Turbo molecular pump for etching reactor, and cathode assembly
Patent Information
- Application Number
- JP2025135062
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2019-03-15
- Filing Date
- 2025-08-14
- Publication Date
- 2026-01-06
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
[Technical Field]
[0001] Priority claims This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 819,223, filed March 15, 2019, which is incorporated herein by reference in its entirety.
[0002] In general, the subject matter disclosed herein relates to semiconductor manufacturing equipment and methods, systems, and programs for using the semiconductor manufacturing equipment. In some examples, the subject matter disclosed herein relates to turbomolecular pumps and etch management provided during operation of the turbomolecular pumps. [Background technology]
[0003] The background discussion provided herein is intended to present the contents of the present disclosure generally. Work by the currently named inventors within the scope of what is described in this background section, as well as aspects of the description that may not otherwise be considered prior art at the time of filing, are not admitted, expressly or impliedly, as prior art against the present disclosure.
[0004] The ever-increasing feature sizes and device geometries of semiconductor devices and integrated circuits continue to require improvements in manufacturing processes and equipment. Currently, integrated circuit manufacturing facilities routinely produce devices with feature sizes of 65 nm (0.065 μm), and next generations will shrink even further.
[0005] In current manufacturing processes, plasma must be introduced into a process chamber to react or promote a reaction with a substrate placed therein. The substrate being processed may be a semiconductor substrate, such as a (silicon) Si substrate. Plasma processing is used for a wide variety of applications, including etching material from a substrate, depositing material onto a substrate, cleaning the substrate surface, and modifying the substrate surface. As the feature sizes of devices on the substrate become smaller, the geometry of the process chamber as well as the operating conditions within the process chamber become more demanding. Summary of the Invention
[0006] The illustrative methods, systems, and apparatus aim to provide a symmetrical processing environment. The examples are merely representative of possible variations. For example, in one embodiment, a processing chamber system includes a processing chamber and a pump. The processing chamber includes a gas port for introducing gas into an upper region of the processing chamber and a stage disposed within the processing chamber below the gas port. The pump is disposed in a lower region of the processing chamber for removing gas from the processing chamber. The pump includes a core having a passage disposed therein. The stage includes a chuck configured to hold a substrate and a stem extending from the chuck, the stem configured to pass entirely through the passage in the core.
[0007] In one embodiment, the lower region of the processing chamber has an opening configured to receive the stem alongside the passage, and one or more spiral grooves are formed in the stem facing the inner surface of the core, each spiral groove having dimensions to provide pumping action in the intermediate flow region and viscous flow region within the gap between the stem and the core to resist backflow of gas from the pump outlet into the processing chamber.
[0008] In one embodiment, the inner surface of the core is flat.
[0009] In one embodiment, the lower region of the processing chamber has an opening configured to receive the stem alongside the passage, and one or more spiral grooves are formed on the inner surface of the core, each spiral groove having dimensions to provide pumping action in the intermediate flow region and viscous flow region within the gap between the stem and the core to resist backflow of gas from the pump outlet into the processing chamber.
[0010] In one embodiment, the surface of the stem facing the inner surface of the core is flat.
[0011] In one embodiment, the stage is positioned symmetrically within the processing chamber relative to the gas port, with the pump core and stem aligned along the centerline below the gas port.
[0012] In one embodiment, the sidewall of the processing chamber has an opening configured for the substrate to pass through during loading of the substrate onto the chuck before etching and during unloading of the substrate from the chuck after etching.
[0013] In one embodiment, the stage is movable between a lower position where substrates can be loaded onto and removed from the stage, and an upper position positioned for processing the substrates.
[0014] In one embodiment, a pump screen is disposed within the processing chamber, the pump screen having an opening through which the stage passes when positioned in the upper position. The pump screen may have one or more adjustable openings. In some embodiments, the pump screen may be formed by overlapping slats. In such embodiments, the opening is adjusted by adjusting the overlap between at least one pair of slats.
[0015] In one embodiment, a radio frequency (RF) is uniformly distributed across the upper region of the processing chamber and an RF bias is coupled to the stage.
[0016] In one embodiment, a radio frequency (RF) and an RF bias are each coupled to a stage to form a capacitive coupling.
[0017] In one embodiment, the lower region of the processing chamber has an opening aligned with the passageway and configured to receive the stem, and a seal is disposed around the core of the pump and the stem of the stage, the seal configured to seal the passageway within the core.
[0018] In one embodiment, the travel stop is configured to control movement of the stage toward the pump. The travel stop may have a hole formed therein that allows the lower region of the chuck to pass through while the upper region of the chuck is stopped. A chamber seal is disposed on the travel stop or in a groove in the lower region of the chuck to separate the upper region of the processing chamber (above the travel stop) from the lower region of the processing chamber (below the travel stop) and isolate the pressures in the upper and lower regions of the processing chamber from each other. The surface of the chamber seal facing the travel stop (if the chamber seal is in the lower region of the chuck) or the lower region of the chuck (if the chamber seal is within the travel stop) may be flat.
[0019] In one embodiment, the processing chamber includes a gas port for introducing gas into an upper region of the processing chamber, a stage positioned below the gas port, the stage including a chuck configured to hold a substrate and a stem extending from the chuck, and a travel stop configured to control movement of the stage toward a pump.
[0020] In one embodiment, the processing chamber further comprises a chamber seal disposed in a groove in either the travel stop or the lower portion of the chuck, the chamber seal configured to separate an upper region of the processing chamber above the travel stop from a lower region of the processing chamber below the travel stop such that the pressures in the upper and lower regions of the processing chamber are independent.
[0021] In one embodiment, a pump is attached to the processing chamber to remove gas from the processing chamber, the pump including a core having a passage disposed therein, a stem passing through the passage in the core, one or more spiral grooves formed in the stem facing an inner surface of the core, the inner surface of the core being flat, or one or more spiral grooves formed in the inner surface of the core, the surface of the stem facing the inner surface of the core being flat, each spiral groove having a dimension to provide pumping action in the intermediate flow region and viscous flow region within the gap between the stem and the core to resist backflow of gas from the pump outlet into the processing chamber.
[0022] In one embodiment, a sidewall of the processing chamber has an opening configured for a substrate to pass through during loading of the substrate onto the chuck before etching and during unloading of the substrate from the chuck after etching, the stage is movable between a first position where the substrate can be loaded onto and unloaded from the stage and a second position where the substrate is positioned for processing, and a pump screen is disposed within the processing chamber, the pump screen having an adjustable opening through which the stage passes when positioned in the first position.
[0023] In one embodiment, the pump apparatus includes rotary stages each having a rotor configured to rotate with rotation of the rotary stage, stationary stages each having a rotor configured to remain stationary with rotation of the stationary stage, the stationary stages being interleaved with the rotary stages, the rotors being positioned at an angle different from the angle of the rotors, and a cylindrical core through which the rotary stage and the stationary stage extend, the cylindrical core having a center having a passage disposed vertically therein, the passage having a diameter formed to receive a stem of a processing chamber stage on which a substrate is held on a chuck, the stem extending from the chuck.
[0024] In one embodiment, the pump device further comprises one or more spiral grooves formed on the inner surface of the cylindrical core, each spiral groove having a dimension to provide pumping action in the intermediate flow region and viscous flow region within the gap between the stem and the cylindrical core and to resist backflow of gas from the pump outlet when the stem is disposed within the cylindrical core.
