Grouping feature of showerheads in substrate processing system

Abstract

To provide a method of manufacturing showerheads for a substrate processing system.SOLUTION: A method includes selecting first features to be machined within a first tolerance range, and second features, which are located at least a predetermined distance apart, to be machined within a second tolerance range of a specified dimension for the selected features. The method includes machining, using a cutting attachment of a tool, the first features within the first tolerance range, and when a parameter associated with the tool causing variation in dimension of the first selected features reaches a predetermined threshold, machining, using the cutting attachment, the second selected features within the second tolerance range. In a second method, a mean value of dimensions of the first and second features is less than or equal to a predetermined mean deviation from the specified dimension, and a standard deviation of the dimensions of the first and second features is less than or equal to a predetermined standard deviation.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 63,017,582, filed April 29, 2020, and U.S. Provisional Application No. 63 / 022,137, filed May 8, 2020, the entire disclosures of which are incorporated herein by reference.

[0002] The present disclosure relates generally to substrate processing systems, and more particularly to showerhead grouping features in substrate processing systems. [Background technology]

[0003] The background art description provided herein is intended to provide a general context for the present disclosure. Work by the presently named inventors, to the extent described in this background art section, as well as aspects of the description that may not qualify as prior art at the time of filing, are not admitted, expressly or impliedly, as prior art against the present disclosure.

[0004] A substrate processing system typically includes multiple processing chambers (also called process modules) for performing deposition, etching, and other processing on substrates, such as semiconductor wafers. Examples of processes that may be performed on a substrate include, but are not limited to, plasma-enhanced chemical vapor deposition (PECVD), chemical-enhanced plasma vapor deposition (CEPVD), sputtering physical vapor deposition (PVD), atomic layer deposition (ALD), and plasma-enhanced ALD (PEALD). Further examples of processes that may be performed on a substrate include, but are not limited to, etching (e.g., chemical etching, plasma etching, reactive ion etching, etc.) and cleaning processes.

[0005] During processing, a substrate is placed on a substrate support assembly, such as a pedestal or electrostatic chuck (ESC), located within a processing chamber of a substrate processing system. A robot typically transports substrates from one processing chamber to another in the order in which the substrates are processed. During deposition, a gas mixture containing one or more precursors is introduced into the processing chamber and a plasma is struck to activate a chemical reaction. During etching, a gas mixture containing an etching gas is introduced into the processing chamber and a plasma is struck to activate a chemical reaction. The processing chamber is periodically cleaned by supplying a cleaning gas into the processing chamber and striking a plasma. Summary of the Invention

[0006] A method for manufacturing a showerhead for a substrate processing system includes placing one or more showerheads on a tool including a cutting attachment. The method includes selecting a first selected feature of the plurality of features to be machined within a first tolerance range of a specified dimension for the plurality of features. The method includes selecting a second selected feature of the plurality of features spaced at least a predetermined distance apart to be machined within a second tolerance range of a specified dimension for the plurality of features. The first tolerance range is smaller than the second tolerance range. The method includes machining the first selected feature of the plurality of features within the first tolerance range using the cutting attachment. The method includes machining the second selected feature of the plurality of features within the second tolerance range when a parameter associated with the tool that causes a variation in a dimension of the first selected feature reaches a predetermined threshold.

[0007] In other aspects, the parameters include one or more of cutting attachment wear, cutting attachment temperature, tool temperature, or temperature of the showerhead being machined.

[0008] In another aspect, the parameter includes cutting attachment wear, and the method further includes estimating cutting attachment wear based on at least one of a machining time that the cutting attachment is used on the tool, a number of features cut using the cutting attachment, and the sensed cutting attachment wear.

[0009] In another aspect, the first selected feature and the second selected feature are located in one of the showerheads.

[0010] In another embodiment, the first selected feature and the second selected feature are the same.

[0011] In another aspect, the first selected feature and the second selected feature are disposed on a plurality of showerheads.

[0012] In another embodiment, the parameter comprises cutting attachment wear, and the method further comprises replacing the cutting attachment of the tool when the cutting attachment reaches a second predetermined threshold greater than the predetermined threshold.

[0013] In another aspect, the method further includes changing the cutting attachment of the tool after machining a predetermined number of showerheads using the cutting attachment.

[0014] In another aspect, the method further includes selecting a third selected feature from the second plurality of features to be machined within a third tolerance range of a second specified dimension for the second plurality of features. The method further includes selecting a fourth selected feature from the second plurality of features spaced at least a second predetermined distance apart to be machined within a fourth tolerance range of the second specified dimension. The third tolerance range is smaller than the fourth tolerance range. The method further includes machining the third selected feature within the third tolerance range using a cutting attachment. The method further includes machining the fourth selected feature within the fourth tolerance range using a cutting attachment when the parameter reaches a second predetermined threshold.

[0015] In other aspects, the third and fourth selected features are different from the first and second selected features, the second specified dimension is different from the specified dimension, the third and fourth tolerance ranges are different from the first and second tolerance ranges, and the second predetermined distance is different from the predetermined distance.

[0016] In another aspect, the first, second, third, and fourth selected features are located in one of the showerheads.

[0017] In another aspect, the first, second, third, and fourth selected features are disposed on a plurality of showerheads.

[0018] In another aspect, the method further includes machining a third selected feature after machining the first selected feature and before machining the second selected feature.

[0019] In another embodiment, the third and fourth selected features modify the first and second selected features.

[0020] In another aspect, the method further includes machining a third and a fourth selected feature after machining the first selected feature and before machining the second selected feature.

[0021] In another aspect, the method further includes machining third and fourth selected features after machining the second selected feature.

[0022] In yet another aspect, a method for manufacturing a showerhead for a substrate processing system includes disposing one or more showerheads on a tool including a cutting attachment. The method includes selecting first selected features from a plurality of features to be machined within a predetermined tolerance range of a specified dimension for the plurality of features. The method includes selecting second selected features from the plurality of features interspersed among the first selected features to be machined within a predetermined tolerance range of a specified dimension for the plurality of features. The method includes using the cutting attachment to machine the first selected feature within the predetermined tolerance range. The method includes using the cutting attachment to machine the second selected feature within the predetermined tolerance range when a parameter associated with the tool that causes variation in the dimension of the first selected feature reaches a predetermined threshold. The average value of the dimensions of the first and second selected features is less than or equal to a predetermined average deviation from the specified dimension. The standard deviation of the dimensions of the first and second selected features is less than or equal to a predetermined standard deviation.

[0023] In other aspects, the parameters include cutting attachment wear, cutting attachment temperature, tool temperature, or the temperature of one or more showerheads being machined.

[0024] In another aspect, the parameter includes cutting attachment wear, and the method further includes estimating cutting attachment wear based on at least one of a machining time that the cutting attachment is used on the tool, a number of features cut using the cutting attachment, and the sensed cutting attachment wear.

[0025] In another aspect, the first selected feature and the second selected feature are located in one of the showerheads.

[0026] In another embodiment, the first selected feature and the second selected feature are the same.

[0027] In another aspect, the first selected feature and the second selected feature are disposed in a plurality of showerheads.

[0028] In another embodiment, the parameter comprises cutting attachment wear, and the method further comprises replacing the cutting attachment of the tool when the cutting attachment reaches a second predetermined threshold greater than the predetermined threshold.

[0029] In another aspect, the method further includes changing the cutting attachment of the tool after machining a predetermined number of showerheads using the cutting attachment.

[0030] In yet another aspect, a showerhead includes a stem portion for connecting to a processing chamber and a base portion extending from the stem portion and including a plurality of features for introducing gases into the processing chamber. A first feature of the plurality of features has a dimension within a first tolerance range of a specified dimension for the plurality of features. A second feature of the plurality of features has a dimension within a second tolerance range of the specified dimension but outside the first tolerance range and is spaced at least a predetermined distance apart. The first tolerance range is smaller than the second tolerance range.

[0031] In another aspect, the plurality of features comprises through holes and the dimension comprises a diameter of the through holes.

[0032] In another embodiment, the plurality of features comprises more than N hundred features, where N is an integer greater than one.

[0033] In another embodiment, the plurality of features comprises more than N thousand features, where N is an integer greater than one.

[0034] In yet another aspect, a showerhead includes a stem portion for connecting to a processing chamber and a base portion extending from the stem portion and including a plurality of features for introducing gases into the processing chamber. A first feature of the plurality of features has a dimension within a predetermined tolerance range of a specified dimension for the plurality of features. A second feature of the plurality of features, having a dimension smaller than the first feature, is interspersed among the first features and has a dimension within the predetermined tolerance range. An average value of the dimensions of the first and second features is equal to or less than a predetermined average deviation from the specified dimension. A standard deviation of the dimensions of the first and second features is equal to or less than a predetermined standard deviation.

