Independently adjustable flowpath conductance in multi-station semiconductor processing

Abstract

SOLUTION: Methods and apparatuses are provided herein for independently adjusting flowpath conductance. One multi-station processing apparatus may include a processing chamber, a plurality of process stations in the processing chamber that each includes a showerhead having a gas inlet, and a gas delivery system including a junction point and a plurality of flowpaths, in which each flowpath includes a flow element, includes a temperature control unit that is thermally connected with the flow element and that is controllable to change the temperature of the flow element, and fluidically connects one corresponding gas inlet of a process station to the junction point such that each process station of the plurality of process stations is fluidically connected to the junction point by a different flowpath.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] Incorporation by Reference A PCT application is being filed contemporaneously herewith as a part of this application, and each application identified in that contemporaneously filed PCT application to which this application claims benefit or priority is hereby incorporated by reference in its entirety for all purposes. [Background technology]

[0002] During semiconductor processing operations, a substrate is typically supported on a pedestal in a processing chamber, and process gases are flowed into the chamber to deposit one or more layers of material on the substrate. In commercial-scale manufacturing, each substrate or wafer contains multiple copies of the particular semiconductor device being manufactured, and many substrates are required to achieve the required quantity of devices. The commercial viability of semiconductor processing operations depends heavily on the within-wafer uniformity and wafer-to-wafer repeatability of process conditions. Thus, efforts are made to ensure that each portion of a given wafer and each wafer that is processed is exposed to the same processing conditions. Variations in processing conditions and semiconductor processing tools can cause variations in deposition conditions, resulting in unacceptable variations in the overall process and product. Techniques and apparatus for minimizing process variations are needed.

[0003] The background and contextual discussion contained herein is provided for the sole purpose of generally presenting the contents of the present disclosure. Much of the present disclosure presents work by the inventors, and merely because such work is described in the Background section or presented as context elsewhere herein does not mean that it is admitted to be prior art. Summary of the Invention

[0004] The systems, methods, and devices of the present disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein, including at least the following embodiments, although additional embodiments are described in the detailed description or may be apparent from the description provided herein.

[0005] In some embodiments, a multi-station processing apparatus can be provided. The apparatus can include a processing chamber, a plurality of process stations within the processing chamber, each including a showerhead having a gas inlet and a faceplate, and a gas delivery system including a junction and a plurality of flow paths. Each flow path includes a flow element, includes a temperature control unit thermally connected to the flow element and controllable to change a temperature of the flow element, and fluidly connects a corresponding gas inlet of one of the process stations to the junction such that each process station of the plurality of process stations is fluidly connected to the junction by a different flow path.

[0006] In some embodiments, the temperature control unit may be controllable to change the flow conductance of a flow element in thermal contact therewith via a change in temperature.

[0007] In some embodiments, the temperature control unit may include a heating element configured to heat a flow element in thermal contact therewith.

[0008] In some such embodiments, the heating element may include a resistive heating element, a thermoelectric heater, and / or a fluid conduit configured to flow a heated fluid therethrough.

[0009] In some embodiments, each showerhead may further include a temperature control unit thermally connected to the showerhead and controllable to alter a temperature of a portion of the showerhead, and each flow path may further fluidly connect a showerhead faceplate to the junction.

[0010] In some such embodiments, the temperature control unit may be thermally coupled to the stem of the showerhead and controllable to alter the temperature of the stem.

[0011] In some such embodiments, the temperature control unit may be thermally coupled to the faceplate and controllable to alter the temperature of the faceplate.

[0012] In some such embodiments, the showerhead may further include a backplate, and the temperature control unit may be thermally coupled to the backplate and controllable to alter the temperature of the backplate.

[0013] In some such embodiments, the showerhead may be a flush-mount showerhead.

[0014] In some embodiments, the temperature control unit may be positioned at least partially inside the flow element in which the temperature control unit is positioned.

[0015] In some embodiments, the flow element of each flow path may include a valve, and the temperature control unit of each flow path may be controllable to heat the valve to change the flow conductance of the valve.

[0016] In some embodiments, the flow element of each flow path may include a monoblock, and the temperature control unit of each flow path may be controllable to heat the monoblock to change the flow conductance of the monoblock.

[0017] In some embodiments, the flow elements of each flow path may include a gas line, and the temperature control unit of each flow path may be controllable to heat the gas line to change the flow conductance of the gas line.

[0018] In some such embodiments, the junction is a mixing bowl.

[0019] In some embodiments, the flow element of each flow path may include a fitting, and the temperature control unit of each flow path is controllable to heat the fitting to change the flow conductance of the fitting.

[0020] In some such embodiments, the fitting may be a tee fitting.

[0021] In some embodiments, each flow path may further include two temperature control units, and each temperature control unit in each flow path may be in thermal contact with a different flow element of that flow path.

[0022] In some embodiments, the apparatus may further include a controller configured to control the multi-station deposition apparatus to deposit material on the substrate at the plurality of process stations. For a first flow path fluidly connected to a first station of the plurality of process stations, the first temperature control unit may be in thermal contact with the first flow element, and for a second flow path fluidly connected to a second station of the plurality of process stations, the second temperature control unit may be in thermal contact with the second flow element, and the controller may include control logic for providing a substrate to each of the process stations, simultaneously depositing a first layer of material on the first substrate at the first process station and depositing a second layer of material on the second substrate at the second process station, maintaining the first flow element at a first temperature and maintaining the second flow element at a second temperature different from the first temperature during at least a portion of the deposition.

[0023] In some such embodiments, maintaining the first flow element at a first temperature may include causing a first temperature control unit to heat the first flow element to the first temperature, and maintaining the second flow element at a second temperature may include causing a second temperature control unit not to heat the second flow element.

[0024] In some such embodiments, maintaining the first flow element at a first temperature may include causing a first temperature control unit to heat the first flow element to the first temperature, and maintaining the second flow element at a second temperature may include causing a second temperature control unit to heat the second flow element to the second temperature.

[0025] In some such embodiments, the controller may further include control logic for maintaining the first flow element at a third temperature, different from the first temperature, and maintaining the second flow element at a fourth temperature, different from the second temperature, during at least a second portion of the deposition.

[0026] In some such embodiments, while maintaining the first flow element at a first temperature, the first flow path may have a first flow conductance, and while maintaining the second flow element at a second temperature, the second flow path may have a second flow conductance that is different from the first flow conductance.

[0027] In some such embodiments, while maintaining the first flow element at a first temperature, the first flow path may have a first flow conductance, and while maintaining the second flow element at a second temperature, the second flow path may have a second flow conductance substantially equal to the first flow conductance.

[0028] In some such embodiments, a first layer of material deposited on a first substrate may have a first value of a property, and a second layer of material deposited on a second substrate may have a second value of the property that is substantially the same as the first value.

[0029] In some further such embodiments, the property may be wet etch rate, dry etch rate, composition, thickness, density, amount of crosslinking, reaction completion, stress, refractive index, dielectric constant, hardness, etch selectivity, stability, and hermeticity.

[0030] In some such embodiments, a first layer of material deposited on a first substrate may have a first value of the property, and a second layer of material deposited on the first substrate may have a second value of the property that is different from the first value.

[0031] In some such embodiments, deposition may further include temperature soaking the substrate, indexing, flowing a precursor, flowing a purge gas, flowing a reactant gas, generating a plasma, and / or activating the precursor on the substrate, thereby depositing material on the substrate.

[0032] In some embodiments, a method of depositing material onto a substrate in a multi-station deposition apparatus having a first station with a first showerhead and a second station with a second showerhead can be provided, the method including providing a first substrate on a first pedestal of the first station, providing a second substrate on a second pedestal of the second station, simultaneously depositing a first layer of material onto the first substrate and a second layer of material onto the second substrate, maintaining a first flow element of a first flow path at a first temperature during at least a portion of the simultaneous deposition, the first flow path fluidly connecting a junction to the first showerhead, and maintaining a second flow element of a second flow path at a second temperature different from the first temperature, the second flow path fluidly connecting a junction to the second showerhead. may include.

[0033] In some embodiments, maintaining the first flow element at a first temperature may include maintaining the first flow path at a first flow conductance, and maintaining the second flow element at a second temperature may include maintaining the second flow path at a second flow conductance different from the first flow conductance.

[0034] In some embodiments, maintaining the first flow element at a first temperature may include maintaining the first flow path at a first flow conductance, and maintaining the second flow element at a second temperature may include maintaining the second flow path at a second flow conductance substantially the same as the first flow conductance.

[0035] In some embodiments, maintaining the first flow element at a first temperature may include heating the first element, and maintaining the second flow element at a second temperature may include not heating the second element.

[0036] In some embodiments, maintaining the first flow element at a first temperature may include heating the first element, and maintaining the second flow element at a second temperature may include heating the second element.

[0037] In some embodiments, the method may further include providing a third substrate on the first pedestal before providing the first substrate and the second substrate, providing a fourth substrate on the second pedestal before providing the first substrate and the second substrate, and simultaneously depositing a third layer of material on the first substrate and a fourth layer of material on the second substrate without maintaining the first flow element at the first temperature and without maintaining the second flow element at the second temperature, wherein a first non-uniformity between properties of the first layer of material on the first substrate and properties of the second layer of material on the second substrate may be less than a second non-uniformity between properties of the third layer of material on the third substrate and properties of the fourth layer of material on the fourth substrate. [Brief description of the drawings]

[0038] Various embodiments disclosed herein are illustrated by way of example, and not limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements and in which:

[0039] [Figure 1] FIG. 1 illustrates a first exemplary multi-station semiconductor processing tool.

[0040] [Diagram 2] FIG. 2 is a diagram illustrating a second exemplary multi-station processing tool.

[0041] [Diagram 3] FIG. 3 illustrates a first exemplary technique for performing film deposition in a multi-station semiconductor processing chamber.

[0042] [Figure 4] FIG. 4 is a diagram illustrating a fourth technique for performing film deposition in a multi-station semiconductor processing chamber.

[0043] [Diagram 5] FIG. 5 illustrates a fifth exemplary technique for performing film deposition in a multi-station semiconductor processing chamber.

[0044] [Figure 6] FIG. 6 is a diagram illustrating a sixth exemplary technique for performing film deposition in a multi-station semiconductor processing chamber.

[0045] [Figure 7] FIG. 7 is a flowchart of an exemplary sequence of operations for forming a film of a material on a substrate via an ALD process.

[0046] [Figure 8] FIG. 8 is a plot of material thickness for the two substrates.

[0047] [Figure 9] FIG. 9 is a plot of the refractive index (RI) for the two substrates.

[0048] [Figure 10]FIG. 10 is a diagram illustrating a single station substrate processing apparatus for depositing films on semiconductor substrates using any number of processes.

[0049] [Figure 11] FIG. 11 is a diagram illustrating an exemplary multi-station substrate processing apparatus.

[0050] [Figure 12A] FIG. 12A is an isometric view of an exemplary showerhead according to disclosed embodiments.

[0051] [Figure 12B] FIG. 12B is a cross-sectional isometric view of the example showerhead of FIG. 12A.

[0052] [Figure 13] FIG. 13 is a cross-sectional side view of an exemplary flush mounted showerhead.

[0053] [Figure 14] FIG. 14 is a diagram illustrating a third exemplary multi-station semiconductor processing tool.

[0054] [Figure 15] FIG. 15 is an isometric view of an exemplary thermally controlled showerhead.

[0055] [Figure 16] FIG. 16 is an isometric cross-sectional view of the exemplary thermally controlled showerhead of FIG.

[0056] [Figure 17] FIG. 17 is an isometric, partially exploded view of a portion of the thermally controlled showerhead of FIG.

[0057] [Figure 18] FIG. 18 is another isometric, partially exploded view of a portion of the thermally controlled showerhead of FIG.

[0058] [Figure 19] FIG. 19 is an isometric cross-sectional view of a gas distribution manifold, according to some embodiments.

[0059] [Figure 20] FIG. 20 is an exploded view of the exemplary gas distribution manifold of FIG. 19, according to some embodiments.

[0060] [Figure 21] FIG. 21 is a top view of one example of a heater plate assembly of the exemplary gas distribution manifold of FIG. 19, according to some embodiments.

