A metrology machine

Abstract

The application provides a measuring machine, which comprises a bearing table for bearing a wafer, a measuring arm arranged above the bearing table, a probe arranged on the measuring arm and comprising a base and a plurality of probes arranged on the base, and a force sensor arranged on the bearing table, wherein the probe is configured to be able to pierce the force sensor, and the force sensor is configured to be able to measure the pressure exerted by each probe on the probe when the probe pierces the force sensor. The force sensor is arranged on the bearing table, and when the probe pierces the force sensor, the force sensor can measure the pressure exerted by each probe on the probe, and then the balance state of the probe can be accurately and efficiently detected based on the measured pressure exerted by each probe.

Description

Technical Field

[0001] This application relates to the field of semiconductor measurement technology, and more specifically to a measurement instrument. Background Technology

[0002] Wafer parameters are typically measured using a metrology equipment, which includes a stage and probes. The wafer is placed on the stage, and the probes include multiple probes. Wafer parameters are measured by bringing the probes on the probes into contact with the wafer.

[0003] One of the key parameters affecting the measurement results is the leveling state of the probe, that is, whether the probe and the stage are parallel to each other (when the wafer is placed on the stage, the probe and the stage being parallel means that the probe and the wafer are parallel). If the probe and the stage are not kept parallel to each other during measurement, it is easy to cause abnormal measurement results.

[0004] Therefore, detecting the balance state of the probe is particularly important. However, it is difficult to accurately and efficiently detect the balance state of the probe in related technologies.

[0005] Therefore, improvements are needed to at least partially address the aforementioned problems. Utility Model Content

[0006] The utility model description section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This utility model description section is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0007] To address the existing problems, this application provides a measuring machine, comprising:

[0008] A support platform is used to support wafers;

[0009] A measuring arm is positioned above the support platform;

[0010] A probe assembly, disposed on the measuring arm, includes a base and a plurality of probes disposed on the base;

[0011] A force sensor is mounted on the support platform;

[0012] The probe is configured to pierce the force sensor, and the force sensor is configured to measure the pressure applied by each probe on the probe assembly when the probe pierces the force sensor.

[0013] For example, the force sensor includes multiple sensing elements, conversion elements and measurement circuits, wherein when the probe is attached to the force sensor, each probe is attached to one of the sensing elements.

[0014] For example, a display is also included.

[0015] For example, the sensing elements are configured to be fixed so that the spacing between the sensing elements is not adjustable; or,

[0016] The sensitive elements are configured to be movable so that the spacing between the sensitive elements is adjustable.

[0017] For example, it also includes a drive unit disposed on the measuring arm, the drive unit being configured to drive the probe to move in a vertical direction, wherein the drive unit includes a cylinder.

[0018] For example, the support platform is configured to rotate about its axis and move in a horizontal direction.

[0019] Exemplarily, it also includes a connector, through which the drive element and the probe element are connected.

[0020] For example, the support stage includes a central region for supporting the wafer and an edge region surrounding the central region, and the force sensor is disposed in the edge region.

[0021] For example, the plurality of probes and the plurality of sensitive elements are arranged at equal intervals along a straight line, and the spacing between adjacent sensitive elements is equal to the spacing between adjacent probes.

[0022] For example, the force sensor includes a resistance strain gauge type force sensor.

[0023] The measuring machine in this embodiment of the application has a force sensor on the support platform. When the probe is inserted into the force sensor, the force sensor can measure the pressure applied by each probe on the probe piece, and then accurately and efficiently detect the balance state of the probe piece based on the measured pressure applied by each probe. Attached Figure Description

[0024] The following drawings, which are incorporated herein by reference and are used to understand this application, illustrate embodiments of the invention and their descriptions, thereby explaining the apparatus and principles of the invention.