[0025] In one embodiment, the pump lacks a valve that covers the inlet of the pump and protects the pump from the higher pressure atmosphere.
[0026] In one embodiment, a method of operating a processing chamber system includes loading a semiconductor substrate onto a chuck of a stage in the processing chamber, the stage having a stem extending from the chuck, moving the stage with the semiconductor substrate to a processing position, rotating the stage when the stage is in the processing position and introducing an etching gas into an upper region of the processing chamber to etch the rotating semiconductor substrate, exhausting the processing gas from the processing chamber using a pump having a passage in the center of a core of the pump, the stem being configured to pass through the passage in the core and extend from an end of the pump facing the processing chamber, and introducing a spiral groove into either a surface of the stem or an inner surface of the core facing the stem to restrict backflow of gas from an outlet of the pump to the processing chamber in an intermediate flow region and a viscous flow region within a gap between the stem and the core, the spiral groove having a dimension to provide pumping action and resist backflow of gas.
[0027] In some embodiments, a processing apparatus includes a pump for evacuating gas from a chamber and a stage. The pump includes a rotary stage including rotors configured to rotate with the rotation of the stage, a stationary stage including rotors configured to remain stationary with the rotation of the stage, the rotors being positioned at an angle different from that of the rotors, and the stationary stage being interleaved with the rotary stage, and a cylindrical core from which the rotary stage and the stationary stage extend, the cylindrical core having a passageway with a center of the cylindrical core disposed vertically therein. The stage includes a chuck configured to hold a substrate and a stem extending from the chuck through the passageway. A spiral groove is formed in the passageway of only one of the stem or the inner surface of the core to provide pumping action in the intermediate flow region and the viscous flow region within the gap between the stem and the core and to resist backflow of gas from the pump outlet.
[0028] In some embodiments, a method of etching a substrate includes loading a substrate onto a chuck of a stage in a processing chamber, moving the stage with the substrate from a loading position to an etching position by moving a stem of the stage via a pump core located at the bottom of the processing chamber, etching the substrate using a plasma of a gas introduced into an upper region of the processing chamber, after etching the substrate, moving the stem of the stage via the pump core to move the stage from the etching position to the loading position, and unloading the substrate from the chuck after moving the stage from the etching position to the loading position.
[0029] In some embodiments, the method further includes engaging the chuck with a pump screen disposed within the processing chamber, the pump screen having an opening through which the chuck passes when disposed in the load position.
[0030] In some embodiments, the method further includes using a travel stop disposed within the processing chamber to control movement of the stage via the pump core, the travel stop having a hole therein that allows the lower region of the chuck to pass through while the upper region of the chuck is stopped, and using a chamber seal disposed in a groove in either the travel stop or the lower region of the chuck to separate the upper region of the processing chamber above the travel stop from the lower region of the processing chamber below the travel stop, so that the pressures in the upper and lower regions of the processing chamber are independent.
[0031] In some embodiments, an apparatus for etching a substrate comprises means for loading a substrate onto a chuck of a stage in a processing chamber; means for moving the stage containing the substrate from a loading position to an etching position by moving a stem of the stage via a pump core located at the bottom of the processing chamber; means for etching the substrate using a plasma of a gas introduced into an upper region of the processing chamber; means for moving the stage from the etching position to the loading position by moving the stem of the stage via the pump core after etching the substrate; and means for unloading the substrate from the chuck after moving the stage from the etching position to the loading position.
[0032] In some embodiments, the apparatus further comprises means for engaging the chuck with a pump screen disposed within the processing chamber, the pump screen having an opening through which the chuck passes when disposed in the load position.
[0033] In some embodiments, the apparatus further comprises: means for controlling movement of the stage via the pump core using a travel stop disposed within the processing chamber, means for the travel stop having a hole disposed therein that allows the lower region of the chuck to pass while the upper region of the chuck is stopped, and means for isolating the upper region of the processing chamber above the travel stop from the lower region of the processing chamber below the travel stop using a chamber seal disposed in a groove in either the travel stop or the lower region of the chuck, so that the pressures in the upper and lower regions of the processing chamber are independent. Other means for achieving other operations indicated herein may be present in addition to or instead of the means indicated above.
[0034] In some embodiments, a computer-readable storage medium (whether transient or non-transitory) may store instructions for execution by one or more processors that, when executed, configure the one or more processors to load a substrate onto a chuck of a stage within a processing chamber, move the stage with the substrate from a load position to an etch position by moving a stem of the stage via a pump core disposed at the bottom of the processing chamber, etch the substrate using a plasma of a gas introduced into an upper region of the processing chamber, and, after etching the substrate, move the stem of the stage via the pump core to move the stage from the etch position to the load position, and unload the substrate from the chuck after moving the stage from the etch position to the load position.
[0035] In some embodiments, the instructions, when executed by one or more processors, configure the one or more processors to engage the chuck with a pump screen disposed within the processing chamber, the pump screen having an opening through which the chuck passes when disposed in the load position.
[0036] In some embodiments, the instructions, when executed by the one or more processors, configure the one or more processors to control movement of the stage via a pump core using a travel stop located within the processing chamber, the travel stop having a hole therein that allows a lower region of the chuck to pass through while the upper region of the chuck is stopped, and to separate the upper region of the processing chamber above the travel stop from the lower region of the processing chamber below the travel stop using a chamber seal located in a groove either on the travel stop or in the lower region of the chuck, such that the pressures in the upper and lower regions of the processing chamber are independent. Other instructions for accomplishing other operations set forth herein may be present in addition to or in place of the instructions set forth above. [Brief explanation of the drawings]
[0037] The various views of the accompanying drawings merely depict exemplary embodiments of the present disclosure and are not to be considered as limiting the scope of the present disclosure.
[0038] [Figure 1A] FIG. 1A illustrates a processing chamber, according to some example embodiments. [Figure 1B] FIG. 1B illustrates a processing chamber, according to some example embodiments.
[0039] [Figure 2] FIG. 2 illustrates a portion of a turbomolecular pump, according to some example embodiments.
[0040] [Figure 3] FIG. 3 illustrates a processing chamber, according to some example embodiments.
[0041] [Figure 4] FIG. 4 illustrates a processing chamber, according to some example embodiments.
[0042] [Figure 5]FIG. 5 illustrates a processing chamber, according to some example embodiments.
[0043] [Figure 6] FIG. 6 is a flowchart illustrating operations in a method according to an example embodiment. DETAILED DESCRIPTION OF THE INVENTION
[0044] In some examples, deposition control and particle management within a processing chamber may be provided during operation of a processing chamber equipped with a turbomolecular pump. Unless otherwise specified, components and functions are optional and may be combined or subdivided, and operations may be out of sequence or combined or subdivided. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the exemplary embodiments. However, it will be apparent to one skilled in the art that the inventive subject matter may be practiced without these specific details.
