Backside Deposition for Wafer Bow Management

Abstract

Embodiments disclosed herein include a semiconductor processing tool. In embodiments, the semiconductor processing tool includes a chamber, a pedestal within the chamber, and a first gas supply system on a first side of the pedestal. In embodiments, the first gas supply system includes a first exhaust line having a first valve for opening and closing the first exhaust line, and a first source gas supply line having a second valve for opening and closing the first source gas supply line. In embodiments, the semiconductor processing tool further includes a second gas supply system on a second side of the pedestal. In embodiments, the second gas supply system includes a second exhaust line having a third valve for opening and closing the second exhaust line, and a second source gas supply line having a fourth valve for opening and closing the second source gas supply line.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Patent Application No. 17 / 946,947, filed September 16, 2022, the entire contents of which are incorporated herein by reference.

[0002] Embodiments relate to the field of semiconductor manufacturing, and more particularly to semiconductor processing tools for depositing films on the backside of substrates for wafer bow management. [Background technology]

[0003] In semiconductor processing applications, one or more layers are deposited on the top surface of a substrate. One or more layers may be under stress. The stress in the layers may be transferred to the substrate itself. This stress may cause the substrate to bend or warp. When the substrate bends or warps, features on the substrate (e.g., pillars, lines, etc.) may become displaced. For example, pillars may lean towards or away from each other due to the warping. Additionally, chucking the substrate becomes more difficult.

[0004] Therefore, some architectures may include a stress compensation film on the backside of the substrate. Ideally, the stress inherent in the stress compensation film is opposite to the stress imposed by the layers on top of the substrate. This compensates for any warping or bending and results in a substantially flat substrate for further processing. Providing a backside layer on a substrate is not without its challenges. In particular, backside deposition processes cannot generate particles or deposits on the frontside of the substrate. Furthermore, it is typically undesirable to flip the substrate orientation (i.e., turn the substrate upside down). Therefore, existing deposition tools are generally not suitable for backside deposition processes. Summary of the Invention

[0005] Embodiments disclosed herein include a semiconductor processing tool. In embodiments, the semiconductor processing tool includes a chamber, a pedestal within the chamber, and a first gas supply system on a first side of the pedestal. In embodiments, the first gas supply system includes a first exhaust line having a first valve for opening and closing the first exhaust line, and a first source gas supply line having a second valve for opening and closing the first source gas supply line. In embodiments, the semiconductor processing tool further includes a second gas supply system on a second side of the pedestal. In embodiments, the second gas supply system includes a second exhaust line having a third valve for opening and closing the second exhaust line, and a second source gas supply line having a fourth valve for opening and closing the second source gas supply line.

[0006] Embodiments may also include a semiconductor processing tool comprising a pedestal; a showerhead above the pedestal, the showerhead including a first plate having a first hole and a second plate having a second hole above the first plate; and lift pins configured to lift a substrate above the pedestal and the showerhead.

[0007] Embodiments may also include a semiconductor processing tool comprising a chamber, a pedestal within the chamber, the pedestal coupled to an RF source, and a plate above the pedestal, the plate coupled to electrical ground. In embodiments, the semiconductor processing tool further comprises a gas distribution assembly between the pedestal and the plate. In embodiments, the gas distribution assembly is configured to supply process gas to the backside of the substrate. [Brief explanation of the drawings]

