Showerhead grouping features in a substrate processing system

Abstract

The method includes selecting a first feature to be machined within a first tolerance range and a second feature spaced at least a predetermined distance apart to be machined within a second tolerance range of a specified dimension for the selected feature. The method includes using a cutting attachment of a tool to machine the first feature within the first tolerance range and, when a parameter associated with the tool that causes a dimensional variation of the first selected feature reaches a predetermined threshold, using the cutting attachment to machine the second selected feature within the second tolerance range. In the second method, an average value of the dimensions of the first and second features is no more than a predetermined average deviation from the specified dimension, and a standard deviation of the dimensions of the first and second features is no more than a predetermined standard deviation.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of U.S. Provisional Application No. 63 / 017,582, filed Apr. 29, 2020, and U.S. Provisional Application No. 63 / 022,137, filed May 8, 2020. The entire disclosures of these applications are incorporated herein by reference.

[0002] This disclosure generally relates to substrate processing systems, and more particularly to showerhead grouping features in substrate processing systems.

Background Art

[0003] The description of the background art provided herein is for the purpose of generally presenting the context of the present disclosure. The research by the inventors named at the present time, to the extent within the scope described in this background art section, cannot be regarded as prior art at the time of filing, whether explicitly or implicitly, in the same way as aspects of the description that cannot be regarded as prior art against the present disclosure.

[0004] Substrate processing systems typically include a plurality of processing chambers (also referred to as process modules) for performing deposition, etching, and other processes on substrates such as semiconductor wafers. Examples of processes that can be performed on a substrate include, but are not limited to, plasma - enhanced chemical vapor deposition (PECVD), catalytic - enhanced plasma vapor deposition (CEPVD), sputter physical vapor deposition (PVD), atomic layer deposition (ALD), and plasma - enhanced ALD (PEALD). Further examples of processes that can 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, the substrate is placed on a substrate support assembly such as a pedestal or an electrostatic chuck (ESC) disposed within the processing chamber of the substrate processing system. The robot typically transports the substrate from one processing chamber to another in the order in which the substrates are to be processed. During deposition, a gas mixture containing one or more precursors is introduced into the processing chamber and plasma is collided to activate a chemical reaction. During etching, a gas mixture containing an etching gas is introduced into the processing chamber and plasma is collided to activate a chemical reaction. The processing chamber is periodically cleaned by supplying a cleaning gas into the processing chamber and colliding plasma.

SUMMARY OF THE INVENTION

[0006] A method of 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 a plurality of features that is 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 that is disposed at least a predetermined distance apart and is 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 using the cutting attachment when a parameter associated with a tool that causes variation in the dimension of the first selected feature reaches a predetermined threshold.

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

[0008] In other aspects, the parameter includes wear of the cutting attachment, and the method further includes estimating the wear of the cutting attachment based on at least one of machining time during which the cutting attachment is used on the tool, the number of features cut using the cutting attachment, and the perceived wear of the cutting attachment.

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

[0010] In another aspect, 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 other aspects, the parameter includes wear of the cutting attachment, and the method further includes replacing the cutting attachment of the tool when the cutting attachment reaches a second predetermined threshold that is greater than a predetermined threshold.

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

[0014] In other aspects, the method further includes selecting a third selected feature of the second plurality of features that is machined within a third tolerance range of a second defined dimension. The method further includes selecting a fourth selected feature of the second plurality of features that is disposed at least a second predetermined distance apart and is machined within a fourth tolerance range of the second defined 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 the cutting attachment when a 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 defined dimension is different from the defined dimension. 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.

[0016] In another aspect, the first, second, third, and fourth selected features are disposed on 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 the third selected feature after machining the first selected feature and before machining the second selected feature.

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

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

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

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

[0023] In another aspect, the parameter includes wear of the cutting attachment, temperature of the cutting attachment, temperature of the tool, or temperature of one or more showerheads being machined.

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

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

[0026] In another aspect, 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 on a plurality of showerheads.

[0028] In other aspects, the parameter includes wear of the cutting attachment, and the method further includes replacing the cutting attachment of the tool when the cutting attachment reaches a second predetermined threshold that is greater than a predetermined threshold.

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

[0030] In yet another aspect, the showerhead includes a stem portion for connecting to the processing chamber and a base portion extending from the stem portion and including a plurality of features for introducing gas 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 not within the first tolerance range and is disposed at least a predetermined distance apart. The first tolerance range is smaller than the second tolerance range.

[0031] In other aspects, the plurality of features includes through-holes, and the dimension includes the diameter of the through-holes.

[0032] In another aspect, the plurality of features includes more than N hundred features, where N is an integer greater than 1.

[0033] In another aspect, the plurality of features includes more than N thousand features, where N is an integer greater than 1.

[0034] In yet another aspect, the 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 gas into the processing chamber. A first one of the plurality of features has a dimension within a predetermined tolerance range of a specified dimension for the plurality of features. A second one 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. The average value of the dimensions of the first and second features is below a predetermined average deviation from the specified dimension. The standard deviation of the dimensions of the first and second features is below a predetermined standard deviation.

[0035] In other aspects, the plurality of features includes through-holes, and the dimension includes the diameter of the through-holes.

[0036] In another aspect, the plurality of features includes more than N hundred features, where N is an integer greater than 1.

[0037] In another aspect, the plurality of features includes more than N thousand features, where N is an integer greater than 1.

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

Brief Description of the Drawings

[0039] This disclosure will be more fully understood from the detailed description and the accompanying drawings.