[0061] [Figure 22] FIG. 22 is a top view of an example cooling plate assembly of the exemplary gas distribution manifold of FIG. 19, according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0062] Semiconductor processing tools having multi-station processing chambers typically deliver process gases to each station by flowing the process gas from a common source to a junction and then through individual, typically nominally identical, flow paths to gas distribution devices at each station. The flow conductance between identically constructed flow paths is known to differ due to inherent variations, such as variations in manufacturing tolerances. Furthermore, the flow conductance within these flow paths is known to affect the properties of the material deposited on the substrate, such as the thickness and refractive index of the material. Such variations are often small enough that they did not affect the process conditions for performing semiconductor device fabrication operations in earlier technology nodes or in single-station reactors. However, design constraints and advanced fabrication techniques leave little room for even what were previously considered minor variations in flow conductance.

[0063] It has been discovered that the flow conductance of an element in a flow path can be adjusted, inter alia, by adjusting the temperature of that element. Thus, techniques and devices are described herein for adjusting one or more flow conductances of an element in a flow path to modify or adjust the flow characteristics of the flow path. This in turn can help to adjust the properties of the deposited material and / or improve station-to-station consistency of the properties of the deposited material. To improve station-to-station consistency, the conductances of flow elements in lines to different stations of a single multi-station chamber can be adjusted independently of each other, for example, by independently controlling the temperatures of flow elements in different lines to different stations.

[0064] As previously mentioned, the flow conductance of two nominally identical flow elements in different flow paths may differ due to variations in manufacturing tolerances. By adjusting the temperature of one of these elements, the flow conductance of that element is correspondingly adjusted so that the flow conductance of the two flow elements match. In another example, the properties of the deposited material at two different stations in the same processing chamber may differ. At one of the stations, the temperature of one of the flow elements in the flow path relative to that station may be adjusted to adjust the flow conductance of that flow path to adjust the properties of the material deposited at that station to more closely match the properties at the other station. In another example, the flow rate or other flow properties through the inlet line to the process chamber may deviate slightly from specifications. The temperature of the elements along the inlet line may be strategically adjusted to adjust the flow properties to fall within specifications.

[0065] Several semiconductor processes are used to deposit one or more layers of material onto a substrate using various techniques such as chemical vapor deposition ("CVD"), plasma-enhanced CVD ("PECVD"), atomic layer deposition ("ALD"), low pressure CVD, ultra-high pressure CVD, and physical vapor deposition ("PVD"). CVD processes deposit films onto a wafer surface by flowing one or more gaseous reactants (also called precursors) into a reactor, where the gaseous reactants react, optionally with the aid of a plasma as in PECVD, to form a product (typically a film) on the substrate surface. In ALD processes, precursors are transported to the wafer surface, where they are adsorbed onto the wafer and then transformed by chemical or physicochemical reactions to form a thin film on the substrate. A plasma may be present in the chamber to facilitate the reaction. ALD processes employ multiple film deposition cycles, each resulting in a "discrete" film thickness.

[0066] ALD generates relatively conformal films, since a single cycle of ALD deposits only a single thin layer of material. Thickness is limited by the amount of one or more film precursor reactants that can adsorb (i.e., form an adsorption-limited layer) on the substrate surface prior to the film-forming chemical reaction itself. Multiple "ALD cycles" can then be used to build up a film of the desired thickness, and because each layer is thin and conformal, the resulting film substantially matches the shape of the underlying device structure. In certain embodiments, each ALD cycle includes the following steps: 1. Exposure of a substrate surface to a first precursor. 2. Purging the reaction chamber in which the substrate is located. 3. Activation of a reaction at the substrate surface, optionally by exposure to high temperature and / or plasma and / or by exposure to a second precursor. 4. Purging the reaction chamber in which the substrate is located.

[0067] The duration of each ALD cycle may be less than 25 seconds, less than 10 seconds, or less than 5 seconds. The plasma exposure step (or steps) of an ALD cycle may be of short duration, such as, for example, 1 second or less in duration. The precursor exposure step may be of similarly short duration. During such short durations, precise control of the flow properties of the gases introduced into the process chamber is critical. This challenge is further complicated by the continuing shrinkage of semiconductor device feature sizes and the increasing use of complex feature geometries, such as 3D device structures. In such applications, film deposition processes must generate films of precisely controlled thickness, often with high conformality (films of material having uniform thickness relative to the shape of the underlying structure, even if non-planar).

[0068] For purposes of this disclosure, the term "fluidically connected" is used in reference to volumes, plenums, holes, etc. that may be connected to one another to form a fluid connection, similar to the way the term "electrically connected" is used in reference to components connected together to form an electrical connection. The term "fluidically inserted", when used, may be used to refer to a component, volume, plenum, or hole that is fluidly connected to at least two other components, volumes, plenums, or holes such that fluid flowing from one of those other components, volumes, plenums, or holes to the other or another component, volume, plenum, or hole first flows through the "fluidically inserted" component before reaching those other or another component, volume, plenum, or hole. For example, if a pump is fluidly inserted between a reservoir and an outlet, fluid flowing from the reservoir to the outlet will first flow through the pump before reaching the outlet.

[0069] I. Overview of flow conductance As a fluid travels through a flow path from one plenum to another, the flow path represents a restriction that resists the flow of the fluid. The relative ease with which the fluid flows is referred to as the conductance or flow conductance, which is generally represented by the following equation:

number

[0070] A multi-station processing tool typically has a single processing chamber that includes multiple stations, such as 2, 4, 6, or 8 stations, and can process substrates simultaneously. Each station generally includes a substrate support structure, such as a pedestal or electrostatic chuck, and a showerhead for delivering process gases to the substrates at the station. A multi-station processing tool also typically includes a gas delivery system with gas (or liquid) sources, valves, gas lines, and other flow elements configured to transport process gases to each station's showerhead, each showerhead configured to distribute the process gas relatively evenly across the substrates in the station. Part of the gas delivery system includes multiple flow paths, each flow path fluidly connecting one corresponding showerhead to a common junction. Typically, it is desirable to create the same uniform flow conditions at all stations, so that parallel processing at these stations will produce uniform processing results between the stations. For this reason, the flow paths are typically constructed to be as identical as possible, so that the flow of gas between a junction, such as a mixing chamber, and the showerhead is as similar as possible. For example, more gas will tend to flow through the higher conductance flow paths, which can result in inconsistent flows at corresponding processing stations if the flow paths have mismatched flow conductance.

[0071] In some cases, each flow path may be considered to include the showerhead itself, and thus each flow path may extend between a common junction and the showerhead's fluid connection to a processing station. The showerheads within a station may also be constructed similarly to one another to create uniform flow conditions within and between the stations.

[0072] Despite using the same components and designs, many flow paths have different conductances for a number of reasons, including inherent variations in flow elements within a flow path, very small variations, and these differences can adversely affect process characteristics and wafer uniformity. For example, valves used in a flow path may vary in flow conductance due to manufacturing tolerances (such as + / - 3%). This variation may prevent tight enough control of the flow conductance through that flow path in some applications and may also cause different flows in that flow path compared to other flow paths. The variation in flow conductance of and between flow paths is compounded when additional flow elements, each with their own variable flow conductance, are included in the flow path. As an example, a single flow path may include multiple valves arranged in series. It is therefore advantageous to have the ability to adjust the flow conductance of one or more flow elements in a flow path to account for, among other things, variations in the flow conductance of the individual elements and the overall flow path.

[0073] In addition, deviations from precisely specified flow properties (e.g., flow rate) due to deviations in the flow conductance of the flow path from a precisely specified flow conductance can affect one or more properties of the material deposited on the substrate, such as the thickness and / or refractive index ("RI") of the material. For example, as described in more detail below, increasing the flow conductance to the flow path can decrease the thickness of the resulting material and increase the resulting RI. Of course, other deposited film properties can also be affected. Examples include composition, crystallinity, internal stress, extinction coefficient, dielectric constant, density, breakdown voltage, etc. Adjusting the flow conductance of one or more flow elements in the flow path can allow for fine tuning of any one or more of these properties. Methods and apparatus can also be implemented that reduce station-to-station non-uniformity by allowing independent adjustment of the flow conductance in different input lines feeding different stations of a multi-station chamber.

[0074] II. Regulation of flow conductance According to certain embodiments, the flow conductance through a flow element is adjusted by changing the temperature of the flow element. In some cases, as a first approximation of the ideal gas law, increasing temperature decreases the flow conductance and increases the flow resistance because increasing temperature tends to increase the pressure and increase the viscosity of gases. Separately, flow conductance may increase or decrease with increasing temperature because thermal expansion changes the geometry of the flow element. For example, a heated tube may expand and become larger, which may increase the flow conductance through the tube. In another example, a heated polymer valve seat of a valve may also expand, limiting the flow conductance through the valve.

[0075] Thus, the apparatus and techniques described herein adjust the temperature of flow elements in the flow path to adjust the flow conductance through these flow elements, adjust the properties of the deposited material, and reduce station-to-station variation. FIG. 1 illustrates a first exemplary multi-station semiconductor processing tool (hereafter "tool"). The tool 100 includes a processing chamber 102 with four processing stations 104A-104D, each enclosed in a dotted box. Each station includes a pedestal 106 with a substrate 108A on the pedestal 106A, and a showerhead 110 with a gas inlet 112; these items are labeled with processing station 104A.

[0076] The tool 100 also includes a gas delivery system 114 fluidly coupled to each processing station 104A-104D for delivering process gases to the showerhead 110, which may include liquids and / or gases, e.g., film precursors, carrier and / or purge and / or process gases, secondary reactants, etc. The gas delivery system 114 may include other features, represented diagrammatically as boxes 115A-115C, such as one or more gas sources, mixing vessels, and vaporization points for vaporizing liquid reactants provided to the mixing vessels, as well as valves and gas lines that direct and control the flow of gases and liquids throughout the gas delivery system 114. The showerhead distributes process gases and / or reactants (e.g., film precursors) toward substrates at the processing stations.

[0077] As also seen in FIG. 1, the gas delivery system 114 includes four flow paths 116A-116B, each of which is fluidly connected to a junction 118 and a gas inlet 112 of a corresponding processing station. For example, flow path 116A is fluidly connected to and spans between junction 118 and gas inlet 112 of processing station 104A, each of which extends from junction 118 to gas inlet 112, such that gas flows through flow path 116A from junction 118 to gas inlet 112. These flow paths are surrounded by dashed line shapes shown as an exemplary representation and not an exact or precise schematic of the gas delivery system. Junction 118 may be considered a common point in the gas delivery system from which two or more individual flow paths or legs branch off to individual processing stations. In some embodiments, this may be considered a point where identical or nearly identical flow paths to the processing stations begin. In some embodiments, there may be multiple junctions or sub-junctions, such that some flow paths begin at a first junction and other flow paths begin at a second junction. With reference to FIG. 1, flow paths 116A and 116B may extend from a first junction, and flow paths 116C and 116D may extend from a different second junction to their respective processing stations. As described below, in some embodiments, each flow path may further include a corresponding showerhead to span between junction 118 and one or more points on each showerhead at each station, such as a fluid connection between the showerhead and the plenum volume of the processing station.

[0078] 1, the gas inlet 112 may be considered to be outside the processing chamber 102. In these embodiments, the flow path may be considered to be positioned outside the processing chamber. In some other embodiments, the gas inlet may be inside or partially inside the processing chamber 102, and in these embodiments, the flow path may extend inside or partially inside the processing chamber 102.

[0079] Each of the flow paths also includes a temperature control unit configured and controllable to change the temperature of the flow element in that flow path. As seen in FIG. 1, each of the flow paths 116A-116D has a single temperature control unit 120A-120D. In some embodiments, the temperature control unit may be configured to heat the flow element and may include a heating element, such as a resistive heater, a thermoelectric heater, or a fluid conduit for flowing a heating fluid. In some embodiments, the temperature control unit may also be configured to cool the flow element, for example, by having a fluid conduit through which a cooling fluid can flow. The temperature control unit may be positioned on, around, or within the flow element. For example, the temperature control unit may be a heater jacket and may be positioned on the flow element by being wrapped around a pipe or valve, and in another example, the temperature control unit may be a resistive heating element positioned within the flow element by being embedded within a pipe, or a valve or block through which the fluid flows.

