Gap measuring device and method of measuring thereof

Abstract

The application provides a gap measuring device and a measuring method thereof. The device comprises a workpiece for measuring the gap between the workpiece edge and a focusing ring. At least the following components are arranged on the workpiece: a light measuring component comprising a light deflection device for emitting incident light towards the focusing ring, the light deflection device deflecting the incident light into the workpiece and reflecting it to the focusing ring to form a light spot on the focusing ring; a collecting component for collecting the actual measurement value of the light spot and transmitting the actual measurement value to a processor, the processor obtaining the actual gap value between the workpiece edge and the focusing ring in the horizontal direction according to the actual measurement value. The application solves the problem that the gap measurement between the wafer edge and the focusing ring in the horizontal direction cannot be completed when the height of the focusing ring is lower than the height of the wafer upper surface.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor device detection, and in particular to a gap measurement device and a measurement method thereof. BACKGROUND

[0002] In the plasma etching process of semiconductor device manufacturing, the relative position accuracy between the wafer and the carrier is a very important index. In the actual production process, the relative distance between the focus ring and the reference surface (such as the wafer surface or the carrier surface) needs to be measured in real time or periodically to monitor the relative distance between the focus ring and the wafer, ensure the centering of the wafer, and monitor the degree of wear of the focus ring to determine whether the focus ring needs to be replaced, thereby avoiding problems such as uneven etching and edge device scrap due to abnormal position of the focus ring. The distance measuring technology in the prior art is a laser distance measuring method, as shown in Figure 3 When the upper edge height of the focus ring is higher than the upper surface height of the wafer, such measurement is easy to implement because the light emitted by the distance measuring device arranged on the wafer surface can directly reach the surface of the focus ring.

[0003] Referring to Figure 1 and Figure 2 When the upper edge height of the focus ring is lower than the upper surface height of the wafer (for example, due to inevitable wear (such as surface wear and size reduction) caused by plasma bombardment and chemical corrosion, as the wear accumulates, the upper edge height of the focus ring will gradually be lower than the initial assembly height, eventually forming a state in which the upper surface of the wafer is higher than the upper edge of the focus ring), the existing laser distance measuring method has a significant technical defect: when the upper edge height of the focus ring is lower than the upper surface height of the wafer, the edge of the wafer will physically block the light beam, causing the light beam to be unable to reach the surface of the focus ring located below the wafer; at the same time, the straightness of the light makes it impossible to bypass the edge of the wafer to extend to the area below the wafer surface, ultimately resulting in the inability to measure the gap between the edge of the wafer and the focus ring in the horizontal direction.

[0004] Therefore, it is necessary to provide a gap measurement device and a measurement method thereof to solve the above problems. SUMMARY

[0005] The purpose of the present application is to provide a gap measurement device and a measurement method thereof to solve the problem that the gap between the edge of the wafer and the focus ring in the horizontal direction cannot be measured when the upper edge height of the focus ring is lower than the upper surface height of the wafer.

[0006] The present application provides a gap measurement device, comprising a workpiece for measuring the gap between the edge of the workpiece and the focus ring, at least the following components are arranged on the workpiece:

[0007] The light measurement assembly comprises a light deflection device for emitting incident light towards the focusing ring, deflecting the incident light into the workpiece by the light deflection device and reflecting the light to the focusing ring to form a light spot on the focusing ring.

[0008] The acquisition assembly is configured to acquire an actual measurement value of the light spot and transmit the actual measurement value to a processor, and the processor is configured to obtain an actual gap value between the workpiece edge and the focusing ring in the horizontal direction according to the actual measurement value.

[0009] In an embodiment, the processor stores a corresponding relationship between the measurement value of the light spot and the gap value, and the processor is configured to obtain the actual gap value according to the actual measurement value and the corresponding relationship.

[0010] In an embodiment, the light measurement assembly emits one incident light, the actual measurement value is an actual pixel coordinate value of the light spot, and the corresponding relationship is a corresponding relationship between the pixel coordinate value of the light spot and the gap value.