[0025] In the attached image:

[0026] Figure 1 A schematic diagram of a measuring machine according to a specific embodiment of this application is shown;

[0027] Figure 2 A partially enlarged schematic diagram of a measuring instrument according to a specific embodiment of this application is shown;

[0028] Figure 3 A top view schematic diagram of a measuring machine according to a specific embodiment of this application is shown;

[0029] Figure 4 The image shows a front view of a measuring machine tool according to a specific embodiment of this application, with the probe striking the force sensor.

[0030] Figure 5 A side view of a measuring machine tool according to a specific embodiment of this application is shown when the probe is inserted into a force sensor.

[0031] Figure 6 A schematic diagram of a probe and a force sensor according to a specific embodiment of this application is shown.

[0032] Explanation of reference numerals in the attached figures:

[0033] 110-Landing stage, 120-Measuring arm, 130-Probe component, 131-Base, 132-Probe, 140-Force sensor, 141-Sensitive element, 142-Conversion element, 150-Driver component, 160-Connector component. Detailed Implementation

[0034] In the following description, numerous specific details are set forth to provide a more thorough understanding of this application. However, it will be apparent to those skilled in the art that this application can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described to avoid confusion with this application. It should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of this application to those skilled in the art. In the accompanying drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated. The same reference numerals denote the same elements throughout.

[0035] It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or parts, these elements, components, areas, layers, and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or part from another element, component, area, layer, or part. Therefore, without departing from the teachings of this application, the first element, component, area, layer, or part discussed below may be referred to as the second element, component, area, layer, or part.

[0036] Spatial relation terms such as "below," "under," "below," "under," "above," and "above" are used here for convenience to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of devices in use and operation.

[0037] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “including,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0038] Embodiments of the utility model are described herein with reference to cross-sectional views that serve as schematic diagrams of preferred embodiments (and intermediate structures) of this application. Thus, variations in the shown shape can be anticipated due to, for example, manufacturing techniques and / or tolerances. Therefore, embodiments of this application should not be limited to the specific shapes shown herein, but include shape deviations due to, for example, manufacturing processes. Consequently, the figures are substantially schematic, and their shapes are not intended to show the actual shape of the device and are not intended to limit the scope of this application.

[0039] Sheet resistance (RS) is an important parameter of wafers. It is generally measured using a specialized measurement equipment (such as an RS measurement equipment). The measurement equipment includes a stage and probes. The wafer is placed on the stage, and the probes include multiple probes. When measuring sheet resistance, the sheet resistance is measured by contacting the probes on the probes with the wafer.

[0040] As the film thickness in wafers becomes increasingly thinner, the requirements for measurement equipment in sheet resistance measurement are also becoming more stringent. One key parameter affecting the measurement results is the leveling state of the probes, specifically whether the probes and the stage are parallel to each other (if the probes and stage are parallel, then the wafer is parallel to each other). If the probes and stage are not kept parallel during measurement, abnormal measurement results are likely to occur.

[0041] Taking the four-probe measurement method (also known as the Kelvin four-terminal method) for measuring sheet resistance as an example, the probe assembly includes four probes, which can be set at equal intervals along a straight line (e.g., the distance between adjacent probes is S). When the balance of the probe assembly is poor (i.e., the probe assembly and the stage are not parallel to each other), when it is pressed onto the wafer, the pressure applied to the wafer by the four probes is different, and the distance between the actual points where adjacent probes are pressed onto the wafer will also change (i.e., the distance between the actual points where adjacent probes are pressed onto the wafer is not equal to S), thus leading to measurement abnormalities. Therefore, it is necessary to check the balance of the probe assembly before the formal measurement.

[0042] In related technologies, the balance of the probe is generally detected by the following method: the original probe is removed and a knife-edge ruler is installed in the original probe position. A piece of white paper is placed on the back of the knife-edge ruler and the knife-edge ruler is illuminated. The balance of the knife-edge ruler is judged by observing the light on the white paper through the gap between the knife-edge ruler and the wafer with the naked eye, thereby characterizing the balance of the probe.