[0035] In another aspect, the plurality of features comprises through holes and the dimension comprises a diameter of the through holes.

[0036] In another embodiment, the plurality of features comprises more than N hundred features, where N is an integer greater than one.

[0037] In another embodiment, the plurality of features comprises more than N thousand features, where N is an integer greater than one.

[0038] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. [Brief explanation of the drawings]

[0039] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0040] [Figure 1] FIG. 1 shows an example of a substrate processing system.

[0041] [Figure 2A] FIG. 2A shows an example of a showerhead used in a substrate processing system. [Figure 2B] FIG. 2B illustrates an example of a showerhead used in a substrate processing system. [Figure 2C] FIG. 2C illustrates an example of a showerhead used in a substrate processing system.

[0042] [Figure 3A] FIG. 3A shows an example feature size histogram for a showerhead fabricated using a first method according to the present disclosure. [Figure 3B] FIG. 3B shows an example feature size histogram for a showerhead fabricated using a first method according to the present disclosure. [Figure 3C] FIG. 3C shows an example feature size histogram for a showerhead fabricated using a first method according to the present disclosure. [Figure 3D] FIG. 3D shows an example feature size histogram for a showerhead fabricated using a first method according to the present disclosure. [Figure 3E] FIG. 3E shows an example feature size histogram for a showerhead fabricated using a first method according to the present disclosure. [Figure 3F] FIG. 3F shows an example feature size histogram for a showerhead fabricated using a first method according to the present disclosure. [Figure 3G] FIG. 3G shows an example feature size histogram for a showerhead fabricated using a first method according to the present disclosure.

[0043] [Figure 3H] FIG. 3H shows a flowchart of a first method according to the present disclosure.

[0044] [Figure 4A] FIG. 4A shows a table including symbols and descriptions of statistical parameters used in a second method for manufacturing and qualifying manufactured components according to the present disclosure. [Figure 4B] FIG. 4B shows a table including symbols and descriptions of statistical parameters used in a second method for manufacturing and qualifying components according to the present disclosure.

[0045] [Figure 4C] FIG. 4C shows an example feature size histogram for a showerhead fabricated using a second method according to the present disclosure. [Figure 4D] FIG. 4D shows an example feature size histogram for a showerhead fabricated using a second method according to the present disclosure. [Figure 4E] FIG. 4E shows an example feature size histogram for a showerhead fabricated using a second method according to the present disclosure. [Figure 4F] FIG. 4F shows an example feature size histogram for a showerhead fabricated using a second method according to the present disclosure. [Figure 4G] FIG. 4G shows an example feature size histogram for a showerhead fabricated using a second method according to the present disclosure. [Figure 4H] FIG. 4H shows an example feature size histogram for a showerhead fabricated using a second method according to the present disclosure.

[0046] [Figure 4I] FIG. 4I shows a flowchart of a second method according to the present disclosure.

[0047] [Figure 5]FIG. 5 shows a simplified block diagram of a system capable of manufacturing components using the first and second methods of the present disclosure.

[0048] [Figure 6] FIG. 6 shows a flow chart of a method for manufacturing a feature of a component according to the specifications of the first method of the present disclosure.

[0049] [Figure 7] FIG. 7 shows a flowchart of a method for fabricating features of a component such as a showerhead according to the specifications of the second method of the present disclosure.

[0050] In the drawings, reference numbers may be reused to identify similar and / or identical elements. DETAILED DESCRIPTION OF THE INVENTION

[0051] A gas distribution apparatus, commonly referred to as a showerhead, is used to introduce one or more gases, such as process gases, purge gases, or cleaning gases, into a processing chamber. FIG. 1 and the description of FIG. 1 below provide an example of a substrate processing system including a processing chamber with a showerhead. The showerhead includes an inlet for receiving one or more gases from the gas distribution system and includes multiple outlets or features, such as slots or through-holes, for injecting one or more gases into the processing chamber. The dimensions (i.e., size) and geometric shape (i.e., shape) of the features are specified depending on the application (e.g., process) used in the processing chamber. Examples of dimensions include feature size (e.g., diameter or perimeter), feature distribution / density (e.g., number of features per square inch), etc. Examples of geometric shape include feature shape (e.g., circular, cylindrical, conical, polygonal, etc.).

[0052] Showerheads are typically constructed of metals such as aluminum. Showerheads can also be constructed of alloys or ceramic materials. Showerhead features are manufactured using tools with attachments, such as cutters or drill bits, of specific sizes. After drilling a certain number of features (e.g., after manufacturing a few showerhead features), the attachments begin to wear. Continued use of worn attachments will result in the manufacture of features that do not meet specifications.

[0053] When non-conforming features are fabricated in clusters, the clustering of non-conforming features can lead to thickness non-uniformities in substrates processed using processes that are highly sensitive to showerhead feature dimensions. To avoid clustering of non-conforming features, some fabricators adhere to a prescribed order, sequence, or pattern of feature fabrication, but this can be burdensome. Alternatively, fabricators must frequently replace attachments such as cutters or drill bits (e.g., after fabricating features for one showerhead or two showerheads), which is costly.

[0054] The present disclosure provides two methods for avoiding the clustering of non-conforming features and allowing manufacturers to use worn attachments to some extent. These methods can be used to manufacture components without frequently replacing attachments and to verify whether manufactured components meet specifications. The first method uses or defines two criteria: the first criterion is a smaller subrange of a larger tolerance range, and the second criterion is a minimum distance rule. All dimensions of the showerhead features must be within the larger tolerance range. In addition, most, if not all, of the features' dimensions must also be within the smaller subrange of the larger tolerance range. Furthermore, if the dimensions of some features are not within the smaller subrange (i.e., outside the range), each of these features must be separated from the others by at least a predetermined distance.

[0055] For example, if F (e.g., 3931) is the total number of features of a showerhead, all dimensions (e.g., diameters) of the F features of the showerhead must be within a first tolerance range of a specified nominal diameter for the F features. For example, all of the F features of the showerhead must be within X% (e.g., 5%) of the specified nominal diameter. Further, most (e.g., M) dimensions, if not all of the F features, must be within a second tolerance range (referred to as a sub-range) that is stricter (i.e., smaller) than the first tolerance range. For example, the diameters of the M features must be within Y% (e.g., 1.25%) of the specified nominal diameter, where Y < X. Further, if N dimensions of the F features are not within the second tolerance range (i.e., out of range), then N = F - M and N ≧ 2, and each of the N features must be at least a predetermined distance D apart from the others of the N features (referred to as the minimum distance rule). That is, the first of the N features must be at least distance D apart from the rest of the N features, the second of the N features must be at least distance D apart from the rest of the N features, and so on.

[0056] By employing a sub-range and applying the minimum distance rule, the first method of the present disclosure prevents clustering of non-conforming features. The first method allows a manufacturer to use worn attachments as long as the features manufactured using the worn attachments meet the sub-range and the minimum distance rule. Also, the first method allows a manufacturer to manufacture features in any manner, rather than following a particular drilling pattern or sequence, as long as the manufactured features meet the sub-range and the minimum distance rule.

[0057] A second method according to the present disclosure defines statistically based feature tolerances, rather than traditional pass / fail methods, for components with a sufficiently large or statistically significant population of process-critical features. The statistics can include diameter, location, and pattern distribution of the defined features. A component (e.g., a showerhead) passes inspection for feature size (e.g., diameter) if the following three statistical requirements are met (the requirements and statistical term definitions are explained in detail below): First, the feature diameter does not exceed the cutoff tolerance range t; and second, the population mean is within the maximum mean deviation D. T Third, the population standard deviation (SD) must not exceed SD max The manufacturing sequence of the features in the prescribed large population is randomized by the manufacturer to distribute any forms of tool wear, thermal effects, and / or other step-dependent effects evenly across the feature population. Once a manufacturing sequence is empirically optimized and verified to produce features that meet the three statistical requirements for the component, the sequence is used repeatedly to manufacture a predetermined quantity of the component.

[0058] The second method also allows a manufacturer to use a worn attachment, as long as the features produced using the worn attachment meet the three statistical requirements of the second method. Additionally, the second method also allows a manufacturer to produce features in any empirically tested manner, instead of adhering to a prescribed drilling pattern or sequence, as long as the produced features meet the three statistical requirements of the second method.

[0059] These and other aspects of the first and second methods of the present disclosure are described in detail below. Throughout this disclosure, showerheads are used only as an example of components manufactured using the first and second methods to illustrate the teachings of the present disclosure. The present teachings are not limited to showerheads. Furthermore, the present teachings are not limited to semiconductor manufacturing equipment components. Rather, the present teachings are applicable to any component having a statically significant (i.e., sufficiently large) population of one or more features.

