] The flow of gases through the gas flow channels 122, 126 can also be arranged so that the one or more gases flowing through the first gas flow channel 122 have a higher ionization energy than the one or more gases flowing through the second gas flow channel 126 to further reduce the likelihoodof generating the plasma P in the inner region 108 of the interior volume 109. In some embodiments, the gases flowing through the separate gas flow channels 122, 126 can also be gases that only react with each other to any significant degree when a plasma is generated, which further reduces the likelihood of performing the process (e.g., plasma deposition) on the inner region 57 of the substrate 50A.

[0056] At block 2008, with reference to Figures 1 A and 3B, RF power from the RF power source 160 is applied to the conductive outer portion 130 of the gas delivery assembly 120 to deposit a second layer 70A over the outer region 56 of the substrate 50A. The second layer 70A is not deposited over the inner region 57 of the substrate 50A. The lower surface 131 of the outer portion 130 of the gas delivery assembly 120 is located to have direct exposure to the outer region 107 of the interior volume 109 without direct exposure to the inner region 108 of the interior volume 109. The RF power applied to the lower surface 131 of the outer portion 130 of the gas delivery assembly 120 is grounded through the electrode 116 in the substrate support 112. The electrode 116 directly underlies the outer region 107 of the interior volume 109 without directly underlying the inner region 108 of the interior volume 109. The location of the lower surface 131 of the outer portion 130 of the gas delivery assembly 120 as well as the location of the electrode 116 in the substrate support 112 causes the plasma P to only be generated in the outer region 107 of the interior volume 109 while not being generated in the inner region 108 the interior volume 109.

[0057] Avoiding the generation of plasma P in the inner region 108 can be useful when the plasma P can potentially damage an existing layer on the inner region 57 of the substrate 50, such as the deposited first layer 60A shown in Figure 3A. Generating the plasma P only in the outer region 107 causes the process being performed by the plasma P on the substrate 50A to only be performed on the outer region 56 of the substrate 50A while not being performed on the inner region 57 of the substrate 50A, for example as shown with reference to the second layer 70A of Figure 3B. The plasma P can also perform the intended process (e.g., plasma deposition) over the curve of the beveled outer edge 55 shown. For example, the Figure 3B shows the secondlayer 70A deposited over portions of the beveled outer edge 55. Performing the deposition over the beveled outer edge 55 can prepare the substrate 50 to make a stronger bond in a subsequent wafer-bonding process for the substrate 50. In some embodiments, which can be combined with other embodiments, the deposition of the second layer 70A performed at the wafer edge during block 2010 can have a thickness from about 1 micron to about 20 micron, such as about 5 micron to about 10 micron. The thickness of the second layer 70A can also be configured to ensure that all of the defects, such as D1-D4 are fully covered by the second layer 70A as shown in Figure 3B.

[0058] At block 2010, the controller 185 determines the process is complete. For example, in one embodiment, the controller 185 can determine that the process is complete after a duration of time has passed (e.g., five minutes).

[0059] At block 2012, the RF power from the RF power source 160 is stopped, and the flow of one or more of the gases from the gas supply system 140 is also stopped. In some embodiments, the flow of some gases from the gas supply system 140, such as inert gases, may continue at block 2012. The substrate 50 can also be removed from the process chamber 101 at block 2012.

[0060] At block 2014, subsequent processing of the substrate 50 can be performed. In one embodiment, which can be combined with other embodiments, an additional layer (not shown) is deposited over the existing layer(s) already deposited on the substrate 50A. The deposition of the additional layer can be improved, for example, when blocks 2002-2012 are used to address a thickness non-uniform ity at an edge region of the substrate.

[0061] With reference to Figure 3C, in another embodiment, which can be combined with other embodiments, the substrate 50A can be bonded to a second substrate 50B in a wafer bonding process at block 2014. In one of these embodiments, the second substrate 50B is substantially similar to the first substrate 50A. For example, the second substrate 50B can have a first layer 60B deposited over the inner region of the substrate 50B that is the same as or substantially similar to the first layer 60A deposited over the first substrate 50A. Furthermore, the second substrate 50B can have defects D1-D3 over the outerregion of the substrate 50B that are substantially similar to the defects D1-D4 described above for the first substrate 50A. Additionally, a second layer 70B can be deposited over the defects D1-D3 of the second substrate 50B in a similar manner as the second layer 70A that is deposited over the defects D1-D4 of the first substrate 50A.

[0062] The second layers 70A, 70B can be used to form defect-free or substantially defect-free surfaces over the outer regions of the corresponding substrates 50A, 50B. These defect-free or substantially defect-free surfaces can then be bonded together using a bonding material 80 in a wafer bonding process as shown in Figure 3C. The wafer bonding process can be improved, for example, when blocks 2002-2012 are used to deposit the second layers 70A, 70B only over the outer regions 56 of the substrates 50A, 50B. These newly deposited second layers 70A, 70B can be used to cover defects near the outer edge of the substrates 50A, 50B, such as defects D1 -D4 near the beveled edge 55 shown in Figure 3A. By depositing the second layers 70A, 70B over these defects D1-D4 near the outer edge 55, a stronger bond can be obtained when the method 2000 is performed on one or both of the substrates involved in the wafer bonding process.

