Wafer levelness detection device used in horizontal electroplating cavity

Abstract

The utility model discloses a wafer levelness detection device used in a horizontal electroplating cavity, which is characterized in that detection assemblies are symmetrically arranged on the two sides of a wafer rotating platform, and a photoelectric sensor is used for replacing a traditional mechanical probe to detect wafer warping, so that warping detection of the whole peripheral edge of a wafer can be completed in a single rotating period, and the wafer levelness detection efficiency is greatly improved. The problem of a blind area of traditional single-point detection is avoided, the surface of the wafer can be prevented from being scratched or polluted, and the method is particularly suitable for a semiconductor electroplating process with an extremely high requirement on cleanliness; and the height of the detection assembly for fixing the sensor is adjustable, so that different wafer sizes or process parameters can be quickly adapted, the height of the detection assembly can be adjusted according to the height of the wafer on the wafer rotating platform, the position of the light path of the sensor is accurately calibrated, the ideal values of the light path and the edge of the wafer are ensured, and the conditions of detection sensitivity and false triggering prevention are considered.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor electroplating technology, and in particular to a wafer level detection device for use in a horizontal electroplating cavity. Background Technology

[0002] In horizontal electroplating, wafers are placed on a rotating platform for surface metallization. Due to factors such as high-speed rotation and the impact of the electroplating solution, wafers are prone to micron-level warping, leading to a decrease in coating uniformity.

[0003] Traditional testing methods typically involve offline measurements or mechanical probe contact testing, which suffer from problems such as poor real-time performance and the potential to scratch or contaminate the wafer surface. Summary of the Invention

[0004] In view of this, the present invention provides a wafer levelness detection device for use in a horizontal electroplating cavity, in order to solve the problems existing in the background art.

[0005] A wafer levelness detection device for use in a horizontal electroplating cavity includes detection components symmetrically arranged on both sides of a wafer rotation platform in the radial direction of the wafer. A photoelectric sensor transmitter is fixed to the detection component located on one side of the wafer rotation platform, and a photoelectric sensor receiver is fixed to the detection component located on the opposite side of the wafer rotation platform.

[0006] The detection assembly includes a height-adjustable support, a sensor bracket fixed on the support, and a sensor mounting box covering the sensor bracket. The transmitter or receiver of the photoelectric sensor passes vertically through the sensor bracket, with its lower part placed inside the support and its upper probe placed inside the sensor mounting box. A straight slot is provided on the side of the sensor mounting box facing the wafer rotation platform to allow the horizontal beam of the photoelectric sensor to pass through.

[0007] Preferably, the outer surfaces of the transmitter and receiver probes of the photoelectric sensor are both covered with a protective film.

[0008] Preferably, the protective film is made of PFA material.

[0009] Preferably, the sensor bracket includes a bracket base plate and a sensor fixing block fixed on the surface of the bracket base plate. The lower surface of the bracket base plate is provided with a groove. A through hole is longitudinally opened in the center of the sensor fixing block for the transmitter or receiver of the photoelectric sensor to pass through. A first fixing hole is opened laterally on the sensor fixing block. The transmitter or receiver of the photoelectric sensor is fixed by a set screw passing through the first fixing hole.

[0010] Preferably, the support base includes a fixed base and a support rod sleeved on the fixed base. Multiple slots are symmetrically arranged in the circumferential direction on the upper part of the fixed base. Multiple protrusions that are locked in the slots extend from the corresponding positions on the inner wall of the support rod. Multiple second fixing holes are opened in the circumferential direction on the lower part of the support rod. The support rod is fixed to the fixed base by a set screw passing through the second fixing hole.

[0011] Preferably, the support base, sensor bracket, and sensor mounting box are all made of any one of the following materials: PVC, PTFE, PEEK, PP, aluminum alloy, glass fiber reinforced plastic, and aluminum alloy.

[0012] Preferably, the straight slot hole is oval.

[0013] Preferably, the wafer rotation platform has multiple sets of detection components arranged in the circumferential direction.

[0014] The beneficial effects of this utility model are:

[0015] 1. This application symmetrically arranges detection components on both sides of the wafer rotation platform, using photoelectric sensors to replace traditional mechanical probes to detect wafer warpage. This not only completes the detection of warpage around the entire circumference of the wafer in a single rotation cycle, avoiding the blind zone problem of traditional single-point detection, but also avoids scratches or contamination on the wafer surface. It is especially suitable for semiconductor electroplating processes with extremely high cleanliness requirements. Furthermore, the height of the detection components with fixed sensors is adjustable, which can quickly adapt to different wafer sizes or process parameters. The height of the detection components can be adjusted according to the height of the wafer on the wafer rotation platform, so that the position of the sensor optical path is accurately calibrated, ensuring that the optical path and the wafer edge are at the ideal value, taking into account both detection sensitivity and prevention of false triggering.