[0060] This disclosure is organized as follows: First, an example of a processing chamber in which a showerhead manufactured according to the present disclosure can be used is shown and described with reference to FIG. 1. Then, an example of a showerhead and its features is shown and described with reference to FIGS. 2A-2C. Then, a first method is described with reference to FIGS. 3A-3H, and a second method is described with reference to FIGS. 4A-4I. Finally, a block diagram of a system in which components can be manufactured using the first and second methods is shown and described with reference to FIG. 5.

[0061] 1 illustrates an example of a substrate processing system 100 including a processing chamber 102 configured to generate a capacitively coupled plasma. While this example is described in the context of plasma-enhanced chemical vapor deposition (PECVD), the teachings of this disclosure are applicable to other types of substrate processing, such as atomic layer deposition (ALD), plasma-enhanced ALD (PEALD), CVD, or other processes, including etching.

[0062] The substrate processing system 100 includes a processing chamber 102 that surrounds the other components of the substrate processing system 100 and contains an RF plasma (if used). The processing chamber 102 includes an upper electrode 104 and an electrostatic chuck (ESC) 106 or other type of substrate support. During operation, a substrate 108 is positioned on the ESC 106.

[0063] For example, the upper electrode 104 may include a gas distribution apparatus 110, such as a showerhead, for introducing and distributing process gases into the processing chamber 102. The gas distribution apparatus 110 may include a stem including one end connected to the top surface of the processing chamber 102. The base of the showerhead is generally cylindrical and extends radially outward from the opposite end of the stem at a location spaced from the top surface of the processing chamber 102. The substrate-facing surface or faceplate of the showerhead base includes a plurality of outlets or features (e.g., slots or through-holes) for the flow of vaporized precursors, process gases, cleaning gases, or purge gases.

[0064] The ESC 106 includes a base plate 112 that functions as a lower electrode. The base plate 112 supports a heating plate 114, which may correspond to a ceramic multi-zone heating plate. A thermal resistance layer 116 may be disposed between the heating plate 114 and the base plate 112. The base plate 112 may include one or more channels 118 for flowing coolant through the base plate 112.

[0065] When a plasma is used, an RF generation system (or RF source) 120 generates and outputs an RF voltage to one of the upper electrode 104 and the lower electrode (e.g., the base plate 112 of the ESC 106). Note that the other of the upper electrode 104 and the base plate 112 may be DC grounded, AC grounded, or ungrounded. For example, the RF generation system 120 may include an RF generator 122 that generates RF power that is supplied to the upper electrode 104 or the base plate 112 by a match and distribution network 124. In other examples, not shown, a plasma may be generated inductively or remotely and then supplied to the processing chamber 102.

[0066] Gas delivery system 130 includes one or more gas sources 132-1, 132-2, ... 132-N (collectively gas sources 132), where N is an integer greater than 0. Gas sources 132 are connected to manifold 140 by valves 134-1, 134-2, ... 134-N (collectively valves 134) and mass flow controllers 136-1, 136-2, ... 136-N (collectively mass flow controllers 136). Vapor delivery system 142 supplies vaporized precursors to manifold 140 or a separate manifold (not shown) connected to processing chamber 102. The output of manifold 140 is supplied to processing chamber 102. Gas sources 132 may supply process gases, cleaning gases, or purge gases.

[0067] The temperature controller 150 may be connected to a plurality of thermal control elements (TCEs) 152 disposed on the heating plate 114. The temperature controller 150 may be used to control the plurality of TCEs 152 to control the temperature of the ESC 106 and the substrate 108. The temperature controller 150 may be in communication with a coolant assembly 154 to control the flow of coolant through the channel 118. For example, the coolant assembly 154 may include a coolant pump, a reservoir, and one or more temperature sensors (not shown). The temperature controller 150 operates the coolant assembly 154 to selectively flow coolant through the channel 118 to cool the ESC 106. Valves 156 and pumps 158 may be used to evacuate reactants from the processing chamber 102. A system controller 160 controls the components of the substrate processing system 100.

[0068] 2A-2C show an example of a showerhead assembly. FIG. 2A is a perspective view of the showerhead assembly. FIGS. 2B and 2C show example features of the showerhead assembly. FIG. 2B shows features on the substrate-facing surface or faceplate of the showerhead assembly. FIG. 2C shows the features in detail.

[0069] 2A, a showerhead assembly 200, such as the gas distribution apparatus 110 shown in FIG. 1, includes a stem portion 202 that includes one end that connects to the top surface of a processing chamber, such as the processing chamber 102 shown in FIG. 1. The stepped portion 202 includes an inlet for receiving a vaporized precursor, process gas, cleaning gas, or purge gas from a gas delivery system, such as the gas delivery system 130 shown in FIG.

[0070] The base 204 of the showerhead assembly 200 is generally cylindrical and extends radially outward from the opposite end of the stem 202 at a location spaced from the top surface of the processing chamber. A substrate-facing surface or faceplate 210 (shown in FIG. 2B ) of the base 204 includes a plurality of outlets or features (e.g., slots or through-holes) 212. Vaporized precursors, process gases, cleaning gases, or purge gases from the inlets flow through the features 212 into the processing chamber.

[0071] In FIG. 2B , the faceplate 210 of the showerhead assembly 200 includes a plurality of features 212. In some examples, all of the features 212 may be the same size and shape. For example, all of the features 212 may be circular and have the same diameter. In some examples, the features 212 may include multiple sets of features. For example, a first set of features having a first size and a first shape may be disposed in a first position on the showerhead assembly 200, while a second set of features having a second size and a second shape may be disposed in a second position on the showerhead assembly 200. At least one of the second size and the second shape may be different from the first size and the first shape. For example, in FIG. 2C , two sets of features are shown. The first set includes feature 212-1, and the second set includes feature 212-2. Both features 212-1 and 212-2 are circular, but feature 212-1 has a larger diameter than feature 212-2.

[0072] 2C , as an example, features 212-2 are quantitatively very small relative to the first features 212-1. For example, the first set of features 212-1 may include thousands of statistically significant features, while the second set of features 212-2 may include far fewer than 50 or 100 features (e.g., one or two dozen) that are not statistically significant. As a result, the process impact of the second set of features 212-2 is negligible, and the first method need not be applied to these second set of features 212-2.

[0073] However, in some examples, the first set of features 212-1 and the second set of features 212-2 may each include a statistically significant population of features. For example, the number of features in each of the first set of features 212-1 and the second set of features 212-2 may include hundreds or thousands of features. Thus, the first method can be applied with separate specifications for subranges and minimum distances for each of the first set of features 212-1 and the second set of features 212-2.

[0074] In other words, some showerheads (or components in general) may include two sets of features. The first set may include a first feature having a first size (e.g., diameter) D1 and may be fabricated in a quantity F1. The second set may include a second feature having a second size (e.g., diameter) D2 and may be fabricated in a quantity F2. The first and second features may be fabricated in separate regions of the showerhead, or may be scattered across one or more regions of the showerhead (e.g., as shown in FIG. 2C, although both F1 and F2 may be statistically significant). D1 may be greater than, less than, or equal to D2 in some applications. Nevertheless, the teachings of the subrange and minimum distance rules apply to both the first and second features. The subrange and minimum distance values ​​for the second features may differ from those of the first features due to their size, quantity, and location.

[0075] The first method, involving subranges and minimum distance rules, will now be described in more detail with reference to Figures 3A-3H. Current showerhead specifications control feature size using a relatively large tolerance range. While a large tolerance range is desirable for efficient manufacturability and competitive cost of the showerhead, the large tolerance range adversely affects flow-sensitive processes. This is because the specifications do not include constraints controlling the crowding of features of the same size within a large tolerance range, which can be problematic for sensitive processes. As a result, current specifications for feature size result in thickness non-uniformities across the substrate due to the crowding of similarly sized features relative to the rest of the showerhead features.

[0076] According to the first method, feature grouping is controlled to ensure that features above or below a feature size range are not clustered together at any location on the showerhead. This control is designed to ensure that sensitive processes are not affected by feature size variations within an acceptable tolerance range. Features sized outside a specified tolerance range are fabricated at least a predetermined distance away from other similar features sized outside the specified range. This method ensures that similarly sized features sized outside the acceptable tolerance range are not fabricated in clusters. The first method maintains a larger tolerance range for the overall feature size and uses additional smaller subranges along with minimum distance rules to ensure that a large population of features is within the acceptable feature size and that out-of-range features (called outliers) do not cluster together to form patterns. In this way, the first method ensures a uniform distribution of features on the showerhead. While current specifications may produce random patterns of similarly sized features within a tolerance range, the first method allows for the fabrication of features with the same tolerance range but with the added control of subranges and minimum distance rules.