[0043] However, the above solution requires removing the original probe and installing a knife-edge ruler. Inevitably, human manipulation variables and mechanical errors will be introduced in this process, and interference factors will also be introduced when observing with the naked eye, making it difficult to accurately detect the balance state of the probe.

[0044] Alternatively, the following method is used in related technologies to detect the balance of the probe: after the probe is attached to the wafer, the wafer is placed on an optical microscope (OM) instrument. The probe marks on the wafer are observed through the lens of the OM instrument to determine the balance of the probe. When the probe marks on the wafer are consistent, it means that the balance of the probe is good. When the probe marks on the wafer are inconsistent, it means that the balance of the probe is poor.

[0045] However, the above method will damage the wafer, and the steps are complicated and require the use of an OM machine, which increases the cost. In addition, human error will inevitably be introduced when observing the state of the probe marks on the wafer, making it difficult to accurately detect the balance state of the probe.

[0046] Therefore, in view of the aforementioned technical problems, this application proposes a measuring machine, comprising:

[0047] A support platform is used to support wafers;

[0048] The measuring arm is positioned above the support platform;

[0049] A probe assembly, mounted on a measuring arm, includes a base and multiple probes mounted on the base;

[0050] Force sensors are mounted on the support platform;

[0051] The probe is configured to be able to pierce the force sensor, and the force sensor is configured to measure the pressure applied by each probe on the probe assembly when the probe pierces the force sensor.

[0052] The measuring machine in this embodiment of the application has a force sensor on the support platform. When the probe is inserted into the force sensor, the force sensor can measure the pressure applied by each probe on the probe piece, and then accurately and efficiently detect the balance state of the probe piece based on the measured pressure applied by each probe.

[0053] Below, for reference Figures 1 to 6 The measuring machine of this application is described in detail, wherein, Figure 1 A schematic diagram of a measuring machine according to a specific embodiment of this application is shown. Figure 2 This paper shows a partially enlarged schematic diagram of a measuring machine according to a specific embodiment of this application. Figure 3 The diagram shows a top view of a measuring machine according to a specific embodiment of this application. Figure 4 This is a front view of a measuring machine's probe when it strikes a force sensor, according to a specific embodiment of this application. Figure 5 This paper shows a side view of a measuring machine tool according to a specific embodiment of the present application, in which the probe is inserted into the force sensor. Figure 6 A schematic diagram of a probe and a force sensor according to a specific embodiment of this application is shown.

[0054] In one example, such as Figures 1 to 6 As shown, the measurement equipment includes a platform 110, a measurement arm 120, probes 130, and a force sensor 140. The platform 110 supports the wafer; the measurement arm 120 is positioned above the platform 110; the probes 130 are mounted on the measurement arm 120, each probe including a base 131 and a plurality of probes 132 mounted on the base 131; and the force sensor 140 is mounted on the platform 110. The probes 132 are configured to engage with the force sensor 140, and the force sensor 140 is configured to measure the pressure applied by each probe 132 when the probes engage with it. Exemplarily, the measurement arm 120 is vertically positioned above the platform 110, and the platform 110 is horizontally positioned. For example, the probe element 130 being disposed on the measurement arm 120 means that the probe element 130 can be directly disposed on the measurement arm 120, or the probe element 130 can be indirectly disposed on the measurement arm 120 through other components. For example, the probe element 130 is movably disposed on the measurement arm 120, that is, the probe element 130 can move relative to the measurement arm 120.

[0055] In one example, the balance of probe 130 is detected by measuring the pressure applied by each probe 132 on probe 130. When probe 130 is found to be in good balance, probes can be inserted onto the wafer to measure parameters such as sheet resistance. When probe 130 is found to be in poor balance, the balance of probe 130 is adjusted and its balance is detected again until probe 130 is in good balance.