[0016] 2. In this application, the sensor is fixed to the sensor bracket, with its lower part placed inside the support base and its upper probe placed inside the sensor mounting box. The light beam emitted by the sensor can pass through the box body through the straight slot hole on the sensor mounting box to form a light beam emission and reception circuit. Under the condition of ensuring normal use of the sensor, the support base, sensor bracket and sensor mounting box can wrap the sensor, isolate and protect the sensor, and prevent it from being exposed to corrosive media in the horizontal electroplating cavity, which would damage its structure. This can increase the service life of the sensor and will not interfere with the sensor signal.

[0017] 3. In order to further and effectively protect the sensor probe so that it can be used in different corrosive environments, this application also wraps a layer of PFA protective film on the outer surface of the photoelectric sensor probe so that it can be used in high temperature, high humidity and chemical corrosion environments.

[0018] 4. Multiple sets of detection components are arranged along the circumference of the wafer rotation platform, enabling multi-point synchronous detection of wafer warpage. This significantly improves the accuracy and coverage of wafer warpage detection and reduces the probability of missed detections. By comparing signals from two or more sets of detection components, the detection results can be dynamically calibrated, eliminating environmental interference or false triggers and enhancing detection reliability. Simultaneously, multiple sets of data support complex warpage morphology analysis, generating a three-dimensional warpage distribution map, providing a more accurate basis for process optimization. Furthermore, the design of multiple detection components enhances the equipment's compatibility, enabling it to adapt to wafers of different sizes and laying the foundation for future functional expansion (such as higher-precision detection), further enhancing the system's practicality and scalability. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of this utility model.

[0021] Figure 2 This is an exploded view of this utility model.

[0022] Figure 3 This is a schematic diagram of the sensor bracket.

[0023] The meanings of the labels in the diagram are as follows:

[0024] 1 is the sensor mounting box, and 11 is a straight slot hole.

[0025] 2 is the sensor bracket, 21 is the bracket base plate, 22 is the sensor fixing block, 23 is the through hole, and 24 is the first fixing hole.

[0026] 3 represents the transmitter or receiver of the photoelectric sensor.

[0027] 4 is the support base, 41 is the fixed base, 42 is the support rod, 43 is the slot, and 44 is the second fixing hole. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the present utility model. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the present utility model.

[0029] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0030] It should be understood that although the terms first, second, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms and should not be construed as indicating or implying relative importance. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0031] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0032] In the description of this utility model, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0033] To better understand the technical solution of this utility model, the following detailed description of this utility model is provided in conjunction with the accompanying drawings.

[0034] This invention provides a wafer leveling detection device for use in a horizontal electroplating cavity, comprising detection components symmetrically arranged on both sides of a wafer rotation platform in the radial direction of the wafer. A photoelectric sensor transmitter is fixed on one side of the detection component on the wafer rotation platform, and a photoelectric sensor receiver is fixed on the opposite side of the detection component on the other side of the wafer rotation platform. The photoelectric sensor transmitter and receiver form a detection optical path parallel to the wafer rotation platform on both sides of the wafer. During the rotation of the wafer with the wafer on the wafer rotation platform, the degree of wafer warpage is determined in real time by calculating the frequency and duration of optical path obstruction. The wafer is fixed to the wafer rotation platform by vacuum adsorption or electrostatic clamping.

[0035] Specifically, the detection assembly includes a height-adjustable support base 4, a sensor bracket 2 fixed on the support base 4, and a sensor mounting box 1 covering the sensor bracket 2. The transmitter or receiver 3 of the photoelectric sensor passes vertically through the sensor bracket 2 and its lower part is placed inside the support base 4, while its upper probe is placed inside the sensor mounting box 1. A straight slot hole 11 is opened on the side of the sensor mounting box 1 facing the wafer rotation platform to allow the horizontal beam of the photoelectric sensor to pass through.

[0036] The support base 4 includes a fixed base 41 and a support rod 42 sleeved on the fixed base 41. Multiple slots 43 are symmetrically arranged circumferentially on the upper part of the fixed base 41. Multiple protrusions extend from the corresponding positions on the inner wall of the support rod 42, engaging within the slots 43. Multiple second fixing holes 44 are opened circumferentially on the lower part of the support rod 42. During installation, align the protrusions on the inner wall of the support rod 42 with the slots 43 on the upper part of the fixed base 41, and sleeve the support rod 42 onto the upper part of the fixed base 41. Then, move the support rod 42 up and down to adjust the height of the entire support base 4. After the height is adjusted, insert a set screw into each of the second fixing holes 44 and tighten each set screw, so that the set screws press against the support rod 42 from different circumferential positions, thus fixing the support rod 42 and the fixed base 41 as a single unit.