[0077] 3A-3H illustrate how the first method can be used to apply subrange and minimum distance rules to fabricate a showerhead and to qualify or disqualify the fabricated showerhead. FIGS. 3A-3G illustrate various examples of applying subrange and minimum distance rules to a set of features (e.g., the first set of features 212-1 shown in FIG. 2B). These figures show histograms of feature sizes for showerheads fabricated using the first method. In these figures, a showerhead with 3931 features of a specified diameter is used as an example. For example, the showerhead used in these figures may be similar to showerhead assembly 200 shown in FIG. 2A, where the first set of features 212-1 equals 3931.

[0078] All dimensions (e.g., diameters) of the 3931 features of the showerhead must be within a first tolerance range. For example, all diameters of the 3931 features must be within X% (e.g., 5%) of the specified diameter. As an example, any suitable value of the first tolerance range may be used, but the value of the first tolerance range used in these figures is 0.04 inches (1.016 mm) ± 0.001 inches (0.0254 mm), and 0.04 inches is the specified nominal diameter in these figures. Further, most (e.g., M) dimensions, if not all 3931 features, must be within a second tolerance range (referred to as a subrange) that is smaller (i.e., more stringent) than the first tolerance range. For example, the diameters of the M features must be within Y% (e.g., 1.25%) of the specified nominal diameter, which is 0.04 inches in these figures, and Y < X. As an example, any suitable value may be used for the subrange, but the value of the subrange used in these figures is 0.0005 inches (0.0127 mm). Further, when N dimensions of the urchin features are not within the subrange (i.e., outside the subrange), N = 3931 - M and N ≧ 2, and each of the N features must be at least a distance D away from the others of the N features (referred to as the minimum distance rule). For example, any suitable value may be used for the minimum distance, but the value of the minimum distance used in these figures is 1.0 inches.

[0079] In FIG. 3A , in a first example of a showerhead assembly manufactured according to the first method, all diameters of the 3,931 features fall within a first tolerance range, which in this example is 0.04 inches ±0.001 inches, where 0.04 inches is the specified nominal diameter. Furthermore, all diameters of the 3,931 features fall within five different ranges (bins), each of 0.0001 inches (0.00254 mm). Therefore, all feature diameters fall within the specified subrange (shown by the two vertical dotted lines), which in this example is 0.0005 inches. Therefore, the showerhead assembly in this example is acceptable for the first method (i.e., manufactured according to the tolerance and subrange specifications). Conversely, a manufacturer may continue to use previously used drill bits that may have previously produced features with more uniform diameters than those shown in this example, as long as they can manufacture showerhead assemblies with feature sizes such as those shown in this example.

[0080] In FIG. 3B , in a second example of a showerhead assembly manufactured according to the first method, all diameters of the 3,931 features fall within a first tolerance range, which in this example is 0.04 inches ±0.001 inches, where 0.04 inches is the specified nominal diameter. Furthermore, all diameters of the 3,931 features fall within five different ranges (bins) of 0.0001 inches each. Therefore, all feature diameters fall within the specified subrange (shown by the two vertical dotted lines), which in this example is 0.0005 inches. Therefore, the showerhead assembly in this example is also acceptable for the first method (i.e., manufactured according to the tolerance and subrange specifications). Conversely, a manufacturer may continue to use previously used drill bits that may have previously produced features with more uniform diameters than those shown in this example, as long as they can manufacture showerhead assemblies with feature sizes such as those shown in this example.

[0081] 3C and 3D , in a third example of a showerhead assembly manufactured according to the first method, all diameters of the 3931 features fall within a first tolerance range, which in this example is 0.04 inches ±0.001 inches, where 0.04 inches is the specified nominal diameter. Furthermore, the diameters of all but two of the 3931 features, identified as 250 and 252, fall within five different ranges (bins) of 0.0001 inches. The diameters of the two features identified as 250 and 252 are within the first tolerance range but are not within a specified subrange (indicated by two vertical dotted lines), which in this example is within 0.0005 inches of the specified nominal diameter, and are therefore referred to as outliers 250 and 252. That is, the difference between the specified nominal diameter and the diameter of each of the two outliers 250 and 252 is greater than the specified subrange, which in this example is 0.0005 inches. Thus, the diameters of the two outliers 250, 252 are within the first tolerance range, but the diameters of the two outliers 250, 252 are not within the specified sub-range.

[0082] However, as FIG. 3D shows, the two outliers 250, 252 are separated from each other by at least 1 inch (25.4 mm), which is the required minimum distance between features that are not within the specified subrange in this example. Therefore, the showerhead assembly in this example is acceptable for the first method (i.e., manufactured according to the tolerance and minimum distance rule specifications). Conversely, a manufacturer may continue to use previously used drill bits that may have previously produced features with more uniform diameters than those shown in this example, as long as they can produce showerhead assemblies with feature sizes such as those shown in this example.

[0083] In FIG. 3E , in a fourth example of a showerhead assembly manufactured according to the first method, all diameters of the 3,931 features fall within a first tolerance range, which in this example is 0.04 inches ±0.001 inches, where 0.04 inches is the specified nominal diameter. Furthermore, all diameters of the 3,931 features fall within five different ranges (bins) of 0.0001 inches each. Therefore, all feature diameters fall within the specified subrange (shown by the two vertical dotted lines), which in this example is 0.0005 inches. Therefore, the showerhead assembly in this example is also acceptable for the first method (i.e., manufactured according to the tolerance and subrange specifications). Conversely, a manufacturer may continue to use previously used drill bits that may have previously produced features with more uniform diameters than those shown in this example, as long as they can manufacture showerhead assemblies with feature sizes such as those shown in this example.

[0084] 3F and 3G, in a fifth example of a showerhead assembly manufactured according to the first method, all diameters of the 3,931 features fall within a first tolerance range, which in this example is 0.04 inches ±0.001 inches, where 0.04 inches is the specified nominal diameter. However, 26 of the 3,931 features, identified by 260 and 262, have diameters that are not within the specified subrange (indicated by the two vertical dotted lines), which in this example is within 0.0005 inches of the specified nominal diameter, and are therefore referred to as outliers 260 and 262. That is, the difference between the specified nominal diameter and the diameter of each of the outliers 260 and 262 is greater than the specified subrange, which in this example is 0.0005 inches. Thus, although the diameters of the outliers 260 and 262 fall within the first tolerance range, the diameters of the outliers 260 and 262 are not within the specified subrange.

[0085] Furthermore, as shown at 270 in FIG. 3G, at least some of the outliers 250, 252 are not separated from one another by at least 1 inch, which is the required minimum distance between features that are not within the specified sub-range in this example. Thus, although manufactured according to the first tolerance range, the showerhead assembly in this example is unacceptable because it fails the specifications of the first method's sub-range minimum distance rule.

[0086] FIG. 3H illustrates a first method (identified at 300) for manufacturing and / or qualifying a showerhead using sub-range and minimum distance rules. At 302, the first method 300 determines whether the sizes of all features are within a first tolerance range (i.e., a larger tolerance range, e.g., 0.04 inches ± 0.001 inches, where 0.04 inches is the specified nominal diameter). If the sizes of all features are not within the first tolerance range, the first method 300 terminates at 304 and the component is rejected at 304. If the sizes of all features are within the first tolerance range, the first method 300 determines at 306 whether the sizes of two or more of the features are outside a second tolerance range (i.e., a sub-range, e.g., 0.0005 inches of the specified nominal diameter). If the sizes of two or more features are not outside the second tolerance range, the first method 300 terminates at 308 and the component is accepted at 308. If the size of the two or more features is outside the second tolerance range, the first method 300 determines at 310 whether the two or more features are separated by a predetermined minimum distance (e.g., at least one inch). If the two or more features are separated by the predetermined minimum distance, the first method 300 ends at 308 and the component is accepted at 308. If the two or more features are not separated by the predetermined minimum distance, the first method 300 ends at 304 and the component is rejected at 304.