[0080] As mentioned, in some embodiments, the temperature control unit can be positioned within or at least partially inside the flow element in which it operates. In some embodiments, at least a portion of the temperature control unit is embedded within a portion of the flow element. For example, the resistive heating element or heated fluid conduit may be embedded inside the wall of a pipe or inside the body of a valve. In some cases, the embedded portion of the temperature control unit is positioned so that it does not contact the fluid. For example, a resistive heating element embedded in a pipe wall may not extend through the inner pipe wall into the pipe interior (where the gas flows). A fluid conduit may be a pathway, such as a channel or tube, through which a fluid can flow, and the fluid is heated to an elevated temperature, e.g., a temperature above ambient temperature, which may be at least as high as the desired temperature of the fluid conduit, such as at least 80°C, 100°C, or 110°C in some cases. The heated fluid may be a heated gas (e.g., an inert gas such as argon or nitrogen) or a heated liquid (e.g., water, a glycol / water mixture, a hydrocarbon oil, or a refrigerant / phase change fluid).

[0081] By adjusting the temperature of a flow element, such as by heating, the temperature control unit can be further configured and controlled to adjust the flow conductance of that flow element. As described above, changing the temperature for some flow elements, such as a pipe or a valve, can change the flow conductance through that flow element. Generally speaking, using temperature to control flow conductance is advantageous because the flow conductance of a flow element cannot be changed once the element is manufactured or installed. For example, the flow conductance of a valve is typically fixed after manufacture and therefore cannot be adjusted "on the fly." For example, as described above, most valves have manufacturing tolerances (such as + / - 3%) that typically cannot be changed without physical modification of the valve. However, adjusting the temperature of a valve as described herein can adjust the flow conductance of the valve to reduce the variation of the valve, for example, to reduce the variation to + / - 2%, + / - 1%, or + / - 0.5% or less.

[0082] Although tool 100 is shown with four stations, other embodiments of the tool may have more or fewer stations, e.g., 2, 6, 8, or 10 stations. These tools may be similarly configured such that each processing station has a corresponding flow path extending between that station and a junction and includes at least one temperature control unit. In some embodiments, each flow path may have two or more temperature control units, and each flow path may have multiple different flow elements.

[0083] For example, in some embodiments as illustrated in FIG. 1, the tool 100 may have a single junction 118 that may be considered a mixing bowl through which process gases flow and mix. Four identical (or intended to be identical except for minor structural and manufacturing differences, for example) flow paths 116A-116D may be connected to the mixing bowl 118, although in FIG. 1 they are not shown as identical and each extends to a gas inlet at a corresponding processing station, as described above. For example, flow path 116A extends from the mixing bowl 118 to the gas inlet 112 of processing station 114A, and similarly, flow path 116D extends from the mixing bowl 118 to the gas inlet 112D of processing station 114D. In some such embodiments, these flow paths may include tube elements and may not include valves. Each temperature control element may be a heater positioned around a portion of the tube for that flow path. This portion may be considered a circumferential portion along some or all of the circumference of the tube, and a longitudinal portion along some or all of the length of the tube.

[0084] In some other embodiments, the tool may have flow paths that include multiple different flow elements that may be temperature controlled. FIG. 2 illustrates a second exemplary multi-station processing tool. Here, the tool 200 includes the same four processing stations 204A-204D as FIG. 1, but the four flow paths of the gas delivery system 214 are different. Each flow path 216A-216D, only one of which is identified in dashed form, extends between a junction 218 and a gas inlet 212 of the corresponding processing station. Each flow path also includes multiple flow elements such as those identified for flow path 216A, including a valve 222, a monoblock 224 to which other flow components such as a second valve 226 and a mass flow controller 228 are attached, and one or more gas lines 230. Although not identified, the other three flow paths 216B-216D include these same flow elements. As further shown, a temperature control unit 220 may be positioned on or within one or more of these flow elements. For example, as seen in FIG. 2, temperature control units 220 are positioned on valve 222, in monoblock 224, and on gas line 230. The temperature control units can adjust the flow conductance of each of these elements by adjusting the temperature of that flow element. Although not shown in FIG. 1 or FIG. 2, in some embodiments, each flow path may include other flow paths that may be temperature controlled, such as fittings including tee fittings at junctions in the flow paths (other than junction 118), which may include fittings at junctions between two or three lines in the flow path. As with the other flow elements, temperature control units can be positioned on or within these other flow elements and configured to adjust the flow conductance of each of these elements by adjusting the temperature of that flow element.

[0085] As mentioned above, each flow path may further include a corresponding showerhead, and the flow conductance of each showerhead may be adjustable by controlling the temperature of one or more aspects of the showerhead. The showerheads described herein may include a plenum volume bounded by a backplate and a faceplate in front of a semiconductor processing volume in which a semiconductor substrate may be processed. The faceplate may include a number of gas distribution holes that allow gas in the plenum volume to flow through the faceplate to a reaction space between the substrate and the faceplate (or between a wafer support that supports a wafer and the faceplate). As with other flow elements through which gas flows, some features of the showerhead, such as the configuration of the inner surfaces and features of the backplate and / or faceplate, and the configuration of the through-holes (e.g., their diameters and spacing from each other), may affect and restrict the flow of gas through the showerhead. By controlling the temperature of one or more aspects of the showerhead, the flow conductance through the showerhead may be adjusted, for example, to cause a more uniform flow through the showerhead and / or reduce non-uniformity of the wafer.

[0086] Showerheads typically fall into the broad categories of flush-mount and chandelier-type. Flush-mount showerheads are typically integrated into the lid of a processing chamber, i.e., the showerhead functions as both the showerhead and the chamber lid. Chandelier-type showerheads do not function as the lid of a processing chamber, but instead are suspended within those semiconductor processing chambers by a stem that connects such showerhead with such chamber lid and functions to provide one or more fluid flow paths for processing gases delivered to such showerhead. The showerheads in Figures 1, 2, 12, and 14 are shown as chandelier-type showerheads. In some embodiments, any of the showerheads described herein can be flush-mount showerheads.

[0087] FIG. 12A illustrates an isometric view of an exemplary showerhead according to disclosed embodiments, and FIG. 12B illustrates a cross-sectional isometric view of the showerhead of FIG. 12A. The cross-sectional view of FIG. 12B is taken along section line AA of FIG. 12A. The showerhead 1210 is an exemplary chandelier type showerhead having a stem 1218. In these figures, the showerhead 1210 includes a backplate 1202 with a plenum inlet 1203 and a faceplate 1204 connected to the backplate 1202. The gas inlet 1205 of the showerhead 1210 can be considered the point at which gas enters the stem of the showerhead 1210, and this gas inlet 1205 can be considered a gas inlet as described herein, such as the gas inlets 112 and 212 of FIGS. 1, 2, and 13. The backplate 1202 and faceplate 1204 together partially define a plenum volume 1208 within the showerhead 1210, and optionally a baffle plate (not shown) can be positioned within the plenum volume 1208. The backplate 1202 and faceplate 1204 can be positioned opposite one another within the showerhead such that they have surfaces facing one another. The faceplate 1204 partially defines the plenum volume 1208 and includes a back surface 1212 that faces the backplate 1202 and a front surface 1214 configured to face a substrate positioned within the processing chamber. The faceplate 1204 also includes a number of through holes 1216 (one identified in FIG. 12B ) that extend through the faceplate 1204 from the back surface 1212 to the front surface 1214 and allow fluid to travel from the plenum volume 1208 outside the showerhead 1210 and onto the substrate.

[0088] Some showerheads may include one or more temperature control units that control the temperature of one or more aspects and thus adjust the flow conductance of the showerhead. The showerhead of FIG. 12A and FIG. 12B includes a temperature control unit that can be used to control the temperature of the showerhead. In some embodiments, the showerhead 1210 may include one or more temperature control units configured to control the temperature of the showerhead stem 1218. In some cases, controlling the temperature, and therefore the flow conductance, of the stem upstream of the restrictive flow elements of the showerhead, such as the plenum volume 1208 and the plurality of through-holes 1216, allows for more precise and uniform control and adjustment of the flow conductance through the showerhead. As representatively shown in FIG. 12A and FIG. 12B, the showerhead 1210 includes one temperature control unit 1220A positioned on the stem 1218 to heat the stem 1218 and control the temperature of the stem 1218 and thus the flow conductance of the stem 1218. The temperature control unit 1220A may be a single unit or multiple units. The temperature control unit 1220A may include one or more resistive heaters positioned around and / or within the stem 1218, one or more fluid conduits positioned around or within the stem 1218 and configured to flow a heat transfer fluid such as heated water to heat the stem, or one or more cartridge heaters positioned in holes in the stem 1218.

[0089] In some embodiments, the temperature control unit 1220A may also include one or more cooling elements configured to actively cool the stem 1218, such as one or more fluid conduits positioned around or within the stem 1218 and configured to flow a heat transfer fluid, such as cooling water, to cool the stem 1218. In some such embodiments, the temperature control unit 1220A may have two portions, a first portion present as a heating portion configured to heat the stem 1218 and a second portion present as a cooling portion configured to cool the stem 1218. Each of these portions may include a subset of portions, such as a first portion including multiple heating elements.

[0090] FIG. 15 illustrates an isometric view of an exemplary thermally controlled showerhead. FIG. 16 illustrates an isometric cross-sectional view of the exemplary thermally controlled showerhead of FIG. 15. In FIGS. 15 and 16, a showerhead 1500 is shown. The showerhead 1500 includes a faceplate 1514, which may have a number of gas distribution holes 1544 on an underside (not visible in FIG. 15, see FIG. 16). The faceplate 1514 may be connected to a backplate 1546, which may in turn be structurally and thermally connected to a cooling plate assembly 1502 by a stem 1512 and, in some implementations, a stem base 1518. The stem 1512 may include one or more holes, e.g., gun-drilled holes, which may be sized to receive, for example, a cartridge heater or heater element 1510. In the illustrated exemplary showerhead 1500, there are three heater elements 1510 positioned along three sides of the gas inlet 1504 of the stem 1512 and extending along nearly the entire length of the central gas passage 1538 (see FIG. 16 ). In some implementations, additional holes or bores extending to a similar depth can be provided and configured to accept a temperature probe, e.g., a thermocouple, that can be inserted therein to measure the temperature within the showerhead 1500 proximate the gas distribution plenum.

[0091] The cooling plate assembly 1502 may have a layered structure as shown, although other embodiments may provide a similar structure using other manufacturing techniques, such as additive manufacturing or casting. The cooling plate assembly 1502 may include a cover plate 1532 that is coupled to a first plate 1526, for example, via diffusion bonding or brazing, which is then coupled to a second plate 1528, which is then coupled to a third plate 1530. Although such structures are referred to as "plates" in this application, it will be understood that they may include features that extend away from an otherwise generally planar surface, leaving the "plate" as having a three-dimensional structure that gives such structures a non-planar appearance.

[0092] The cooling plate assembly 1502 may include an inner cooling channel 1536 that generally extends around the stem 1512 and is fluidly connected within the cooling plate assembly 1502 such that coolant flowing through the channel from the coolant inlet 1506 may then flow through an outer cooling channel 1534 that may surround (or at least partially surround) the inner cooling channel 1536 before flowing to the coolant outlet 1508.

[0093] When the showerhead 1500 is installed in a semiconductor processing system, the showerhead 1500 may be connected to a number of additional systems. For example, the heater elements 1510 may be connected to a heater power supply 1564, which may provide power to the heater elements 1510 under the direction of a controller 1566. The controller 1566 may have, for example, one or more processors 1568 and one or more memory devices 1570. The one or more memory devices may store computer-executable instructions for controlling the one or more processors to perform various functions or to control various other hardware, as described later herein.

[0094] 17 and 18 illustrate isometric, partially exploded views of a portion of the thermally controlled showerhead of FIG. 15. In FIGS. 17 and 18, both the cover plate 1532 and the first plate 1526 have been removed, exposing the cooling channels in the cooling plate assembly 1502. As can be seen, the central gas passage 1538 can be located in close proximity to the heater cartridge 1510, which can be used to provide heat to the gas flowing in the central gas passage 1538. The inner cooling channel 1536 and the outer cooling channel 1534 can be clearly seen. As can be seen, the outer cooling channel 1534 is formed by two matching channels in the first plate 1526 and the second plate 1528 that align when the various plates are assembled. The outer cooling channel 1534 can extend around all or nearly all of the central gas passage 1538, for example, about 300° of arc. One end of the outer cooling channel 1534 may be fluidly connected to the inner cooling channel 1536 such that the coolant flowing through the inner cooling channel 1536 may then flow through the outer cooling channel 1534, and then through the coolant outlet 1508, without leaving the cooling plate assembly.

