A novel gap measuring device and system

Abstract

This invention discloses a novel gap measuring device and system for measuring the gap between a support base and a target conductor component within a vacuum chamber. The device includes a circuit board, electrode components, and a processing module placed on the support base. Both the electrode components and the processing module are electrically connected to the circuit board. The electrode components consist of at least one first electrode plate and at least one second electrode plate, forming a single unit. During operation, the two electrode plates have opposite polarities, forming a capacitor with the target conductor component. The processing module includes a controller and an amplification circuit. The amplification circuit increases the excitation voltage range. The controller obtains the corresponding capacitance value by applying an excitation voltage of the same polarity to the electrode components, and then converts this into target gap data indicating the gap. This invention reduces and eliminates measurement interference by using electrode components with opposite polarities and mutual compensation of different capacitance values. Furthermore, the external battery design facilitates quick replacement or maintenance, reducing downtime due to power failures and offering greater practicality and convenience.

Description

Technical Field

[0001] This application relates to semiconductor integrated circuit manufacturing technology and industrial measurement in the high-end equipment manufacturing industry, and particularly to a novel gap measuring device, and correspondingly to a novel gap measuring system and control method adapted to the novel gap measuring device. Background Technology

[0002] As semiconductor component sizes continue to shrink, advanced semiconductor integrated circuit etching equipment is facing significant challenges in the wafer fabrication etching process. To ensure product consistency and maximum throughput, many critical process steps rely on precise measurement of the gap distance between the substrate or wafer pedestal and the target conductor component, as well as adjustments to the parallelism of the two planes.

[0003] In related technologies, common methods for measuring gaps and parallelism involve using motor drive pulses and lead screw pitch in a machine tool servo system for position calibration and measurement, and then measuring the tilt angle relative to the horizontal position using a level. Building upon this, a method using capacitance principles for distance measurement has emerged, improving measurement accuracy to some extent. In existing technologies, the distance between a wafer substrate or wafer and a target conductor component within a vacuum chamber is typically measured using multiple capacitors. The technical solution involves calculating the distance between the electrodes of one or more capacitors based on their capacitance values, thereby determining the distance between the wafer substrate or wafer and the target conductor component (e.g., the upper surface of the cavity or components on that surface).

[0004] A significant drawback of the existing technology that uses the capacitor principle for measurement is that environmental noise, such as electromagnetic interference and temperature gradients, which may occur within the vacuum chamber, can easily cause common-mode interference to the coplanar electrodes, resulting in capacitance signal drift and affecting measurement accuracy. Therefore, the usual technical solution is to provide interference compensation, such as through algorithms. One technical solution involves setting different electrodes at intervals on the electrode assembly and controlling two electrodes separately to measure different capacitance values. The different capacitance values ​​formed by the spaced electrodes are used to compensate for interference, thus solving the measurement interference problem to some extent. The question remains whether the technical solutions considered by engineers can find even better solutions to resist measurement interference based on existing technologies. Summary of the Invention

[0005] The purpose of this application is to provide a novel gap measuring device for measuring the gap distance between a support base and a target conductor component, minimizing measurement interference. Simultaneously, it allows for battery replacement without disassembling the casing, improving product efficiency.

[0006] To achieve the objectives of this application, the technical solution adopted is as follows: A novel gap measuring device for measuring the gap between a support base and a target conductor component, characterized in that it is placed on a support base inside a vacuum cavity and includes at least: a circuit board 1, an electrode component 2, and a processing module 3. Both the electrode component 2 and the processing module 3 are electrically connected to the circuit board 1. The electrode component 2 is electrically connected to the processing module 3 through the circuit board 1. The electrode component 2 and the target conductor component form a capacitor. The electrode component 2 is composed of at least one first electrode plate 91 and at least one second electrode plate 92 as an integral component. In the working state, the polarities of the first electrode plate 91 and the second electrode plate 92 are opposite. Processing module 3 includes controller 31 and amplifier circuit 32. Amplifier circuit 32 is electrically connected to controller 31. Amplifier circuit 32 is used to increase the range of excitation voltage. Controller is used to apply excitation voltage to electrode component 2 and obtain corresponding capacitance value, which is then converted to obtain target gap data. Target gap data is used to indicate the gap between the carrier base and the target conductor component.