[0040]

Figure 1

[0041]

Figure 2A

Figure 2B

Figure 2C

[0042]

Figure 3A

Figure 3B

Figure 3C

Figure 3D

Figure 3E

Figure 3F

Figure 3G

[0043]

Figure 3H

[0044]

Figure 4A

Figure 4B

[0045]

Figure 4C

Figure 4D

Figure 4E

Figure 4F

Figure 4G

Figure 4H

[0046]

Figure 4I

[0047]

Figure 5

[0048]

Figure 6

[0049]

Figure 7

[0050] In the drawings, reference numerals may be reused to identify similar and / or identical elements.

DETAILED DESCRIPTION OF THE INVENTION

[0051] A gas distribution device commonly referred to as a showerhead is used to introduce one or more gases, such as process gas, purge gas, or cleaning gas, into a processing chamber. FIGS. 1 and the description of FIG. 1 provided below provide an example of a substrate processing system including a processing chamber having a showerhead. The showerhead includes an inlet for receiving one or more gases from a gas distribution system and features such as a number of outlets or 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 according to the application (e.g., process) used in the processing chamber. Examples of dimensions include the size of the feature (e.g., diameter or perimeter length), the distribution / density of the features (e.g., the number of features per square inch), etc. Examples of geometric shapes include the shape of the feature (e.g., circular, cylindrical, conical, polygonal, etc.).

[0052] Showerheads are typically composed of metals such as aluminum. Showerheads can also be composed of alloy or ceramic materials. The features of the showerhead are manufactured using tools with attachments such as cutters or drill bits of a specific size. The attachment begins to wear after perforating a certain number of features (for example, after manufacturing the features of several showerheads). Continuing to use a worn attachment will produce features that do not conform to the specifications.

[0053] When non-conforming features are produced in clusters, the thickness of the substrate being processed, which is processed using a process that is very susceptible to the density of non-conforming features, can become non-uniform due to the clustering of non-conforming features. To avoid the clustering of non-conforming features, some manufacturers follow a prescribed order, arrangement, or pattern of feature production, but this can be a burden. Alternatively, the manufacturer must frequently replace attachments such as cutters or drill bits (for example, after manufacturing the features of one or two showerheads), which is costly.

[0054] The present disclosure provides two methods for avoiding the clustering of non-conforming features and allowing the manufacturer to use worn attachments to a certain extent. These methods can be used to manufacture components without frequently replacing attachments and to verify whether the manufactured components conform to the specifications. The first method uses or prescribes two criteria. The first criterion is a sub-range smaller than a larger tolerance range, and the second criterion is a minimum distance rule. All dimensions of the features of the showerhead must be within the larger tolerance range. In addition, most, if not all, of the dimensions of the features must also be within a smaller sub-range of the larger tolerance range. Further, if the dimensions of some of the features are not within the smaller sub-range (i.e., out of range), each of these features must be at least a predetermined distance away from the other of these features.

[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 separated from the others of the N features by at least a predetermined distance D (referred to as the minimum distance rule). That is, the first of the N features must be separated from the rest of the N features by at least distance D, the second of the N features must be separated from the rest of the N features by at least distance D, and so on.

[0056] By employing the 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 instead of following a particular drilling pattern or sequence as long as the manufactured features meet the sub-range and the minimum distance rule.

[0057] The second method according to the present disclosure defines statistically-based feature tolerances in components having a sufficiently large or statistically significant population of process-critical features, rather than conventional pass / fail methods. The statistics can include the diameter, position, and pattern distribution of a given feature. A component (e.g., a showerhead) passes an inspection regarding the size (e.g., diameter) of a feature if the following three statistical requirements (the requirements and definitions of statistical terms are described in detail below) are met. First, the diameter of the feature does not exceed a cutoff tolerance range t, second, the population mean does not exceed the maximum mean deviation D T and third, the standard deviation (SD) of the population does not exceed SD max . The manufacturing order of the features of the indicated large population is randomized by the manufacturer in order to evenly distribute any form of tool wear, thermal effects, and / or other step-dependent effects across the feature population. Once the manufacturing order is empirically optimized and it is verified that features conforming to the three statistical requirements for the component are produced, that order is repeatedly used to manufacture a predetermined quantity of the component.

[0058] The second method also allows the manufacturer to use worn attachments as long as the features produced using the worn attachments meet the three statistical requirements of the second method. Further, the second method allows the manufacturer to produce features in any empirically tested method instead of following a specified drilling pattern or order as long as the features produced 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 the present disclosure, the showerhead is used only as an example of a component manufactured using the first and second methods to illustrate the teachings of the present disclosure. The present teachings are not limited to showerheads. Further, the present teachings are not limited to components of semiconductor manufacturing equipment. Rather, the present teachings are applicable to any component having a statically significant (i.e., sufficiently large) population of one or more features.

[0060] The present disclosure is configured as follows. First, an example of a processing chamber capable of using a showerhead manufactured in accordance with the present disclosure is shown and described with reference to FIG. 1. Thereafter, an example of the showerhead and its features is shown and described with reference to FIGS. 2A-2C. Thereafter, the first method is described with reference to FIGS. 3A-3H, and the second method is described with reference to FIGS. 4A-4I. Finally, a block diagram of a system capable of manufacturing components using the first and second methods is shown and described with reference to FIG. 5.

[0061] FIG. 1 shows an example of a substrate processing system 100 including a processing chamber 102 configured to generate capacitively coupled plasma. This example is described in the context of plasma-enhanced chemical vapor deposition (PECVD), but the teachings of the present disclosure are also 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 other components of the substrate processing system 100 and includes an RF plasma (when used). The processing chamber 102 includes an upper electrode 104 and an electrostatic chuck (ESC) 106 or other type of substrate support. During operation, the substrate 108 is placed on the ESC 106.