[0063] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

What is claimed is:

1. A process chamber comprising:a chamber body disposed around an interior volume;a substrate support in the interior volume, the substrate support having a substrate supporting surface;a gas delivery assembly positioned over the substrate support, wherein a central vertical axis extends through the gas delivery assembly and through a center of the substrate support, andthe substrate support includes an inner portion and an outer portion, the outer portion located further from the central vertical axis than the inner portion is to the central vertical axis; andan electrode in the substrate support, the electrode located in the outer portion of the substrate support without extending into the inner portion of the substrate support.

2. The process chamber of claim 1 , wherein the electrode is an only electrode in the substrate support.

3. The process chamber of claim 1 , wherein the electrode is grounded and the electrode is an only grounded electrode in the substrate support.

4. The process chamber of claim 1 , wherein greater than 80% of the substrate supporting surface of the substrate support is part of the inner portion of the substrate support.

5. The process chamber of claim 1 , wherein greater than 90% of the substrate supporting surface of the substrate support is part of the inner portion of the substrate support.

6. The process chamber of claim 1 , wherein the gas delivery assembly includes an electrically insulating inner portion and an electrically conductive outer portion disposed around the inner portion of the gas delivery assembly,the outer portion of the gas delivery assembly located further from the central vertical axis than the inner portion of the gas delivery assembly is to the central vertical axis.

7. The process chamber of claim 6, wherein the electrically conductive outer portion of the gas delivery assembly directly overlies the electrode.

8. The process chamber of claim 6, whereinthe electrically conductive outer portion of the gas delivery assembly includes a lower surface, andlower surface is an only surface of the electrically conductive outer portion exposed to the interior volume of the process chamber.

9. The process chamber of claim 6, wherein the gas delivery assembly includes a first gas flow channel configured to direct gas into the interior volume in a radially outward direction relative to the central vertical axis.

10. The process chamber of claim 9, whereinthe gas delivery assembly includes a second gas flow channel configured to direct gas into the interior volume in a radially outward direction relative to the central vertical axis, andthe first gas flow channel is independent of the second gas flow channel.

11. A process chamber comprising:a chamber body disposed around an interior volume;a substrate support in the interior volume, the substrate support having a substrate supporting surface; anda gas delivery assembly positioned over the substrate support, wherein a central vertical axis extends through the gas delivery assembly and through a center of the substrate support, andthe gas delivery assembly includes an electrically insulating inner portion and an electrically conductive outer portion disposed around theinner portion, the outer portion located further from the central vertical axis than the inner portion is to the central vertical axis.

12. The process chamber of claim 11, wherein the gas delivery assembly includes a first gas flow channel configured to direct gas into the interior volume in a radially outward direction relative to the central vertical axis.

13. The process chamber of claim 12, whereinthe gas delivery assembly includes a second gas flow channel configured to direct gas into the interior volume in a radially outward direction relative to the central vertical axis, andthe first gas flow channel is independent of the second gas flow channel.

14. The process chamber of claim 11 , whereinthe electrically conductive outer portion of the gas delivery assembly includes a lower surface, andthe lower surface is an only surface of the electrically conductive outer portion exposed to the interior volume of the process chamber.

15. The process chamber of claim 11 , further comprising an electrode in the substrate support.

16. The process chamber of claim 15, wherein the electrode directly underlies the electrically conductive outer portion of the gas delivery assembly without directly underlying the electrically insulating inner portion of the gas delivery assembly.

17. A system for process a substrate comprising:a chamber body disposed around an interior volume;a substrate support in the interior volume, the substrate support having a substrate supporting surface;a gas delivery assembly positioned over the substrate support, whereina central vertical axis extends through the gas delivery assembly and through a center of the substrate support, andthe gas delivery assembly includes an electrically insulating inner portion and an electrically conductive outer portion disposed around the inner portion, the outer portion of the gas delivery assembly located further from the central vertical axis than the inner portion is to the central vertical axis,the substrate support includes an inner portion and an outer portion, the outer portion of the substrate support located further from the central vertical axis than the inner portion is to the central vertical axis, anda radio frequency power source electrically connected to the conductive outer portion of the gas delivery assembly.

18. The system of claim 17, further comprising an electrode in the substrate support.

19. The system of claim 18, wherein the electrode directly underlies the conductive outer portion of the gas delivery assembly without directly underlying the electrically insulating inner portion of the gas delivery assembly.

20. The system of claim 17, whereinthe gas delivery assembly includes a first gas flow channel configured to direct gas into the interior volume in a radially outward direction relative to the central vertical axis,the gas delivery assembly further includes a second gas flow channel configured to direct gas into the interior volume in a radially outward direction relative to the central vertical axis, andthe first gas flow channel is independent of the second gas flow channel.

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