[0056] Specifically, when the pressure applied by each probe 132 measured by the force sensor 140 is equal, it means that the probe 130 is in a horizontal state. At this time, the probe 130 is parallel to the support stage 110, that is, the probe 130 is parallel to the wafer on the support stage 110. At this time, the probe 130 has a good balance state.

[0057] When the pressure applied by each probe 132 as measured by the force sensor 140 is unequal, it indicates that the probe 130 is not in a horizontal state. At this time, the probe 130 is not parallel to the support stage 110, that is, the probe 130 is not parallel to the wafer on the support stage 110, and the balance of the probe 130 is poor. In this case, the probe 130 tilts towards the side where the probe 132 with greater pressure is located.

[0058] In this way, the introduction of human manipulation variables and mechanical errors can be avoided, and the repeated disassembly and assembly of probe 130 is not required. Based on the pressure applied by each probe 132, the balance state of probe 130 can be accurately and efficiently detected, thereby providing correct guidance for subsequent adjustment of the balance state of probe 130.

[0059] In one example, such as Figure 1 and Figure 5 As shown, the measurement arm 120 also includes a drive member 150 disposed on the measuring arm 120. The drive member 150 is configured to drive the probe member 130 to move vertically, thereby causing the probe 132 on the probe member 130 to move vertically. Exemplarily, the drive member 150 is disposed at the end of the measuring arm 120 near the support stage 110. Exemplarily, the drive member 150 includes a cylinder; alternatively, the drive member 150 may be any other suitable element capable of driving the probe member 130 to move, and this application does not limit this to any particular type.

[0060] In one example, the support platform 110 is configured to rotate about its axis and move horizontally. Thus, through the cooperation of the support platform 110 and the drive member 150, the probe 132 can be positioned onto the force sensor 140. For example, by first rotating and horizontally moving the support platform 110, the force sensor 140 is moved below the probe 130 and positioned corresponding to the probe. At this time, the drive member 150 drives the probe 130 to move vertically downwards so that the probe 132 is positioned onto the force sensor 140. The force sensor 140 can measure the pressure exerted by each probe 132 on itself, thereby measuring the balance state of the probe 130 based on the pressure exerted by each probe 132.

[0061] In one example, after the probe 130 is detected to be in a good balanced state, the drive unit 150 drives the probe 130 to move vertically upward away from the force sensor 140, and then moves the support stage 110 to move the wafer below the probe 130. When the wafer moves below the probe 130, the drive unit 150 drives the probe 130 to move vertically downward so that the probe 132 is inserted into the wafer to measure parameters such as sheet resistance.

[0062] In one example, such as Figure 5 As shown, it also includes a connector 160, through which the drive member 150 and the probe member 130 are connected. Exemplarily, the connector 160 may include, but is not limited to, components such as clips, inserts, etc.

[0063] In one example, as a setting method, such as Figure 5 As shown, the probe 130 is disposed on the connector 160, and the drive 150 is connected to the connector 160. The drive 150 is disposed on the measuring arm 120, and the probe 130 is indirectly disposed on the measuring arm 120 through the connector 160 and the drive 150. The drive 150 can drive the connector 160 to move vertically, thereby causing the probe 130 to move vertically. In other embodiments, other suitable arrangements may be used, and this application does not limit them.

[0064] In one example, the stage 110 includes a central region for supporting the wafer and an edge region surrounding the central region. A force sensor 140 is disposed in the edge region, so that the balance state of the probe 130 can be detected without affecting the subsequent measurement of the sheet resistance of the wafer.