[0037] In this embodiment, the fixed base 41 is made of PVC material. During use, the fixed base will not interfere with the signal of the fiber optic sensor inserted in the support rod 42. In order to improve the installation stability of the overall structure while ensuring installation accuracy, the bottom of the fixed base 41 is also equipped with a dual positioning method of countersunk hole and conical hole.

[0038] In this embodiment, the support rod 42 is also made of PVC material. The lower half of the support rod 42 is a circular sleeve, and the upper half is a cylinder with a central insertion hole. The size of the insertion hole matches the size of the photoelectric sensor.

[0039] The sensor bracket 2 includes a bracket base plate 21 and a sensor fixing block 22 fixed on the surface of the bracket base plate 21.

[0040] The lower surface of the support base plate 21 is provided with a groove, the shape and size of which match the shape and size of the upper end of the support rod 42, so that the upper end of the support rod 42 can be stably locked in the groove of the support base plate 21 during installation. In this embodiment, the lower surface of the support base plate 21 is provided with a circular groove.

[0041] The sensor fixing block 22 has a through hole 23 extending longitudinally through its center, and a first fixing hole 2 extending laterally on its surface. The through hole 23 is connected to the first fixing hole 2 and the circular groove on the lower surface of the support base plate 21. The transmitter or receiver 3 of the photoelectric sensor passes vertically through the through hole 23, and its lower end is inserted into the support rod 42. Then, a set screw is inserted into the first fixing hole 24, and the set screw is tightened to press the transmitter or receiver 3 of the photoelectric sensor firmly onto the sensor support 2.

[0042] The sensor mounting box 1 covers the sensor bracket 2 to isolate and protect the probe of the photoelectric sensor's transmitter or receiver 3, preventing it from coming into contact with corrosive media, which could damage it and affect its service life. A straight slot 11 is formed on the side of the sensor mounting box 1 facing the wafer rotating platform to allow the horizontal beam of the photoelectric sensor to pass through. The beam emitted by the photoelectric sensor's transmitter can pass through the straight slot 11 in its mounting box 1 and enter through the straight slot 11 on the opposite side of the mounting box 1 to be received by the receiver, thus forming a beam emission and reception circuit.

[0043] In this embodiment, the sensor mounting box 1 is a rectangular cover, and the straight slot hole 11 opened on the side facing the wafer rotation platform is an oval hole with the long axis of the oval hole pointing vertically downward.

[0044] In a preferred embodiment, in order to further and effectively protect the sensor probe so that it can be used in different corrosive environments, a protective film is wrapped around the outer surface of the transmitter and receiver probes of the photoelectric sensor. The protective film may be made of PFA material.

[0045] The aforementioned support base 4, sensor bracket 2, and sensor mounting box 1 are all made of PVC material, so that the device can be used in the high temperature, high humidity, and chemical corrosion environment of the electroplating chamber without causing signal interference to the internal sensor. In addition, PTFE or PEEK material can be selected in highly corrosive environments. When there is a need for lightweighting, materials such as aluminum alloy, PEEK, PP, and glass fiber reinforced plastic can also be selected. In high-end equipment, titanium alloy material can also be selected.

[0046] In actual use, a detection component is installed on each side of the wafer rotating platform on the same radial direction of the wafer. The transmitter of the photoelectric sensor is fixed on one detection component, and the receiver of the photoelectric sensor is fixed on the other detection component. The two opposing detection components form a group.

[0047] Then, the receivers of each group of detection components are connected to the PLC or host computer respectively. When the wafer rotating platform rotates with the wafer, if the wafer is placed horizontally and without warping, the edge of the wafer will remain horizontal with the rotating plane. The beam emitted by the photoelectric sensor transmitter can be continuously received by the receiver. The sensor optical path is not blocked, and the receiver can continuously output a stable high-level signal.

[0048] If a wafer warps due to stress or process abnormalities, its edges will periodically deviate from the preset plane during rotation, causing the optical path to be blocked. The receiving signal will be periodically interrupted as the wafer rotates, and the interruption frequency is proportional to the wafer rotation speed (for example, at a speed of 30 rpm, it rotates once every 2 seconds. If there is one signal interruption in a single revolution, it indicates that there is single-point warping; if there are multiple interruptions, it reflects a complex warping pattern). The receiver will transmit the output signal to the PLC or host computer. The PLC or host computer will analyze the received signal. When the warping exceeds the preset threshold, the control system will immediately trigger an alarm operation: activate the audible and visual alarm to alert the operator. An automatic shutdown protection function can be selected to prevent wafer breakage or equipment damage.