[0063] For example, the upper electrode 104 may include a gas distribution device 110 such as a showerhead that introduces and distributes a process gas into the processing chamber 102. The gas distribution device 110 may include a stem portion including one end connected to the upper surface of the processing chamber 102. The base of the showerhead is generally cylindrical and extends radially outward from the end opposite the stem portion at a position spaced from the upper surface of the processing chamber 102. The substrate facing surface or faceplate of the base of the showerhead includes a plurality of outlets or features (e.g., slots or through holes) through which the vaporized precursor, process gas, cleaning gas, or purge gas flows.

[0064] The ESC 106 includes a base plate 112 that functions as a lower electrode. The base plate 112 supports a heating plate 114, and the heating plate 114 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 a coolant through the base plate 112.

[0065] When 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 non-grounded. For example, the RF generation system 120 may include an RF generator 122 that generates RF power supplied to the upper electrode 104 or the base plate 112 by a matching / distribution network 124. In another example, although not shown, the plasma may be generated inductively or remotely and then supplied to the processing chamber 102.

[0066] The gas delivery system 130 includes one or more gas sources 132-1, 132-2, … 132-N (collectively gas source 132), where N is an integer greater than 0. The gas source 132 is connected to the 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). The vapor delivery system 142 supplies the vaporized precursor to the manifold 140 connected to the processing chamber 102 or another manifold (not shown). The output of the manifold 140 is supplied to the processing chamber 102. The gas source 132 may supply a process gas, a cleaning gas, or a purge gas.

[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 communicate with the 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. The valves 156 and the pump 158 may be used to discharge reactants from the processing chamber 102. The system controller 160 controls the components of the substrate processing system 100.

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

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

[0070] The base 204 of the showerhead assembly 200 is generally cylindrical and extends radially outward from the opposite end of the stem portion 202 at a position spaced from the upper surface of the processing chamber. The 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. The vaporized precursor, process gas, cleaning gas, or purge gas from the inlet flows into the processing chamber through the features 212.

[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 a plurality of sets of features. For example, a first set of features having a first size and a first shape may be disposed at 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 at 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 features 212-1, and the second set includes features 212-2. Both features 212-1 and 212-2 are circular, but feature 212-1 has a larger diameter than feature 212-2.

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

[0073] However, in some examples, each of the first set of features 212-1 and the second set of features 212-2 may 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 is applicable for each of the first set of features 212-1 and the second set of features 212-2 with separate specifications regarding subranges and minimum distances.

[0074] In other words, some showerheads (or generally components) 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 manufactured in a quantity F1. The second set may include a second feature having a second size (e.g., diameter) D2 and may be manufactured in a quantity F2. The first and second features may be manufactured in separate regions of the showerhead or may be dispersed in one or more regions of the showerhead (e.g., as shown in FIG. 2C. However, both F1 and F2 may be statistically significant). D1 may be larger than, smaller 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 values of the subrange and minimum distance for the second feature may differ from those of the first feature depending on their size, quantity, and location.

[0075] Here, a first method including the subrange and minimum distance rules will be described in more detail with reference to FIGS. 3A - 3H. Current showerhead specifications control feature size using a relatively large tolerance range. A large tolerance range is desirable for efficient manufacturability and competitive cost of the showerhead, but a large tolerance range has an adverse effect on a highly flow - sensitive process. This is because the specification does not include constraints to control the clustering of features of the same size within the large tolerance range, which can be a problem for a sensitive process. As a result, the current specification regarding feature size results in thickness non - uniformity on the substrate due to the clustering of features of similar size compared to the remaining features of the showerhead.

[0076] According to the first method, the grouping of features is controlled to ensure that features above or below the feature size range do not cluster together at any position on the showerhead. This control is designed to ensure that a sensitive process is not affected by variations in feature size within the allowable tolerance range. Features of sizes outside the specified tolerance range are manufactured at least a predetermined distance apart from other similar features of sizes outside the specified range. This method ensures that similar-sized features of sizes exceeding the allowable tolerance range are not manufactured in a clustered pattern. The first method maintains a larger tolerance range for the overall feature size and uses additional smaller sub-ranges along with the minimum distance rule to ensure that a large population of features is within the acceptable feature size and that features outside the range (referred to as outliers) do not cluster together to form a pattern. In this way, the first method ensures a uniform distribution of features on the showerhead. The current specification can form a random pattern of similar-sized features within the tolerance range, but the first method enables the manufacture of features with the same tolerance range but with the addition of control of sub-ranges and the minimum distance rule.

[0077] Figures 3A - 3H show how the first method can be used to manufacture a showerhead applying sub-ranges and the minimum distance rule, and to qualify or disqualify a showerhead manufactured applying sub-ranges and the minimum distance rule. Figures 3A - 3G show various examples of applying sub-ranges and the minimum distance rule to a set of features (e.g., the first set of features 212-1 shown in Figure 2B). These figures show histograms of the feature sizes of showerheads manufactured using the first method. In these figures, a showerhead having 3931 features of a specified diameter is used as an example. For example, the showerhead used in these figures may be similar to the showerhead assembly 200 shown in Figure 2A, where the first set of features 212-1 is equal to 3931.

[0078] All dimensions (e.g., diameter) 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 sub-range) 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 sub-range, but the value of the sub-range used in these figures is 0.0005 inches (0.0127 mm). Further, when the dimensions of N of the 3931 features are not within the sub-range (i.e., outside the sub-range), N = 3931 - M and N ≧ 2, and each of the N features must be separated from the others of the N features by at least a distance D (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, the diameters of all 3,931 features are 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. Further, the diameters of all 3,931 features fit within five different ranges (bins) of 0.0001 inches (0.00254 mm) each. Thus, the diameters of all features are within a specified sub-range (indicated by two vertical dotted lines) of 0.0005 inches in this example. Thus, the showerhead assembly in this example is acceptable under the first method (i.e., manufactured according to the tolerance and sub-range specifications). Conversely, the manufacturer may continue to use a previously used drill bit that is thought to have previously manufactured features with a more uniform diameter than those shown in this example, as long as the manufacturer can manufacture a showerhead assembly having feature sizes as shown in this example.