[0045] Semiconductor manufacturing involves multiple photolithographic, chemical, and chemical-mechanical processing steps to create integrated circuits. Specifically, processes may include deposition, etching, and patterning. Various materials, including metal layers and insulating layers (e.g., dielectrics) such as oxides, nitrides, and photoresists, may be deposited or created on semiconductor (or insulating) substrates. Deposition techniques include chemical vapor deposition (CVD), molecular beam epitaxy (MBE), physical vapor deposition (PVD), electrochemical vapor deposition (ECD), atomic layer deposition (ALD), and others. Materials deposited on the substrate as well as the substrate material may be patterned using photolithography. Etching may involve removing some or all of the exposed layers on the substrate. Etching may be performed using wet chemical etching or dry plasma etching. Chemical mechanical planarization (CMP) may be used to planarize substrate layers between depositions.
[0046] Successive generations of integrated circuits have seen a continuous decrease in feature size, extending the capabilities of existing processing equipment as well as the processes described above, resulting in the development of new processing equipment and technologies. This decrease in feature size has also led to an increase in the aspect ratio of features fabricated on substrates. Aspect ratios for etching deeply recessed features, i.e., the ratio of the feature's depth to its width, are currently approximately 50:1 to 100:1 (or greater). These aspect ratios may be used to fabricate various circuit elements, such as contact trenches and vias. However, such ratios cannot be achieved using anisotropic wet etching and sidewall protection of dielectric layers disposed between metal layers. Instead, dry (plasma) etching may be used to create these structures, providing tight control over the etch profile.
[0047] Plasma etching may operate at pressures between approximately 0.1 and 5 Torr. The plasma may be formed, for example, from chlorine or fluorine gas or an oxygen-rich gas. Different gases may be used to etch different materials. For example, Cl2 or CF4 may be used to etch Si, SiCl4 or CCl4 may be used to etch Al, CF4 may be used to etch other metals such as Mo or W, and CF4 or SF6 may be used to etch SiO2 or SiN. Ashing using oxygen may be used to remove photoresist. To obtain these plasmas, gas molecules may be excited by an external bias and supplied with, for example, 10-30 kW of power at frequencies ranging from 5-10 Hz to microwave frequencies (MHz-GHz).
[0048] Etching structures on a substrate can be complicated by several factors, including etching multi-layer features (e.g., semiconductor, insulator, metal). Different layers may have different etch rates. As a result, etching portions of these layers can produce by-products that adversely affect subsequent etching of the same or different layers. Managing etch rates can be further complicated by features with high aspect ratios and structures with different feature densities. Furthermore, operating conditions such as temperature, bias, and / or pressure within the processing chamber, as well as the chamber layout itself, can affect the etch rate. In the last case, chamber asymmetries can result in perturbed gas flow, and thus plasma etching can produce etch non-uniformities across the substrate. This non-uniformity can be exacerbated by high aspect ratios and different feature densities due to prolonged exposure to different amounts of plasma flow at different locations along the substrate, as discussed above.
[0049] To alleviate some of the above problems, a symmetrical processing chamber design is provided. Modifications to the processing chamber may also result in modifications to the pumps serving the processing chamber. FIGS. 1A and 1B illustrate a processing chamber according to some example embodiments. The processing chamber 100 may include a load port 102 through which a substrate 126 is loaded into and unloaded from the processing chamber 100. The load port 102 may be sealed during processing of the substrate 126. The processing chamber 100 may also include a gas port 104 through which a plasma is introduced into the processing chamber 100. A pump screen 110 may be disposed within the processing chamber 100.
[0050] The movable stage 120 may also be configured to hold a substrate 126 loaded into the processing chamber 100 via the load port 102. The movable stage 120 may include a chuck 122 on which the substrate 126 is held and a stem 124 that supports the chuck 122. The movable stage 120 may hold the substrate 126, for example, via a vacuum port on the chuck 122. Alternatively or additionally, the substrate 126 may be held in a recess in the chuck 122 or by a clip or other retainer (not shown). The movable stage 120 may be centered within the processing chamber 100 such that the edges of the chuck 122 are equidistant from the sidewalls of the processing chamber 100. Similarly, the stem 124 may extend straight downward from the chuck 122 through the bottom of the processing chamber 100 along its central longitudinal axis, such that the stem 124 is also centered within the processing chamber 100.
[0051] The gas port 104 may be located at the top of the processing chamber 100. Similar to the movable stage 120, the gas port 104 may be centrally located within the processing chamber 100 such that the gas port 104 is equidistant from the sidewall of the processing chamber 100. The gas port 104 may be centrally located above the movable stage 120 such that the centerline of the gas port 104 is aligned with the centerline of the movable stage 120 (both the chuck 122 and the entire stem 124).
[0052] The substrate 126 can be etched using a plasma formed by gas introduced through the gas port 104 using an electromagnetic field. The electromagnetic field may be generated by an RF source 142 (anode) and an RF bias 152 (cathode). The RF bias 152 is supplied via a cathode assembly on the stem 124. The RF source 142 and the RF bias 152 may operate at the voltage and frequency parameters described above (frequencies ranging from a few Hz to microwave frequencies and voltage differences on the order of tens to hundreds of volts). As shown in FIGS. 1A and 1B, the RF source 142 may be symmetrically positioned and extend along the outer edge of the top of the processing chamber 100, while the RF bias 152 is applied to the movable stage 120. Both the RF source 142 and the RF bias 152 may be positioned to provide a uniform potential difference between the RF source 142 and the RF bias 152.
[0053] A pump 130 for extracting gases from the processing chamber 100 may be attached to the bottom of the processing chamber 100. A pump screen 110 may prevent debris and other etching byproducts from falling into the inlet of the pump 130. The movable stage 120 may be repositioned between an upper position (shown in FIG. 1A ), where the substrate 126 is etched, and a lower position (shown in FIG. 1B ), where the substrate 126 is loaded onto or unloaded from the chuck 122. In some embodiments, the pump screen 110 may have an opening 112 sized to fit into the chuck 122. In some embodiments, the opening 112 in the pump screen 110 may be adjustable, such that the size of the opening 112 is adjusted (reduced or enlarged) depending on the position of the movable stage 120, for example. Generally, the pump screen 110 may have one or more adjustable openings 112, which may be formed by overlapping slats. The aperture 112 may be adjusted by adjusting the overlap between at least one pair of slats. The overlapping slats may be similar to those used in camera irises and may be arranged in various embodiments, such as spirals (similar to those used in camera irises described above), rings, along one direction, or in a cross-hatch pattern. The overlapping slats may have a substantially constant cross-section or may have a cross-section that varies over at least a portion of the portion of the slat that overlaps another slat, such that the overall thickness of the overlapping slats remains substantially constant.
[0054] Additionally, movable stage 120 may rotate at a rotational speed ranging from several hundred rpm to 1000 rpm (e.g., 400-1000 rpm), which may depend on the operation (e.g., etching, deposition, drying). In other embodiments, movable stage 120 may be limited to vertical movement only during etching, i.e., movable stage 120 may not rotate.
[0055] The pump 130 may be a turbomolecular pump, including a rotatable circular core with several angled blades and multiple stages of fixed, stationary blades interleaved with high-speed turbine blades arranged at different angles. The turbomolecular pump receives reacted process gas (plasma) at low pressure through an inlet and may further compress the gas before it is delivered to a scrubber system at atmospheric pressure. As the circular core rotates, the blades collide with the incoming gas molecules, transferring their mechanical energy to the momentum of the gas molecules, directed from the inlet by a fixed stator with gas transfer holes. The stages are arranged along a drive shaft that rotates at speeds up to approximately 90,000 rpm. The gas is then compressed from stage to stage through the turbomolecular pump to the exhaust, where it is drawn by a backing pump tasked with maintaining the exhaust pressure below approximately 100 milliliters per second. Pumping speeds are approximately 50 to 3,000 liters per second, and final pressures are approximately 10 -5 ~10 -8 It may also be Torr.