[0007] Preferably, the number of the first electrode plates 91 is greater than or equal to the number of the second electrode plates 92.

[0008] Preferably, the number of first electrode plates 91 is one more than the number of second electrode plates 92.

[0009] Preferably, the first electrode plate 91 is connected to the amplifier circuit 32, and the second electrode plate 92 is connected to the amplifier circuit 32 through a power polarity conversion circuit 93.

[0010] Preferably, the positional relationship between the first electrode plate 91 and the second electrode plate 92 is as follows: - Interval setting; or - The first electrode plate 91 is concentrated in the first region, and the second electrode plate 92 is concentrated in the second region.

[0011] Preferably, the novel gap measuring device further includes a housing 7 and a power supply circuit 8. At least the power supply circuit 8 is disposed on the surface of the housing 7, and the power supply circuit 8 is electrically connected to and supplies power to the electrode component 2 and the processing module 3, respectively.

[0012] Preferably, at least the circuit board 1 is disposed within the housing 7.

[0013] According to another aspect of the present invention, a novel gap measurement system is provided for measuring the gap between a support base and a target conductor component. The system is characterized by including at least the aforementioned novel gap measurement device, and further including a host computer, wherein the novel gap measurement device communicates with the host computer via a wireless communication device.

[0014] This invention provides a solution by incorporating electrode components of different polarities within a single measuring device. When performing gap measurements, it allows for the acquisition of capacitance values ​​with opposite polarities. By compensating for these different capacitance values, measurement interference is reduced or eliminated. Furthermore, by placing the battery externally, the battery can be replaced without disassembling the casing when it ages. This external design facilitates quick replacement and maintenance, reduces downtime due to power failures, and enhances convenience and practicality. Attached Figure Description

[0015] Figure 1 A schematic diagram of the first electrode component and the second electrode component of the gap measuring device of this application is shown in one embodiment.

[0016] Figure 2 A schematic diagram of the structure of the gap measuring device of this application, showing the first electrode component and the second electrode component having different arrangements, is shown.

[0017] Figure 3 A system block diagram of the gap measuring device of this application is shown.

[0018] Figure 4 A diagram showing the connection relationship between the first electrode component and the second electrode component of the gap measuring device of this application is provided. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this application pertains. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, but does not exclude other elements or objects.

[0020] As semiconductor component dimensions continue to shrink, advanced semiconductor integrated circuit etching equipment faces significant challenges in the wafer etching stage of wafer manufacturing. To ensure product consistency and maximum throughput, many critical process steps rely on precise measurement of the gap distance between the substrate or wafer support and the target conductor component, as well as the adjustment of the parallelism between the two planes. A common method for measuring gap and parallelism involves using motor drive pulses and lead screw pitch in the machine's servo system for position calibration and measurement. Specifically, the motor driver in the servo system receives a set pulse value and drives the motor to move until the top of the base connected to the motor is level with the bottom of the target conductor component; this point is recorded as zero. The motor then retracts, and the actual movement distance of the base, i.e., the gap distance between the base and the target conductor component, can be obtained by converting the number of drive pulses and the lead screw pitch. The tilt angle relative to the horizontal position is then measured using a level. However, limitations imposed by the motor drive pulses and lead screw pitch, and the inability to calibrate in a real vacuum environment, result in low measurement accuracy and large errors. As semiconductor component dimensions continue to shrink, even small errors can cause products to fail to meet process requirements.

[0021] This embodiment provides a novel gap measuring device, referring to... Figure 1 It is used to place on a support base inside a vacuum chamber to measure the gap between the support base and the target conductor component. In this embodiment, the target conductor component is an etching gas spray component inside the vacuum chamber.

[0022] Reference Figures 1 to 4 The gap measuring device includes a housing 7, a circuit board 1, an electrode component 2, a processing module 3, and a power circuit 8. The circuit board 1 supports the electrode component 2 and the processing module 3, and the electrode component 2, processing module 3, and power circuit 8 are all electrically connected to the circuit board 1. The integration of the electrode component 2 and processing module 3 onto the circuit board 1 allows the gap measuring device to be used as a single unit, improving its ease of use. When the operator needs to use the gap measuring device for gap measurement, they simply place the device on the support base inside the vacuum chamber and activate it to measure the gap distance between the support base and the etching gas spray component inside the vacuum chamber. After measurement, the operator can adjust the height of the support base to ensure the gap distance between the support base and the etching gas spray component inside the vacuum chamber meets the standard. After adjustment, the gap measuring device can be moved for subsequent substrate or wafer processing.