[0011] In an embodiment, the light measurement assembly emits two incident lights and forms an included angle between the two incident lights, the light spot is two, the actual measurement value is an actual pixel distance value of the two light spots, and the corresponding relationship is a corresponding relationship between the pixel distance value of the light spot and the gap value.

[0012] In an embodiment, the material of the workpiece is a material that allows light to pass through.

[0013] In an embodiment, the light deflection device is a refractive prism or an electro-optical deflector.

[0014] In an embodiment, the light measurement assembly further comprises:

[0015] A light source for emitting incident light towards the focusing ring;

[0016] A photodetector for receiving reflected light returned from the focusing ring or light intensity information of the light spot;

[0017] The light deflection device is arranged between the light source and the focusing ring and located in the light path of the incident light.

[0018] In an embodiment, the light measurement assembly further comprises a beam splitter arranged between the light source and the light deflection device, configured to split the incident light into two light beams separated at a set angle and form two light spots on the focusing ring; or,

[0019] The light source is two and spaced apart, each of the light sources emits incident light at a set angle and forms two light spots on the focusing ring.

[0020] In an embodiment, the light source component comprises:

[0021] a light source; or,

[0022] a light source and a fiber connected to the light source, the fiber being used at least for transmitting the incident light externally; or,

[0023] a light source, a fiber connected to the light source, and a lens connected to the fiber, the fiber and the lens being used at least for transmitting the incident light externally.

[0024] In an embodiment, the collection component comprises:

[0025] a microcontroller connected to the light source component and the photodetector, for controlling the operation of the light source component and the photodetector and obtaining the actual measurement value according to the light intensity information of the light spot;

[0026] a transmission module for transmitting the actual measurement value to the processor by wireless communication or wired communication.

[0027] In an embodiment, at least one of the light measurement component and the collection component is fixed to the upper surface of the workpiece; or,

[0028] at least one of the light measurement component and the collection component is fixed in the groove of the workpiece; or,

[0029] at least one of the light measurement component and the collection component is attached and fixed to the outside of the workpiece.

[0030] In an embodiment, the processor is fixed to the workpiece and connected to the collection component; or, the processor is an upper computer and connected to the collection component by wireless communication.

[0031] The present application also provides a gap measurement method, which uses the gap measurement device according to any one of the above embodiments, comprising:

[0032] controlling the light measurement component to emit incident light in the direction of the focusing ring, the incident light being deflected by the light deflection device into the interior of the workpiece and projected on the focusing ring to form a light spot;

[0033] the collection component collects the actual measurement value of the light spot;

[0034] the processor obtains the actual gap value between the edge of the workpiece and the focusing ring in the horizontal direction according to the actual measurement value.

[0035] In one embodiment, the light measuring assembly emits one incident light, and the collection assembly obtains actual pixel coordinate values of the light spot according to light intensity information of the light spot.

[0036] The processor obtains the actual gap value between the workpiece edge and the focusing ring in the horizontal direction according to a corresponding relationship between the actual pixel coordinate values, pixel coordinate values of the light spot, and the gap value.

[0037] In one embodiment, the light measuring assembly emits two incident lights forming an included angle between the two incident lights, and the light spot is two, the collection assembly obtains actual pixel coordinate values of the two light spots according to light intensity information of the two light spots, and further obtains actual pixel distance values of the two light spots.

[0038] The processor obtains the actual gap value between the workpiece edge and the focusing ring in the horizontal direction according to a corresponding relationship between the actual pixel distance values, pixel distance values of the light spot, and the gap value.

[0039] The gap measuring device provided by the application has the following beneficial effects:

[0040] 1. By setting the light deflection device, the incident light emitted by the light measuring assembly is deflected into the workpiece, and the incident light reaches the focusing ring surface through continuous total reflection in the wafer. Even if the height of the focusing ring upper edge is lower than the height of the wafer upper surface, a light spot can be formed on the focusing ring surface, and the gap between the wafer edge and the focusing ring in the horizontal direction can be measured. The gap measurement scheme of the application is suitable for various scenes where the height of the focusing ring upper edge is higher than, (basically) flush with, or lower than the height of the wafer upper surface, and has a wider range of use.