[0080] In FIG. 3B, in a second example of a showerhead assembly manufactured according to the first method, the diameters of all 3,931 features are 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. Further, the diameters of all 3,931 features fit within five different ranges (bins) of 0.0001 inches each. Thus, the diameters of all features are within a specified sub-range (indicated by two vertical dotted lines) of 0.0005 inches in this example. Thus, the showerhead assembly in this example is also acceptable under the first method (i.e., manufactured according to the tolerance and sub-range specifications). Conversely, the manufacturer may continue to use a previously used drill bit that is thought to have previously manufactured features with a more uniform diameter than those shown in this example, as long as the manufacturer can manufacture a showerhead assembly having feature sizes as shown in this example.

[0081] In FIGS. 3C and 3D, in a third example of a showerhead assembly manufactured according to the first method, the diameters of all 3931 features are within a first tolerance range, which in this example is 0.04 inches ± 0.001 inches, and 0.04 inches is the specified nominal diameter. Further, the diameters of all but two features identified as 250 and 252 out of the 3931 features 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 the specified sub-range (indicated by two vertical dotted lines) that is within 0.0005 inches of the specified nominal diameter in this example, so they are called outliers 250, 252. That is, the difference between the specified nominal diameter and the diameter of each of the two outliers 250, 252 is greater than the specified sub-range of 0.0005 inches in this example. 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 shown in FIG. 3D, the two outliers 250, 252 are separated from each other by at least 1 inch (25.4 mm), which is the minimum required distance between features that are not within the specified sub-range in this example. Thus, the showerhead assembly in this example is acceptable according to the first method (i.e., manufactured in accordance with the tolerances and minimum distance rules specifications). Conversely, the manufacturer may continue to use the previously used drill bit that presumably previously manufactured features with a more uniform diameter than those shown in this example, as long as the manufacturer can manufacture a showerhead assembly having feature sizes as shown in this example.

[0083] In FIG. 3E, in a fourth example of a showerhead assembly manufactured according to the first method, all 3931 features have diameters within a first tolerance range, which in this example is 0.04 inches ± 0.001 inches, where 0.04 inches is the nominal diameter. Further, all 3931 feature diameters fall within five different ranges (bins) of 0.0001 inches each. Thus, all feature diameters are within a specified sub-range (indicated by two vertical dotted lines) of 0.0005 inches in this example. Thus, the showerhead assembly in this example is also acceptable under the first method (i.e., manufactured in accordance with the tolerance and sub-range specifications). Conversely, the manufacturer may continue to use the previously used drill bit that is thought to have previously manufactured features with a more uniform diameter than those shown in this example, as long as the manufacturer can manufacture a showerhead assembly with feature sizes as shown in this example.

[0084] In FIGS. 3F and 3G, in a fifth example of a showerhead assembly manufactured according to the first method, all 3931 features have diameters within a first tolerance range, which in this example is 0.04 inches ± 0.001 inches, where 0.04 inches is the nominal diameter. However, 26 diameters identified at 260 and 262 out of the 3931 features are not within the specified sub-range (indicated by two vertical dotted lines) that is within 0.0005 inches of the nominal diameter in this example, and are thus called outliers 260, 262. That is, the difference between the nominal diameter and each of the diameters of outliers 260, 262 is greater than the specified sub-range of 0.0005 inches in this example. Thus, the diameters of outliers 260, 262 are within the first tolerance range, but the diameters of outliers 260, 262 are not within the specified sub-range.

[0085] Furthermore, as shown at 270 in FIG. 3G, at least some of the outliers 250, 252 are not separated from each other by at least 1 inch, which is the required minimum distance between features that are not within the defined subrange in this example. Thus, although manufactured according to the first tolerance range, the showerhead assembly in this example is unacceptable because it fails to meet the specification of the subrange minimum distance rule of the first method.

[0086] FIG. 3H shows a first method (identified at 300) of manufacturing and / or qualifying a showerhead using subranges 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 defined nominal diameter). If the sizes of all features are not within the first tolerance range, the first method 300 ends 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, at 306, determines whether the sizes of two or more features are outside a second tolerance range (i.e., a subrange; e.g., 0.0005 inches of the defined nominal diameter). If the sizes of two or more features are not outside the second tolerance range, the first method 300 ends at 308 and the component is permitted at 308. If the sizes of two or more features are outside the second tolerance range, the first method 300, at 310, determines whether two or more features are separated by a predetermined minimum distance (e.g., at least 1 inch). If two or more features are separated by the predetermined minimum distance, the first method 300 ends at 308 and the component is permitted at 308. If 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 is available to the manufacturer to produce components that comply with subrange and minimum distance specifications and to qualify the components produced. For example, the manufacturer can monitor the wear of the drill bit during manufacturing and / or variations in feature dimensions (e.g., the diameter / geometric shape of the feature). For example, the manufacturer can use metrology tools, coordinate measuring machines (CMMs), and optical probes, or other techniques to inspect the features after drilling and measure the size of the features. When these features are measured, the measured data can be analyzed to determine whether the features meet the criteria of the subrange and minimum distance specifications. Based on the data analysis, the 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 subrange and minimum distance specifications. For example, the manufacturer can determine that up to 4 shower heads (i.e., approximately 16,000 features in total) can be produced using the same drill bit. The manufacturer may determine and use its own drilling pattern to drill all approximately 4000 features on the shower head. For example, the drilling sequence may be divided into multiple zones on the shower head. The manufacturer can freely choose the drilling pattern / sequence / drill bit wear life. Regardless of the choice, the features produced are measured to confirm that the feature size meets the specifications.