[0056] Alternatively, pump 130 may be a molecular drag pump, in which momentum transfer from the machine to the gas is achieved by transferring the motion of a rapidly rotating solid surface to the gas molecules between the stationary and rotating surfaces. The molecular drag pump may be a Holweck pump, in which the surface is in the shape of a rotating spiral drum, or a Gaede pump, in which the surface is in the shape of a slotted rotor disk. Molecular drag pumps may have higher back pressures (approximately 3-25 torr), lower vacuum levels in the chamber, and slower pumping speeds (up to 1 / 3 slower) than turbomolecular pumps.
[0057] Alternatively, pump 130 may be a turbo / drag pump that combines features of a turbomolecular pump and a molecular drag pump, where the rotor / stator array of the turbomolecular pump may be located inside the inlet, while the molecular drag pump may be located closer to the exhaust.
[0058] Regardless of the type of pump, such pump 130 may be centrally located at the bottom of the processing chamber 100 such that the centerline of the pump 130 is aligned with the centerlines of the gas ports 104 and the movable stage 120.
[0059] 1A and 1B may include a rotor core 132 having a through passageway (also referred to as a center hole) 134 in the center of the rotor core 132. The through passageway 134 may extend completely through the pump 130 from the inlet side of the pump 130 adjacent the processing chamber 100 to the exhaust side of the pump 130. The diameter of the through passageway 134 may be slightly larger than the diameter of the stem 124, allowing the through passageway 134 to receive the stem 124 and allow the stem 124 to extend vertically below the pump 130.
[0060] The through passage 134 allows the RF bias 152 to be delivered by the pump 130. This arrangement avoids the use of ducts in the sidewalls of the processing chamber 100 to pass the cathode through the through passage, which is one of the main geometric non-uniformities of the processing chamber 100. The arrangement of the RF source 142 and the RF bias 152 therefore creates a symmetric bias so that the plasma can react with the substrate 122 to produce reacted process gases. This arrangement also allows for symmetric flow within the processing chamber 100, improving azimuthal etch uniformity.
[0061] However, introducing the through passage 134 into the rotor core 132 creates a path between the inlet and exhaust of the pump 130, potentially allowing gas to flow back from the high-pressure exhaust to the low-pressure inlet in the processing chamber 100. To avoid this backflow, a molecular drag pump may be designed with the through passage 134. Accordingly, FIG. 2 illustrates a portion of a pump according to some example embodiments. Specifically, FIG. 2 shows an enlarged perspective view of a portion of the rotor core and stem shown in FIGS. 1A / 1B. As shown, the stem 224 of the movable stage is positioned within the through passage 234 formed in the rotor core 232. Similar to the arrangement in FIGS. 1A / 1B, a small gap may exist between the stem 224 and the rotor core 232. The gap between the rotor core 232 and the stem 224 may be minimized to reduce the amount of backflow gas.
[0062] As shown in FIG. 2 , a portion of the stem 224 has a spiral groove 226 formed therein. During operation, the stem 224 and the rotor core 232 may rotate in opposite directions, thereby displacing gas therebetween. The spiral groove 226 may face the rotor core 232 and, in some embodiments, may terminate before the end of the rotor core 232 (i.e., it may not extend into the processing chamber 100 or outside the rotor core 232) to avoid turbulence where the spiral groove 226 ends. In other embodiments, the spiral groove 226 may terminate either slightly inside the processing chamber 100 or slightly outside the rotor core 232 (e.g., a few millimeters) from the end of the rotor core 232. The addition of the spiral groove 226 on the stem 224 may direct gas between the stem 224 and the rotor core 232 by pumping. Similar to a Holweck pump, which has a rotating spiral drum shape, momentum of the stem 224 and / or rotor core 232 may be transferred to the gas by flowing the gas through the spiral grooves 226. The rotation of the stem 224 may be in the direction of the spiral grooves 226 (while the rotation of the rotor core 232 may be in the opposite direction) to allow the gas to be directed (and momentum transferred to the gas) in the desired direction. The depth and pitch of the spiral grooves 226 (the distance between vertically aligned portions of the spiral grooves 226) may be determined based on empirical determination of these parameters to maintain a desired vacuum within the process chamber 100 during operation. Using a drag pump in this manner may allow the pumping action to counteract the backflow of gas from the exhaust port into the process chamber 100 in the intermediate and viscous flow regions within the gap. In these regions, molecules primarily influence the motion of other molecules through collisions. This differs from the molecular flow regime, where collisions between molecules are largely absent in free space and most molecular interactions occur between molecules and walls.
[0063] While FIG. 2 shows spiral grooves 226 formed in stem 224, in other embodiments, spiral grooves 226 may instead be formed in rotor core 232. In this case, the depth and / or pitch of the grooves may be different from those formed in stem 224 to maintain a vacuum due to the difference in the circumference of the surfaces on which the grooves reside. However, grooves need only be formed in either stem 224 or rotor core 232, not both. This avoids turbulence issues caused by differential drag within the gap. Therefore, the surface opposite the surface containing spiral grooves 226 may be flat (i.e., without any intended grooves or protrusions), and either the inner surface of rotor core 232 facing stem 224 or the surface of stem 224 facing the inner surface of rotor core 232 may be flat. While the amount of drag may vary depending on the groove depth and pitch, in some embodiments, multiple spiral grooves 226 with the same direction and pitch may be used to achieve the same effect. In such an embodiment, the grooves 226 may overlap along a circle at the same height on the stem 224 or rotor core 232 (e.g., on opposite sides of the stem 224 at the same distance from the bottom of the stem 224).
[0064] In an alternative embodiment, a seal may be used to prevent backflow of gas. The stem 224 may extend through a seal located inside the bottom of the processing chamber 100. The seal may be a flange or gasket that seals the processing chamber 100, allowing the movable stage 120 to move vertically within the processing chamber 100 while preventing plasma from exiting through the through-passage 134, thereby venting through the stationary blades and turbine blades. The seal may be formed from one or more metals and / or insulators (e.g., vacuum seal rubber). The seal may be a single-layer or multi-layer structure containing the same or different materials.
[0065] FIG. 3 shows a processing chamber 300 according to some example embodiments. The processing chamber 300 in FIG. 3 is similar to that shown in FIGS. 1A and 1B. The processing chamber 300 may include a load port 302 through which a substrate 326 is loaded into and unloaded from the processing chamber 300. The load port 302 may be sealed during processing of the substrate 326. The processing chamber 300 may also include a gas port 304 through which gases may be introduced into the processing chamber 300 to generate a plasma. A pump screen 310 may be disposed within the processing chamber 300.