[0041] 2. The light measuring assembly and the collection assembly are integrated on the workpiece (such as a wafer), and can measure the gap between the wafer edge and the focusing ring in situ, thereby eliminating the need for a calibration positioning cavity, saving space, and realizing real-time in-situ detection. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 A schematic view of the existing measurement scheme in which light cannot reach the focusing ring.

[0043] Figure 2 A schematic view of the focusing ring upper edge when the height of the focusing ring upper edge is lower than the height of the wafer upper surface.

[0044] Figure 3 A schematic view of the focusing ring upper edge when the height of the focusing ring upper edge is higher than the height of the wafer upper surface.

[0045] Figure 4 A side view of the gap measuring device of the application.

[0046] Figure 5A top view of the gap measuring device of the present application.

[0047] Figure 6 A logic block diagram of the gap measuring device of the present application.

[0048] Figure 7 A schematic diagram of the gap measuring device of the present application in one embodiment.

[0049] Legend: 100, focusing ring; 200, workpiece; 300, light measuring assembly; 310, light source; 320, light deflector; 330, photodetector; 400, acquisition assembly; 410, microcontroller; 420, transmission module; 500, processor. DETAILED DESCRIPTION

[0050] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0051] In view of the problems in the prior art, the embodiments of the present application provide a gap measuring device, which comprises a workpiece 200, and is used for measuring the gap between the edge of the workpiece 200 and a focusing ring 100, as shown in Figure 3 , Figure 4 and Figure 5 At least the following assemblies in the gap measuring device are arranged on the workpiece 200: a light measuring assembly 300 and an acquisition assembly 400. The light measuring assembly 300 comprises a light deflector 320, and is used for emitting incident light to the direction of the focusing ring 100. The light deflector 320 is used for deflecting the incident light into the interior of the workpiece 200 and making the incident light be totally reflected to the focusing ring 100 and form a light spot on the focusing ring 100. The light measuring assembly 300 receives the light intensity information of the reflected light or the light spot. The acquisition assembly 400 is used for acquiring the actual measurement value of the light spot, and transmits the actual measurement value to a processor 500. The processor 500 can obtain the actual gap value between the edge of the workpiece 200 and the focusing ring 100 in the horizontal direction according to the actual measurement value.

[0052] In the embodiment, the light measuring assembly 300 emits incident light to the focusing ring 100, the light deflection device 320 is arranged in the light path of the incident light, the incident light is deflected by the light deflection device 320 and enters the wafer, the incident light is reflected in the wafer and is emitted from the wafer edge to the surface of the focusing ring 100, and a light spot is formed on the focusing ring 100, the light spot is preferably the focal point of the incident light, the incident light is reflected on the focusing ring 100 to form reflected light, and the reflected light returned from the focusing ring 100 can be received by the light measuring assembly 300. The collection assembly 400 can collect the actual measurement value of the light spot, and the processor 500 obtains the actual gap value between the workpiece 200 edge and the focusing ring 100 in the horizontal direction according to the actual measurement value. Therefore, the problem that the gap measurement between the wafer edge and the focusing ring 100 in the horizontal direction cannot be completed when the height of the focusing ring 100 is lower than the height of the wafer upper surface can be solved.

[0053] In the embodiment, the light measuring assembly 300 and the collection assembly 400 are integrated on the workpiece 200 to form the gap measurement device, the workpiece 200 is preferably a wafer, and the size of the wafer is consistent with the wafer processed in the semiconductor manufacturing process. The wafer is placed in the wafer pre-processing position, and the real-time in-situ measurement of the gap between the wafer edge and the focusing ring 100 can be performed. In another variant, the workpiece 200 can be replaced by an object with the same shape and size as the wafer, and the light measuring assembly 300 and the collection assembly 400 are integrated into the object.