[0008] [Figure 1A] 1 is a cross-sectional view of a semiconductor processing tool including a pair of gas delivery systems in a first configuration according to an embodiment. [Figure 1B] 1B is a cross-sectional view of the semiconductor processing tool of FIG. 1A in a second configuration for providing uniform backside film deposition, according to an embodiment. [Figure 2]1 is a cross-sectional view of a semiconductor processing tool including a backside showerhead configuration according to an embodiment. [Figure 3A] 1 is a cross-sectional view of a semiconductor processing tool including a backside film deposition architecture according to an embodiment. [Figure 3B] 1 illustrates a cross-sectional view of a semiconductor processing tool including a bottom processing kit for backside deposition of a substrate, according to an embodiment. [Figure 3C] FIG. 1 illustrates a cross-sectional view of a semiconductor processing tool including a backside film deposition architecture with a frontside inert gas flow around an overlying ground plate according to an embodiment. [Figure 4A] FIG. 1 is a plan view of two-zone gas flow control having an inner zone and an outer zone, according to an embodiment. [Figure 4B] FIG. 10 is a plan view of gas flow control into five zones, with an inner zone and four outer zones, according to an embodiment. [Figure 5A] FIG. 1 is a perspective view of a gas distribution assembly for radial gas distribution, according to an embodiment. [Figure 5B] FIG. 10 is a cross-sectional view of a relief valve for controlling gas distribution of a radial gas distribution assembly, according to an embodiment. [Figure 5C] FIG. 10 is a cross-sectional view of a closure valve for controlling gas distribution of a radial gas distribution assembly. [Figure 6] 1 is a cross-sectional view of a semiconductor processing tool with a tiltable pedestal to provide non-uniform distances to the ground plate according to an embodiment. [Figure 7] FIG. 1 is a block diagram of an exemplary computer system that may be used with a processing tool, according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Systems described herein include semiconductor processing tools for depositing films on the backside of substrates for wafer bow management. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments. It will be apparent to one skilled in the art that the embodiments may be practiced without these specific details. In other instances, well-known aspects have not been described in detail in order to not unnecessarily obscure the embodiments. Furthermore, it should be understood that the various embodiments illustrated in the accompanying drawings are illustrative representations and are not necessarily drawn to scale.

[0010] As discussed above, depositing a film on the backside of a substrate can be effective in correcting a warped or bowed substrate. However, existing processing tools are typically designed to process the top side of a substrate. This means that the substrate must be inverted to form a backside film. This can damage the front side of the substrate, which is undesirable. Accordingly, embodiments disclosed herein include semiconductor processing tools configured to form a plasma below the substrate to deposit a backside film. In some embodiments, process gases are flowed into the chamber from the side. In other embodiments, a showerhead below the substrate faces the backside of the substrate to flow process gases into the chamber.

[0011] Furthermore, it should be understood that different types of curvature may require non-uniform backside film deposition. To this end, embodiments disclosed herein include different methods and architectures for controlling process gas flow, controlling plasma parameters, etc. In other embodiments, architectures may be particularly beneficial for providing uniform film deposition.

[0012] Reference is now made to FIG. 1A, which is a cross-sectional view of a semiconductor processing tool 100 for backside film deposition, according to an embodiment. In an embodiment, the semiconductor processing tool 100 of FIG. 1A is configured to provide uniform backside film deposition. In particular, a first configuration for flowing process gases in a first direction across the substrate 125 is shown in FIG. 1A, and a second configuration for flowing process gases in a second, opposite direction across the substrate 125 is shown in FIG. 1B. While a bidirectional gas supply system is shown in FIG. 1A, it should be understood that a unidirectional gas supply system can be used if the pedestal 120 is rotatable.

[0013] In an embodiment, semiconductor processing tool 100 includes a chamber 130. Chamber 130 may be any suitable material configured to support a vacuum within chamber 130. The bottom of chamber 130 is shown in FIG. 1A. However, additional portions of the chamber (e.g., sidewalls, portions of a lid, etc.) may also be included.