[0088] Here, a second method of defining the three statistical conditions described above will be described with reference to FIGS. 4A-4I. The feature size (e.g., diameter) of a component (e.g., a showerhead) is typically defined by a symmetric plus / minus tolerance range, similar to 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 can deviate from a normal distribution is relatively high. Considering machining capabilities, tool dispersion, material variations, and other factors, the tolerance range of features becomes much wider than that in the case of a relatively small number of features in order to prevent a high defect rate of components during manufacturing inspection. Considering more stringent process control requirements, the conventional tolerance scheme for features has become outdated. A second method of manufacturing a component having a statistically significant population of features is designed to take into account more stringent tolerance constraints while considering manufacturing variations.

[0089] Manufacturing a large population of features using a single tool attachment (e.g., a cutter) can induce a 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, and as a result, the features manufactured last in the sequence will deviate from the first features. When drilling thousands of features, the drill bit wears over time and creates the last features with sizes smaller than expected compared to the first features. When manufacturing a large number of features, the best approach is to develop a random machining sequence for the features in order to distribute the wear across the entire set of features. As a result, a physical averaging of the features is obtained. According to the second method, a component passes an inspection regarding feature size if the following three statistical requirements or specifications of the second method are met. First, the feature diameter does not exceed a cutoff tolerance range t. Second, the population mean does not exceed a maximum mean deviation D T and third, the standard deviation of the population does not exceed SD maxnot exceeding

[0090] Figures 4A and 4B show a table including symbols and descriptions of statistical parameters used in Figures 4C - 4H to explain a second method. Throughout the explanation of the second method, the diameters of the showerhead and its features are used only as examples. The diameter is the cross-sectional width of a circular feature that can be measured by applicable measurement techniques (e.g., CMM, optical, etc.).

[0091] In Figure 4A, the first table shows the statistical parameters used to explain and constrain the variance between features of the diameter. These statistical parameters represent boundary constraints for the feature population and not for individual features. The symbol T represents the nominal target size (e.g., nominal diameter) of the feature and describes the target average value of the diameters of all features together with the target population mean. The symbol t represents a cutoff tolerance range defined by a numerical value with plus and minus. The cutoff tolerance range t is the distance from the nominal target size T that no feature can exceed or the component is rejected. The symbol D T represents the maximum average deviation from the nominal target size T with respect to the average value of the entire feature population. The maximum average deviation D T is the bounding window of the population mean and is defined by a numerical value with plus and minus. The maximum average deviation D T defines the range for the entire population defined within the feature pattern and not for any single feature. The symbol SD max represents the maximum standard deviation. The maximum standard deviation SD max is the maximum allowable standard deviation of the entire feature pattern calculated after inspection and measurement of all features.

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

[0093] Using these statistical parameters, the feature size can be defined in the following format. For example, the diameter of a feature such as a through hole on a shower head (e.g., feature 212 - 1 of the shower head assembly 200 shown in Figures 2A - 2C) can be defined as follows. 3894X0.040±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 SD max is.

[0094] Figures 4C - 4H show histograms of the feature sizes of showerheads manufactured using the second method. In each of Figures 4C - 4H, an overlay of a distribution curve fitting the showerhead data is used to visualize the statistical parameters. Next, the criteria of the second method are applied to determine whether the features meet the 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 based on the population mean, respectively. Figures 4E and 4F show examples of acceptable and unacceptable feature populations based on the standard deviation, respectively. Figures 4G and 4H show examples of acceptable and unacceptable feature populations based on outliers, respectively.

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

[0097] In Figures 4C and 4D, for the feature population to meet the population mean criterion of the second method (i.e., the population mean does not exceed the maximum mean deviation D T the population mean μ needs to be within the UD t and LD t boundaries. In the example shown in Figure 4C, since the population mean μ is within the UD t and LD t boundaries, the feature population meets the population mean criterion of the second method (i.e., the population mean does not exceed the maximum mean deviation D T Furthermore, the feature size does not exceed the cutoff tolerance range, and the standard deviation of the feature population is SD maxThe other two criteria of the second method, including not exceeding, are also met. Therefore, the showerhead in the example shown in FIG. 4C meets all three criteria of the second method and is thus within the tolerance range.

[0098] In the example shown in FIG. 4D, the feature population has a population mean μ that is outside the UD t and LD t boundaries, so it fails the population mean criterion of the second method (i.e., the population mean is too large and exceeds the maximum mean deviation D T ). Therefore, the showerhead in the example shown in FIG. 4D meets the other two criteria of the second method, including that the feature size does not exceed the cutoff tolerance range and the standard deviation of the feature population does not exceed SD max , but since it fails the population mean criterion of the second method, it is unacceptable.

[0099] In FIGS. 4E and 4F, the standard deviation SD max , which is the maximum allowable population standard deviation, controls the spread of the features. In the example shown in FIG. 4E, the feature population meets the standard deviation criterion of the second method (i.e., the population standard deviation does not exceed SD max ). Further, the other two criteria of the second method, including that the size of the feature does not exceed the cutoff tolerance range and the population mean does not exceed the maximum mean deviation D T , are also met. Therefore, the showerhead in the example shown in FIG. 4E meets all three criteria of the second method and is thus acceptable.

[0100] In the example shown in FIG. 4F, the feature population has a standard deviation larger than the defined SD max , so it fails the standard deviation criterion of the second method. Therefore, the showerhead in the example shown in FIG. 4F meets the other two criteria of the second method, including that the feature size does not exceed the cutoff tolerance range and the population mean does not exceed the maximum mean deviation D T , but since the showerhead fails the standard deviation criterion of the second method, it is unacceptable.