[0065] In one example, such as Figure 6As shown, the force sensor 140 includes multiple sensing elements 141, conversion elements 142, and a measurement circuit. When a probe 132 is inserted into the force sensor 140, each probe 132 is inserted into one sensing element 141. The sensing element 141 is configured to deform under the pressure of the probe 132. The conversion element 142 is configured to convert the deformation of each sensing element into a change in an electrical physical quantity (e.g., resistance, capacitance) and output it to the measurement circuit. The measurement circuit is configured to process the electrical physical quantity output by the conversion element 142 and output an electrical signal. Exemplarily, it may include one or more conversion elements 142 and one or more measurement circuits. When multiple conversion elements 142 and multiple measurement circuits are included, the sensing elements 141, conversion elements 142, and measurement circuits are arranged in a one-to-one correspondence. Alternatively, the sensing elements 141, conversion elements 142, and measurement circuits may also be arranged in any other suitable manner, which is not limited in this application.

[0066] In one example, the sensing element 141 can be an elastic diaphragm that can deform under the pressure of the probe 132 to convert the pressure signal into the deformation of the elastic diaphragm.

[0067] In one example, the force sensor 140 includes a resistance strain gauge type force sensor, where the conversion element 142 is a strain gauge. This strain gauge can be positioned below the sensing element 141. When the sensing element 141 deforms, the resistance of the strain gauge changes accordingly, converting the deformation of the sensing element 141 into a change in the strain gauge resistance; that is, the pressure signal is now converted into a change in the strain gauge resistance. In other embodiments, the force sensor 140 can be any suitable other sensor type, for example, a piezoelectric sensor, in which case the conversion element 142 is made of a piezoelectric material.

[0068] In one example, the measurement circuit includes, but is not limited to, amplifying, filtering, linearizing, and other processing of the electrical physical quantity output by the conversion element 142 to output an electrical signal. For example, taking the conversion element 142 as a strain gauge, the measurement circuit may include a Wheatstone bridge, which can convert the resistance change of the strain gauge into a voltage signal for output.

[0069] In one example, a display is also included, configured to display electrical signals output by the measuring circuit, such as voltage signals; or, the display is configured to display the pressure applied by each probe 132 to the sensing element 141. Exemplarily, the display may be independent of or integrated into the force sensor 140. The display has a display interface that visually displays the electrical signals output by the measuring circuit or the pressure applied by each probe to the sensing element 141, thereby facilitating user detection of the balance state of the probes 130.

[0070] When the display is configured to display the electrical signal output by the measurement circuit, the pressure applied by each probe 132 to the sensitive element 141 can be obtained based on the electrical signal displayed on the display and the correspondence between the electrical signal and the pressure applied by the probe 132 to the sensitive element 141 (e.g., the calibration formula of the voltage signal and the pressure applied by the probe 132 to the sensitive element 141), thereby detecting the balance state of the probe 130.

[0071] When the display is configured to display the pressure applied by each probe 132 to the sensitive element 141, it may further include a processor for calculating the pressure applied by each probe 132 to the sensitive element 141 based on the electrical signal output from the measurement circuit and outputting the calculation to the display. Exemplarily, the processor may be integrated into the display, or the processor may be independently configured and integrated into the force sensor, or the processor may be independent of the force sensor. Exemplarily, one or more processors and one or more displays may be included.

[0072] In one example, the processor can be implemented as software, hardware, firmware, or any combination thereof, and can use one or more application-specific integrated circuits (ASICs), one or more general-purpose integrated circuits, one or more microprocessors, one or more programmable logic devices, or any combination of the foregoing circuits and / or devices, or other suitable circuits or devices.

[0073] In one example, the sensing element 141 is configured to be fixed so that the spacing between the sensing elements 141 is not adjustable; or, the sensing element 141 is configured to be movable so that the spacing between the sensing elements 141 is adjustable. When the sensing element 141 is configured to be movable, the spacing between the sensing elements 141 can be adjusted manually or by means of an additional drive.

[0074] In one example, multiple probes 132 and multiple sensing elements 141 are arranged at equal intervals along a straight line, wherein the number of sensing elements 141 may be greater than or equal to the number of probes 132. For example, as shown... Figure 6 As shown, the probe 130 includes four probes 132, and the force sensor 140 includes four sensing elements 141.