[0023] The electrode component 2 is electrically connected to the processing module 3 via the circuit board 1. The processing module 3 includes a controller 31, specifically, the electrode component 2 is electrically connected to the controller 31. Simultaneously, the power supply circuit 8 is electrically connected to both the electrode component 2 and the processing module 3. Specifically, the power supply circuit 8 is connected to the controller 31, thereby providing power to the controller 31. This allows the controller 31 to control the power supply circuit 8 to energize the electrode component 2, thus forming a capacitor between the electrode component 2 and the etching gas spray component within the vacuum chamber. The controller 31 obtains the capacitance value by applying an excitation voltage to the electrode component 2 and calculates the gap value between the support base and the target conductor component based on the capacitance value. The specific calculation formula under vacuum conditions is as follows: d is the gap distance between the carrier base and the target conductor component, is the relative permittivity between the carrier base and the target conductor component, S is the area between the carrier base and the target conductor component, is pi, k is the electrostatic constant, and C is the capacitance between the carrier base and the target conductor component. The target gap data is obtained by processing the gap value.

[0024] Furthermore, as those skilled in the art will recognize, in a preferred embodiment, the present invention also provides a transmission module (not shown in the figure) electrically connected to the controller 31. The transmission module transmits the target gap data to a host computer. The host computer is communicatively connected to the transmission module and compares the target gap data with pre-stored reference gap data, displaying the comparison result. The comparison result indicates the lifting height of the support base. The operator adjusts the support base according to the instructions of the host computer so that the distance between the support base and the spray component is the target gap data, thus ensuring that the gap distance between the support base and the etching gas spray component in the vacuum chamber meets the standard.

[0025] The electrode component 2 is composed of at least one first electrode plate 91 and at least one second electrode plate 92 forming an integral component. In the working state, the polarities of the first electrode plate 91 and the second electrode plate 92 are opposite. For example, the polarities of the first electrode plate 91 and the second electrode plate 92 can be reversed by applying positive and negative excitation voltages respectively during operation. When the electrode component 2 and the spray head (target conductor) form a measurement system: the reverse electric field generated by the reverse polarity electrode can cancel the edge effect, expanding the effective detection area; and common-mode interference is eliminated by differentially measuring the capacitance change values ​​of the two electrodes.

[0026] Furthermore, those skilled in the art will understand that, in the above embodiments, from the perspective of the target conductor component, if the capacitor formed by it and the first electrode plate 91 is a positive to negative electrode structure, then the capacitor formed by it and the second electrode plate 92 is a negative to positive electrode structure. Such variations are all within the protection scope of this utility model.

[0027] As semiconductor component dimensions continue to shrink, even minute gap deviations between the support base and the etching gas spraying components within the vacuum chamber can lead to substandard finished products, affecting product performance. In response, refer to... Figures 1 to 3 The processing module 3 includes an amplifier circuit 32, which is used to increase the range of the excitation voltage. For example, the amplifier circuit 32 includes a capacitor-to-digital converter 321, a digital potentiometer 322, and a high-speed operational amplifier 323. The capacitor-to-digital converter 321 is connected to the electrode component 2 and is used to convert the analog capacitance signal acquired from the electrode component 2 into a digital signal. The digital potentiometer 322 is connected to the capacitor-to-digital converter 321 and is used to adjust the resistance value of the amplifier circuit 32, thereby adjusting the magnitude and range of the excitation voltage. The high-speed operational amplifier 323 is connected to the digital potentiometer 322 and is used to drive and buffer the signal. The digital potentiometer 322 and the high-speed operational amplifier 323 act on the capacitor-to-digital converter 321, enabling the capacitor-to-digital converter 321 to convert to more precise capacitance values ​​and a wider range of capacitance values, thus increasing the measurement range of the processing module 3.

[0028] In one embodiment, the first electrode plate 91 of this application is directly connected to the input terminal of the amplifier circuit 32 to receive the original capacitance signal generated by the gap change. The second electrode plate 92 forms a closed loop with the amplifier circuit 32 through the power polarity conversion circuit 93. This design allows the power polarity conversion circuit 93 to periodically switch the power supply polarity of the second electrode plate, eliminating the electrostatic field accumulation effect and improving the signal-to-noise ratio of the micro-gap measurement.