[0066] The movable stage 320 may also be configured to hold a substrate 326 that has been loaded into the processing chamber 300 via the load port 302. The movable stage 320 may include a chuck 322 on which the substrate 326 is held and a stem 324 that supports the chuck 322. The movable stage 320 may hold the substrate 326 via, for example, a vacuum port on the chuck 322. The movable stage 320 may be centered within the processing chamber 300 so that the edges of the chuck 322 are equidistant from the sidewalls of the processing chamber 300. Similarly, the stem 324 may extend vertically and straight from the chuck 322 to the bottom of the processing chamber 300 so that the stem 324 is also centered within the processing chamber 300.
[0067] The gas port 304 may be located at the top of the processing chamber 300. Similar to the movable stage 320, the gas port 304 may be centrally located within the processing chamber 300 such that the gas port 304 is equidistant from the sidewall of the processing chamber 300. The gas port 304 may be centrally located above the movable stage 320 such that the centerline of the gas port 304 is aligned with the centerline of the movable stage 320 (both the chuck 322 and the entire stem 324).
[0068] The substrate 326 can be etched using a plasma generated from gas introduced through the gas port 304 using an electromagnetic field. The electromagnetic field may be generated by an RF source 342 (anode) and an RF bias 352 (cathode). The RF bias 352 is supplied via a cathode assembly on the stem 324. The RF source and RF bias 352 may operate at the voltage and frequency parameters described above. As shown in FIG. 3, unlike FIGS. 1A and 1B, the RF source 342 and RF bias 352 are capacitively coupled and applied via the movable stage 320. Both the RF source 342 and the RF bias 352 may be positioned to provide a uniform potential difference between them, thereby creating a symmetric bias for the plasma to react with the substrate 322 and generate reacted process gases.
[0069] A pump 330 for extracting gases from the processing chamber 300 may be attached to the bottom of the processing chamber 300. A pump screen 310 may prevent debris and other etching byproducts from falling into the inlet of the pump 330. The movable stage 320 may move between an upper position to etch the substrate 326 and a lower position to load or unload the substrate 326 onto or from the chuck 322. As mentioned above, in some embodiments, the pump screen 310 may have an opening 312 sized to fit over the chuck 322. The pump 330 may be a turbomolecular pump, a molecular drag pump, or a turbo / drag pump.
[0070] The pump 330 may be located in the center of the bottom of the processing chamber 300 such that the centerline of the pump 330 is aligned with the centerlines of the gas ports 304 and the movable stage 320 .
[0071] 3 may include a core 332 with a central through-passage 334. The through-passage 334 may extend completely through the pump 330 from the inlet side of the pump 330 adjacent the processing chamber 300 to the exhaust side of the pump 330. The diameter of the through-passage 334 may be slightly larger than the diameter of the stem 324 so that the through-passage 334 can receive the stem 324 and allow the stem 324 to extend vertically below the pump 330.
[0072] Although not shown, as described above, spiral grooves may be formed in stem 324 or core 332 to prevent backflow of gas. Seals and / or grooves may also be used or may be used instead. Note that, as shown, an outer portion of movable stage 320 may be connected to RF bias 352, while an inner portion of movable stage 320 (shown as the center of movable stage 320) may be connected to RF source 342.
[0073] 4 shows a processing chamber according to some example embodiments. Similar to above, the processing chamber 400 may include a load port 402 through which a substrate 426 is loaded into and unloaded from the processing chamber 400. The load port 402 may be sealed during processing of the substrate 426. The processing chamber 400 may also include a gas port 404 through which a plasma is introduced into the processing chamber 400. A pump screen 410 may be disposed within the processing chamber 400.
[0074] The movable stage 420 may be configured to hold a substrate 426 thereon, the substrate 426 having been loaded into the processing chamber 400 via the load port 402. The movable stage 420 may include a chuck 422 on which the substrate 426 is held and stems 424a and 424b that support the chuck 422. The movable stage 420 may hold the substrate 426 via a vacuum port on the chuck 422. The movable stage 420 may be centered within the processing chamber 400 such that the edges of the chuck 422 are equidistant from the sidewalls of the processing chamber 400.
[0075] The stems 424a, 424b may extend straight downward from the chuck 422, bend at a substantially vertical angle (e.g., within 1-2 degrees depending on mechanical tolerances), and extend through a side portion of the processing chamber 400. Thus, the stems may have a vertical portion 424a extending vertically from the chuck 422 and a horizontal portion 424b extending horizontally from the vertical portion 424a, where the vertical direction is from the top of the processing chamber 400 to the bottom of the processing chamber 400 and the horizontal direction is between opposing sidewalls of the processing chamber 400. One of the sidewalls of the processing chamber 400 may include an opening 402 through which the horizontal portion 424b of the stem extends.
[0076] The gas port 404 may be located at the top of the processing chamber 400. Similar to the movable stage 420, the gas port 404 may be centrally located within the processing chamber 400 such that the gas port 404 is equidistant from the sidewall of the processing chamber 400. The gas port 404 may be centrally located above the movable stage 420 such that the centerline of the gas port 404 and the centerline of the movable stage 420 are aligned.
[0077] The substrate 426 can be etched using a plasma formed by gas introduced through the gas port 404 using an electromagnetic field. The electromagnetic field may be generated by an RF source 442 and an RF bias 452. The RF bias 452 is supplied through a cathode assembly on the stem 424. The RF source 442 and the RF bias 452 may operate at the voltage and frequency parameters described above. The RF source 442 may be symmetrically positioned and extend along the outer edge of the top of the processing chamber 400, while the RF bias 452 is applied to the movable stage 420. Both the RF source 442 and the RF bias 452 may be positioned to provide a uniform potential difference between the RF source 442 and the RF bias 452, thereby creating a symmetric bias for the plasma to react with the substrate 422 and generate reacted process gases.
[0078] A pump 430 for extracting gases from the processing chamber 400 may be attached to the bottom of the processing chamber 400. A pump screen 410 may prevent debris and other etching byproducts from falling into the inlet of the pump 430. The movable stage 420 may be repositioned between an upper position where a substrate 426 is loaded onto or unloaded from the chuck 422, an intermediate position where the substrate 426 is etched, and a lower position where higher pressure processing occurs within the processing chamber 400. The higher pressure is a pressure in excess of the pump 430 used (e.g., greater than about 0.1 mbar) and may be defined by a clearance between the moving and stationary blades (less than the mean free path of particles moving through the pump 430). In some embodiments, the pump screen 410 may have an opening 412 sized to fit within the chuck 422. The movable stage 420 may rotate at the rotational speeds described above or may be limited to vertical movement only during etching.
[0079] The pump 430 may be a turbomolecular pump, a molecular drag pump, or a turbo / drag pump. Regardless of the type of pump, the pump 430 may be centrally located at the bottom of the processing chamber 400 such that the centerline of the pump 430 is aligned with the centerlines of the gas ports 404 and the movable stage 420.
[0080] In some embodiments, when a high-pressure process is performed in chamber 400, pump 430 may be cycled off and then restarted after the high-pressure process is performed in chamber 400. However, this process may take a relatively long time, for example, it may take more than about four minutes to increase the pressure in chamber 400 and then 15-20 minutes to reduce the pressure in chamber 400 to the pressure used in the low-pressure process. Additionally, such cycling may have adverse effects on pump 430.