[0087] The first method can be used by manufacturers to produce parts that comply with subrange and minimum distance specifications and to qualify the manufactured components. For example, a manufacturer can monitor drill bit wear and / or feature dimension (e.g., feature diameter / geometry) variations during production. For example, a manufacturer can use meteorological tools, coordinate measuring machines (CMMs), and optical probes, or other techniques, to inspect features after drilling and measure their size. Once these features are measured, the measured data can be analyzed to determine whether the features meet the criteria for the subrange and minimum distance specifications. Based on the data analysis, a manufacturer can also determine how many components can be manufactured using the same drill bit (i.e., without changing the drill bit) to produce components with features that comply with the subrange and minimum distance specifications. For example, a manufacturer can determine that it can manufacture up to four showerheads (i.e., a total of approximately 16,000 features) using the same drill bit. The manufacturer may determine and use a unique drilling pattern to drill all of the approximately 4,000 features on the showerhead. For example, the drilling sequence may be divided into multiple zones on the showerhead. Manufacturers are free to choose the drilling pattern / sequence / drill bit wear life. Regardless of the choice, the manufactured features are measured to ensure feature size meets specifications.

[0088] A second method for defining the three statistical conditions mentioned above will now be described with reference to Figures 4A-4I. The feature size (e.g., diameter) of a component (e.g., showerhead) is typically defined by a symmetric plus / minus tolerance range, as are most mechanical feature dimensions. However, due to the large number of features (e.g., through-holes or outlets) typical of some components, such as showerheads, the probability that a single feature may deviate from the normal distribution is relatively high. Considering processing capabilities, tool variance, material deviation, and other factors, the tolerance range of a feature is much wider than that for a relatively small number of features to prevent a high component reject rate during manufacturing inspection. Given stricter process control requirements, traditional tolerance schemes for features are becoming obsolete. A second method for producing components with statistically significant feature populations is designed to account for tighter tolerance constraints while accounting for manufacturing variability.

[0089] Using a single tool attachment (e.g., cutter) to manufacture a large population of features can induce linear dispersion in one or more dimensions of the population of features. For example, as the attachment wears, the resulting average feature size (e.g., diameter) tends to drift over time, resulting in the last feature manufactured in a sequence deviating from the first. When drilling thousands of features, the drill bit wears over time, producing the last feature at a predictably smaller size than the first. When manufacturing a large number of features, the best approach is to develop a random machining sequence for the features to distribute wear across the set of features. This results in physical averaging of the features. According to the second method, a component passes inspection for feature size if the following three statistical requirements or specifications of the second method are met: First, the feature diameter does not exceed the cutoff tolerance range t; and, second, the population mean is within the maximum mean deviation D. T Third, the population standard deviation is SD maxThe limit is not to exceed 100%.

[0090] 4A and 4B show a table containing symbols and descriptions of the statistical parameters used in FIGS. 4C-4H to describe the second method. Throughout the description of the second method, the diameters of the showerhead and its features are used for illustration only. The diameters are the cross-sectional widths of the circular features as measured by applicable measurement techniques (e.g., CMM, optical, etc.).

[0091] In FIG. 4A, the first table shows statistical parameters used to describe and constrain feature-to-feature variance in diameter. These statistical parameters represent boundary constraints on a population of features, not individual features. The symbol T represents the nominal target size (e.g., nominal diameter) of a feature and describes the target average diameter of all features along with the target population mean. The symbol t represents the cutoff tolerance range, specified as a ± numerical value. The cutoff tolerance range t is the distance from the nominal target size T that no feature can exceed or the component will be rejected. The symbol D T represents the maximum mean deviation from the nominal target size T relative to the mean value of the entire feature population. T is the bounding window of the population mean, specified by ± values. The maximum mean deviation D T defines the range not for any single feature but for the entire population defined within the feature pattern. The symbol SD max represents the maximum standard deviation. Maximum standard deviation SD max is the maximum allowable standard deviation across the feature pattern, calculated after inspection and measurement of all features.

[0092] In FIG. 4B, the second table shows statistical parameters calculated from the measured population data, which are used to quantify the feature population to determine whether it complies with the second method specifications (i.e., the three statistical requirements). In the second table, the symbol USL is represented as USL=T+t and represents the absolute maximum value any feature diameter can have within the population. USL is calculated from the nominal target T+tolerance range t. The symbol LSL is represented as LSL=Tt and represents the absolute minimum value any feature diameter can have within the population. LSL is calculated from the nominal target T-tolerance range t. The symbol UD T UD T =T+D T and represents the maximum value that the feature population mean can have. T LD T =TD T and represents the smallest value that the feature population mean can have. The symbol μ represents the population mean and describes the actual population mean of the diameter for all features in the population. The symbol D μ is D μ = μ-T, which represents the bounding window for the population mean. D μ (D T (same as ) defines a range not for any single feature, but specifically for the entire population defined within the feature pattern.

[0093] These statistical parameters can be used to define a feature size in the following format: For example, the diameter of a feature such as a through-hole on a showerhead (e.g., feature 212-1 of showerhead assembly 200 shown in Figures 2A-2C) can be defined as: 3894 x 0.040 ± 0.001 D T :±0.0005 SD:6E-5, where 3894 is the number or quantity of features, 0.040 inches is the nominal feature target size T, ±0.001 inches is the cutoff tolerance t, D T : ±0.0005 inches is the maximum mean deviation, and SD is the maximum allowable standard deviation max is.

[0094] Figures 4C-4H show histograms of feature sizes for showerheads fabricated using the second method. In each of Figures 4C-4H, an overlay of a distribution curve fit to the showerhead data is used to visualize statistical parameters. The criteria of the second method are then applied to determine whether the features meet specifications, as described below.

[0095] Figures 4C-4H show examples of acceptable and unacceptable feature populations based on each type of statistical parameter. For example, Figures 4C and 4D show examples of acceptable and unacceptable feature populations, respectively, based on population mean. Figures 4E and 4F show examples of acceptable and unacceptable feature populations, respectively, based on standard deviation. Figures 4G and 4H show examples of acceptable and unacceptable feature populations, respectively, based on outliers.

[0096] In Figures 4C-4H, the population mean μ is the distance D from the feature target T. μ The shaded area is the 1σ standard deviation SD max The shaded region expands as the feature size increases. The USL and LSL bounds are the absolute maximum / minimum bounds for all features in the population.

[0097] In Figures 4C and 4D, the feature population passes the population mean criterion of the second method (i.e., the population mean is within the maximum mean deviation D T In order for the population mean μ to be greater than UD t and LD t In the example shown in Figure 4C, the population mean μ is UD t and LD t Since it is within the bounds, the feature population passes the population mean criterion of the second method (i.e., the population mean is within the maximum mean deviation D T Furthermore, the feature size must not exceed the cutoff tolerance range, and the standard deviation of the feature population must not exceed SD maxThe other two criteria of the second method are also met, including that the difference between the thickness of the showerhead and the thickness of the substrate does not exceed 100 μm. Therefore, the showerhead in the example shown in FIG. 4C passes all three criteria of the second method and is therefore within the tolerance range.

[0098] In the example shown in Figure 4D, the feature population has a population mean μ of UD t and LD t It fails the population mean criterion of the second method because it is not within the bounds (i.e., the population mean is too large and the maximum mean deviation D T Therefore, the showerhead in the example shown in Figure 4D has a feature size that does not exceed the cutoff tolerance range and the standard deviation of the feature population is SD max Although it passes the other two criteria of the second method, including not exceeding , it fails the population mean criterion of the second method and is therefore unacceptable.

[0099] In Figures 4E and 4F, the standard deviation SD max controls the spread of the features. In the example shown in Figure 4E, the feature population passes the standard deviation criterion of the second method (i.e., the standard deviation of the population is SD max Furthermore, the size of the features must not exceed the cut-off tolerance range and the population mean must not exceed the maximum mean deviation D T The other two criteria of the second method are also met, including that the temperature does not exceed 100°C. Therefore, the showerhead in the example shown in FIG. 4E passes all three criteria of the second method and is therefore acceptable.

[0100] In the example shown in Figure 4F, the feature population is calculated using a defined SD max Therefore, the showerhead in the example shown in FIG. 4F fails the standard deviation criterion of the second method because it has a standard deviation greater than 0. Therefore, the showerhead in the example shown in FIG. 4F is designed to ensure that the feature size does not exceed the cutoff tolerance range and that the population mean is within the maximum mean deviation D T Although the showerhead passes the other two criteria of the second method, including not exceeding 1 / 2 the standard deviation criterion of the second method, it is unacceptable.

[0101] 4G and 4H, the cutoff tolerance range t defines the absolute maximum and minimum acceptable values ​​for any feature in the feature population. In the example shown in FIG. 4G, outlier 350 has a feature size that does not exceed USL. As a result, the feature population passes the cutoff tolerance range criteria of the second method (i.e., no feature size exceeds the cutoff tolerance range t). Furthermore, if the standard deviation of the feature population is SD max and the population mean does not exceed the maximum mean deviation D T The other two criteria of the second method are also met, including that the temperature does not exceed 100°C. Therefore, the showerhead in the example shown in FIG. 4G passes all three criteria of the second method and is therefore acceptable.