[0054] In an embodiment, the light measuring assembly 300 receives the reflected light, the collection assembly 400 obtains the light intensity information of the light spot according to the reflected light, and obtains the actual measurement value of the light spot according to the light intensity information of the light spot. In a variant, the light measuring assembly 300 receives the reflected light and obtains the light intensity information of the light spot according to the reflected light, and the collection assembly 400 obtains the actual measurement value of the light spot according to the light intensity information of the light spot.

[0055] In another embodiment, the light measuring assembly 300 receives the light intensity information of the light spot, and the collection assembly 400 obtains the actual measurement value of the light spot according to the light intensity information of the light spot.

[0056] The working process of the gap measurement device of the present application is explained as follows.

[0057] In the first step, the workpiece 200 (such as a wafer) with the light measuring assembly 300 and the collection assembly 400 is placed on the electrostatic chuck by the mechanical hand.

[0058] Secondly, the light measurement assembly 300 sends incident light to the focusing ring 100, and the light deflection device 320 deflects the incident light into the workpiece 200 and reflects the light to the focusing ring 100 by total reflection, and forms a light spot on the focusing ring 100.

[0059] Thirdly, the collection assembly 400 collects the actual measurement value of the light spot, and transmits the actual measurement value to the processor 500.

[0060] Fourthly, the processor 500 obtains the actual gap value between the workpiece 200 edge and the focusing ring 100 in the horizontal direction according to the actual measurement value.

[0061] In an embodiment, the processor 500 stores a corresponding relationship between the measurement value of the light spot and the gap value, and the processor 500 obtains the actual gap value according to the actual measurement value and the corresponding relationship. Compared with the prior art, the actual gap value needs to be calculated according to the actual measurement value, the incident light angle and other data; in the embodiment, the corresponding relationship is obtained by pre-calibration, and the actual gap value between the workpiece 200 edge and the focusing ring 100 in the horizontal direction can be directly obtained or deduced according to the actual measurement value, which saves the complex calculation process and improves the test efficiency. Moreover, a large number of corresponding relationship data can be obtained in advance during calibration to improve the accuracy of subsequent measurement results.

[0062] The single-beam and double-beam conditions of the light measurement assembly 300 are explained and described below.

[0063] In an embodiment, the light measurement assembly 300 sends one incident light, and the actual measurement value is the actual pixel coordinate value of the light spot, and the corresponding relationship is the corresponding relationship between the pixel coordinate value of the light spot and the gap value, which is obtained by pre-calibration simulation experiment before actual semiconductor manufacturing. Given the gap value between the workpiece 200 edge and the focusing ring 100 in the horizontal direction, for example, 200 μm, 500 μm or 1000 μm, etc., the pixel coordinates of the light spot on the focusing ring 100 are measured under different gap values respectively, and the pixel coordinates of the light spot on the focusing ring 100 and the gap value have a correlation. After calibration, a linear or nonlinear corresponding relationship between the pixel coordinates of the light spot and the gap value can be obtained, that is, the pixel coordinates of the light spot and the gap value have a one-to-one corresponding relationship under the same other parameter settings.

[0064] In actual application, the light measuring component 300 receives the light intensity information of the light spot, the collection component 400 obtains the actual measurement value, i.e. the actual pixel coordinate of the light spot on the focusing ring 100, according to the light intensity information of the light spot, and then obtains the actual gap value between the workpiece 200 edge and the focusing ring 100 in the horizontal direction by combining the corresponding relationship between the pixel coordinate value and the gap value of the light spot obtained by pre-calibration.

[0065] In another embodiment, the light measuring component 300 emits two incident lights forming an included angle between the two incident lights, the light deflection device 320 is two, the light spot is two, the actual measurement value is the actual pixel distance value of the two light spots, and the corresponding relationship is the corresponding relationship between the pixel distance value and the gap value of the light spot, which is obtained by pre-calibration simulation experiment measurement before actual semiconductor manufacturing. Given the gap value between the workpiece 200 edge and the focusing ring 100 in the horizontal direction, for example, 200 μm, 500 μm or 1000 μm, etc., the pixel coordinates of the light spot on the focusing ring 100 under different gap values are measured respectively under the condition of ensuring that other parameter settings (such as the position of the light measuring component 300, the power and angle of the incident light, etc.) are the same, and then the pixel distance value of the two light spots is obtained. There is a correlation between the pixel distance value of the light spot on the focusing ring 100 and the gap value. After calibration, a linear or nonlinear corresponding relationship between the pixel distance value of the light spot and the gap value can be obtained, i.e. under the condition that other parameter settings are the same, the pixel distance value of the light spot and the gap value exist one-to-one corresponding relationship.