[0095] 18, the first plate 1526 has a first surface that is coupled to a second surface of the second plate 1528 to form a part of the cooling plate assembly. The first surface may optionally include one of the matching channels described above, as well as a plurality of protrusions 1540, each of which may be positioned and sized to protrude into a corresponding or similarly shaped portion of the inner cooling channel 1536, thereby forming a fluid flow passage having a very thin U-shaped cross section, which generally causes the fluid flowing through the inner cooling channel 1536 to accelerate in the region where the protrusions are present, thereby increasing the Reynolds number of the cooling fluid in such region and increasing heat transfer between the cooling fluid and the walls of the inner cooling channel 1536, and between the cooling fluid and the protrusions 1540. This increases the cooling efficiency of the inner cooling channel 1536.

[0096] The protrusions 1540 can be sized such that the gap between the bottom of the inner cooling channel 1536 and the opposing surface of the protrusions 1540 is approximately the same as the gap between the sidewall of the inner cooling channel 1536 and the opposing surface or sidewall of the protrusions 1540. For example, in the exemplary showerhead 1500, the gap between the sidewall of the inner cooling channel 1536 and the opposing surface or sidewall of the protrusions 1540 is approximately 1 mm, and the gap between the bottom of the inner cooling channel 1536 and the opposing surface of the protrusions 1540 is approximately 1.3 mm. The protrusions 1540 extend approximately 14 mm from the first plate 1526 in this example, resulting in an inner cooling channel having a volume of approximately 7.2 cubic centimeters. In comparison, an outer cooling channel having a height of approximately 6 mm, and a width of approximately 6.3 mm has a volume of approximately 9.6 cubic centimeters, with an additional approximately 1.4 cubic centimeters and 0.8 cubic centimeters contributed by the inlet and outlet volumes, respectively, in the cooling plate assembly. In such a configuration, a coolant flow of about 3800-5700 cubic centimeters per minute may be provided to the cooling channels, resulting in about 200-300 complete exchanges of the cooling fluid, e.g., a coolant such as water, a fluorinated coolant (such as Solvay's Galden® PFPE), or other coolant, in the cooling channels of the cooling plate assembly 1502 per minute. This may allow the cooling plate assembly to be maintained at a temperature of about 20° C.-60° C. while the showerhead faceplate 1514 is maintained at a temperature of about 300° C.-360° C., e.g., 350° C. It will be understood that the specific dimensions and performance characteristics described above with respect to the exemplary showerhead 1500 are not intended to be limiting, and other showerheads having different dimensions and performance characteristics may also be included within the scope of the present disclosure.

[0097] Further, note that the protrusions 1540 extend downward from the first plate 1526 towards the faceplate 1514. Thus, heat from the faceplate 1514 and stems 1512 can flow along the sidewalls of the inner cooling channels 1536 towards the first plate 1526 as well as from the first plate 1526 to the ends of the protrusions 1540, i.e., in the opposite direction. This may have the effect of evenly heating the coolant flowing through the inner cooling channels, since the temperature gradient of the sidewalls of the inner cooling channels 1536 may be highest near the bottom of the inner cooling channels 1536, i.e., closest to the faceplate 1514, and lowest near the top of the inner cooling channels 1536, i.e., near the first plate 1526, while the temperature gradient of the protrusions 1540 may be reversed, i.e., having the highest temperature near the first plate 1526 and the lowest temperature near the bottom of the inner cooling channels 1536. This may promote more efficient heat transfer.

[0098] 12B, the faceplate 1204 of the showerhead 1210 may additionally or alternatively include one or more temperature control units 1220B configured to heat, cool, or both the faceplate 1204. These temperature control units 1220B may include one or more resistive heaters positioned within, in direct contact with, and / or thermally connected to the faceplate 1204. When the temperature control unit 1220B is thermally connected to the faceplate 1204, thermal energy is configured to travel directly between these items or indirectly through other thermally conductive materials, such as a thermally conductive plate (e.g., including a metal) interposed between the temperature control unit 1220B and the faceplate 1204, also as generally described herein. Alternatively or additionally, the temperature control unit 1220B may be positioned within or in thermal contact with the faceplate 1204 and include one or more fluid conduits configured to flow a heat transfer fluid, such as heating water and / or cooling water, and heat and / or the faceplate 1204.

[0099] 19 shows an isometric cross-sectional view of a gas distribution manifold 1906, such as a showerhead, according to some embodiments. The gas distribution manifold 1906 can include various components. For example, the gas distribution manifold 1906 can include a faceplate assembly 1908 that can be in thermally conductive contact with a temperature control assembly 1912, which is in thermally conductive contact with a vacuum manifold 1910 that is in thermally conductive contact with the faceplate assembly 1908. The temperature control assembly 1912 can include a cooling plate assembly 1920, a heating plate assembly 1914 offset from the cooling plate assembly 1920 to form a gap 1916, and a plurality of thermal chokes 1918 distributed within the gap 1916, each of which is described in further detail below.

[0100] Figure 20 shows an exploded isometric cross-sectional view of the gas distribution manifold 1906 of Figure 19, according to some embodiments. Figure 20 separately illustrates some components and features of the gas distribution manifold 1906, such as thermal chokes 1918, which can be seen in Figure 20 between the cooling plate assembly 1920 and the heating plate assembly 1914.

[0101] The thermal chokes 1918 can provide a configurable thermal conduction path between the cooling plate assembly 1920 and the heating plate assembly 1914. In some implementations, the thermal chokes 1918 can be configured to dissipate a specified amount of heat required for the semiconductor manufacturing operations performed by the gas distribution manifold 1906.

[0102] As shown in FIG. 20, each of the thermal chokes 1918 may include a spacer 1974. Each spacer may include a central region 1976, and each thermal choke 1918 may include a bolt 1978 passing through the central region 1976. The thermal chokes 1918 may be constructed of various materials based on the amount of thermal conductivity desired. For example, in order of decreasing thermal conductivity, the thermal chokes 1918 may be constructed of copper, aluminum, steel, or titanium. The thermal chokes 1918 may vary in size between embodiments depending on how much heat dissipation is desired. However, the thermal chokes 1918 may have a total cross-sectional area (including the spacers 1974 and bolts 1978) in a plane parallel to the second outer surface of FIG. 3 that is between 1.7% and 8.0% of the surface area of ​​the first outer surface 1926, e.g., between 1.7% and 8% of the surface area of ​​the faceplate assembly that faces toward the thermal choke and is in conductive contact with the temperature control assembly or vacuum manifold assembly.

[0103] As mentioned above, the gas distribution manifold 1906 of FIG. 19 may include a heater plate assembly 1914. FIG. 21 shows a top view of an example of the heater plate assembly 1914 of the gas distribution manifold 1906 of FIG. 19 according to some embodiments. The heater plate assembly 1914 may include a heater plate, such as, for example, a standard aluminum plate capable of conducting heat. Heat may be provided to the plate by a resistive heating element 1988 that is embedded within the plate or placed in intimate thermal contact with the plate, such as by being pressed into a serpentine groove machined into the plate, as shown. For example, the resistive heating element 1988 may have a metallic outer sheath with an internal insulator (such as magnesium oxide) that separates a resistive component, such as a coil of nichrome wire, from the sheath. The heat provided to the heater plate assembly 1914 may be varied by supplying a varying current through the resistive heating element 1988. This heater plate assembly 1914 is configured to heat the faceplate assembly 108.

[0104] The gas distribution manifold 1906 of FIG. 19 may include a cooling plate assembly 1920. FIG. 22 illustrates a top view of an example of the cooling plate assembly 1920 of the gas distribution manifold 1906 of FIG. 19, according to some embodiments. The cooling plate assembly 1920 may include cooling passages 1980. A cooling fluid, such as water, may flow through the cooling passages 1980 to provide thermal control to the faceplate assembly 1908. By way of example, cooling water having a temperature in the range of 15-30 degrees Celsius may be flowed through the cooling passages 1980 to maintain a temperature of the faceplate assembly 1908 in the range of 200-300 degrees Celsius. Alternatively, such cooling may be achieved using a high temperature compatible heat transfer fluid, such as Galden®.

[0105] Some flush-mount showerheads may be configured similarly to some chandelier-type showerheads. A flush-mount showerhead has a backplate and a faceplate with through holes that together form an internal plenum volume, and can heat the backplate, the faceplate, and / or gas inlets to the backplate to control flow conductance through the showerhead. FIG. 13 illustrates a cross-sectional side view of an exemplary flush-mount showerhead. Here, the flush-mount showerhead 1310 includes a backplate 1302 with a plenum inlet 1303 and a faceplate 1304 connected to the backplate 1302. The gas inlet 1305 of the showerhead 1310 can be considered the point at which gas enters the showerhead 1310, and this gas inlet 1305 can be considered a gas inlet as described herein, such as gas inlets 112 and 212 of FIGS. 1, 2, and 14. The backplate 1302 and faceplate 1304 together partially define a plenum volume 1308 within the showerhead 1310, and optionally a baffle plate (not shown) may be positioned within the plenum volume 1308. The backplate 1302 and faceplate 1304 may be positioned opposite one another within the showerhead such that they have surfaces facing one another. The faceplate 1304 partially defines the plenum volume 1308 and includes a back surface 1312 that faces the backplate 1302 and a front surface 1314 configured to face a substrate positioned therein when installed within a processing chamber. The faceplate 1304 also includes a number of through holes 1316 (two are identified in FIG. 13 ) that extend through the faceplate 1304 from the back surface 1312 to the front surface 1314 to allow fluid to travel from the plenum volume 1308 to outside the showerhead 1310 and onto the substrate.

[0106] The flush mount showerhead may also include one or more temperature control units that control the temperature of one or more aspects and thus regulate the flow conductance of the showerhead. The showerhead of FIG. 13 includes an illustrative example of a temperature control unit that can be used to control the temperature of the showerhead. In some embodiments, the showerhead 1310 may include one or more temperature control units 1320A configured to control the temperature of the backplate 1302. In some cases, controlling the temperature of the backplate 1302 may change the flow conductance in the plenum volume 1308 upstream of the showerhead's restrictive through-holes 1316, thus providing more precise and uniform flow conductance control and regulation through the showerhead. The temperature control unit 1320A may be a single unit or multiple units. The temperature control unit 1320A may include one or more resistive heaters positioned on and / or within the backplate 1302, one or more fluid conduits positioned on or within the backplate 1302 and configured to flow a heat transfer fluid, such as heated water, to heat the stems, or one or more cartridge heaters positioned in holes in the backplate 1302.

[0107] In some embodiments, the temperature control unit 1320A may also include one or more cooling elements configured to actively cool the backplate 1302, such as one or more fluid conduits positioned on or within the backplate 1302 and configured to flow a heat transfer fluid, such as cooling water, to cool the backplate 1302. In some such embodiments, the temperature control unit 1320A may have two portions, a first portion present as a heating portion configured to heat the backplate 1302 and a second portion present as a cooling portion configured to cool the backplate 1302. Each of these portions may include a subset of portions, such as a first portion including multiple heating elements.

[0108] The faceplate 1304 of the showerhead 1310 may also include one or more temperature control units 1320B configured to heat, cool, or both the faceplate 1304. These temperature control units 1320B may include one or more resistive heaters positioned within, in direct contact with, and / or thermally connected to the faceplate 1304 (so that thermal energy is configured to travel directly between these items or indirectly through other thermally conductive materials, such as a thermally conductive plate (e.g., including metal) interposed between the temperature control unit 1320B and the faceplate 1304). Alternatively or additionally, the temperature control unit 1320B may include a heat transfer fluid, such as heating water and / or cooling water, and one or more fluid conduits configured to flow heat and / or the faceplate 1304, positioned within or in thermal contact with the faceplate 1304. Exemplary temperature controlled showerheads are described above and shown in FIGS.

[0109] 14 illustrates an exemplary multi-station semiconductor processing tool 1400. The tool 1400 is similar to the tool 100 of FIG. 1 except that each flow path 1416A, 1416B, 1416C, and 1416D of the tool 1400 includes a corresponding showerhead 110A, 110B, 110C, and 110D, respectively, for each corresponding processing station 104A, 104B, 104C, and 104D, respectively, as described herein. For example, the flow path 1416A includes a showerhead 110A fluidly connected to and positioned within the processing station 104A. These flow paths 1416A, 1416B, 1416C, and 1416D of the tool 1400 can be considered to span between the junction 118 and one or more aspects of the showerheads 110A, 110B, 110C, and 110D, respectively, thereby surrounding and extending beyond the gas inlets 112 of each showerhead. In some embodiments, the point at which each flow path terminates within the showerhead can be considered to be a fluid connection between the showerhead and the interior volume of the processing station, which can be considered a gas distribution port of the showerhead.