[0029] Furthermore, those skilled in the art will understand that when the polarities of the first electrode plate 91 and the second electrode plate 92 are opposite, it is also necessary to set the ground circuits of the first electrode plate 91 and the second electrode plate 92 separately when forming the ground circuit. These changes are all within the protection scope of this utility model.

[0030] Furthermore, depending on different design requirements, the first electrode plate 91 and the second electrode plate 92 can be arranged in different distributions. For example, in a preferred embodiment, the first electrode plate 91 and the second electrode plate 92 are an even number of pairs, and the first electrode plate 91 and the second electrode plate 92 are arranged at intervals, for example, at regular intervals. In another variation, the first electrode plate 91 can be concentrated on one side of the circuit board, and the second electrode plate 92 can be concentrated on the other side of the circuit board. Those skilled in the art will understand that, regardless of the arrangement, multiple first electrode plates 91 and second electrode plates 92 can preferably be provided, and these variations are all within the protection scope of this utility model.

[0031] Furthermore, those skilled in the art will understand that, in a preferred embodiment, each of the first electrode plate 91 or the second electrode plate 92 preferably includes an outer pad (not shown in the figure) and a corresponding inner pad (not shown in the figure). Both the outer pad and the inner pad are connected to the circuit board 1, and preferably both the outer pad and the inner pad are electrically connected to the capacitor-to-digital converter. The outer pad and the inner pad are spaced apart and may be arranged in a ring, etc. One of the outer pads and one of the inner pads form an electrode pair, and through this electrode pair, the first electrode plate 91 or the second electrode plate 92 can form a capacitor with the target conductor component. Such an embodiment is within the protection scope of this utility model.

[0032] In a preferred embodiment, the circuit board 1 is housed within the housing 7, and the power supply circuit 8 is disposed on the surface of the housing 7, outside the electrode component 2. On one hand, since the power supply module 8 generates significant heat, its external design prevents heat conduction to the measurement area, thus preventing thermal deformation of the electrode component 2 and affecting the accuracy of the gap measurement. Furthermore, the limited internal space of the electrode component simplifies its internal wiring and avoids parasitic capacitance introduced by the intersection of high-voltage lines and measurement lines. On the other hand, the electromagnetic noise generated by the power supply circuit 8 may interfere with the high-precision gap measurement signal; its external placement reduces coupling interference to the electrode component 2 and improves the signal-to-noise ratio. As a vulnerable component, the external design facilitates quick replacement or repair, reducing downtime due to power supply failures.

[0033] In another variation, the circuit board 1 is also disposed on the surface of the housing 7. The specific disposal method can be referred to the disposal method of the power supply circuit 8. Such a variation is within the protection scope of this utility model.

[0034] Furthermore, the number of first electrode plates can be greater than the number of second electrode plates, or the number of first electrode plates and the number of second electrode plates can be equal. For example, when three second electrode plates are provided, it is easier to measure the tilt between the support base and the target conductor component.

[0035] In a preferred embodiment, the electrode component 2 and the processing module 3 are both electrically connected to the circuit board 1. The power supply circuit 8 is electrically connected to and supplies power to the electrode component 2 and the processing module 3. The circuit board 1 is housed within the housing 7, and the power supply circuit 8 is disposed on the surface of the housing 7, outside the electrode component 2. On one hand, since the power supply module 8 generates a significant amount of heat, its external design prevents heat conduction to the measurement area, which could cause thermal deformation of the electrode component 2 and affect the accuracy of the gap measurement. Furthermore, the limited internal space of the electrode component simplifies the internal wiring of the electrode component 2 and avoids the introduction of parasitic capacitance due to the intersection of high-voltage lines and measurement lines. On the other hand, the electromagnetic noise generated by the power supply circuit 8 may interfere with the high-precision gap measurement signal. External placement reduces coupling interference to the electrode component 2 and improves the signal-to-noise ratio. As a vulnerable component, the external design facilitates quick replacement or repair, reducing downtime caused by power supply failures.