[0066] In actual application, the light measuring component 300 receives the light intensity information of the light spot, the collection component 400 obtains the actual measurement value, i.e. the actual pixel coordinate of the light spot on the focusing ring 100, according to the light intensity information of the light spot, and then obtains the actual gap value between the workpiece 200 edge and the focusing ring 100 in the horizontal direction by combining the corresponding relationship between the pixel coordinate value and the gap value of the light spot obtained by pre-calibration.

[0067] It should be noted that the gap value does not need to be obtained by calculating the included angle between the two light beams, but the included angle can affect the measurement accuracy and range. The smaller the included angle, the larger the measurement range and the lower the accuracy; the larger the included angle, the smaller the range and the higher the accuracy.

[0068] In an embodiment, the material of the workpiece 200 is a material that allows light to pass through, such as glass, silicon, etc.

[0069] In another embodiment, referring to Figure 4 , the light deflection device 320 is a refractive prism or an electro-optical deflector, which can make the incident light meet the total reflection condition after entering the wafer.

[0070] In an embodiment, referring to Figure 5The light measuring assembly 300 further comprises a light source 310 and a photodetector 330, wherein the light source 310 is configured to emit incident light towards the focusing ring 100, the photodetector 330 is configured to receive the reflected light or the light intensity information of the light spot returned from the focusing ring 100, and the light deflection device 320 is arranged between the light source 310 and the focusing ring 100 and in the light path of the incident light.

[0071] Further, referring to Figure 5 The photodetector 330 comprises at least one optical sensor array configured to receive the reflected light or the light intensity information of the light spot returned from the focusing ring 100 and record the light intensity information of the light spot. The photodetector 330 can be a two-dimensional area array optical sensor, such as an Area CMOS Image Sensor, an Area CCD Image Sensor, an InGaAs Area Image Sensor, an Electron-Multiplying CCD Image Sensor, a Scientific CMOS Image Sensor, etc. These devices are two-dimensional pixel arrays and can directly output a two-dimensional light intensity distribution and generate a light spot projection area image. The pixel coordinate values of the light spot can be collected from the light spot projection area image.

[0072] Specifically, the light measuring assembly 300 can comprise a laser range finder, an infrared range finder, etc.

[0073] In some possible embodiments, the light source 310 can be a laser diode, an LED light source, or other single light source. The light source 310 can further comprise a light source and an optical fiber connected to the light source. The light source can be a laser, which can be arranged at any position and is not limited to be integrated on the workpiece 200. The light can be transmitted to the light deflection device 320 through the optical fiber. Alternatively, the light source 310 can further comprise a light source, an optical fiber connected to the light source, and a lens connected to the optical fiber. The lens can be used to shape or amplify the incident light transmitted by the optical fiber, so as to facilitate the transmission of the incident light to the light deflection device 320 and make the light deflection device 320 deflect the incident light into the workpiece 200.

[0074] In one specific embodiment, the light measuring assembly 300 further comprises a beam splitter arranged between the light source 310 and the light deflection device 320, configured to split the incident light into two light beams separated at a set angle and form two light spots on the focusing ring 100.

[0075] In another embodiment, there are two light source members 310 and they are spaced apart, each of the light source members 310 emits incident light at a set angle and forms two light spots on the focusing ring 100.