[0110] 14, each showerhead 110A, 110B, 110C, and 110D includes one or more temperature control units, represented by items 1420A, 1420B, 1420C, and 1420D, respectively. Each of these showerheads can be configured as described herein with respect to showerhead 1210 of FIGS. 12A and 12B or showerhead 1310 of FIG. 13. For example, one or more temperature control units 1420A, 1420B, 1420C, and 1420D of showerheads 110A, 110B, 110C, and 110D can be configured to control the temperature of the stem (e.g., 1220A), the faceplate (e.g., 1220B), or both. Thus, one or more of these temperature control units 1420A, 1420B, 1420C, and 1420D of showerheads 110A, 110B, 110C, and 110D can be used to control the flow conductance through the showerhead in the same manner as other flow elements described herein for any of the techniques described herein. For example, the flow element of the techniques described with respect to Figures 3-6 can be the showerhead of Figures 12A, 12B, 13, and 14.

[0111] III. Exemplary Techniques The techniques and apparatus herein utilize two or more flow paths at different temperatures to adjust the flow conductance through one flow path, adjust the deposited material properties, and reduce station-to-station variability. In some embodiments, differences in material properties between stations can be reduced by adjusting the temperature of a flow element in a flow path of one station to change the flow conductance and adjust the material properties at that one station, which can be considered as tuning the material properties at that station. Temperature can also be adjusted during the deposition process to generate film properties that have different values ​​throughout the material. For example, distance can be adjusted during deposition to cause one section of the material to have one property value and another section of the material to have a different value of RI, etc., within the material. In some embodiments, the temperature of the flow element, and therefore the flow conductance, can be adjusted to match a desired flow conductance or that of another flow element, which can be considered as a hardware tuning of that flow element. For example, the flow conductance of a valve can be adjusted by changing its temperature so that the valve matches or substantially matches (e.g., within + / - 2%, + / - 1%, or + / - 0.5%) the flow conductance of another valve. Temperature and flow conductance adjustments can be implemented in a variety of ways.

[0112] Thus, in some embodiments, the temperatures of the flow elements of two or more flow paths can differ from one another throughout the deposition, including changes in temperature during the deposition. This may include temperatures that (i) start at different values ​​relative to one another and remain at those different values ​​throughout the deposition, (ii) start at the same values ​​relative to one another and then change to different values ​​later in the deposition process, (iii) start at different values ​​and then change to the same value later in the deposition process, and (iv) start at different values ​​and then change to other different values ​​later in the deposition process. In some other embodiments, the temperatures can remain at the same values ​​relative to one another throughout the deposition, but can change their values ​​throughout the deposition.

[0113] A. Exemplary techniques at different temperatures In a first exemplary technique, the temperatures of the flow elements of two or more flow paths are different from each other during at least a portion of a deposition process that deposits one or more layers of material on a substrate. During this portion, one flow element of one flow path is set to and maintained at a first temperature, and another flow element of a second flow path is set to and maintained at a second temperature. As used herein, a "layer" of material can be the total layer of material deposited after a complete deposition process, which may include multiple sublayers of material, or it can include a single discrete layer or sublayer of material, such as a single discrete layer of material deposited by atomic layer deposition (ALD).

[0114] FIG. 3 illustrates a first example technique for performing film deposition in a multi-station semiconductor processing chamber. Tool 100, processing stations 104A and 104B, and flow paths 116A and 116B of FIG. 1 are referenced to describe this technique. Although features of tool 100 of FIG. 1 are referenced, this technique is equally applicable to any other tools described herein, such as tool 200 of FIG. 2 and tool 1300 of FIG. 13, as well as any flow elements of the flow paths described herein, including, for example, valves, monoblocks, one or more gas lines, tee fittings, fittings, and showerheads. These techniques can also be used to control flow conductance through different flow elements, such as a valve in one flow path and a monoblock in another flow path. In block 301, a first substrate 108A is positioned on a first pedestal 106A of a first station 104A, and in operation 303, a second substrate 108B is positioned on a second pedestal 106B of a second station 104B. In some embodiments, blocks 301 and 303 may be performed in reverse order or simultaneously.

[0115] Once the substrates are positioned on their respective pedestals, one or more layers of material may be simultaneously and individually deposited on the first and second substrates, as represented by block 305. This may result in one or more first layers on the first substrate and one or more second layers on the second substrate. As described in more detail herein, part of the deposition process generally involves flowing one or more process gases from a showerhead onto the substrate, for example, during a dosing phase for ALD deposition or activation in chemical vapor deposition (CVD). These process gases flow to the substrate via the aforementioned flow paths, which may have flow paths set at different temperatures relative to other flow paths. As shown in block 307, during at least a portion of the deposition of one or more first and second layers onto the first and second substrates, respectively, a first flow element of a first flow path, such as 116A, may be maintained at a first temperature, and a second flow element of a second flow path, such as 116B, may be simultaneously maintained at a second temperature, different from the first temperature. In some embodiments, maintaining the temperature can be active heating of the flow element, such as by a resistive heater that generates heat, in some other embodiments, maintaining the temperature can be no heating or no heating of the flow element, such that the temperature control unit is not actively heating the flow element, and thus the flow element can remain at the temperature of the ambient environment surrounding the flow element.

[0116] In some embodiments, these different temperatures can be maintained throughout the deposition process required to deposit all of the desired layers of material. For example, if an ALD process performs 500 cycles, these first and second temperatures can be maintained consistently throughout all 500 cycles. This temperature adjustment and setting can occur, for example, before the deposition process begins or during some start-up operations. These operations may include loading the substrate, temperature soaking (heating) the substrate, indexing, and filling the ampoule.

[0117] In some cases, maintaining the flow paths with flow elements at different temperatures throughout the deposition can result in layers of material at different stations having substantially the same properties as each other (e.g., substantially the same meaning within 10%, 5%, 1%, 0.5%, or 0.1% of each other), such as thickness and RI. This can improve consistency between stations. For example, if it is determined that the thickness between two stations does not match within a certain threshold of each other, the temperature of the flow elements in the flow path for one of the stations can be adjusted to change the flow conductance, which in turn changes the thickness deposited at that station, for a subsequent deposition process, to bring the thickness between the stations closer together. In some other embodiments, the deposited layers of material at each station can have different properties from each other, such as different thicknesses. This can improve consistency with other material properties. For example, the material properties may have different densities from each other, but still result in the same thickness (this can be due to other process conditions, such as deposition rate).

[0118] In some embodiments, different flow element temperatures of different flow paths can be maintained for only a portion of the deposition process to change the properties of only a portion of the deposited material. Depositing layers on the same substrate with different properties can be advantageous to fine-tune the properties of only that one section (e.g., one or more layers) of the overall deposited material. This can also be advantageous to adjust for drift in process conditions or material properties during processing of that substrate. For example, when material is simultaneously deposited on a set of substrates at different stations, the process conditions at one of the stations, such as increasing or decreasing plasma power, can drift during this processing, which can result in a layer of material having different material properties than the other layers, such as a different thickness, resulting in non-uniformity between the stations. Adjusting the flow conductance of one or more flow paths during this portion of processing may allow adjustment of the drift process conditions to reduce the resulting non-uniformity. For example, if the plasma power of one station drifts over the course of a process, changing the thickness of the deposited material, then the flow conductance of the flow paths for that station can be adjusted to account for that drift condition by adjusting the temperature of that station to result in a desired amount of material thickness at that station.

[0119] In another similar example, process conditions tend to drift across an entire batch of substrates (e.g., 200 or 500 substrates), and these drifting conditions can result in non-uniformity or increased non-uniformity in material properties, such as different thicknesses. Adjusting the flow conductance of one or more flow paths during a portion of the batch of substrates may adjust the drifting process conditions and reduce the resulting non-uniformity. For example, if the plasma power of one station drifts during the course of processing a batch, such as after processing a certain number of substrates in the batch, the thickness deposited at that station may drift beyond an acceptable threshold, and the flow conductance of the flow paths to that station can be adjusted to account for that drifting condition to result in a desired amount of material thickness.

[0120] A batch of substrates can be defined as the number of substrates that can be processed for a particular deposition process before or when a limit, such as an accumulation limit, is reached. For example, when material is deposited on multiple substrates, material from the deposition process accumulates on one or more internal chamber surfaces (e.g., the chamber walls, pedestal, and showerhead), referred to herein as "accumulation." As multiple substrates are processed in the same chamber during cleaning of that chamber, the accumulation increases as more substrates are processed. When accumulation in a chamber reaches a certain thickness, adverse effects may occur to the chamber, and when accumulation reaches such a thickness, which may be referred to as an accumulation limit, processing of substrates is stopped and the chamber is cleaned. In such an example, the accumulation limit for an ALD process in a particular chamber is 20,000 Å, which is the point at which accumulation to the chamber adversely affects substrates processed in that chamber. Thus, a batch of substrates processed in that chamber is limited to the number of substrates that can be processed in that chamber before the accumulation limit of 20,000 Å is reached.

[0121] In a second exemplary technique, the temperatures of the flow elements in the different flow paths may start at the same temperature as each other and then be adjusted to different temperatures later in the deposition process. Here, some deposition may occur when the two temperatures are the same, which may be the case, for example, when no heat is applied by the respective temperature control units or at the same heating temperature above ambient temperature. After this first portion of deposition, the temperatures of the flow elements in the different flow paths may be adjusted, including heating the first flow element to a first temperature and heating the second flow element to a second temperature. Following this adjustment, additional deposition is performed on the first and second substrates while the first flow element is maintained at the first temperature and the second flow element is maintained at the second temperature. As noted above, in some embodiments, only one flow element may be actively heated and the other flow element is not. For example, the first temperature of the first flow element may be reached and maintained by actively heating the flow element while heat is not applied to the second flow element. With reference to FIG. 3, a first portion of the deposition and channel conditioning can be considered to occur after blocks 301 and 303 and before blocks 305 and 307 .

[0122] In a third exemplary technique, similar to but reversed from the second exemplary technique, the temperatures of flow elements in different flow paths may start at different temperatures from one another and then be varied to be at the same temperature later in the deposition process. Here, the tuning to the same temperature may be done using active cooling, such as with a cooling fluid, passive cooling, or active heating. In some such embodiments, the temperature of one flow element may be tuned to be the same as the temperature of the other flow element. In some other such embodiments, the temperature of both flow elements may be tuned to another same temperature. With reference to FIG. 3, the conditioning of the flow paths and the latter portion of the deposition may be considered to occur after blocks 301-307.

[0123] Similarly, a fourth exemplary technique may include performing a first portion of a simultaneous deposition on a substrate while maintaining the temperatures of the flow elements in different flow paths at different temperatures from one another, and then performing another portion of the simultaneous deposition while maintaining the temperatures of the flow elements in different flow paths at other different temperatures. FIG. 4 illustrates a fourth technique for performing film deposition in a multi-station semiconductor processing chamber, where blocks 401-407 are the same as blocks 301-307 described above with respect to FIG. 3. Here, in FIG. 4, blocks 401, 403, 405, and 407 are performed, after which, in block 409, the temperature of the first flow element is adjusted to a third temperature different from the first temperature, and the temperature of the second flow element is adjusted to a fourth temperature different from the second temperature. After the flow elements are at these other different temperatures, another simultaneous deposition is performed on the two substrates in block 411 while the flow elements are maintained at these other different temperatures for the second portion of the deposition.

[0124] In some embodiments, the amount of temperature adjustment for each station may be different for each station. For example, a first flow element may be adjusted by X degrees from a first temperature, and a second flow element may be adjusted by Y degrees from a second temperature. In some other embodiments, it may be desirable to maintain the flow elements at different temperatures from each other, but adjust them by the same amount (e.g., adjust both temperatures by X degrees). This allows for uniform control and adjustment of properties for all substrates.