[0102] In the example shown in Figure 4H, outlier 352 has a feature size that exceeds USL. As a result, the feature population fails the cutoff tolerance range criteria of the second method (i.e., the feature size exceeds the cutoff tolerance range t). Therefore, the showerhead in the example shown in Figure 4H has a feature population standard deviation of SD max and the population mean does not exceed the maximum mean deviation D T Although the showerhead passes the other two criteria of the second method, including not exceeding the USL, it is unacceptable because it fails the cutoff tolerance range criterion of the second method. The showerhead in the example shown in Figure 4H is unacceptable even though both the mean and standard deviation are within the specifications of the second method because a single outlier exceeds the USL.

[0103] The maximum standard deviation D for the second method T Note that is the same as the subrange specification of the first method. Furthermore, the first method would also reject the showerhead in the example shown in FIG. 4H because the size of outlier 352 exceeds the larger tolerance band of the first method. However, if the outlier were outside the subrange but still satisfied the minimum distance rule, the first method would accept the showerhead.

[0104] 4I illustrates a second method (identified at 400) for manufacturing and / or qualifying showerheads using statistical criteria. At 402, the second method 400 determines whether a feature population meets a first criterion, i.e., whether the mean for a population of features of a component, such as a showerhead, is greater than or equal to the maximum mean deviation D of the population. T Determine whether the population mean exceeds D T If it exceeds this, the component will be rejected with a 404.

[0105] The population mean is D T If not, then at 406, the second method 400 determines whether the feature population satisfies a second condition, i.e., whether the standard deviation of the population of the component features is greater than or equal to the maximum population standard deviation, SD max Determine whether the population standard deviation is greater than SD max If it exceeds this, the component will be rejected with a 404.

[0106] The population standard deviation is also SD max If not, then at 408, the second method 400 determines whether the feature population meets a third condition, i.e., whether the size of any of the component's features exceeds the cutoff tolerance range t. If the size of any of the component's features exceeds the cutoff tolerance range t, the component is rejected at 404. If the size of any of the component's features does not exceed the cutoff tolerance range t, all three conditions of the second method are met and the component is accepted at 410.

[0107] The second method can be used by manufacturers to not only produce components that comply with the three statistical conditions, but also to qualify the produced components. For example, a manufacturer can monitor drill bit wear and / or feature dimension (e.g., feature diameter / geometry) variations during production. For example, a manufacturer can use meteorological tools, coordinate measuring machines (CMMs), and optical probes, or other techniques, to inspect features after drilling and measure their size. Once these features are measured, the measured data can be analyzed to determine whether the features meet the criteria of all three statistical conditions of the second method. Based on the data analysis, a manufacturer can also determine how many components can be produced using the same drill bit (i.e., without changing the drill bit) to produce components with features that comply with the criteria of the second method. For example, a manufacturer can determine that a maximum of four showerheads (i.e., a total of approximately 16,000 features) can be produced using the same drill bit while still meeting the criteria of the second method.

[0108] The manufacturer can randomize the fabrication order of features in a prescribed large population to ensure that any form of tool wear, thermal effects, or other step-dependent effects are uniformly distributed throughout the feature population. This fabrication order can be empirically verified and then repeated to produce components that meet the specifications of the second method. The manufacturer is free to choose the drilling pattern / sequence / drill bit wear life. Regardless of the choice, the fabricated features are measured to verify that the feature size meets the specifications of the second method.

[0109] 5 shows a simplified block diagram of a system capable of fabricating features of a component, such as a showerhead (e.g., showerhead 200 shown in FIGS. 2A-2C ), using the first and second methods of the present disclosure. For example, fabrication system 500 includes a computer system 502 and a tool controller 504 that controls a tool 506. Computer system 502 provides code to tool controller 504 for fabricating features in a component, such as a showerhead, according to the specifications of the methods of the present disclosure. Computer system 502 also provides a user interface on a display for an operator to operate, monitor, and control tool 506.

[0110] The component is fixed on a table 510, which is disposed on a base 512. The tool 506 includes an attachment 508 (e.g., a drill bit or a cutter) coupled to a motor for producing features in the component. Based on the code, the tool controller 504 controls the rotational speed of the motor. The tool 506 further includes actuators (not shown) that can move the motor in the X, Y, and Z directions. The tool controller 504 controls the X, Y, and Z movement of the motor using an X-axis driver 514, a Y-axis driver 516, and a Z-axis driver 518. The drivers 514, 516, and 518 drive their respective actuators to move the motor in the X, Y, and Z directions to the correct positions in / on the component to produce features according to specifications.

[0111] In some tools, the component is held in a vertical orientation (rather than the horizontal orientation shown), and the attachment 514 operates on the component in a horizontal orientation (rather than the vertical orientation shown) to fabricate features in the component. In some applications, the table 510 can be moved relative to the attachment 514. The tool controller 504 controls the movement of the table 516 in the X and Y axes.

[0112] The feedback system 520 provides feedback to the tool controller 504 regarding the position, velocity, etc. of the motors and actuators. The feedback system 520 includes position and velocity transducers that monitor / measure the position and velocity of the motors and actuators. The tool controller 504 receives signals from these transducers and generates control signals based on these signals to correct position and velocity errors.

[0113] Additionally, although not shown, the tool 506 may include a lubrication / cooling system that dispenses a lubricant / coolant proximate the attachment 514, such as onto the workpiece 514, during operation. The tool controller 504 may also perform auxiliary control functions such as turning the lubricant / coolant on and off and changing the attachment 514.

[0114] After a predetermined number of components have been manufactured according to the specifications, the tool 506 may automatically change the attachment 514, or the user interface of the computer system 502 may prompt an operator to change the attachment 514. Thus, the tool 506 manufactures features on the components according to the specifications of each of the first and second methods of the present disclosure.

[0115] 6 and 7 illustrate methods that a manufacturer can use to manufacture features on a component, such as a showerhead, according to the specifications of the first and second methods of the present disclosure, respectively. In FIGS. 6 and 7, tool attachment wear is used as an example of a parameter that can cause variation in feature dimensions. Other non-limiting examples of parameters that can cause variation in feature dimensions include cutting attachment temperature, tool temperature, temperature of the component being machined, coolant flow rate, coolant temperature, operator error, foreign objects, and the setup, settings, and general tolerances associated with the tool. These parameters can be measured and / or detected using appropriate sensors installed on the tool or using external sensing / measuring devices. These parameters, alone or in any combination, can cause variation in feature dimensions. The methods of the present disclosure consider these parameters and produce features on the component that meet the requirements of the specifications of the methods of the present disclosure.

[0116] FIG. 6 illustrates a method 600 that a manufacturer can use to fabricate features on a component, such as a showerhead, according to the specifications of the first method of the present disclosure. Method 600 can be performed using system 500 shown in FIG. 5. Using a tool 506 and an attachment 508 (e.g., a cutting attachment, described below), method 600 can fabricate features on one component at a time or on multiple components simultaneously. Additionally, method 600 can fabricate a first feature across one or more showerheads. Method 600 can fabricate a second (i.e., different) feature using the same attachment across one or more components, where the second feature has different specifications than the first feature. For example, the second feature can have a smaller specified dimension than the first feature and can be fabricated using an attachment that is slightly worn after fabricating the first feature. Alternatively, the second feature can include a modification to the first feature, such as adding a conical tip to a cylindrical through-hole.

[0117] In method 600, at 602, one or more showerheads are placed on a tool (e.g., tool 506 shown in FIG. 5 ) having a cutting attachment (e.g., attachment 508 shown in FIG. 5 ). At 604, method 600 selects first selected features of the plurality of features to be machined within a first tolerance range of a specified dimension for the plurality of features. At 606, method 600 selects second selected features of the plurality of features that are spaced at least a predetermined distance apart and that are machined within a second tolerance range of a specified dimension for the plurality of features. The first tolerance range is smaller than the second tolerance range (i.e., the second tolerance range is a larger tolerance range, and the first tolerance range is a smaller subrange described above). Thus, if there is no or only minor wear on the cutting attachment, features with tighter tolerances are produced first.

[0118] For example, a first selected feature and a second selected feature may be located on one of the showerheads. The first selected feature and the second selected feature may be the same. If the first selected feature and the second selected feature are different, the second selected feature may require different specifications than the first selected feature. The first selected feature and the second selected feature may be located on multiple showerheads and fabricated in parallel. For example, all of the first selected features may be fabricated on all of the showerheads first, and then all of the second selected features may be fabricated on all of the showerheads.