[0076] The light source member 310 projects a light beam with a set angle onto the focusing ring 100, for example, a laser, which can be selected from the wavelength spectrum of visible light, microwave, infrared light, and ultraviolet light, which is not limited here. The light source can be a vertical cavity surface emitting laser (VCSEL), an edge emitting laser diode (EELD), or an optical fiber connected to the light source member 310, which can be a laser diode or a laser. The position of the light source member 310 is not limited, which is arranged on the workpiece 200, or the light emitting member is arranged externally, and the light beam is formed by the optical fiber arranged on the workpiece 200. The light beam projected by the light source member 310 is deflected by the light deflection member 320 into the interior of the workpiece 200 and reaches the light spot on the focusing ring 100 by total reflection. Two light spots are generated by the beam splitter or two light source members 310, and the distance between the two light spots is usually proportional to the set angle of the incident light and the projection distance.

[0077] In a preferred embodiment, referring to Figure 6 , the acquisition assembly 400 includes a microcontroller 410 and a transmission module 420, wherein the microcontroller 410 is connected to the light source member 310 and the photodetector 330 respectively, and the microcontroller 410 is used to control the operation of the light source member 310 and the photodetector 330 and obtain the actual measurement value according to the light intensity information of the light spot. The transmission module 420 is used to transmit the actual measurement value to the processor 500 through wireless communication or wired communication.

[0078] In an example, the photodetector 330 receives reflected light; the microcontroller 410 obtains the light intensity information of the light spot according to the reflected light, and obtains the actual measurement value of the light spot according to the light intensity information of the light spot. In a variant, the photodetector 330 receives reflected light and obtains the light intensity information of the light spot according to the reflected light; the microcontroller 410 obtains the actual measurement value of the light spot according to the light intensity information of the light spot.

[0079] In another example, the photodetector 330 receives the light intensity information of the light spot, and the microcontroller 410 obtains the actual measurement value of the light spot according to the light intensity information of the light spot.

[0080] Specifically, referring to Figure 6 , the transmission module 420 can be a wireless communication module (such as Bluetooth, ZigBee, Wi-Fi, etc.).

[0081] In some embodiments, referring to Figure 4 and Figure 5At least one of the light measuring assembly 300 and the collection assembly 400 is fixed on the upper surface of the workpiece 200, or at least one of the light measuring assembly 300 and the collection assembly 400 is fixed in the recess of the workpiece 200, or at least one of the light measuring assembly 300 and the collection assembly 400 is attached to the outer side of the workpiece 200.

[0082] The components on the gap measuring device, such as the light measuring assembly 300 and / or the collection assembly 400, can be arranged on the upper surface of the workpiece 200, or embedded in the recess of the workpiece 200, so as to meet the requirements of the wafer transfer height in the semiconductor process. Further, those skilled in the art understand that, when the light measuring assembly 300 is embedded in the recess, if the emission and reception of the incident light and the reflected light are considered, a groove can be formed on the outer side of the workpiece 200 corresponding to the collection assembly 400, so that the light measuring assembly 300 can emit or receive light beams outside the workpiece 200, which is also within the protection scope of the present application. Specifically, corresponding grooves can be formed on the workpiece 200 corresponding to the mounting positions of the components of the light measuring assembly 300, and the depths of the grooves are respectively adapted to the heights of the components of the light measuring assembly 300, so as to reduce the height of the light measuring assembly 300 exposed outside the upper surface of the workpiece 200, and to meet the requirements of the semiconductor process. Further, in another variant, the collection assembly 400 and the like are attached to the outer side of the workpiece 200 and arranged towards the measured gap and the focusing ring 100, which is also within the protection scope of the present application.

[0083] In an embodiment, referring to Figure 6 The processor 500 is fixed on the workpiece 200 and connected to the collection assembly 400. In another variant, the processor 500 is a host computer and connected to the collection assembly 400 through wireless communication.

[0084] The processor 500 can be integrated on the workpiece 200 or independently arranged, such as a host computer. The functions of the host computer can be changed according to different embodiments, for example, the host computer can be a control host in a wafer processing system, or other auxiliary systems cooperating with the control host, or a host in the gap measuring device provided by the present application, such as a computer or industrial computer receiving, displaying or processing the wireless data of the gap between the wafer edge and the focusing ring 100, and these variants are within the protection scope of the present application.