[0081] In some embodiments, the pump 430 may have a valve at its inlet adjacent to the chamber 400. The valve may be a plate covering the inlet of the pump 430. The valve may be used to seal the pump 430 from the chamber 400, thereby isolating the pump 430 from the chamber 400 while keeping the pump 430 operational when a high-pressure process is performed in the chamber 400. However, such valves may be made of metal and therefore relatively expensive. Therefore, in some embodiments, as shown in FIG. 4, a valve may not be present in the pump 430. Instead, the chamber 400 may include a travel stop 414 that controls the progression of the movable stage 420 downward, away from the gas port 404. The travel stop 414 may be integral with or non-integral to the chamber 400 and may be formed from a non-volatile rigid material, such as a polymer. The travel stop 414 may have a hole disposed therein that is sized to allow the stem 424 and the lower portion of the chuck 422 to pass through while retaining the upper portion of the chuck 422 on which the substrate 426 is held. A horizontal portion of the stem 424 may be disposed below the travel stop 414, between the travel stop 414 and the bottom surface of the processing chamber 400.
[0082] The chamber seal 416 may be disposed in a groove on the travel stop 414 to engage the bottom surface of the upper portion of the chuck 422. In some embodiments, the portion of the chamber seal 416 facing the bottom surface of the upper portion of the chuck 422 may be flat. The chamber seal 416 may be formed from a flexible, non-conductive, non-volatile material, such as a halogen-resistant polymer, e.g., a fluoropolymer such as perfluoropentane (PFP) or FKM, although the material forming the chamber seal 416 may depend on the chamber use / application operated in the chamber 400. While FIG. 4 shows the chamber seal 416 disposed in a groove on the travel stop 414, in other embodiments, the chamber seal 416 may be disposed in a groove on the bottom surface of the upper portion of the chuck 422. In such embodiments, the portion of the chamber seal 416 facing the top surface of the travel stop 414 may be flat.
[0083] As described above, the horizontal portion 424b may be fixed, while the vertical portion 424a may be movable. As shown in FIG. 4, the horizontal portion 424b may be a sealed duct having a hole through which the vertical portion 424a passes. The vertical portion 424a may be movable within the horizontal portion 424b from a bottom position to at least an upper position. In the bottom position, the chuck 422 contacts the chamber seal 416 and seals the lower portion of the processing chamber 400, separating the pump 430 from the upper portion of the processing chamber 400 containing the substrate 426. In the upper position, the substrate 426 is positioned to be loaded into or unloaded from the chamber via the load port 402. As shown, in some embodiments, when vertical portion 424a is in its lowest position, up to several centimeters may remain between the vertical portion 424a and the bottom of horizontal portion 424b, and similarly, when vertical portion 424a is in its upper position, up to several centimeters may remain between the vertical portion 424a and the top of horizontal portion 424b.
[0084] In some embodiments, the movable stage 420 may be driven by a motor (not shown) or may use a bellows. The movable stage 420 may be driven by a motor or bellows to raise or lower the movable stage 420 vertically, for example, until the movable stage 420 contacts and compresses the chamber seal 416. At this point, a current limiter on the motor may stop the lowering movement of the movable stage 420 in the lower position until the motor drive is reversed to raise the movable stage 420 to the processing position. When the movable stage 420 is in the lower position, the chamber seal 416 may allow the lower portion of the chamber 400 (essentially below the travel stop 414), and therefore the pump 430, to be isolated from the upper portion of the chamber 400 (essentially above the travel stop 414).
[0085] In some embodiments, a flange or gasket (not shown) may be used to seal the area around the hole in horizontal portion 424b. Electrical connections associated with supplying the cathode voltage, as well as cooling lines for cooling movable stage 420, may be flexible. In some embodiments, the electrical connections and / or cooling lines may be located within horizontal portion 424b, while in other embodiments, the electrical connections and / or cooling lines may be on the exterior surface of the interior of horizontal portion 424b.
[0086] 5 shows a processing chamber according to some example embodiments. Similar to above, the processing chamber 500 may include a load port 502 through which a substrate 526 is loaded into and unloaded from the processing chamber 500. The load port 502 may be sealed during processing of the substrate 526. The processing chamber 500 may also include a gas port 504 through which a plasma is introduced into the processing chamber 500. A pump screen 510 may be disposed within the processing chamber 500.
[0087] The movable stage 520 may be configured to hold a substrate 526 loaded into the processing chamber 500 via the load port 502. The movable stage 520 may include a chuck 522 on which the substrate 526 is held and a stem 524 that supports the chuck 522. The movable stage 520 may hold the substrate 526 via a vacuum port on the chuck 522. The movable stage 520 may be centered within the processing chamber 500 such that the edges of the chuck 522 are equidistant from the sidewalls of the processing chamber 500. Similarly, the stem 524 may extend straight down from the chuck 522 through the bottom of the processing chamber 500 along its central vertical axis, so that the stem 524 is also centered within the processing chamber 500.
[0088] The gas port 504 may be located at the top of the processing chamber 500. Similar to the movable stage 520, the gas port 504 may be centrally located within the processing chamber 500 such that the gas port 504 is equidistant from the sidewall of the processing chamber 500. The gas port 504 may be centrally located above the movable stage 520 such that the centerline of the gas port 504 and the centerline of the movable stage 520 are aligned.
[0089] The substrate 526 can be etched using a plasma formed by gas introduced through the gas port 504 using an electromagnetic field. The electromagnetic field may be generated by an RF source 542 and an RF bias 552. The RF bias 552 is supplied through a cathode assembly on the stem 524. The RF source 542 and the RF bias 552 may operate at the voltage and frequency parameters described above. The RF source 542 may be symmetrically positioned and extend along the outer edge of the top of the processing chamber 500, while the RF bias 552 is applied to the movable stage 520. Both the RF source 542 and the RF bias 552 may be positioned to establish a uniform potential difference between them, thereby creating a symmetric bias for the plasma to react with the substrate 522 and generate reacted process gases.
[0090] A pump 530 for extracting gases from the processing chamber 500 may be mounted to the bottom of the processing chamber 500. A pump screen 510 may prevent debris and other etch byproducts from falling into the inlet of the pump 530. The movable stage 520 may be repositioned between an upper position where the substrate 526 is etched and a lower position where the substrate 526 is loaded onto or unloaded from the chuck 522. In some embodiments, the pump screen 510 may have an opening 512 sized to fit over the chuck 522. The movable stage 520 may also rotate at the rotational speeds described above or may be limited to moving vertically only during etching.
[0091] The pump 530 may be a turbomolecular pump, a molecular drag pump, or a turbo / drag pump. Regardless of the type of pump, the pump 530 may be centrally located at the bottom of the processing chamber 500 such that the centerline of the pump 530 is aligned with the centerlines of the gas port 504 and the movable stage 520. The pump 530 may include a rotor core 532 with a central through-passage 534. The through-passage 534 may extend completely through the pump 530 from the inlet side of the pump 530 adjacent the processing chamber 500 to the exhaust side of the pump 530. The diameter of the through-passage 534 may be slightly larger than the diameter of the stem 524 so that the through-passage 534 can receive the stem 524, allowing the stem 524 to extend vertically below the pump 530.
[0092] The pump 530 may not have the valve described above. Instead, the chamber 500 may include a travel stop 514, spaced from the gas port 504, that slows the downward progress of the movable stage 520. The travel stop 514 may be integral with the chamber 500 or may be non-integral with the chamber 500 and may be formed from a non-volatile, rigid material such as a polymer. The travel stop 514 may have an aperture disposed therein sized to allow the lower portion of the chuck 522 to pass through while stopping the upper portion of the chuck 522, on which the substrate 526 is held.