[0119] At 608, method 600 uses the cutting attachment to machine a first selected feature of the plurality of features within a first tolerance range. At 610, method 600 determines whether wear on the cutting attachment has reached a predetermined wear threshold. For example, method 600 estimates wear on the cutting attachment based on at least one of the machining time the cutting attachment is used on the tool, the number of features cut using the cutting attachment, and sensed wear on the cutting attachment. At 608, method 600 continues machining the first selected feature within the first tolerance range until wear on the cutting attachment reaches the predetermined wear threshold. At 612, once wear on the cutting attachment has reached the predetermined wear threshold, method 600 uses the cutting attachment to machine a second selected feature of the plurality of features within a second tolerance range.

[0120] At 614, method 600 determines whether the wear on the cutting attachment has reached a second wear threshold at which the cutting attachment is unable to produce features according to the specifications of the first method. At 616, method 600 continues to produce features using the same cutting attachment until the wear on the cutting attachment reaches the second wear threshold. At 618, method 600 stops using the cutting attachment when the wear on the cutting attachment reaches the second wear threshold, and method 600 replaces (i.e., replaces) the cutting attachment when the wear on the cutting attachment reaches the second wear threshold. In this manner, method 600 can replace the cutting attachment after machining a predetermined number of features of the showerhead using the same cutting attachment. In other words, method 600 can produce a predetermined number of features of the showerhead without replacing the cutting attachment.

[0121] Additionally, as described above, method 600 can add smaller features of corresponding specifications while using the same but slightly worn attachment. For example, before machining the first and second selected features as described above, method 600 can additionally select a third selected feature of the second plurality of features to be machined within a third tolerance range of a second specified dimension for the second plurality of features. Method 600 can select a fourth selected feature of the second plurality of features spaced at least a second predetermined distance apart and to be machined within a fourth tolerance range of the second specified dimension, the third tolerance range being smaller than the fourth tolerance range.

[0122] After or while machining the first and second selected features as described above, method 600 can machine a third selected feature within a third tolerance range using the same cutting attachment. When wear on the cutting attachment reaches a second predetermined wear threshold, method 600 can machine a fourth selected feature within a fourth tolerance range using the same cutting attachment.

[0123] The third and fourth selected features are different from the first and second selected features. For example, the third and fourth selected features can include smaller features or modifications to the first and second selected features. The third and fourth selected features have different specifications than the first and second selected features according to the first method. The second specified dimensions for the third and fourth features are different from the specified dimensions for the first and second selected features. The third and fourth tolerance ranges are different from the first and second tolerance ranges. The second predetermined distance is different from the predetermined distance. The first, second, third, and fourth selected features can be located on one showerhead. Alternatively, the first, second, third, and fourth selected features can be located on multiple showerheads and fabricated in parallel as described above.

[0124] In some embodiments, depending on the specifications, method 600 can machine a third selected feature after machining a first selected feature and before machining a second selected feature. Alternatively, method 600 can machine the third and fourth selected features after machining the first selected feature and before machining the second selected feature. Alternatively, method 600 can machine the third and fourth selected features after machining the second selected feature.

[0125] In one example, a showerhead fabricated using method 600 includes a stem portion for connecting to a processing chamber and a base portion extending from the stem portion and including a plurality of features for introducing gases into the processing chamber (see, e.g., FIG. 1 and corresponding description). A first feature of the plurality of features fabricated using method 600 has a dimension within a first tolerance range of a specified dimension for the plurality of features. A second feature of the plurality of features fabricated using method 600 has a dimension within a second tolerance range of the specified dimension, the first tolerance range being smaller than the second tolerance range. Furthermore, the second feature has a dimension not within the first tolerance range (i.e., the dimension is out of range) and is spaced at least a predetermined distance apart.

[0126] In some examples, the plurality of features comprises through holes and the dimension comprises a diameter of the through holes. In some examples, the plurality of features comprises more than N hundred features, where N is an integer greater than 1. In some examples, the plurality of features comprises more than N thousand features, where N is an integer greater than 1.

[0127] FIG. 7 illustrates a method 700 that a manufacturer can use to fabricate features on a component, such as a showerhead, according to the specifications of the second (statistical) method of the present disclosure. Method 700 can be performed using system 500 shown in FIG. 5. Using tool 506 and attachment 508 (e.g., a cutting attachment, described below), method 700 can fabricate features on one component at a time or on multiple components simultaneously. Additionally, method 700 can fabricate a first feature across one or more showerheads. Method 700 can fabricate a second (i.e., different) feature using the same attachment across one or more components, where the second feature has different specifications than the first feature. For example, the second feature can have a smaller specified dimension than the first feature and can be fabricated using an attachment that is slightly worn after fabricating the first feature. Alternatively, the second feature can include a modification to the first feature, such as adding a conical tip to a cylindrical through-hole.

[0128] In method 700, at 702, one or more showerheads are placed on a tool (e.g., tool 506 shown in FIG. 5 ) having a cutting attachment (e.g., attachment 508 shown in FIG. 5 ). At 604, method 600 selects first selected features of the plurality of features to be machined within a predetermined tolerance range of a specified dimension for the plurality of features. At 606, method 600 selects second selected features of the plurality of features to be machined within a predetermined tolerance range of a specified dimension for the plurality of features that are interspersed among the first selected features.

[0129] For example, a first selected feature and a second selected feature can be located on one of the showerheads. The first selected feature and the second selected feature can be the same. If the first selected feature and the second selected feature are different, the second selected feature requires different specifications than the first selected feature. The first selected feature and the second selected feature can be located on multiple showerheads and fabricated in parallel. For example, all of the first selected features can be fabricated on all of the showerheads first, and then all of the second selected features can be fabricated on all of the showerheads.

[0130] At 708, method 700 uses the cutting attachment to machine a first selected feature of the plurality of features within a predetermined tolerance range. At 710, method 700 determines whether wear on the cutting attachment has reached a predetermined wear threshold. For example, method 700 estimates wear on the cutting attachment based on at least one of the machining time the cutting attachment is used on the tool, the number of features cut using the cutting attachment, and the sensed cutting attachment wear. At 708, method 700 continues machining the first selected feature within the predetermined tolerance range until wear on the cutting attachment reaches the predetermined wear threshold. At 712, once wear on the cutting attachment has reached the predetermined wear threshold, method 700 uses the cutting attachment to machine a second selected feature of the plurality of features within the predetermined tolerance range.

[0131] Method 700 machines the first and second selected features such that, after machining, not only are the first and second features within a predetermined tolerance range, but also the average value of the dimensions of the first and second selected features is no more than a predetermined average deviation from the specified dimension, and the standard deviation of the dimensions of the first and second selected features is no more than a predetermined standard deviation. In this way, the dimensions of the first and second selected features meet all three criteria of the second method.

[0132] At 714, method 700 determines whether the wear on the cutting attachment has reached a second wear threshold at which the cutting attachment is unable to produce features according to the specifications of the second method. At 716, method 700 continues to produce features using the same cutting attachment until the wear on the cutting attachment reaches the second wear threshold. At 718, method 700 stops using the cutting attachment when the wear on the cutting attachment reaches the second wear threshold, and method 700 replaces (i.e., replaces) the cutting attachment when the wear on the cutting attachment reaches the second wear threshold. In this manner, method 700 can replace the cutting attachment after machining a predetermined number of features of the showerhead using the same cutting attachment. In other words, method 700 can produce a predetermined number of features of the showerhead without replacing the cutting attachment.

[0133] In one example, a showerhead fabricated using method 700 includes a stem portion for connecting to a processing chamber and a base portion extending from the stem portion and including a plurality of features for introducing gases into the processing chamber (see, e.g., FIG. 1 and corresponding description). A first feature of the plurality of features fabricated using method 700 has a dimension within a predetermined tolerance range of a specified dimension for the plurality of features. A second feature of the plurality of features fabricated using method 700 has a smaller dimension than the first feature, is interspersed among the first features, and has a dimension within the predetermined tolerance range. The first and second features are fabricated using method 700 not only to have the same predetermined tolerance range, but also such that the average value of the dimensions of the first and second features is no more than a predetermined average deviation from the specified dimension and the standard deviation of the dimensions of the first and second features is no more than a predetermined standard deviation.

[0134] In some examples, the plurality of features comprises through holes and the dimension comprises a diameter of the through holes. In some examples, the plurality of features comprises more than N hundred features, where N is an integer greater than 1. In some examples, the plurality of features comprises more than N thousand features, where N is an integer greater than 1.

[0135] The foregoing description is merely exemplary in nature and is not intended to limit the disclosure, its application, or uses. The broad teachings of the present disclosure can be embodied in a variety of forms. Accordingly, while the present disclosure includes specific examples, the true scope of the disclosure should not be so limited, as other variations will become apparent from a study of the drawings, the specification, and the following claims.