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

[0102] In the example shown in FIG. 4H, the outlier 352 has a feature size that exceeds the 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). Thus, the showerhead in the example shown in FIG. 4H meets the other two criteria of the second method including that the standard deviation of the feature population does not exceed SD max and the population mean does not exceed the maximum mean deviation D T but is unacceptable because the showerhead fails the cutoff tolerance range criteria of the second method. Since a single outlier exceeds the USL, the showerhead in the example shown in FIG. 4H is unacceptable even though both the mean and the standard deviation are within the specifications of the second method.

[0103] Note that the criteria maximum mean deviation D T of the second method is the same as the subrange specification of the first method. Further, since the size of the outlier 352 exceeds the larger tolerance range band of the first method, the first method would also reject the showerhead in the example shown in FIG. 4H. However, if the outlier is outside the subrange but meets the minimum distance rule, the first method would permit the showerhead.

[0104] Figure 4I shows a second method (identified by 400) of manufacturing and / or qualifying a showerhead using statistical conditions. At 402, the second method 400 determines whether the feature population meets a first condition, i.e., whether the mean of the population of features of a component such as a showerhead exceeds the maximum mean deviation D T of the population. If the population mean exceeds D T , the component is rejected at 404.

[0105] If the population mean does not exceed D T , at 406, the second method 400 determines whether the feature population meets a second condition, i.e., whether the standard deviation of the population of features of the component exceeds the maximum standard deviation SD max of the population. If the standard deviation of the population exceeds SD max , the component is rejected at 404.

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

[0107] The second method can be used not only for a manufacturer to produce components that comply with three statistical conditions but also to qualify the manufactured components. For example, the manufacturer can monitor the wear of a drill bit during manufacturing and / or the variation in feature dimensions (e.g., the diameter / geometric shape of a feature). For example, the manufacturer can use a metrology tool, a coordinate measuring machine (CMM), and an optical probe, or other technologies to inspect the features after drilling and measure the sizes of the features. When these features are measured, the measured data can be analyzed to determine whether the features meet all the criteria of the three statistical conditions of the second method. Based on the data analysis, the 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 criteria of the second method. For example, the manufacturer can determine that up to four shower heads (i.e., a total of approximately 16,000 features) can be manufactured using the same drill bit while meeting the criteria of the second method.

[0108] The manufacturer can randomize the manufacturing order of the features of the indicated large population to evenly distribute any form of tool wear, thermal effects, or other step-dependent effects across the entire feature population. This manufacturing order can be empirically verified and then repeated to produce components that meet the specifications of the second method. The manufacturer can freely select the drilling pattern / order / drill bit wear life. Regardless of the selection, the manufactured features are measured to confirm that the feature sizes meet the specifications of the second method.

[0109] FIG. 5 shows a simplified block diagram of a system that can manufacture features of components 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, manufacturing system 500 includes computer system 502 and tool controller 504 that controls tool 506. Computer system 502 provides code to tool controller 504 for manufacturing features on components 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 secured on table 510 disposed on base 512. Tool 506 includes an attachment 508 (e.g., a drill bit or cutter) coupled to a motor for manufacturing features on the component. Based on the code, tool controller 504 controls the rotational speed of the motor. Tool 506 further includes an actuator (not shown) that can move the motor in the X, Y, and Z directions. Tool controller 504 controls the movement of the motor in the X, Y, and Z directions using X-axis driver 514, Y-axis driver 516, and Z-axis driver 518. Drivers 514, 516, 518 drive their respective actuators to move the motor in the X, Y, and Z directions to the correct position within / on the component to manufacture features according to the specifications.

[0111] In some tools, the component is held in a vertical direction (not the horizontal direction shown), and attachment 514 operates on the component in a horizontal direction (not the vertical direction shown) to manufacture features on the component. In some applications, table 510 can be moved relative to attachment 514. Tool controller 504 controls the movement of table 516 in the X and Y axis directions.

[0112] Feedback system 520 provides feedback regarding the position, speed, etc. of the motor and actuator to tool controller 504. Feedback system 520 includes a position / velocity transducer that monitors / measures the position and velocity of the motor and actuator. Tool controller 504 receives signals from these transducers and generates control signals based on these signals to correct position and velocity errors.

[0113] Furthermore, although not shown, tool 506 may include a lubrication / cooling system that discharges a lubricant / coolant onto workpiece 514, etc. in proximity to attachment 514 during operation. Tool controller 504 can also perform auxiliary control functions such as turning the lubricant / coolant on / off and exchanging attachment 514.

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

[0115] Figures 6 and 7 each show a method that a manufacturer can use to manufacture features of components such as shower heads in accordance with the specifications of the first and second methods of the present disclosure. In Figures 6 and 7, wear of the tool attachment 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 the temperature of the cutting attachment, the temperature of the tool, the temperature of the component being machined, the flow rate of the coolant, the temperature of the coolant, operator error, foreign objects, and the installation, setting, 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 / measurement devices. These parameters can, alone or in any combination, cause variation in feature dimensions. The methods of the present disclosure take these parameters into account and generate features on components that meet the requirements of the specifications of the methods of the present disclosure.

[0116] Figure 6 shows a method 600 that a manufacturer can use to manufacture features of components such as shower heads in accordance with the specifications of the first method of the present disclosure. Method 600 can be executed using the system 500 shown in Figure 5. Using the tool 506 and the attachment 508 (e.g., a cutting attachment described below), method 600 can manufacture features on one component at a time or on multiple components simultaneously in parallel. Further, method 600 can manufacture a first feature across one or more shower heads. Method 600 can manufacture a second (i.e., different) feature using the same attachment across one or more components, and the second feature has different specifications than the first feature. For example, the second feature can have a defined dimension that is smaller than the first feature and can be manufactured using an attachment that has slightly worn after manufacturing 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 disposed 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 a first selected feature of a plurality of features that are machined within a first tolerance range of specified dimensions for the plurality of features. At 606, method 600 selects a second selected feature of the plurality of features that are spaced apart by at least a predetermined distance and are machined within a second tolerance range of specified dimensions 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 sub-range as described above). Thus, if there is no wear or very little wear on the cutting attachment, the feature with the stricter tolerance is manufactured first.