[0014] In embodiments, the semiconductor processing tool 100 may further include a first gas supply system 110A and a second gas supply system 110B. In embodiments, the first gas supply system 110A and the second gas supply system 110B may be substantially similar to each other and may be located on opposite sides of the semiconductor processing tool 100. In embodiments, the gas supply systems 110A and 110B may include an exhaust line 112 and a process gas supply line 114. Further, a set of valves may be provided in each gas supply system 110A and 110B. For example, in the first gas supply system 110A, a first valve 101 may control the flow of gas into the exhaust line 112, and a second valve 102 may control the flow of gas from the gas supply line 114 into the chamber 130. Similarly, in the second gas supply system 110B, a third valve 103 can control gas flow to the exhaust line 112, and a fourth valve 104 can control gas flow from the gas supply line 114 to the chamber 130. In embodiments, each of the gas supply systems 110A and 110B can also include a showerhead 116 for distributing gases into the chamber 130. In some embodiments, one or both of the showerheads 116 can be omitted.

[0015] In embodiments, the semiconductor processing chamber 100 may include a pedestal 120. The pedestal 120 may be coupled to an RF source to strike a plasma between the substrate 125 and the top of the pedestal 120. The substrate 125 may be lifted from the top of the pedestal 120 by lift pins 122. In some embodiments, the pedestal 120 may be stationary. In other embodiments, the pedestal 120 may be rotatable. A rotating pedestal 120 may further improve film deposition uniformity in some examples. In certain examples, the inclusion of a rotating pedestal 120 may enable the use of a single-sided gas delivery system (e.g., a semiconductor processing tool 100 with a single gas delivery line 110A) while still enabling uniform film deposition.

[0016] In embodiments, substrate 125 may be any type of substrate typically processed in semiconductor manufacturing equipment. In certain embodiments, substrate 125 may be a wafer (e.g., a silicon wafer or any other semiconductor wafer). Substrate 125 may have any form factor (e.g., 150 mm, 200 mm, 300 mm, 450 mm, etc.). Other materials and form factors may also be used for substrate 125 (e.g., glass substrate, sapphire substrate, etc.). That is, substrate 125 may be any substrate that can benefit from the inclusion of backside film deposition.

[0017] In embodiments, the deposited backside film may be a film capable of inducing a high level of stress in the substrate 125. In certain embodiments, the backside film may include silicon and nitrogen (e.g., silicon nitride). A silicon nitride film may be a high-temperature film. For example, the backside film may be deposited at a temperature of 500° C. or greater, or 700° C. or greater. The high temperature may be achieved in part by using a heatable pedestal 120. Alternatively (or in addition to a heated pedestal), an array of lamps 142 may be provided above the substrate 125 to heat the substrate 125.

[0018] In embodiments, a grounded plate 141 may be provided above the substrate 125. The grounded plate 141 may be coupled to an electrical ground to enable plasma formation within the chamber 130. The grounded plate 141 may also be a showerhead in some embodiments. For example, an inert process gas may be flowed into the chamber through the grounded plate 141 in some embodiments. The grounded plate 141 may be relatively close to the top surface of the substrate 125. A minimum spacing (and flow of inert gas) between the grounded plate 141 and the substrate 125 may help prevent plasma formation between the grounded plate 141 and the top surface of the substrate 125. For example, the grounded plate 141 may be about 10 mm or less, about 5 mm or less, or about 1 mm or less from the top surface of the substrate 125. By preventing plasma from forming above the substrate 125, the top surface of the substrate remains intact and undamaged during the backside film deposition process.

[0019] In the embodiment shown in FIG. 1A, a first tool configuration is provided. The first tool configuration allows for a flow of process gas from the right of the substrate 125 to the left of the substrate 125, as indicated by the arrows. In particular, the first tool configuration includes a first valve 101 that is closed and a second valve that is open, allowing process gas to enter the chamber through a first gas supply system 110A. The first tool configuration also includes a third valve 103 that is open and a fourth valve 104 that is closed, allowing process gas to be exhausted from the chamber 130 through a second gas supply system 110B.

[0020] 1A and 1B, the second valve 102 and the fourth valve 104 are shown as two separate valves. However, in some embodiments, a single valve can be used to selectively flow process gas into either the first gas supply system 110A or the second gas supply system 110B. Furthermore, the two separate exhaust lines 112 can be coupled to each other outside the example shown in FIGS. 1A and 1B. That is, a single exhaust system can be used to evacuate the chamber 130.