[0125] Additionally, although the techniques herein are described with respect to two flow paths in two stations, these techniques are applicable to any number of multiple stations and flow paths. For example, in a tool with a four-station chamber as shown in FIG. 1, the temperature of at least one flow element in each flow path may be different from the corresponding flow element in the other flow paths. In some cases, as shown in FIG. 5 illustrating a fifth exemplary technique for performing film deposition in a multi-station semiconductor processing chamber, for at least a first portion of a deposition process in which one or more layers of material are simultaneously deposited on four substrates in four stations 104A-104D, a first flow element in a first flow path 116A may be at a first temperature, a second flow element in a second flow path 116B may be at a second temperature, a third flow element in a third flow path 116C may be at a third temperature, and a fourth flow element in a fourth flow path 116D may be at a fourth temperature. In some embodiments, at least two of these temperatures may be different from each other, and the other temperatures may be the same or different. For example, all temperatures may be different from one another, the first and second temperatures may be different from one another while the third and fourth temperatures may be the same as the first or second temperatures, or the first, second, and third temperatures may all be different from one another while the fourth temperature is the same as any of the other temperatures.

[0126] The techniques described herein are also applicable to temperature control of multiple flow elements within each flow path. For example, two or more flow elements may be heated to different temperatures to generate a desired flow conductance through that flow path. For example, referring to FIG. 2, this may include heating two or more flow elements 222, 224, 226, and 228 of each flow path 216A-216D.

[0127] B. Exemplary techniques at the same temperature As mentioned above, the flow elements of different flow paths can remain at the same temperature relative to each other during deposition, but are maintained at different temperatures during the deposition process relative to a reference temperature. This concept is shown in FIG. 6, which illustrates a sixth exemplary technique for performing film deposition in a multi-station semiconductor processing chamber. Here, blocks 601 and 603 are the same as blocks 301 and 303 described above. For blocks 605 and 607, the first and second flow elements are both maintained at the same first temperature while simultaneously depositing one or more layers of material on the first and second substrates. In block 609, the first and second flow elements are both adjusted to the same second temperature, and then, in blocks 611 and 613, the first and second flow elements are both maintained at the same second temperature while simultaneously depositing one or more layers of material on the first and second substrates.

[0128] Here, the flow elements remain at the same temperature relative to each other during the deposition process, but are at different distances relative to a reference temperature, such as the tool's ambient environment. These embodiments can form deposited materials that have different values ​​of properties throughout the material. For example, a material deposited on a first substrate has two different properties within the material, such as two different RIs. The distances can be adjusted additional times to create additional values ​​and gradients within the deposited material.

[0129] C. Use of Exemplary Techniques in Various Deposition Processes All of the exemplary techniques can be used in various deposition processes, such as CVD and ALD. For example, referring to FIG. 3, the simultaneous deposition and first and second temperature maintenance of blocks 305 and 307 can be performed for the entire CVD or ALD deposition process for the first and second substrates. After this process, a post-processing operation can be performed and the substrate can be removed from the chamber. In the case of a cyclic deposition process, such as ALD, the simultaneous deposition and temperature maintenance of blocks 305 and 307, 405 and 407, 411 and 413, 605 and 607, and 611 and 613 described above can be performed for one or more cycles of deposition, such that these blocks can be repeated throughout the deposition process.

[0130] As described above, a typical ALD cycle includes (1) exposure of a substrate surface to a first precursor, (2) purging of the reaction chamber in which the substrate is located, (3) activation of a reaction on the substrate surface, typically with a plasma and / or a second precursor, and (4) purging of the reaction chamber in which the substrate is located. FIG. 7 illustrates a flow chart of an exemplary sequence of operations for forming a film of a material on a substrate via an ALD process. As seen in FIG. 7, item 1 above corresponds to block 758, item 2 above corresponds to block 760, item 3 above corresponds to block 762, and item 4 above corresponds to block 764. The four blocks are performed for N cycles, after which the process is stopped.

[0131] In techniques involving multiple simultaneous deposition and temperature maintenance blocks, such as the exemplary techniques of Figures 4 and 6, the overall deposition process may be divided into two or more portions, each portion having a specific number of deposition cycles, and for each portion cycle, those blocks associated with the respective portion are performed. For example, one portion may have X cycles, another portion may have Y cycles, and referring to Figure 4, for example, blocks 405 and 407 are performed for X cycles such that the first and second temperatures are maintained constant for all of the X cycles, and then for the second portion of the deposition, the third and fourth temperatures are maintained constant for all of the Y deposition cycles. All other exemplary techniques may be similarly performed such that each simultaneous deposition and temperature block is performed for a specific number of deposition cycles in a portion of the overall deposition process.

[0132] For all of the exemplary techniques described herein, depending on other processing conditions, the deposited layers of material simultaneously deposited on the substrate may be the same or different, e.g., they may have the same thickness or different densities.

[0133] D. Additional Techniques for Calibration In some embodiments, a calibrated deposition process can be performed to determine the temperature of the flow elements and correlate them with different material property values. The calibrated deposition process can include positioning a first set of substrates at the stations, setting and maintaining the temperature of the flow elements in each flow path for each station at a first temperature, simultaneously depositing material onto the first set of substrates, and then determining, such as by measurement, a resultant value of the material property, such as thickness or RI. A second set of substrates can then be loaded onto the pedestal, the temperature of the flow elements can be set and maintained at a second temperature, the deposition process can be repeated on the second set of substrates, and the resultant value of the material property can again be determined. This deposition and determination can be repeated for a set of N substrates at N different distances. The determined value of the material property for each station is correlated to the temperature of the flow element at which deposition occurred at each station, and this information can be used in any of the techniques described above to adjust the temperature and deposit a known value of the material property.

[0134] IV. Experimental Results FIG. 8 illustrates a plot of material thickness for two substrates. Here, four sets of two substrates were processed in the two-station chamber. For each set, one flow element in the flow path of station 1, i.e., the gas line, was heated to a different temperature for each set. The average material thickness measured for a total of eight substrates is shown in FIG. 8. The horizontal axis is the temperature of the gas line (in degrees Celsius) and the vertical axis is the average thickness of the material deposited on the substrate. As can be seen, as the temperature of the flow elements for station 1 increased, the overall thickness of the deposited material decreased. For example, set 1 has the lowest temperature of about 42.5° C. and the highest thickness of about 127 angstroms (Å). This first set also has the greatest thickness non-uniformity between the two stations. In set 4, the flow elements are at the highest temperature of about 80° C. and station 1 has the lowest thickness at about 117 Å. This fourth set also has the least non-uniformity between the two stations. According to these results, thickness non-uniformity can be reduced by increasing the temperature of one flow element in the flow path of one station. Although the flow elements were not heated in the flow path of station 1, the thickness of the deposit is seen to vary between different sets of substrates. Nevertheless, the figure shows that the thickness difference between each station can be adjusted by adjusting the temperature of at least one flow element in one station. This trend in station 1 may be caused by various other conditions in the processing chamber or process parameters. In some cases, this may be offset by a certain offset in the flow rate or substrate temperature. Alternatively or additionally, as FIG. 10 shows, the non-uniformity between stations can be reduced by increasing the temperature of at least one flow element in the flow path of one station.

[0135] In another similar experiment, the RI was measured and compared with various flow element temperatures. Figure 9 illustrates a plot of the refractive index (RI) for two substrates. Here, four sets of two substrates were processed in a two-station chamber. For each set, one flow element in the flow path of station 1, i.e., the gas line, was heated to a different temperature for each set. The measured RI of the material deposited on a total of eight substrates is shown in Figure 9. The horizontal axis is the temperature of the gas line (in degrees Celsius) and the vertical axis is the average RI of the material deposited on the substrate. As can be seen, as the temperature of the flow element for station 1 increases, the RI increases, in contrast to the thickness seen in Figure 8. For example, the lowest temperature for set 1 is about 42.5°C, with a minimum RI of about 1.45. This first set also has the least non-uniformity in RI between the two stations. In set 4, the flow elements are at a maximum temperature of about 80°C, and the RI for station 1 is highest at about 1.65. This fourth set has the greatest non-uniformity between the two stations. According to these results, the non-uniformity of RI can be reduced by decreasing the temperature of one flow element in the flow path of one station. In addition, although the material deposited in station 1 in FIG. 11 is reduced by increasing the RI and temperature for each of the set of substrates, the figure shows that the difference between each station can be adjusted by adjusting the temperature of at least one flow element of one station. The trend of station 1 shown in FIG. 11 may be the result of each unit flow rate reduced from station 2 being obtained by the remaining stations such as station 1, because the total flow rate may be controlled by a single source such as a single MFC. Therefore, if all other conditions are kept constant, the reduction of the parameters for station 2 controlled by heating may show a reverse effect of reduced than the remaining stations.

[0136] V. Additional Exemplary Apparatus In some embodiments, a semiconductor processing tool or apparatus may have a controller, described in more detail below, with program instructions for performing any and all of the exemplary techniques described herein. For example, the tools of Figures 1 and 2 may have additional features, such as a controller for performing the exemplary techniques. This includes controlling a controllably configured temperature control unit. The controller may have program instructions to control the apparatus to deposit material on a substrate at a station, including performing the techniques described above. This may include providing a first substrate on a first pedestal at a first station (e.g., station 104A), providing a second substrate on a second pedestal at a second station (e.g., station 104B), simultaneously depositing one or more first layers of material on the first substrate and one or more second layers of material on the second substrate, and maintaining a first flow element of a first flow path (e.g., 116A) to that first station at a first temperature and a second flow element of a second flow path (e.g., 116B) to that second station at a second temperature different from the first temperature during at least a portion of the simultaneous deposition.

[0137] Each of the tools or apparatus may include additional features described herein. FIG. 10 illustrates a single station substrate processing apparatus for depositing a film on a semiconductor substrate using any number of processes. The apparatus 1000 of FIG. 10 has a single processing chamber 1010 with a single substrate holder 1018 (e.g., pedestal) within an interior volume that may be maintained under vacuum by a vacuum pump 1030. Also, a gas delivery system 1002 and a showerhead 1004 are fluidly coupled to the chamber for delivering (e.g.) film precursors, carrier and / or purge and / or process gases, secondary reactants, etc. Equipment for generating plasma in the processing chamber is also illustrated in FIG. 10. The apparatus illustrated generally in FIG. 10 is for performing ALD, but may be adapted for performing other film deposition operations, such as conventional CVD, particularly plasma-enhanced CVD.

[0138] For simplicity, the processing apparatus 1000 is illustrated as a stand-alone process station having a process chamber body 1010 for maintaining a low pressure environment. However, as described herein, it will be understood that multiple process stations may be included in a common process tool environment, e.g., within a common reaction chamber. For example, FIG. 11 illustrates one embodiment of a multi-station processing tool, which is described in more detail below. Additionally, it will be understood that in some embodiments, one or more hardware parameters of the processing apparatus 1000 (including those described in more detail herein) may be programmatically adjusted by one or more system controllers.

[0139] The process station 1010 is in fluid communication with a gas delivery system 1002 for delivering process gases, which may include liquids and / or gases, to a distribution showerhead 1004. The gas delivery system 1002 includes a mixing vessel 1006 for blending and / or conditioning the process gases for delivery to the showerhead 1004. One or more mixing vessel inlet valves 1008 and 1008A can control the introduction of process gases into the mixing vessel 1006.

[0140] Some reactants may be stored in liquid form prior to vaporization and subsequent delivery to the process chamber 1010. The embodiment of FIG. 10 includes a vaporization point 1012 for vaporizing the liquid reactants delivered to the mixing vessel 1006. In some embodiments, the vaporization point 1012 may be a heated liquid injection module. In some other embodiments, the vaporization point 1012 may be a heated vaporizer. In still other embodiments, the vaporization point 1012 may be eliminated from the process station. In some embodiments, a liquid flow controller (LFC) may be provided upstream of the vaporization point 1012 to control the mass flow rate of the liquid that is vaporized and delivered to the processing chamber 1010.

[0141] As described above, the showerhead 1004 distributes process gases and / or reactants (e.g., film precursors) to the substrate 1014 at the process station, with the flow controlled by one or more valves (e.g., valves 1008, 1008A, and 1016) upstream of the showerhead. In the embodiment shown in FIG. 10, the substrate 1014 is shown positioned below the showerhead 1004 and resting on a pedestal 1018. The showerhead 1004 can have any suitable shape and can have any suitable number and arrangement of ports for distributing process gases to the substrate 1014. In some embodiments with more than one station, the gas delivery system 1002 can include valves or other flow control structures upstream of the showerhead to independently control the flow of process gases and / or reactants to each station such that gas can flow to one station but not another. Additionally, the gas delivery system 1002 can be configured to independently control the process gases and / or reactants delivered to each station in a multi-station apparatus such that the gas compositions provided to different stations are different, e.g., the partial pressures of gas components can be varied simultaneously between stations.