[0118] For example, the first selected feature and the second selected feature are disposed on one of the showerheads. The first selected feature and the second selected feature are the same. If the first selected feature and the second selected feature are different, the second selected feature requires a different specification than the first selected feature. The first selected feature and the second selected feature can be disposed on a plurality of showerheads and manufactured simultaneously in parallel. For example, all of the first selected features can be manufactured first on all of the showerheads, and then all of the second selected features can be manufactured on all of the showerheads.

[0119] At 608, method 600 uses a cutting attachment to machine a first selected feature among a plurality of features within a first tolerance range. At 610, method 600 determines whether the wear of the cutting attachment has reached a predetermined wear threshold. For example, method 600 estimates the wear of 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 perceived wear of the cutting attachment. Method 600 continues to machine the first selected feature within the first tolerance range at 608 until the wear of the cutting attachment reaches the predetermined wear threshold. At 612, when the wear of the cutting attachment reaches the predetermined wear threshold, method 600 uses the cutting attachment to machine a second selected feature among the plurality of features within a second tolerance range.

[0120] At 614, method 600 determines whether the wear of the cutting attachment has reached a second wear threshold at which the cutting attachment can no longer manufacture features according to the specifications of the first method. At 616, method 600 continues to manufacture features using the same cutting attachment until the wear of the cutting attachment reaches the second wear threshold. At 618, method 600 stops using the cutting attachment when the wear of the cutting attachment reaches the second wear threshold, and method 600 replaces (i.e., exchanges) the cutting attachment when the wear of the cutting attachment reaches the second wear threshold. Thus, method 600 can replace the cutting attachment after machining a predetermined number of features of the shower head using the same cutting attachment. In other words, method 600 can manufacture a predetermined number of features of the shower head without replacing the cutting attachment.

[0121] Furthermore, as described above, method 600 can add smaller features of corresponding specifications while using an attachment that is the same but slightly worn. 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 that is machined within a third tolerance range of a second defined dimension for the second plurality of features. Method 600 can select a fourth selected feature of the second plurality of features that is disposed at least a second predetermined distance apart and is machined within a fourth tolerance range of the second defined dimension, and the third tolerance range is smaller than the fourth tolerance range.

[0122] After or while machining the first and second selected features as described above, method 600 can machine the third selected feature within the third tolerance range using the same cutting attachment. When the wear of the cutting attachment reaches a second predetermined wear threshold, method 600 can machine the fourth selected feature within the 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 can include modifications to the first and second selected features. The third and fourth selected features have a different specification from the first and second selected features according to the first method. The second defined dimension for the third and fourth features is different from the defined dimension 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 disposed on one of the shower heads. Alternatively, the first, second, third, and fourth selected features can be disposed on a plurality of shower heads and can be manufactured simultaneously in parallel as described above.

[0124] In some embodiments, depending on the specifications, method 600 can machine a third selected feature 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 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 manufactured 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 gas into the processing chamber (see, for example, FIG. 1 and the corresponding description). The first feature of the plurality of features manufactured using method 600 has dimensions within a first tolerance range of a specified dimension for the plurality of features. The second feature of the plurality of features manufactured using method 600 has dimensions within a second tolerance range of the specified dimension, and the first tolerance range is smaller than the second tolerance range. Further, the second feature has dimensions outside the first tolerance range (i.e., the dimensions are out of range) and is disposed at least a predetermined distance apart.

[0126] In some examples, the plurality of features includes through-holes and the dimensions include the diameters of the through-holes. In some examples, the plurality of features includes more than N hundred features, where N is an integer greater than 1. In some examples, the plurality of features includes more than N thousand features, where N is an integer greater than 1.

[0127] FIG. 7 shows a method 700 that a manufacturer can use to manufacture features of components such as a shower head according to the specifications of a second (statistical) method of the present disclosure. Method 700 can be executed using the system 500 shown in FIG. 5. Using tool 506 and attachment 508 (e.g., a cutting attachment described below), method 700 can manufacture features on one component at a time or on multiple components simultaneously in parallel. Further, method 700 can manufacture a first feature across one or more shower heads. Method 700 can manufacture 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 defined dimension that is smaller than the first feature and can be manufactured using an attachment that has slightly worn after manufacturing 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 shower heads 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 a first selected feature of a plurality of features that are machined within a predetermined tolerance range of defined dimensions for the plurality of features. At 606, method 600 selects a second selected feature of the plurality of features that are machined within a predetermined tolerance range of defined dimensions for the plurality of features, where the second selected feature is interspersed among the first selected features.

[0129] For example, the first selected feature and the second selected feature are disposed on one of the showerheads. The first selected feature and the second selected feature are the same. If the first selected feature and the second selected feature are different, the second selected feature requires a different specification from the first selected feature. The first selected feature and the second selected feature can be disposed on a plurality of showerheads and manufactured simultaneously in parallel. For example, all of the first selected features can be manufactured first on all of the showerheads, and then all of the second selected features can be manufactured on all of the showerheads.

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

[0131] Method 700 machines the first and second selected features such that not only are the first and second features within the predetermined tolerance range after machining, but also the average value of the dimensions of the first and second selected features is below a predetermined average deviation from the specified dimension, and the standard deviation of the dimensions of the first and second selected features is below a predetermined standard deviation. In this way, the dimensions of the first and second selected features satisfy all three criteria of the second method.