[0021] Reference is now made to FIG. 1B, which is a cross-sectional view of the semiconductor processing tool 100 in a second tool configuration, according to an embodiment. The second tool configuration may be substantially opposite to the first tool configuration. Thus, process gases may flow from the left of the substrate 125 to the right of the substrate 125, as indicated by the arrows. In an embodiment, the second tool configuration may include the first valve 101 being open and the second valve 102 being closed. Additionally, the third valve 103 is closed and the fourth valve 104 is open. Thus, process gases may flow into the chamber 130 from the second gas supply system 110B, and the gases may be exhausted from the chamber 130 by the first gas supply system 110A.

[0022] In embodiments, the semiconductor processing tool 100 can be switched between a first tool configuration and a second tool configuration to uniformly deposit a backside film on the substrate 125. In certain embodiments, the semiconductor processing tool 100 can be in the first tool configuration for a first duration, and the semiconductor processing tool 100 can be switched to the second tool configuration for a second duration. The first duration and the second duration can be substantially similar to one another. In other embodiments, the semiconductor processing tool 100 can be alternately switched between the first tool configuration and the second tool configuration. In yet other embodiments, either the first tool configuration or the second tool configuration can be selected, and the substrate 125 can be rotated. In embodiments, the rotation can be at a constant angular velocity while varying the gas flow to generate a uniform or intentionally non-uniform backside film.

[0023] While embodiments having a uniform backside film are possible, it is also possible to form a non-uniform backside film. For example, to form a thick backside film on one side of the substrate, the first duration can be longer than the second duration. Alternatively, only one of the first tool configuration or the second tool configuration can be selected without rotating the substrate 125. In other embodiments, rotation at a variable angular velocity and constant (or variable) process gas flow can be used to intentionally create a non-uniform backside film deposition.

[0024] Reference is now made to Figure 2, which is a cross-sectional view of a portion of a semiconductor processing tool 200 according to an additional embodiment. In contrast to the cross-flow of process gases shown in Figures 1A and 1B, process gases are flowed into the chamber from below the substrate 225. Flowing process gases from the bottom of the substrate 225 may, in some embodiments, enable more uniform backside film deposition. In particular, it may not be necessary to rotate the substrate 225 or switch configurations of the semiconductor processing tool 200 to achieve the desired backside film uniformity.

[0025] In an embodiment, the semiconductor processing tool may include a pedestal 220. The pedestal 220 may be coupled to an RF source to strike a plasma between the substrate 225 and the pedestal 220. In an embodiment, the pedestal 220 may further include a heater to provide a high temperature backside film. A ground plate to complete the circuit has been omitted for simplicity. However, it should be understood that an electrically grounded plate (e.g., a showerhead) may be provided above the substrate 225. Lift pins 222 may be provided to support the substrate 225 in an elevated position relative to the pedestal 220.

[0026] In an embodiment, a showerhead 250 may be provided between the substrate 225 and the pedestal 220. In an embodiment, the showerhead 250 may include a pair of plates 251 and 252. However, it should be understood that in some embodiments, a showerhead having a single plate configuration may also be used. In an embodiment, process gases (indicated by arrows) may flow between the pedestal 220 and the first plate 251. The gases may flow upward through holes 253 in the first plate 251. A gap may be provided between the first plate 251 and the second plate 252 to further distribute the process gases. In an embodiment, the process gases then flow through holes 254 in the second plate 252 and enter the chamber.

[0027] In embodiments, the number of holes 253 may be different from the number of holes 254. For example, the number of holes 253 may be less than the number of holes 254. Furthermore, the diameter of holes 253 may be larger than the diameter of holes 254. Also, the position of holes 253 relative to holes 354 may be offset to enhance diffusion of the process gas before it enters the chamber below substrate 225.