[0085] The transmission module 420 transmits the actual measurement value in the collection assembly 400 to the input / output (I / O) module of the host computer, and receives any control signal from the I / O module of the host computer. The communication connection between the modules uses a wireless communication module (such as infrared, Bluetooth, ZigBee, Wi-Fi, etc.), or can directly communicate through an inductive induction coil.

[0086] In one specific embodiment, the gap measuring device further includes a power supply module that provides power to the various components of the gap measuring device (such as the light source 310, photodetector 330, microcontroller 410, and transmission module 420). The power supply module may be a rechargeable lithium battery. The power supply module may include a wired charging module and / or a wireless charging module.

[0087] Preferably, the workpiece 200 of the gap measuring device is a silicon wafer, but it can also be made of other materials that can be used in the manufacture of integrated circuits, such as gallium arsenide, glass, ceramics, nitrides, or carbides. The diameter of the workpiece 200 is preferably 200 mm or 300 mm, etc., to conform to current wafer dimensions, but it can have any diameter or arbitrary shape.

[0088] It should be noted that the number of 300 optical measurement units is not limited here, but four are preferred. Figure 7 As shown, higher positioning accuracy can be obtained by increasing the number of optical measuring components 300. In another variation, the number of optical measuring components 300 can be reduced, for example, by using two or three optical measuring components 300 to achieve the gap measurement described in this invention. Multiple optical measuring components 300 can measure the gap value at different positions of the workpiece, and the acquisition component 400 obtains the actual measurement value of multiple light spots based on the light intensity information of the light spots of multiple optical measuring components 300, and transmits the multiple actual measurement values ​​to the processor 500, thereby obtaining the actual gap value between the edge of the workpiece 200 and the focusing ring 100 at different positions in the horizontal direction.

[0089] Based on the specific examples above, the operation flow of the gap measuring device of the present invention is as follows:

[0090] Step 1: Start the gap measuring device and the robot arm will transfer the gap measuring device to the electrostatic chuck.

[0091] Step 2: The processor 500 (which can be a host computer) sends a wireless signal to notify the gap measuring device to start the measurement.

[0092] Step 3: The gap measuring device wirelessly transmits the actual measured value of the light spot to the host computer.

[0093] Step 4: The host computer obtains the actual gap value in the horizontal direction between the edge of workpiece 200 and focusing ring 100 based on the actual measurement value.

[0094] Step 5: The test is complete. The robotic arm retrieves the gap measuring device and shuts down the machine.

[0095] In addition, the present invention also provides a gap measurement method, employing the gap measurement device as described in any of the above embodiments, comprising the following steps:

[0096] Step S1: the light measurement assembly 300 emits incident light towards the focusing ring 100, the incident light is deflected by the light deflection device 320 into the workpiece 200 and forms a light spot on the focusing ring 100, and the light measurement assembly 300 receives the reflected light from the focusing ring 100 and the light intensity information of the light spot.

[0097] Step S2: the collection assembly 400 collects the actual measurement value of the light spot.

[0098] Step S3: the processor 500 obtains the actual gap value between the workpiece 200 edge and the focusing ring 100 in the horizontal direction according to the actual measurement value.

[0099] In an embodiment, for the single-beam case of the light measurement assembly 300, i.e., the light measurement assembly 300 emits one incident light, the specific steps are as follows:

[0100] The specific steps of step S1 include: the microcontroller 410 controls the light source 310 and the photodetector 330 to start working, the light source 310 emits incident light towards the focusing ring 100, the incident light is deflected by the light deflection device 320 into the workpiece 200 and forms a light spot on the focusing ring 100, and the photodetector 330 receives the reflected light from the focusing ring 100 and the light intensity information of the light spot.

[0101] The specific steps of step S2 include: the microcontroller 410 obtains the actual pixel coordinate value of the light spot according to the light intensity information of the light spot, and the transmission module 420 transmits the actual pixel coordinate value of the light spot to the processor 500 through wireless communication or wired communication.