[0132] At 714, method 700 determines whether the wear of the cutting attachment has reached a second wear threshold at which the cutting attachment can no longer manufacture features according to the specifications of the second method. At 716, method 700 continues to manufacture features using the same cutting attachment until the wear of the cutting attachment reaches the second wear threshold. At 718, when the wear of the cutting attachment reaches the second wear threshold, method 700 stops using the cutting attachment and method 700 replaces (i.e., exchanges) the cutting attachment when the wear of the cutting attachment reaches the second wear threshold. Thus, 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 manufacture a predetermined number of features of the showerhead without replacing the cutting attachment.

[0133] In one example, a showerhead manufactured 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 gas into the processing chamber (see, for example, FIG. 1 and the corresponding description). A first feature of the plurality of features manufactured using method 700 has dimensions within a predetermined tolerance range of a specified dimension for the plurality of features. A second feature of the plurality of features manufactured using method 700 has dimensions smaller than the first feature, is scattered among the first features, and has dimensions within a predetermined tolerance range. The first and second features are manufactured using method 700 such that not only do they have the same predetermined tolerance range, but also the average value of the dimensions of the first and second features is below a predetermined average deviation from the specified dimension, and the standard deviation of the dimensions of the first and second features is below a predetermined standard deviation.

[0134] In some examples, the plurality of features includes through-holes and the dimension includes the diameter of the through-holes. In some examples, the plurality of features includes more than N hundred features, where N is an integer greater than 1. In some examples, the plurality of features includes 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 present disclosure, its application, or uses. The broad teachings of the present disclosure can be implemented in a variety of forms. Accordingly, while this disclosure includes specific examples, the true scope of the present disclosure should not be so limited since other modifications will become apparent upon 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 executed in a different order (or simultaneously) without changing the principles of the present disclosure. Further, each of the embodiments has been described as having certain features, but any one or more of those features described with respect to any embodiment of the present disclosure may be implemented in and / or combined with any other feature of any other embodiment, even if the 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 with each other.

[0137] The 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 explicitly stated to be "direct", when the relationship between a first and a second element is described in the above disclosure, the relationship can be a direct relationship with no other intervening elements between the first and second elements, but can also be an indirect relationship with one or more intervening elements (spatially or functionally) 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) using non-exclusive logical OR and should not be interpreted 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, and the system can be part of the above examples. Such a system can include a semiconductor processing apparatus including one or more processing tools, one or more chambers, one or more processing platforms, and / or specific processing components (such as pedestals, gas flow systems, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of a semiconductor wafer or substrate. The electronics may be referred to as a "controller" and may control various components or sub-components of one or more systems.

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

[0140] Broadly speaking, the controller can be defined as an electronic device having various integrated circuits, logic, memory, and / or software, such as receiving commands, issuing commands, controlling operations, enabling cleaning operations, and enabling endpoint measurements. The integrated circuit may include a chip in the form of firmware that stores 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 operating parameters for performing a specific process on, for, or to a semiconductor wafer. The operating parameters may, in some embodiments, be part of a recipe defined by a process engineer to achieve one or more processing steps during the manufacture of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0142] In some embodiments, the controller may be part of a computer that is integrated into, connected to, or otherwise network-connected to the system, or may be connected to such a computer. For example, the controller may be part of the "cloud," i.e., all or part of a fab host computer system, which enables remote access to wafer processing. The computer may enable remote access to the system to monitor the current progress of manufacturing operations, investigate the history of past manufacturing operations, investigate trends or performance criteria from multiple manufacturing operations, change the parameters of the current process, set processing steps to track the current process, or initiate a new process.

[0143] In some examples, a remote computer (e.g., a server) can provide process recipes to the system via a network, which may include a local network or the Internet. The remote computer may include a user interface that enables input or programming of parameters and / or settings, and the parameters and / or settings are then transmitted from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specify the parameters for each of the process 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 configured to interface with or be controlled by the controller.

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

[0145] Examples of systems may include, but are not limited to, a plasma etching 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 etching 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 etching (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing system that may be related to or used in the fabrication and / or manufacture of semiconductor wafers.

[0146] As described above, depending on one or more process steps executed by a tool, the controller may communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools disposed throughout the factory, the main computer, another controller, or a tool used for material transfer to carry a wafer container into and out of a tool location and / or load port within a semiconductor manufacturing 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 feature of the plurality of features to be machined within a first tolerance range of a specified dimension for the plurality of features; selecting a second feature 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, the selected first feature and the selected second feature having the same or different dimensions; using the cutting attachment to machine the first selected feature of the plurality of features within the first tolerance range; and machining the selected second 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 selected first 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 selected first feature and the selected second 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 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 a fourth feature of the second plurality of features spaced at least a second predetermined distance apart and machined within a fourth tolerance range of the second specified dimension; using the cutting attachment to machine the selected third feature within the third tolerance range; and machining the selected fourth 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 selected third feature and the selected fourth feature are different from the selected first feature and the selected second 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 selected first feature, the selected second feature, the selected third feature, and the selected fourth feature are disposed in one of the showerheads.

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

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

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

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

14. 8. The method of claim 7, further comprising machining the selected third feature and the selected fourth feature after machining the selected second 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 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 features of the plurality of features interspersed among the selected first features and machined within the predetermined tolerance range of the specified dimension for the plurality of features, the selected first features and the selected second features having the same or different dimensions; machining the selected first feature within the predetermined tolerance range using the cutting attachment; and machining the selected second feature within the predetermined tolerance range using the cutting attachment when a parameter associated with the tool that causes a dimensional variation of the selected first feature reaches a predetermined threshold. Equipped with an average value of a dimension of the selected first feature and the selected second feature is less than or equal to a predetermined average deviation from the specified dimension; and a standard deviation of the dimensions of the selected first feature and the selected second 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 selected first feature and the selected second 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.

Images