[0028] Reference is now made to FIG. 3A , which illustrates a cross-sectional view of a semiconductor processing tool 300 according to an embodiment. In an embodiment, the semiconductor processing tool 300 may include a chamber 330. In an embodiment, the chamber 330 may include a bellows 331 for allowing a pedestal 361 to be raised and lowered. In an embodiment, the pedestal 361 may include a heater, etc. Further, the pedestal 361 may be coupled to an RF source 335, such as low-frequency RF and / or high-frequency RF. In an embodiment, a showerhead 350 may be provided above the pedestal 361. The showerhead 350 may include passages through which gas (shown by arrows) can enter the processing region to form the plasma 360. In an embodiment, the gas may flow around the pedestal 361. For example, gas sources 334 and 336 may be provided below the pedestal 360. The gas source 334 may be a processing gas, and the gas source 336 may be a dilution gas (e.g., an inert gas). The gas sources 334 and 336 may be mixed before passing through the showerhead 350 into the processing region between the substrate 325 and the showerhead 350 .

[0029] In embodiments, the showerhead 350 may be any suitable material. In certain embodiments, the showerhead 350 may be a ceramic showerhead 350. In other embodiments, the showerhead 350 may comprise a conductive material, such as aluminum. Furthermore, while a showerhead 350 having a single plate is illustrated, it should be understood that a multi-plate showerhead 350 (similar to the embodiments described above) may be used according to embodiments. Furthermore, although described as a showerhead, the component 350 may be any suitable process kit that allows gases to flow into the processing region of the chamber 330.

[0030] In an embodiment, the substrate 325 may be supported above the showerhead 350 by lift pins 322. The substrate 325 may be elevated to the height of a process ring 337. The process ring 337 may surround the periphery of the substrate 325 when the substrate is in the elevated position. In an embodiment, an overhead showerhead 339 may be provided above the upper surface of the substrate 325. The overhead showerhead 339 may be electrically grounded to complete the circuit for forming the plasma 360. An inert gas 338 may be supplied to the overhead showerhead 339. The inert gas flows through the overhead showerhead 339 during processing to provide an inert environment above the upper surface of the substrate 325. Furthermore, to prevent the plasma from being shot above the substrate 325, the distance between the top of the substrate 325 and the bottom of the overhead showerhead 339 may be about 10 mm or less, about 5 mm or less, or about 1 mm or less. This minimizes damage to the front side of the substrate 325. The overhead showerhead 339 can be heated to perform high temperature film deposition on the backside of the substrate 325 .

[0031] Reference is now made to FIG. 3B, a cross-sectional view of a semiconductor processing tool 300 according to an additional embodiment. As shown, gas inlets 334 and 336 may extend through the chamber 330, with a bellows 363 coupling the gas inlets 334 and 336 to the holes through an isolator 362. The isolator 362 may also be coupled to the chamber 330 through an outer bellows 331. The bellows 363 and 331 allow for vertical displacement of the system. In embodiments, a showerhead or process kit 350 may be located above the isolator 362. Gases from the gas inlets 334 (process gas) and 336 (dilution gas) may be mixed before passing through the showerhead 350 into the processing region of the chamber 330 where the plasma 360 is struck.

[0032] In embodiments, the substrate 325 is supported by lift pins 322 in a raised position to provide space for the plasma 360 between the substrate 325 and the showerhead 350. In embodiments, the substrate 325 may be surrounded by a process ring 337. An overhead showerhead 339 may be provided above the substrate 325. An inert gas 338 may be supplied to the overhead showerhead 339. The overhead showerhead 339 may be electrically grounded in some embodiments. Additionally, the showerhead 339 may be heated to perform high temperature film deposition on the backside surface of the substrate 325.