[0075] In one example, the spacing between adjacent sensing elements 141 is equal to the spacing between adjacent probes 132. This allows the spacing between sensing elements 141 in the force sensor 140 to be designed based on the spacing between probes 132 on the probe element 130, preventing measurement failures due to inappropriate spacing between sensing elements 141. Exemplarily, the sensing element 141 is cylindrical, and its diameter is equal to the diameter of the probe. Exemplarily, the spacing between adjacent sensing elements 141 is 1 mm, 1.59 mm, or 0.635 mm.

[0076] This concludes the introduction to the structure of the measuring machine of this application. A complete measuring machine may also include other components, which will not be described in detail here.

[0077] In summary, the measuring machine of this application embodiment has a force sensor on the support platform. When the probe is inserted into the force sensor, the force sensor can measure the pressure applied by each probe on the probe piece, and thus can accurately and efficiently detect the balance state of the probe piece based on the measured pressure applied by each probe.

[0078] Although exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above exemplary embodiments are merely illustrative and are not intended to limit the scope of this application. Various changes and modifications can be made therein by those skilled in the art without departing from the scope and spirit of this application. All such changes and modifications are intended to be included within the scope of this application as claimed in the appended claims.

[0079] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of this application may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0080] Similarly, it should be understood that, in order to streamline this application and aid in understanding one or more of the various aspects of the invention, features of this application may sometimes be grouped together in a single embodiment, figure, or description thereof in the description of exemplary embodiments of this application. However, this approach should not be construed as reflecting an intention that the claimed application requires more features than are expressly recited in each claim. Rather, as reflected in the corresponding claims, the inventive point lies in solving the corresponding technical problem with fewer features than all of those in a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of this application.

[0081] Those skilled in the art will understand that, apart from the mutual exclusion of features, all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or elements of any method or apparatus so disclosed can be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature serving the same, equivalent, or similar purpose.

[0082] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features but not others included in other embodiments, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

[0083] It should be noted that the above embodiments are illustrative of this application and not restrictive of this application, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims.

Claims

1. A measuring machine, characterized in that, include: A support platform is used to support wafers; A measuring arm is positioned above the support platform; A probe assembly, disposed on the measuring arm, includes a base and a plurality of probes disposed on the base; A force sensor is mounted on the support platform; The probe is configured to pierce the force sensor, and the force sensor is configured to measure the pressure applied by each probe on the probe assembly when the probe pierces the force sensor.

2. The measuring machine according to claim 1, characterized in that, The force sensor includes multiple sensitive elements, conversion elements, and measurement circuits, wherein when the probe is attached to the force sensor, each probe is attached to one of the sensitive elements.

3. The measuring machine according to claim 2, characterized in that, It also includes the display.

4. The measuring machine according to claim 2, characterized in that, The sensing elements are configured to be fixed, so that the spacing between the sensing elements is not adjustable; or... The sensitive elements are configured to be movable so that the spacing between the sensitive elements is adjustable.

5. The measuring machine according to claim 1, characterized in that, It also includes a drive unit disposed on the measuring arm, the drive unit being configured to drive the probe to move in a vertical direction, wherein the drive unit includes a cylinder.

6. The measuring machine according to claim 5, characterized in that, The support platform is configured to rotate about its axis and move horizontally.

7. The measuring machine according to claim 5, characterized in that, It also includes a connector, through which the drive element and the probe element are connected.

8. The measuring machine according to claim 1, characterized in that, The support platform includes a central region for supporting the wafer and an edge region surrounding the central region, and the force sensor is disposed in the edge region.

9. The measuring machine according to claim 2, characterized in that, The multiple probes and multiple sensitive elements are arranged at equal intervals along a straight line, and the distance between adjacent sensitive elements is equal to the distance between adjacent probes.

10. The measuring machine according to any one of claims 1-9, characterized in that, The force sensor includes a resistance strain gauge type force sensor.

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