[0093] The chamber seal 516 may be disposed in a groove on the travel stop 514 to engage the bottom surface of the upper portion of the chuck 522. In some embodiments, the portion of the chamber seal 516 facing the bottom surface of the upper portion of the chuck 522 may be flat. The chamber seal 516 may be formed from a flexible, non-conductive, non-volatile material, such as a halogen-resistant polymer, e.g., a fluoropolymer such as perfluoropentane (PFP) or FKM, although the material forming the chamber seal 516 may depend on the chamber use / application operated in the chamber 500. While FIG. 5 shows the chamber seal 516 disposed in a groove on the travel stop 514, in other embodiments, the chamber seal 516 may be disposed in a groove on the bottom surface of the upper portion of the chuck 522. In such embodiments, the portion of the chamber seal 516 facing the top surface of the travel stop 514 may be flat.
[0094] In some embodiments, the movable stage 520 may be driven by a motor (not shown). The movable stage 520 may be driven downward until the movable stage 520 contacts and compresses the chamber seal 516. At this point, a current limiter on the motor may stop the downward movement of the movable stage 520 in the lower position until the motor drive is reversed to raise the movable stage 520 to the processing position. When the movable stage 520 is in the lower position, the chamber seal 516 may allow the separation of the lower part of the chamber 500 (essentially below the travel stop 514) from the upper part of the chamber 500 (essentially above the travel stop 514), and therefore the pump 530.
[0095] 6 is a flowchart illustrating operations in a method according to an example embodiment. While various operations are shown in FIG. 6, the illustrated embodiment is merely an example, and other operations may be present and / or some of the illustrated operations may not be present. A method 600 for etching a substrate is shown, in which, in operation 602, a substrate is loaded into a processing chamber. The substrate may also be loaded onto a chuck of a stage having a stem. The substrate may be held on the chuck using a vacuum supplied through holes in the chuck.
[0096] The chuck may be in a load position when a substrate is loaded onto the chuck. The chuck may extend through an opening in the pump screen during load. The opening may be formed to allow the chuck to pass through. After load, the stage containing the substrate may be moved to the etching position in operation 604. If the opening is adjustable, the opening may be adjusted when the stage is in the etching position to adjust the pressure within the chamber. Specifically, one or more pressure sensors may be provided at one or more locations within the processing chamber. The pressure sensors may determine whether the pressure within the chamber is changing over time and / or distance by more than a predetermined threshold. A controller may be used to detect the pressure and control the opening to maintain a stable pressure.
[0097] The stage may be moved by using a motor to move the stem of the stage through a pump core located at the bottom of the processing chamber. In some embodiments, the stage may be moved by rotating the stage to engage one or more spiral grooves formed on either the stem or the inner surface of the core, which faces the inner surface of the core. In the former case, the inner surface of the core may be flat, while in the latter case, the surface of the stem facing the inner surface of the core may be flat. The spiral groove may be sized to provide pumping action in the intermediate flow region and viscous flow region within the gap between the stem and the core, preventing backflow of gas from the pump outlet into the processing chamber. A travel stop located in the processing chamber may be used to slow the movement of the stage. Specifically, the travel stop may have an internal hole sized to allow the lower part of the chuck to pass through while the upper part of the chuck is stopped.
[0098] After the stage is moved to the etching position, the substrate may be etched using gases introduced into the upper region of the processing chamber in operation 606. After etching is completed, the stage may be moved from the etching position to a loading position in operation 608 by moving the stem of the stage through the core of the pump. The etched substrate may then be unloaded in operation 610.
[0099] The processing chamber may be used for processes other than etching, and may be cleaned after etching a substrate before loading another substrate into the processing chamber for etching or other processes. In some cases, when the processing chamber is used for processes at higher pressures, the processing chamber may be isolated from the pump. The pump may have a shield configured to seal the pump, or a chamber seal located in a groove in the travel stop or the bottom of the chuck may be used to separate the upper region of the processing chamber above the travel stop from the lower region of the processing chamber below the travel stop. This allows for independent pressures in the upper and lower regions of the processing chamber.
[0100] Although only semiconductor substrates have been described above, particularly with reference to Si substrates, other substrates may be used in the processing chamber. Such substrates include elemental semiconductors other than Si (e.g., Ge), and compound semiconductors such as binary compounds (e.g., GaAs, InP), ternary compounds (e.g., AlGaAs, InGaP), quaternary compounds (e.g., InGaAsP), or other III-V or II-VI compounds (e.g., GaN). Additionally, substrates may include non-metallic and non-semiconductor materials such as polyethylene terephthalate (PET) or other types of semi-crystalline polymers, such as flat panel displays or films, used in ultra-lightweight semiconductor device fabrication.
[0101] A computer may be used to operate the systems shown in FIGS. 1-5 and control operational parameters such as gas flow rates, applied bias, and chuck rotation speed, among others, to load / unload semiconductor substrates, activate pumps and / or motors, adjust the position of screen openings and / or movable stages, and etch semiconductor substrates. The computer may include a hardware processor (e.g., a central processing unit (CPU), a GPU, a hardware processor core, or any combination thereof), main memory, and static memory, some or all of which may communicate with each other via an interlink (e.g., a bus). The main memory may include any or all of removable and non-removable storage, volatile memory, and / or non-volatile memory. The computer may further include a display device such as a video display, an alphanumeric input device (e.g., a keyboard), and a user interface (UI) navigation device (e.g., a mouse). As an example, the display device, input device, and navigation device may be a touchscreen display. The computer may also include storage devices (e.g., drive units), signal generating devices (e.g., speakers), network interface devices, and one or more sensors, such as a global positioning system (GPS) sensor, a compass, an accelerometer, or other sensors. The computer may further include an output controller, such as a serial (e.g., Universal Serial Bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection, for communicating with or controlling one or more peripheral devices (e.g., printers, card readers, etc.).
[0102] The storage device may include a non-transitory machine-readable medium (hereinafter simply referred to as machine-readable medium) on which is stored one or more data structures or sets of instructions (e.g., software) embodied in or utilized by any one or more of the techniques or functions described herein. The instructions may reside, completely or at least partially, in main memory, static memory, and / or within a hardware processor during execution by a computer. While the machine-readable medium is illustrated as a single medium, the term "machine-readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database and / or associated caches and servers) configured to store one or more instructions.
[0103] The term "machine-readable medium" may include any medium capable of storing, encoding, or carrying instructions for execution by a computer and causing a computer to perform any one or more of the techniques of this disclosure, or any medium capable of storing, encoding, or carrying data structures used in or associated with such instructions. Non-limiting examples of machine-readable media include solid-state memory, as well as optical and magnetic media. Specific examples of machine-readable media include non-volatile memory such as semiconductor memory devices (e.g., electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM)) and flash memory devices, magnetic disks such as internal hard disks and removable disks, magneto-optical disks, random access memory (RAM), and CD-ROM and DVD-ROM disks.