[0049] In this embodiment, the photoelectric sensor is a high-precision infrared photoelectric sensor (FU-96). The sensor is powered by a DC regulated power supply, the power supply voltage of which can be selected as DC 12V, and is equipped with a filter capacitor to eliminate power supply noise. The sensor output signal is transmitted to the signal processing module through a shielded cable, and the outer layer of the cable is grounded to suppress electromagnetic interference (EMI).

[0050] In practical applications, multiple sets of detection components can be arranged circumferentially on the wafer rotation platform as needed. This enables multi-point synchronous detection of wafer warpage, significantly improving the accuracy and coverage of wafer warpage detection while reducing the probability of missed detections. By comparing signals from two or more sets of detection components, the detection results can be dynamically calibrated, eliminating environmental interference or false triggers and enhancing detection reliability. Simultaneously, multiple sets of data support complex warpage morphology analysis, generating a three-dimensional warpage distribution map, providing a more accurate basis for process optimization. Furthermore, the design of multiple detection components improves equipment compatibility, enabling adaptation to wafers of different sizes and laying the foundation for future functional expansion (such as higher-precision detection), further enhancing the system's practicality and scalability.

[0051] It should be understood that the described embodiments are merely some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

Claims

1. A wafer levelness detection device for use in a horizontal electroplating cavity, characterized in that, The device includes detection components symmetrically arranged on both sides of a wafer rotation platform in the radial direction of the wafer. A photoelectric sensor transmitter is fixed to the detection component located on one side of the wafer rotation platform, and a photoelectric sensor receiver is fixed to the detection component located on the opposite side of the wafer rotation platform. The detection assembly includes a height-adjustable support base (4), a sensor bracket (2) fixed on the support base (4), and a sensor mounting box (1) covering the sensor bracket (2). The transmitter or receiver (3) of the photoelectric sensor passes vertically through the sensor bracket (2) with its lower part placed inside the support base (4) and its upper probe placed inside the sensor mounting box (1). A straight slot (11) is opened on the side of the sensor mounting box (1) facing the wafer rotation platform to allow the horizontal beam of the photoelectric sensor to pass through.

2. The wafer levelness detection device for a horizontal electroplating cavity according to claim 1, characterized in that, The outer surfaces of the transmitter and receiver probes of the photoelectric sensor are both covered with a protective film.

3. The wafer levelness detection device for a horizontal electroplating cavity according to claim 2, characterized in that, The protective film is made of PFA material.

4. The wafer levelness detection device for a horizontal electroplating cavity according to claim 1, characterized in that, The sensor bracket (2) includes a bracket base plate (21) and a sensor fixing block (22) fixed on the surface of the bracket base plate (21). The lower surface of the bracket base plate (21) is provided with a groove. A through hole (23) is longitudinally opened in the center of the sensor fixing block (22) for the transmitter or receiver (3) of the photoelectric sensor to pass through. A first fixing hole (24) is opened laterally on the sensor fixing block (22). The transmitter or receiver (3) of the photoelectric sensor is fixed by a set screw passing through the first fixing hole (24).

5. The wafer levelness detection device for a horizontal electroplating cavity according to claim 1, characterized in that, The support base (4) includes a fixed base (41) and a support rod (42) sleeved on the fixed base (41). Multiple slots (43) are symmetrically arranged in the circumferential direction on the upper part of the fixed base (41). Multiple protrusions that are locked in the slots (43) extend from the corresponding positions on the inner wall of the support rod (42). Multiple second fixing holes (44) are opened in the circumferential direction on the lower part of the support rod (42). The support rod (42) is fixed to the fixed base (41) by a set screw passing through the second fixing hole (44).

6. The wafer levelness detection device for a horizontal electroplating cavity according to claim 1, characterized in that, The support base (4), sensor bracket (2) and sensor mounting box (1) are all made of any one of the following materials: PVC, PTFE, PEEK, PP, aluminum alloy, glass fiber reinforced plastic, and aluminum alloy.

7. The wafer levelness detection device for a horizontal electroplating cavity according to claim 1, characterized in that, The straight slot hole (11) is oval.

8. The wafer levelness detection device for a horizontal electroplating cavity according to claim 1, characterized in that, The wafer rotation platform is equipped with multiple sets of detection components along its circumference.

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