[0136] It should be understood that one or more steps within a method may be performed in a different order (or simultaneously) without altering the principles of the present disclosure. Furthermore, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the present disclosure can be implemented in and / or combined with any feature of any other embodiment, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and it is within the scope of the present disclosure to interchange one or more embodiments.

[0137] Spatial and functional relationships between elements (e.g., modules, circuit elements, semiconductor layers, etc.) are described using various terms, such as "connected," "engaged," "coupled," "adjacent," "next to," "on," "above," "below," and "disposed." Unless expressly described as "direct," when a relationship between a first and second element is described in the above disclosure, the relationship may be a direct relationship, with no other intervening elements present between the first and second elements, but may also be an indirect relationship, with one or more intervening elements (spatial or functional) present between the first and second elements. As used herein, the phrase "at least one of A, B, and C" should be interpreted to mean a logical (A or B or C) with a non-exclusive logical OR, and not to mean "at least one of A, at least one of B, and at least one of C."

[0138] In some embodiments, the controller is part of a system, which may be part of the examples described above. Such a system may include semiconductor processing equipment, including one or more processing tools, one or more chambers, one or more processing platforms, and / or specific processing components (e.g., pedestals, gas flow systems, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of semiconductor wafers or substrates. The electronics, sometimes referred to as a "controller," may control various components or sub-parts of one or more systems.

[0139] The controller may be programmed to control any of the processes disclosed herein, including process gas delivery, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, liquid delivery settings, position and motion settings, wafer loading and unloading into the tool, and wafer loading and unloading into other transport tools and / or load locks connected or interfaced with the particular system, depending on the processing requirements and / or type of system.

[0140] Broadly speaking, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receives instructions, issues instructions, controls operations, enables cleaning operations, enables endpoint measurements, etc. Integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software).

[0141] The program instructions may be instructions communicated to the controller in the form of various individual settings (or program files) that define operational parameters for performing a particular process on, for, or for a semiconductor wafer or system. The operational parameters, in some embodiments, may be part of a recipe defined by a process engineer to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of the wafer.

[0142] The controller, in some embodiments, may be part of or connected to a computer that is integrated into the system, connected to the system, or otherwise networked to the system, or a combination thereof. For example, the controller may be all or part of a "cloud," or fab host computer system, which allows remote access of wafer processing. The computer may allow remote access to the system to monitor the current progress of a manufacturing operation, examine the history of past manufacturing operations, examine trends or performance criteria from multiple manufacturing operations, change parameters of a current process, set processing steps to track a current process, or initiate a new process.

[0143] In some examples, a remote computer (e.g., a server) can provide the process recipe to the system over a network, which may include a local network or the Internet. The remote computer may include a user interface that allows for entry or programming of parameters and / or settings, which are then communicated from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed and the type of tool the controller is configured to interface with or control.

[0144] Thus, as described above, the controller may be distributed, such as by including one or more individual controllers networked together and operating toward a common purpose, such as the processes and controls described herein. One example of a distributed controller for such purposes is one or more integrated circuits on the chamber that are located remotely (e.g., at the platform level or as part of a remote computer) and communicate with one or more integrated circuits that cooperatively control the processes in the chamber.

[0145] Examples of systems may include, but are not limited to, a plasma etch chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing system that may be associated with or used in the fabrication and / or manufacturing of semiconductor wafers.

[0146] As described above, depending on one or more process steps being performed by the tool, the controller may communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools located throughout the factory, a main computer, another controller, or tools used to transport materials to and from tool locations and / or load ports of wafers within a semiconductor fabrication factory.

Claims

1. 1. A method of manufacturing a showerhead for a substrate processing system, comprising: placing one or more of the showerheads on a tool including a cutting attachment; selecting a first selected feature of the plurality of features to be machined within a first tolerance range of a specified dimension for the plurality of features; selecting second selected features of the plurality of features spaced at least a predetermined distance apart and machined within a second tolerance range of the specified dimension for the plurality of features; using the cutting attachment to machine the first selected feature of the plurality of features within the first tolerance range; and machining the second selected feature of the plurality of features within the second tolerance range using the cutting attachment when a parameter associated with the tool that causes a dimensional variation of the first selected feature reaches a predetermined threshold. Equipped with the first tolerance range is smaller than the second tolerance range; method.

2. 10. The method of claim 1, wherein the parameters include wear of the cutting attachment, a temperature of the cutting attachment, a temperature of the tool, or the one or more temperatures of the showerhead being machined.

3. 2. The method of claim 1 , wherein the parameter includes wear on the cutting attachment, the method further comprising estimating the wear on the cutting attachment based on at least one of a machining time that the cutting attachment is used on the tool, a number of features cut using the cutting attachment, and sensed wear on the cutting attachment.

4. 10. The method of claim 1, wherein the first selected feature and the second selected feature are disposed in one or more of the showerheads.

5. 2. The method of claim 1, wherein the parameter includes wear on the cutting attachment, the method further comprising replacing the cutting attachment of the tool when the cutting attachment reaches a second predetermined threshold greater than the predetermined threshold.

6. 10. The method of claim 1, further comprising replacing the cutting attachment of the tool after machining a predetermined number of the showerheads using the cutting attachment.

7. The method of claim 1 further comprises: selecting a third selected feature of the second plurality of features that is machined within a third tolerance range of a second specified dimension for the second plurality of features; selecting fourth selected features of the second plurality of features spaced apart by at least a second predetermined distance and machined within a fourth tolerance range of the second specified dimension; using the cutting attachment to machine the third selected feature within the third tolerance range; and machining the fourth selected feature within the fourth tolerance range using the cutting attachment when the parameter reaches a second predetermined threshold. Equipped with the third tolerance range is smaller than the fourth tolerance range; method.

8. 8. The method of claim 7, the third selected feature and the fourth selected feature are different from the first selected feature and the second selected feature; the second specified dimension is different from the specified dimension; the third tolerance range and the fourth tolerance range are different from the first tolerance range and the second tolerance range; and the second predetermined distance is different from the predetermined distance; method.

9. 8. The method of claim 7, wherein the first selected feature, the second selected feature, the third selected feature, and the fourth selected feature are disposed on one of the showerheads.

10. 8. The method of claim 7, wherein the first selected feature, the second selected feature, the third selected feature, and the fourth selected feature are disposed on a plurality of the showerheads.

11. 8. The method of claim 7, further comprising machining the third selected feature after machining the first selected feature and before machining the second selected feature.

12. 8. The method of claim 7, wherein the third selected feature and the fourth selected feature modify the first selected feature and the second selected feature.

13. 8. The method of claim 7, further comprising machining the third selected feature and the fourth selected feature after machining the first selected feature and before machining the second selected feature.

14. 8. The method of claim 7, further comprising machining the third selected feature and the fourth selected feature after machining the second selected feature.

15. 1. A method of manufacturing a showerhead for a substrate processing system, comprising: placing one or more of the showerheads on a tool including a cutting attachment; selecting a first selected feature of the plurality of features to be machined within a predetermined tolerance range of a specified dimension for the plurality of features; selecting second selected features of the plurality of features interspersed among the first selected features and machined within the predetermined tolerance range of the specified dimension for the plurality of features; machining the first selected feature within the predetermined tolerance range using the cutting attachment; and machining the second selected feature within the predetermined tolerance range using the cutting attachment when a parameter associated with the tool that causes a dimensional variation of the first selected feature reaches a predetermined threshold. Equipped with an average dimension of the first selected feature and the second selected feature is less than or equal to a predetermined average deviation from the specified dimension; and a standard deviation of the dimensions of the first selected feature and the second selected feature is less than or equal to a predetermined standard deviation; method.

16. 16. The method of claim 15, wherein the parameter comprises wear of the cutting attachment, a temperature of the cutting attachment, a temperature of the tool, or a temperature of the one or more showerheads being machined.

17. 16. The method of claim 15, wherein the parameter includes wear on the cutting attachment, the method further including estimating the wear on the cutting attachment based on at least one of a machining time that the cutting attachment is used on the tool, a number of features cut using the cutting attachment, and sensed wear on the cutting attachment.

18. 16. The method of claim 15, wherein the first selected feature and the second selected feature are disposed in one or more of the showerheads.

19. 16. The method of claim 15, wherein the parameter includes wear on the cutting attachment, the method further comprising replacing the cutting attachment of the tool when the cutting attachment reaches a second predetermined threshold greater than the predetermined threshold.

20. 16. The method of claim 15, further comprising replacing the cutting attachment of the tool after machining a predetermined number of the showerheads using the cutting attachment.

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