[0142] In FIG. 10, the showerhead 1004 and pedestal 1018 are electrically connected to an RF power source 1022 and a matching network 1024 for powering the plasma. In some implementations, the plasma energy may be controlled (e.g., via a system controller having suitable machine-readable instructions and / or control logic) by controlling one or more of the process station pressure, gas concentration, RF source power, RF source frequency, and plasma power pulse timing. For example, the RF power source 1022 and the matching network 1024 may be operated at any suitable power to form a plasma having a desired composition of radical species. Similarly, the RF power source 1022 may provide RF power of any suitable frequency and power. The apparatus 1000 also includes a DC power source 1026 configured to provide direct current to the pedestal, which may be an electrostatic chuck ("ESC") 1018 for generating and providing an electrostatic clamping force to the ESC 1018 and the substrate 1014. The pedestal 1018 may also have one or more temperature control elements 1028 configured to heat and / or cool the substrate 1014. The pedestal 1018 is also configured to rise and lower to various heights or distances, as measured between the pedestal surface and the showerhead.

[0143] In some implementations, the apparatus is controlled with suitable hardware and / or suitable machine-readable instructions in a system controller that may provide control instructions via a series of input / output control (IOC) instructions. In one example, instructions for setting plasma conditions for plasma ignition or maintenance are provided in the form of a plasma activation recipe of a process recipe. In some cases, process recipes may be arranged in a sequence, whereby all instructions of a process are executed simultaneously with that process. In some implementations, instructions for setting one or more plasma parameters may be included in a recipe that precedes a plasma process. For example, a first recipe may include instructions for setting the flow rate of an inert gas (e.g., helium) and / or a reactant gas, instructions for setting a plasma generator to a power set point, and a time delay instruction of the first recipe. A subsequent second recipe may include instructions for enabling the plasma generator, and a time delay instruction of the second recipe. A third recipe may include instructions for disabling the plasma generator, and a time delay instruction of the third recipe. It will be understood that these recipes may be further subdivided and / or repeated in any suitable manner within the scope of this disclosure.

[0144] As mentioned above, two or more process stations may be included in a multi-station substrate processing tool. FIG. 11 illustrates an exemplary multi-station substrate processing apparatus. By using a multi-station processing apparatus as shown in FIG. 11, various efficiencies can be achieved in terms of equipment costs, operational expenses, as well as increased throughput. For example, a single vacuum pump can be used to create a single high vacuum environment for all four process stations by evacuating spent process gases, etc., from all four process stations. Depending on the implementation, each process station may have a showerhead dedicated to gas delivery, but may share the same gas delivery system. Similarly, certain elements of the plasma generating equipment may be shared between process stations (e.g., power supplies), but depending on the implementation, certain aspects may be process station specific (e.g., when a showerhead is used to apply a plasma generating potential). Again, it should also be understood that such efficiencies may be achieved to a greater or lesser extent by using a greater or lesser number of process stations per process chamber (e.g., 2, 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16 or more process stations per reaction chamber).

[0145] The substrate processing apparatus 1100 of FIG. 11 employs a single substrate processing chamber 1110 that includes multiple substrate processing stations, each of which may be used to perform a processing operation on a substrate held on a wafer holder, e.g., a pedestal, at that process station. In this particular embodiment, a multi-station substrate processing apparatus 1100 is shown having four process stations 1131, 1132, 1133, and 1134. Other similar multi-station processing apparatus may have a greater or lesser number of processing stations depending on the implementation and, e.g., the desired level of parallel wafer processing, size / space constraints, cost constraints, etc. Also shown in FIG. 11 is a substrate handler robot 1136 and a controller 1138.

[0146] 11, the multi-station processing tool 1100 has a substrate loading port 1140 and a robot 1136 configured to move substrates from a cassette loaded through a pod 1142, through the atmospheric port 1140, into the processing chamber 1110, and then to one of four stations 1131, 1132, 1133, or 1134. These processing stations may be the same as or similar to the processing stations of FIGS.

[0147] RF power is generated in an RF power system 1122 and distributed to each of the stations 1131, 1132, 1133, or 1134. Similarly, a DC power source 1126 is distributed to each of the stations. The RF power system may include one or more RF power sources, e.g., high frequency (HFRF) and low frequency (LFRF) power sources, impedance matching modules, and filters. In certain implementations, the power source may be limited to only high frequency or low frequency power sources. The distribution system of the RF power system may be symmetrical with respect to the reactor and have a high impedance. This symmetry and impedance allows approximately equal amounts of power to be delivered to each station.

[0148] 11 also illustrates one embodiment of a substrate transport device 1190 for transporting substrates between process stations 1131, 1132, 1133, and 1134 within processing chamber 1114. It will be understood that any suitable substrate transport device may be used. Non-limiting examples include a wafer carousel and a wafer handling robot.

[0149] 11 also illustrates one embodiment of a system controller 1138 used to control the process conditions and hardware states of the process tool 1100 and its process stations. The system controller 1138 can include one or more memory devices 1144, one or more mass storage devices 1146, and one or more processors 1148. The processor 1148 can include one or more CPUs, ASICs, general purpose computers, and / or special purpose computers, one or more analog and / or digital input / output connections, one or more stepper motor controller boards, etc.

[0150] The system controller 1138 can execute machine-readable system control instructions 1150 on the processor 1148, which in some implementations are loaded from the mass storage device 1146 to the memory device 1144. The system control instructions 1150 can include instructions for controlling the timing, mixture of gas and liquid reactants, chamber and / or station pressures, chamber and / or station temperatures, wafer temperatures, target power levels, RF power levels, RF exposure times, DC power and duration for clamping the substrate, substrate pedestal, chuck, and / or susceptor positions, plasma formation at each station, flow of gas and liquid reactants, vertical height of the pedestal, and other parameters of the particular processes performed by the process tool 1100. These processes can include various types of processes, including, but not limited to, processes associated with the deposition of a film on a substrate. The system control instructions 1158 may be configured in any suitable manner.

[0151] In some implementations, the system control software 1158 may include input / output control (IOC) instructions for controlling the various parameters described above. For example, each step of one or more deposition processes may include one or more instructions for execution by the system controller 1150. Instructions for setting process conditions for a primary film deposition process may be included in a corresponding deposition recipe, for example, as well as for a capping film deposition. In some implementations, a recipe may be arranged in sequence such that all instructions for a process are executed simultaneously with that process.

[0152] Other computer readable instructions and / or programs stored on the mass storage device 1154 and / or memory device 1156 associated with the system controller 1150 may be used in some implementations. Examples of programs or sections of programs include a substrate positioning program, a process gas control program, a pressure control program, a heater control program, and a plasma control program.

[0153] In some implementations, there may be a user interface associated with the system controller 1150. The user interface may include a display screen, a graphical software display of equipment and / or process conditions, and user input devices such as a pointing device, keyboard, touch screen, microphone, etc.

[0154] In some implementations, the parameters adjusted by the system controller 1150 relate to process conditions. Non-limiting examples include process gas composition and flow rates, temperature, pressure, plasma conditions (RF bias power levels, frequency, exposure time, etc.), etc. In addition, the controller can be configured to independently control conditions within the process stations, e.g., the controller provides instructions to ignite plasma at some but not all stations. These parameters may be provided to a user in the form of a recipe and can be entered utilizing a user interface.

[0155] Signals for monitoring the process may be provided by analog and / or digital input connections of the system controller 1150 from various process tool sensors. Signals for controlling the process can be output at analog and / or digital output connections of the process tool 1100. Non-limiting examples of process tool sensors that can be monitored include mass flow controllers (MFCs), pressure sensors (such as pressure gauges), thermocouples, load sensors, OES sensors, instrumentation for measuring physical properties of the shake in-situ, and the like. Appropriately programmed feedback and control algorithms can be used with data from these sensors to maintain process conditions.

[0156] The system controller 1150 can provide machine-readable instructions for carrying out the deposition process. The instructions can control various process parameters such as DC power levels, RF bias power levels, station-to-station variations such as RF power parameter variations, frequency adjustment parameters, pressure, temperature, etc. The instructions can control parameters for operating the in-situ deposition of a film stack according to various embodiments described herein.

[0157] The system controller typically includes one or more memory devices and one or more processors configured to execute machine-readable instructions such that the apparatus performs operations according to the processes disclosed herein. A machine-readable non-transitory medium including instructions for controlling operations according to the substrate doping processes disclosed herein may be coupled to the system controller.

[0158] As discussed above, processing multiple substrates at multiple process stations in a common substrate processing chamber can increase throughput by allowing film deposition to proceed in parallel on multiple substrates while utilizing common processing equipment across the various stations. Some multi-station substrate processing tools can be utilized to process wafers simultaneously with the same number of cycles (e.g., for some ALD processes). Given this configuration of process stations and substrate loading and transfer devices, a variety of process sequences are possible in which film deposition (e.g., N cycles of film deposition for ALD processes, or equal exposure duration for CVD processes) can occur in parallel (e.g., simultaneously) across multiple substrates.

[0159] As discussed above, various efficiencies can be achieved by using multi-station tools in terms of equipment costs, operational expenses, and increased throughput. However, simultaneous processing of multiple substrates in a common chamber can result in station-to-station differences in the deposited materials, including, for example, differences in average film thickness, uniformity across the surface of the wafer, physical properties such as wet etch rate (WER) and dry etch rate (DER), chemical properties, and optical properties. Although there may be various thresholds for acceptable station-to-station deviations in material properties, it is desirable to reduce these differences to repeatedly produce uniform substrates for commercial-scale manufacturing. The techniques described herein can tune one or more of these properties, such as wet etch rate, dry etch rate, composition, thickness, density, amount of crosslinking, chemistry, reaction completion, stress, refractive index, dielectric constant, hardness, etch selectivity, stability, and hermeticity.

[0160] While the above disclosure focuses on adjusting flow conductance to control deposition parameters, the same controls can be used to control etching characteristics in etching processes. Some semiconductor fabrication processes involve patterning and etching a variety of materials, including conductors, semiconductors, and dielectrics. Some examples include conductors, such as metals or carbon, semiconductors, such as silicon or germanium, and dielectrics, such as silicon oxide, aluminum dioxide, zirconium dioxide, hafnium dioxide, silicon nitride, and titanium nitride. Atomic layer etching ("ALE") processes use successive self-limiting reactions to remove thin layers of material. Generally, an ALE cycle is the minimum set of operations used to perform an etching process once, such as etching a monolayer. One ALE cycle results in etching at least a portion of a film layer on the substrate surface. Typically, an ALE cycle includes a modification operation to form a reaction layer, followed by a removal operation to remove or etch only this reaction layer. A cycle may include certain auxiliary operations, such as removing one of the reactants or by-products. Generally, a cycle includes one instance of a unique sequence of operations.

[0161] As an example, a conventional ALE cycle may include the following operations: (i) delivery of a reactant gas, (ii) purging the reactant gas from the chamber, (iii) delivery of a removal gas and optional plasma, and (iv) purging the chamber. In some embodiments, the etching may be performed non-conformally. The modification operation generally forms a thin reactive surface layer having a thickness less than that of the unmodified material. In an exemplary modification operation, the substrate may be chlorinated by introducing chlorine into the chamber. Chlorine is used as an exemplary etchant species or etching gas, but it will be understood that different etching gases may be introduced into the chamber. The etching gas may be selected depending on the type and chemistry of the substrate to be etched. When the plasma is ignited, the chlorine may react with the substrate for the etching process, and the chlorine may react with the substrate or adsorb on the surface of the substrate. Species generated from the chlorine plasma may be generated directly by forming a plasma in the process chamber containing the substrate, or may be generated remotely in a process chamber not containing the substrate and delivered to the process chamber containing the substrate.

[0162] Thus, any of the techniques and apparatus described above can be used for etching. In some embodiments, instead of depositing a layer of material at each station, the technique can remove a portion of the material in each station. This can improve wafer-to-wafer uniformity in either the etching or deposition process. For example, in FIG. 3, block 305 can be an etching stage in which simultaneous etching can be performed on the first and second substrates while the first and second flow elements of the first and second flow paths are maintained at first and second temperatures, respectively, for a first portion of the etching process to remove first and second portions of material from the first and second substrates.