[0033] Reference is now made to FIG. 3C , which is a cross-sectional view illustrating a semiconductor processing tool 300 according to an additional embodiment. In an embodiment, the semiconductor processing tool 300 of FIG. 3C may be substantially similar to the semiconductor processing tool 300 illustrated in FIG. 3B , except for the grounded overhead feature. Instead of providing a showerhead (e.g., a perforated plate), the overhead function may include a non-perforated plate 339. An enclosure 341 may be provided around the non-perforated plate 339 to supply inert gas 338 to the top surface of the substrate 325. As indicated by the arrows, the inert gas 338 flows around the perforated plate 339 to reach the processing region of the chamber 330. In an embodiment, the non-perforated plate 339 may be electrically grounded. Additionally, the non-perforated plate 339 may include a heater to enable high-temperature film deposition on the backside of the substrate 325.

[0034] In the above-described embodiments, processing conditions can be maintained to deposit a substantially uniform backside film on the backside of the substrate. However, in some embodiments, to correct for certain types of bow (e.g., saddle bow), stress must be applied in a non-uniform manner. In such embodiments, modifications can be made to the semiconductor processing tool to control the flow of gas into the chamber to deposit a non-uniform backside film.

[0035] Reference is now made to Figure 4A, which illustrates a processing tool with dual-zone control of film thickness. As shown, a first zone 471 is located at the center of the substrate, and a second zone 472 is located radially around the first zone. Such an embodiment allows a substrate to have a film with different thicknesses at the center and edge of the substrate. The different zones 471 and 472 can be controlled with any combination of valves, etc., to provide a desired film profile.

[0036] Similarly, Figure 4B illustrates a processing tool having five control zones 471-475, according to embodiments. The use of five zones allows for even better control of the backside film profile. In certain embodiments, the five control zones 471-475 can be used to reduce warpage in saddle-shaped substrates.

[0037] Reference is now made to FIG. 5A , which illustrates a perspective view of a showerhead 580 that enables radial distribution of gas into a chamber, according to an embodiment. As illustrated, the showerhead may have an inlet 585 that feeds multiple holes 581 around the periphery of the showerhead 580. In addition to controlling the flow of gas into the inlet 585, valves 582 may be used to control the flow in specific sections of the showerhead 580. For example, the flow of process gas through the multiple holes 581 may be adjusted by fully opening, fully closing, or partially closing the valves 582. In the illustrated embodiment, a total of six valves 582 are shown (three visible in the front and three in the back, one of which is visible). However, it should be understood that any number of valves 582 may be used to provide the desired control for a semiconductor processing tool.

[0038] 5B, which is a cross-sectional view illustrating valve 582 in an open position, according to an embodiment. As shown, an outer portion of valve 582 may be coupled to plate 587 adjacent hole 581. By rotating the outer portion of valve 582, plate 587 can be moved up and down. In the state shown in FIG. 5B, the plate is completely removed from hole 581 (e.g., positioned below hole 581). This allows process gas to flow freely through hole 581.

[0039] Reference is now made to Figure 5C, a cross-sectional view illustrating valve 582 in a closed position, according to an embodiment. As shown, plate 587 is biased against hole 581 to prevent gas flow through hole 581. While shown in a fully open configuration (Figure 5B) and a fully closed configuration (Figure 5C), it should be understood that valve 582 can be partially closed. In such an embodiment, the flow of process gas is limited, but not completely stopped.

[0040] Reference is now made to FIG. 6 , which is a cross-sectional view of yet another embodiment of a semiconductor processing tool 600. Instead of controlling the flow of process gases, the embodiment shown in FIG. 6 uses adjusting the gap between the RF source and the grounded plate 633. For example, the showerhead 639 includes a grounded plate 633. However, it should be understood that the showerhead 639 may be conductive, and the entire showerhead 639 may be grounded. Additionally, the process kit 650 (e.g., the showerhead) may be coupled to the RF source 692. Instead of lifting and lowering the process kit horizontally, it may be tilted. The tilting can be accommodated by the bellows 631 of the chamber 630. In an embodiment, tilting the isolator 662 and process kit 650 may result in one side of the process kit 650 being closer to the grounded plate 633. This exposes the substrate 625 (supported by the lift pins 622 and within the process ring 637) to a non-uniform plasma 660 across the surface of the substrate. The non-uniform plasma 660 results in non-uniform deposition of a backside film.