[0104] The instructions may further be sent or received over a communications network utilizing any one of several transport protocols (e.g., frame relay, Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), Hypertext Transfer Protocol (HTTP), etc.) using a transmission medium via a network interface device. Examples of communications networks may include local area networks (LANs), wide area networks (WANs), packet data networks (e.g., the Internet), mobile phone networks (e.g., cellular networks), plain old telephone (POTS) networks, and wireless data networks. Communications over the network may include one or more different protocols, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards known as Wi-Fi, the IEEE 802.16 family of standards known as WiMax, the IEEE 802.15.4 family of standards, the Long Term Evolution (LTE) family of standards, the Universal Mobile Telecommunications System (UMTS) family of standards, peer-to-peer (P2P) networks, next-generation (NG) / fifth-generation (5G) standards, etc. In one example, a network interface device may include one or more physical jacks (eg, Ethernet, coaxial, or telephone jacks) or one or more antennas for connecting to a transmission medium.
[0105] Throughout this specification, multiple examples may implement components, operations, or structures described as a single example. Although individual operations of one or more methods are illustrated and described as separate operations, one or more of the individual operations may occur simultaneously, and there is no requirement that the operations occur in the order illustrated. In example configurations, structures and functionality presented as separate components may be implemented as composite structures or components. Similarly, structures and functions presented as single components may be implemented as separate components. These and other variations, modifications, additions, and improvements are included within the scope of the subject matter of this specification.
[0106] The embodiments illustrated herein are described in sufficient detail to enable those skilled in the art to practice the disclosed teachings. Other embodiments may be utilized and derived therefrom, and structural and logical substitutions and changes may be made without departing from the scope of the present disclosure. Therefore, the detailed description is not to be construed in a limiting sense, and the scope of various embodiments is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled.
[0107] As used herein, the term "or" may be interpreted in either an inclusive or exclusive sense. Furthermore, multiple instances of a resource, operation, or structure described herein as a single example may apply. Moreover, boundaries between various resources, operations, modules, engines, and data stores are somewhat arbitrary, and particular operations are illustrated in the context of specific exemplary configurations. Other allocations of functionality are contemplated and may be included within the scope of various embodiments of the present disclosure. In general, structures and functionality presented as separate resources in an exemplary configuration may be implemented as a composite structure or resource. Similarly, structures and functionality presented as a single resource may be implemented as separate resources. These and other variations, modifications, additions, and improvements are within the scope of the embodiments of the present disclosure, as indicated by the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative sense, and not a restrictive sense.
Claims
1. 1. A processing chamber comprising: a gas port for introducing gas into an upper region of the processing chamber; a stage disposed below the gas port, the stage including a chuck configured to hold a substrate and a stem extending from the chuck; a travel stop configured to control movement of the stage toward a pump, the travel stop having an aperture disposed therein sized to allow a lower portion of the chuck to pass therethrough while the upper portion of the chuck is stopped; A processing chamber comprising:
2. 10. The processing chamber of claim 1, further comprising: a chamber seal disposed in a groove in one of the travel stop or the lower portion of the chuck, the chamber seal separating an upper region of the processing chamber above the travel stop from a lower region of the processing chamber below the travel stop, the chamber seal configured to maintain independent pressures within the upper and lower regions of the processing chamber.
3. 3. The processing chamber of claim 2, A processing chamber, wherein a surface of the chamber seal facing the travel stop or the lower region of the chuck is flat.
4. 3. The processing chamber of claim 2, The process chamber, wherein the chamber seal is formed from a flexible, non-conductive, non-volatile, halogen-resistant fluoropolymer.
5. 10. The processing chamber of claim 1, The processing chamber, wherein the stages are positioned symmetrically within the processing chamber with respect to the gas port.
6. 10. The processing chamber of claim 1, a sidewall of the processing chamber having an opening configured to allow the substrate to pass through during loading of the substrate onto the chuck before etching and during unloading of the substrate from the chuck after etching.
7. 7. The processing chamber of claim 6, The processing chamber, wherein the stage is movable between a lower position where the substrate can be loaded onto and unloaded from the stage, and an upper position where the substrate is positioned for processing.
8. 1. A processing chamber system comprising: a processing chamber having a gas port for introducing gas into an upper region thereof; a stage disposed within the processing chamber below the gas port, the stage including a chuck configured to hold a substrate and a stem extending from the chuck; a spiral groove provided on at least one of a surface of the stem or an inner surface of the pump core facing the stem; A processing chamber system comprising:
9. 9. The processing chamber system of claim 8, A processing chamber system, wherein the spiral groove has dimensions to provide pumping action and resist backflow of gas from the pump outlet to the processing chamber in an intermediate region and a viscous flow region within the gap between the stem and the core.
10. 9. The processing chamber system of claim 8, The processing chamber system, wherein the stem and the core are rotatable in opposite directions.
11. 9. The processing chamber system of claim 8, further comprising: A processing chamber system comprising a pump screen disposed within the processing chamber, the pump screen having an opening through which the stage passes.
12. 12. A processing chamber system according to claim 11, comprising: The opening in the pump screen is adjustable.
13. 13. A processing chamber system according to claim 12, comprising: A processing chamber system, wherein the pump screen is formed by overlapping slats, and the opening is adjusted by adjusting the overlap between at least one pair of slats.
14. 1. A processing chamber system comprising: a processing chamber having a gas port disposed at the top thereof; a stage including a chuck configured to hold a substrate and a stem extending from the chuck, the stem having a vertical portion extending vertically from the chuck and a horizontal portion extending horizontally from the vertical portion; A processing chamber system, wherein a sidewall of the processing chamber includes an opening through which the horizontal portion of the stem extends.
15. 15. The processing chamber system of claim 14, The horizontal portion is a sealed duct having an aperture through which the vertical portion passes, and the vertical portion is movable within the horizontal portion from a lowermost position to at least an upper position.
16. 15. The processing chamber system of claim 14, The vertical portion bends at a substantially vertical angle to form the horizontal portion.
17. 1. A pump device comprising: a plurality of rotation stages, each including a rotor configured to rotate with rotation of the rotation stage; a plurality of stationary stages, each including a stationary wing configured to remain stationary as the stationary stage rotates, interleaved with the plurality of rotating stages; a cylindrical core through which the plurality of rotary stages and the plurality of stationary stages extend, the center of the cylindrical core having a vertically disposed passage therein for a stem; A pump device, wherein a spiral groove is provided on at least one of a surface of the stem or an inner surface of the cylindrical core facing the stem.
18. 18. The pump device of claim 17, The pump apparatus, wherein the pump lacks a valve covering an inlet to the pump.
19. 1. A method of operating a processing chamber, comprising: loading a semiconductor substrate onto a chuck of a stage within a processing chamber, the stage having a stem extending from the chuck; moving the stage containing the semiconductor substrate to a processing position; rotating the stage when the stage is in the processing position; introducing a gas into an upper region of the processing chamber to etch the rotating semiconductor substrate; exhausting process gas from the process chamber using a pump having a passageway in the center of its core, the stem configured to pass through the passageway in the core; restricting backflow of the gas from the pump outlet to the processing chamber in an intermediate flow region and a viscous flow region within the gap between the stem and the core by introducing a spiral groove into one of the surface of the stem or the inner surface of the core facing the stem; A method comprising:
20. 20. The method of claim 19, The method wherein the stage rotates at a rotational speed in the range of one hundred to one thousand rpm.