[0163] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the presented concepts. The presented concepts may be practiced without some or all of these specific details. In other instances, well-known process operations have not been described in detail so as not to unnecessarily obscure the described concepts. While some concepts will be described in connection with specific embodiments, it will be understood that these embodiments are not intended to be limiting.

[0164] In this application, the terms "semiconductor wafer," "wafer," "substrate," "wafer substrate," and "partially fabricated integrated circuit" are used interchangeably. Those skilled in the art will appreciate that the term "partially fabricated integrated circuit" can refer to silicon wafers at any of the many stages of fabricating an integrated circuit. Wafers or substrates used in the semiconductor device industry typically have diameters of 200 mm, or 300 mm, or 450 mm. The following detailed description assumes that the invention is implemented for use with such wafers. However, the invention is not so limited. Workpieces can be of various shapes, sizes, and materials. In addition to semiconductor wafers, other workpieces that may utilize the invention include various products such as printed circuit boards, magnetic recording media, magnetic recording sensors, mirrors, optical elements, micromechanical devices, and the like.

[0165] Unless the context of this disclosure clearly requires otherwise, throughout the description and claims, words such as "comprises," "comprising," and the like, should be interpreted in an inclusive sense, i.e., "including but not limited to," rather than an exclusive or exhaustive sense. Words using the singular or plural generally also include the plural or singular, respectively. In addition, the words "herein," "below," "on," "below," and words of similar meaning refer to this application as a whole and not to a particular layer of this application. When the word "or" is used in reference to a list of two or more items, the word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list. The term "embodiment" refers to an embodiment of the techniques and methods described herein, as well as a physical object that embodies a structure and / or incorporates the techniques and / or methods described herein. The term "substantially" as used herein means within 5% of a referenced value, unless otherwise specified. For example, substantially perpendicular means within + / - 5% of parallel.

[0166] It should also be understood that the use of ordinal indicators herein, e.g., (a), (b), (c), ..., is for organizational purposes only and is not intended to convey a particular order or importance to the items associated with each ordinal indicator. Nonetheless, there may be cases where some items associated with ordinal indicators inherently require a particular order, e.g., "(a) obtain information about X, (b) determine Y based on information about X, (c) obtain information about Z," in which example (a) must be performed before (b) because (b) is dependent on information obtained in (a), but (c) can be performed before or after either (a) and / or (b).

[0167] It should be understood that the use of the word "each," as in the phrases "for each <item> of one or more <items>" or "of each <item>," as used herein, should be understood to include both single and multiple items; i.e., the phrase "for each..." is used in the sense that it is used in programming languages ​​to refer to each item of a population of referenced items. For example, if the population of referenced items is a single item, then "each" refers only to that single item (despite the fact that dictionary definitions of "each" often define the term to refer to "one of two or more things") and does not mean that there must be at least two of those items. Similarly, it will be understood that a selected item may have one or more sub-items, and when one of those sub-items is selected, if the selected item has only one sub-item, then the selection of that one sub-item is unique to the selection of the item itself.

[0168] It will also be understood that references to multiple controllers configured as a whole to perform various functions are intended to encompass situations in which only one controller is configured to perform all of the disclosed or described functions, as well as situations in which the various controllers each perform a subportion of the described functionality.

[0169] Various modifications to the embodiments described in this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the claims are not intended to be limited to the embodiments shown herein, but are to be accorded the widest scope consistent with the disclosure, the principles and novel features disclosed herein.

[0170] Certain features described herein in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment can also be implemented separately in multiple embodiments or in any suitable subcombination. Moreover, although features may be described above as acting in a combination and may be initially claimed as such, one or more features from the claimed combination may, in some cases, be deleted from the combination, and the claimed combination may be directed to a subcombination or a variation of the subcombination.

[0171] Similarly, although operations may be depicted in the figures in a particular order, it should be understood that such operations need not be performed in the particular order depicted, or in a sequential order, or that all of the depicted operations need not be performed, to achieve desirable results. Additionally, the figures may generally depict one or more exemplary processes in the form of a flow diagram. However, other operations not depicted may be incorporated into the generally depicted exemplary process. For example, one or more additional operations may be performed before, after, simultaneously with, or between the depicted operations. In some circumstances, multitasking and parallel processing may be advantageous. Furthermore, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems may generally be integrated together in a single software product or packaged into multiple software products. Additionally, other embodiments are within the scope of the following claims. In some cases, the actions recited in the claims may be performed in a different order and still achieve desirable results.

Claims

1. 1. A multi-station processing apparatus comprising: a processing chamber; a plurality of process stations within the processing chamber, each process station including a showerhead having a gas inlet; A gas delivery system including a junction and a plurality of flow paths, each flow path comprising: Contains flow elements, a temperature control unit thermally connected to the flow element and controllable to vary a temperature of the flow element; Fluidly connecting a corresponding gas inlet of one of the plurality of process stations to the junction such that each process station of the plurality of process stations is fluidly connected to the junction by a different flow path. Gas delivery system An apparatus comprising:

2. 2. The apparatus of claim 1, The apparatus, wherein the temperature control unit is controllable to change a flow conductance of the flow element in thermal contact therewith via a change in temperature.

3. 2. The apparatus of claim 1, The apparatus, wherein the temperature control unit includes a heating element configured to heat the flow element in thermal contact therewith.

4. 4. The apparatus of claim 3, The apparatus, wherein the heating element comprises a resistive heating element, a thermoelectric heater, and / or a fluid conduit configured to flow a heated fluid through the fluid conduit.

5. 2. The apparatus of claim 1, Each showerhead further includes a faceplate and a temperature control unit thermally coupled to the showerhead and controllable to change a temperature of a portion of the showerhead; Each flow channel further fluidly connects the showerhead faceplate to the junction. Device.

6. 6. The apparatus of claim 5, The apparatus, wherein the temperature control unit is thermally coupled to a stem of the showerhead and is controllable to vary a temperature of the stem.

7. 6. The apparatus of claim 5, The apparatus, wherein the temperature control unit is thermally coupled to the faceplate and is controllable to vary a temperature of the faceplate.

8. 6. The apparatus of claim 5, The showerhead further includes a backplate. the temperature control unit is thermally connected to the backplate and is controllable to change a temperature of the backplate; Device.

9. 6. The apparatus of claim 5, The apparatus, wherein the showerhead is a flush mount showerhead.

10. 2. The apparatus of claim 1, An apparatus, wherein the temperature control unit is positioned at least partially inside the flow element in which the temperature control unit is positioned.

11. 2. The apparatus of claim 1, the flow element in each flow path comprises a valve; the temperature control unit of each flow path is controllable to heat the valve and change the flow conductance of the valve; Device.

12. 2. The apparatus of claim 1, the flow element of each flow path comprises a monoblock; the temperature control unit of each flow path is controllable to heat the monoblock and change the flow conductance of the monoblock; Device.

13. 2. The apparatus of claim 1, The flow element of each flow path comprises a gas line; the temperature control unit of each flow path is controllable to heat the gas line to change the flow conductance of the gas line; Device.

14. 14. The apparatus of claim 13, The apparatus, wherein the junction is a mixing bowl.

15. 2. The apparatus of claim 1, the flow element of each flow path comprises a fitting; the temperature control unit of each flow path is controllable to heat the joint to change the flow conductance of the joint; Device.

16. 16. The apparatus of claim 15, The apparatus, wherein the fitting is a tee fitting.

17. 2. The apparatus of claim 1, Each flow path further includes two temperature control units; Each temperature control unit in each flow path is in thermal contact with a different flow element of that flow path. Device.

18. 2. The apparatus of claim 1, a controller configured to control the multi-station deposition apparatus to deposit material onto a substrate at the plurality of process stations; For a first flow path fluidly connected to a first one of the plurality of process stations, a first temperature control unit is in thermal contact with a first flow element; for a second flow path fluidly connected to a second one of the plurality of process stations, a second temperature control unit is in thermal contact with a second flow element; The controller: providing a substrate at each of said process stations; simultaneously depositing a first layer of material on a first substrate at the first process station and a second layer of material on a second substrate at the second process station; maintaining the first flow element at a first temperature and maintaining the second flow element at a second temperature different from the first temperature during at least a portion of the deposition. a control logic for Device.

19. 20. The apparatus of claim 18, maintaining the first flow element at the first temperature includes causing the first temperature control unit to heat the first flow element to the first temperature; maintaining the second flow element at the second temperature includes not causing the second temperature control unit to heat the second flow element. Device.

20. 20. The apparatus of claim 18, maintaining the first flow element at the first temperature includes causing the first temperature control unit to heat the first flow element to the first temperature; maintaining the second flow element at the second temperature includes causing the second temperature control unit to heat the second flow element to the second temperature. Device.

21. 20. The apparatus of claim 18, The controller: maintaining the first flow element at a third temperature different from the first temperature and maintaining the second flow element at a fourth temperature different from the second temperature during at least a second portion of the deposition. The apparatus further comprises control logic for:

22. 20. The apparatus of claim 18, while maintaining the first flow element at a first temperature, the first flow path has a first flow conductance; While maintaining the second flow element at a second temperature, the second flow path has a second flow conductance different from the first flow conductance. Device.

23. 20. The apparatus of claim 18, while maintaining the first flow element at a first temperature, the first flow path has a first flow conductance; while maintaining the second flow element at a second temperature, the second flow path has a second flow conductance substantially equal to the first flow conductance. Device.

24. 20. The apparatus of claim 18, the first layer of material deposited on the first substrate has a first value of a property; a second layer of the material deposited on the second substrate having a second value of the property substantially the same as the first value; Device.

25. 25. The apparatus of claim 24, The property is selected from the group consisting of wet etch rate, dry etch rate, composition, thickness, density, amount of crosslinking, reaction completion, stress, refractive index, dielectric constant, hardness, etch selectivity, stability, and hermeticity.

26. 20. The apparatus of claim 18, the first layer of material deposited on the first substrate has a first value of a property; a second layer of the material deposited on the first substrate having a second value of the property different from the first value; Device.

27. 20. The apparatus of claim 18, The deposition further includes one or more of temperature soaking, indexing the substrate, flowing a precursor, flowing a purge gas, flowing a reactant gas, generating a plasma, and activating the precursor on the substrate, thereby depositing the material on the substrate.

28. 1. A method of depositing material onto a substrate in a multi-station deposition apparatus having a first station with a first showerhead and a second station with a second showerhead, comprising: Providing a first substrate on a first pedestal of the first station; providing a second substrate on a second pedestal at the second station; simultaneously depositing a first layer of material on the first substrate and a second layer of material on the second substrate; During at least a portion of the co-deposition, maintaining a first flow element of a first flow path at a first temperature, the first flow path fluidly connecting a junction to the first showerhead; maintaining a second flow element of a second flow path at a second temperature different from the first temperature, the second flow path fluidly connecting a junction to the second showerhead; A method comprising:

29. 29. The method of claim 28, maintaining the first flow element at the first temperature includes maintaining the first flow path at a first flow conductance; maintaining the second flow element at the second temperature includes maintaining the second flow path at a second flow conductance different from the first flow conductance. method.

30. 29. The method of claim 28, maintaining the first flow element at the first temperature includes maintaining the first flow path at a first flow conductance; maintaining the second flow element at the second temperature includes maintaining the second flow path at a second flow conductance substantially the same as the first flow conductance. method.

31. 29. The method of claim 28, maintaining the first flow element at the first temperature includes heating the first element; maintaining the second flow element at the second temperature includes not heating the second element. method.

32. 29. The method of claim 28, maintaining the first flow element at the first temperature includes heating the first element; maintaining the second flow element at the second temperature includes heating the second element. method.

33. 29. The method of claim 28, providing a third substrate on the first pedestal prior to providing the first substrate and the second substrate; providing a fourth substrate on the second pedestal prior to providing the first substrate and the second substrate; simultaneously depositing a third layer of material on the first substrate and a fourth layer of material on the second substrate without maintaining the first flow element at the first temperature and without maintaining the second flow element at the second temperature. Further comprising: a first non-uniformity between a property of the first layer of material on the first substrate and a property of the second layer of material on the second substrate is less than a second non-uniformity between a property of the third layer of material on the third substrate and a property of the fourth layer of material on the fourth substrate; method.

Images