[0041] Reference is now made to FIG. 7 , a block diagram illustrating an exemplary computer system 700 of a processing tool, according to an embodiment. In an embodiment, the computer system 700 is coupled to the processing tool and controls processing within the processing tool. The computer system 700 may be connected (e.g., networked) to other machines within a local area network (LAN), an intranet, an extranet, or the Internet. The computer system 700 may operate in the capacity of a server or a client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The computer system 700 may be a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a mobile phone, a web appliance, a server, a network router, switch, or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be performed by that machine. Furthermore, while only a single machine is illustrated for the computer system 700, the term “machine” is intended to include any collection of machines (e.g., computers) that individually or jointly execute a set (or sets) of instructions to perform any one or more of the methodologies described herein.

[0042] Computer system 700 may include a computer program product, or software 722, having a non-transitory machine-readable medium with instructions stored thereon, which may be used to program computer system 700 (or other electronic devices) to perform processes according to embodiments. A machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, machine-readable (e.g., computer-readable) media includes machine- (e.g., computer) readable storage media (e.g., read-only memory (“ROM”), random-access memory (“RAM”), magnetic disk storage media, optical storage media, flash memory devices, etc.), machine- (e.g., computer) readable transmission media (electrical, optical, acoustic, or other forms of propagated signals (e.g., infrared signals, digital signals, etc.)), etc.

[0043] In an embodiment, computer system 700 includes a system processor 702, a main memory 704 (e.g., read only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM)), a static memory 706 (e.g., flash memory, static random access memory (SRAM), etc.), and a secondary memory 718 (e.g., a data storage device), which communicate with each other via a bus 730.

[0044] System processor 702 represents one or more general-purpose processing devices, such as a microsystem processor, a central processing unit, or the like. More specifically, the system processor may be a complex instruction set computing (CISC) microsystem processor, a reduced instruction set computing (RISC) microsystem processor, a very long instruction word (VLIW) microsystem processor, a system processor implementing other instruction sets, or a system processor implementing a combination of instruction sets. System processor 702 may also be one or more special-purpose processing devices, such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal system processor (DSP), a network system processor, or the like. System processor 702 is configured to execute processing logic 726 for performing the processes described herein.

[0045] The computer system 700 may further include a system network interface device 708 for communicating with other devices or machines. The computer system 700 may also include a video display device 710 (e.g., a liquid crystal display (LCD), a light emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device 712 (e.g., a keyboard), a cursor control device 714 (e.g., a mouse), and a signal generating device 716 (e.g., a speaker).

[0046] The secondary memory 718 may include a machine-accessible storage medium 732 (or more specifically, a computer-readable storage medium) having stored thereon one or more sets of instructions (e.g., software 722) that embody any one or more of the methodologies or functions described herein. The software 722 may also reside, completely or at least partially, within the main memory 704 and / or within the system processor 702 during its execution by the computer system 700, with the main memory 704 and the system processor 702 also constituting machine-readable storage media. The software 722 may further be transmitted or received over the network 720 via the system network interface device 708. In an embodiment, the network interface device 708 may operate using RF, optical, acoustic, or inductive coupling.

[0047] Although machine-accessible storage medium 732 is shown to be a single medium in the exemplary embodiment, the term "machine-readable storage medium" should be interpreted to include a single medium or multiple media (e.g., a centralized or distributed database and / or associated caches and servers) that store one or more sets of instructions. The term "machine-readable storage medium" is also intended to include any medium that is capable of storing or encoding a set of instructions for execution by a machine, causing the machine to perform any one or more methodologies. Thus, the term "machine-readable storage medium" is intended to include, but is not limited to, solid-state memory, optical media, and magnetic media.