[0036] In another variation, the circuit board 1 is also disposed on the surface of the housing 7. The specific disposal method can be referred to the disposal method of the power supply circuit 8. Such a variation is within the protection scope of this utility model.

[0037] This application incorporates a processing module 3, which energizes the electrode component 2 to drive it to form a capacitor with the etching gas spray component within the vacuum chamber. The processing module 3 measures the capacitance value of the electrode component 2 to obtain the gap value between the support base and the spray component, and processes this gap value to obtain the target gap data. The processing module 3 includes an amplifier circuit 32, which comprises a capacitance-to-digital converter 321, a digital potentiometer 322, and a high-speed operational amplifier 323. The digital potentiometer 322 and the high-speed operational amplifier 323 act on the capacitance-to-digital converter 321, enabling it to convert to more precise capacitance values ​​and a wider range of capacitance values, thus increasing the measurement range of the processing module 3. Since the gap distance between the support base and the spray component varies in different vacuum chambers, increasing the measurement range of the processing module 3 makes the gap measuring device suitable for different machine tools, improving its applicability.

[0038] Furthermore, those skilled in the art will understand that this application improves measurement accuracy by simultaneously setting two capacitors of opposite polarities during operation to compensate for the capacitance values ​​measured by different capacitors. Specifically, those skilled in the art will understand that by setting the relative positions of the first electrode plate 91 and the second electrode plate 92, in conjunction with the setting of the ground electrode, the capacitance formed between the first electrode plate 91 and the ground electrode can be of positive polarity, while the capacitance formed between the second electrode plate 92 and the ground electrode can be of negative polarity. This ensures that, during operation, at least two capacitors of different polarities are working in the same measuring device to measure the gap addressed in this patent application. The accuracy of gap calculation is improved through mutual compensation between different capacitance values. These variations are all within the protection scope of this utility model.

[0039] While the embodiments of this application have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of this application. Furthermore, the application described herein may have other embodiments and can be implemented or carried out in various ways.

[0040] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A novel gap measuring device for measuring the gap between a support base and a target conductor component, characterized in that, The support base for placement within a vacuum cavity includes at least: Circuit board (1), electrode components (2), and processing module (3); The electrode component (2) and the processing module (3) are both electrically connected to the circuit board (1). The electrode component (2) is electrically connected to the processing module (3) through the circuit board (1). The electrode component (2) and the target conductor component form a capacitor. The electrode component (2) is composed of at least one first electrode plate (91) and at least one second electrode plate (92) forming an integral component. In the working state, the polarities of the first electrode plate (91) and the second electrode plate (92) are opposite. The processing module (3) includes a controller (31) and an amplifier circuit (32). The amplifier circuit (32) is electrically connected to the controller (31). The amplifier circuit (32) is used to increase the range of the excitation voltage. The controller is used to apply an excitation voltage of the same polarity to the electrode component (2) and obtain the corresponding capacitance value, and then convert it to obtain the target gap data. The target gap data is used to indicate the gap between the bearing base and the target conductor component.

2. The novel gap measuring device according to claim 1, characterized in that, The number of the first electrode plates (91) is greater than or equal to the number of the second electrode plates (92).

3. The novel gap measuring device according to claim 1 or 2, characterized in that, The first electrode plate (91) is connected to the amplifier circuit (32), and the second electrode plate (92) is connected to the amplifier circuit (32) through a power polarity conversion circuit (93).

4. The novel gap measuring device according to claim 3, characterized in that, The positional relationship between the first electrode plate (91) and the second electrode plate (92) is as follows: - Interval setting; or - The first electrode plate (91) is concentrated in the first region, and the second electrode plate (92) is concentrated in the second region.

5. The novel gap measuring device according to claim 1, 2, or 4, characterized in that, It also includes a housing (7) and a power supply circuit (8), at least the power supply circuit (8) is disposed on the surface of the housing (7), and the power supply circuit (8) is electrically connected to and supplies power to the electrode component (2) and the processing module (3) respectively.

6. The novel gap measuring device according to claim 5, characterized in that, At least the circuit board (1) is disposed within the housing (7).

7. A novel gap measurement system for measuring the gap between a support base and a target conductor component, characterized in that, The device includes at least the novel gap measuring device according to any one of claims 1 to 6, and also includes a host computer, wherein the novel gap measuring device communicates with the host computer via a wireless communication device.

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