[0048] In the foregoing specification, certain exemplary embodiments have been described. It will be apparent that various changes may be made thereto without departing from the scope of the following claims. The specification and drawings are, therefore, to be regarded in an illustrative rather than a restrictive sense.

Claims

1. 1. A semiconductor processing tool comprising: a chamber; a pedestal within the chamber; a first gas supply system on a first side of the pedestal, a first exhaust line having a first valve for opening and closing the first exhaust line; a first source gas supply line having a second valve for opening and closing the first source gas supply line; a first gas supply system including: a second gas supply system on a second side of the pedestal, a second exhaust line having a third valve for opening and closing the second exhaust line; a second source gas supply line having a fourth valve for opening and closing the second source gas supply line; a second gas supply system including:

1. A semiconductor processing tool comprising:

2. Lift pins extending from the pedestal and configured to lift the substrate The semiconductor processing tool of claim 1 , further comprising:

3. a first showerhead at the inlet of the first gas supply system; a second showerhead at an inlet to the second gas supply system; The semiconductor processing tool of claim 1 , further comprising:

4. The semiconductor processing tool of claim 3 , wherein the first showerhead and the second showerhead are substantially similar to one another.

5. a grounded electrode on the pedestal The semiconductor processing tool of claim 1 , further comprising:

6. The semiconductor processing tool of claim 5 , wherein the pedestal is coupled to an RF source.

7. A heater is provided on the pedestal. The semiconductor processing tool of claim 1 , further comprising:

8. an inert gas line configured to flow an inert gas into the chamber above the pedestal; The semiconductor processing tool of claim 1 , further comprising:

9. 9. The semiconductor processing tool of claim 8, wherein the inert gas line flows the inert gas through a showerhead above the pedestal.

10. 10. The semiconductor processing tool of claim 9, wherein a substrate is supported between the pedestal and a showerhead above the pedestal, and a plasma is directed beneath the substrate.

11. The semiconductor processing tool of claim 1 , wherein the substrate is configured to rotate at a constant angular velocity or a variable angular velocity.

12. 1. A semiconductor processing tool comprising: The pedestal and a showerhead above the pedestal, the showerhead including a first plate having a first hole and a second plate above the first plate having a second hole; lift pins configured to lift a substrate above the pedestal and the showerhead; 1. A semiconductor processing tool comprising:

13. The semiconductor processing tool of claim 12 , wherein a gap is provided between the first plate and the second plate.

14. 13. The semiconductor processing tool of claim 12, wherein the showerhead distributes process gas across a bottom surface of a substrate supported by the lift pins.

15. The semiconductor processing tool of claim 12 , wherein the pedestal is coupled to an RF source.

16. 1. A semiconductor processing tool comprising: a chamber; a pedestal within the chamber, the pedestal coupled to an RF source; a plate above the pedestal, the plate being coupled to electrical ground; a gas distribution assembly between the pedestal and the plate, the gas distribution assembly being configured to supply process gas to a backside of the substrate; 1. A semiconductor processing tool comprising:

17. 17. The semiconductor processing tool of claim 16, wherein the gas distribution assembly is configured to have two or more zones, each zone configured to have an independently controllable gas flow rate.

18. 20. The semiconductor processing tool of claim 17, wherein the two or more zones include a central zone and four peripheral zones outside the central zone.

19. 17. The semiconductor processing tool of claim 16, wherein the pedestal is configured to slope such that a first side of the pedestal is closer to the plate than a second side of the pedestal.

20. a plurality of valves coupled to the gas distribution assembly, the valves being independently controllable to vary the flow of gas from the gas distribution assembly; The semiconductor processing tool of claim 16 further comprising:

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