[0102] The specific steps of step S3 include: the processor 500 obtains the actual gap value between the workpiece 200 edge and the focusing ring 100 in the horizontal direction according to the actual pixel coordinate value of the light spot, the corresponding relationship between the pixel coordinate value of the light spot and the gap value.

[0103] In another embodiment, for the double-beam case of the light measurement assembly 300, i.e., the light measurement assembly 300 emits two incident lights and forms an included angle between the two incident lights, the specific steps are as follows:

[0104] The specific steps of step S1 include:

[0105] For the case that the light measurement assembly 300 includes a beam splitter, the microcontroller 410 controls the light source 310 and the photodetector 330 to start working, and if the beam splitter is controlled by the microcontroller 410, the beam splitter also needs to be controlled to start working. The light source 310 emits incident light towards the focusing ring 100, and the incident light is divided into two beams of light separated at a set angle by the beam splitter, and then the two beams of light are deflected by the light deflection device 320 into the workpiece 200 and emitted from the wafer edge. The two incident lights are respectively projected on the focusing ring 100 to form two light spots with a certain interval after intersecting. The photodetector 330 receives the two reflected lights returned from the focusing ring 100 and the light intensity information of the two light spots.

[0106] For the case that the light source 310 is two, the microcontroller 410 controls the light source 310 and the photodetector 330 to start working, and the two light sources 310 emit incident light towards the focusing ring 100 at a set angle. The two incident lights are deflected by the light deflection device 320 into the workpiece 200 and emitted from the wafer edge. The two incident lights are respectively projected on the focusing ring 100 to form two light spots with a certain interval after intersecting. The photodetector 330 receives the two reflected lights returned from the focusing ring 100 and the light intensity information of the two light spots.

[0107] The specific steps of step S2 include: the microcontroller 410 obtains the actual pixel coordinate values of the two light spots according to the light intensity information of the two light spots, and then obtains the actual pixel distance values of the two light spots. The transmission module 420 transmits the actual pixel distance values of the two light spots to the processor 500 through wireless communication or wired communication.

[0108] The specific steps of step S3 include: the processor 500 obtains the actual gap value between the workpiece 200 edge and the focusing ring 100 in the horizontal direction according to the actual pixel distance values of the two light spots, and the corresponding relationship between the pixel coordinate values of the light spot and the gap value.

[0109] In the description of the present application, it should be understood that the terms "include" and "have" and any variations thereof used herein are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units need not be limited to those clearly listed steps or units, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0110] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like refer to the orientation or position of the device or element shown in the drawings, and are used only for convenience in describing the present application and simplifying the description, and are not intended to indicate or imply that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed or interpreted as limiting the application.

[0111] In addition, the terms "first", "second", "third", etc. are used herein only to describe various conditions, and should not be construed or interpreted as indicating or implying relative importance or a specific number of the technical features indicated thereby. Thus, the features defined with "first", "second", "third" can include one or more of the features explicitly or implicitly. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specified.

[0112] Although the embodiments of the present application have been described in detail above, it should be apparent to those skilled in the art that various modifications and changes can be made thereto without departing from the spirit and scope of the present application. It is to be understood that this application can have other embodiments and be practiced or carried out in various ways. Unless otherwise defined, technical terms or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

Claims

1. A gap measuring device, comprising a workpiece (200), for measuring the gap between the edge of the workpiece (200) and a focusing ring (100), characterized in that, At least the following components are disposed on the workpiece (200): The optical measurement assembly (300) includes an optical deflection device (320) for emitting incident light toward the focusing ring (100), wherein the incident light is deflected by the optical deflection device (320) and enters the interior of the workpiece (200) and is reflected to the focusing ring (100) to form a light spot on the focusing ring (100); The acquisition component (400) is used to acquire the actual measurement value of the light spot and transmit the actual measurement value to the processor (500). The processor (500) obtains the actual gap value between the edge of the workpiece (200) and the focusing ring (100) in the horizontal direction based on the actual measurement value.

2. The gap measuring device according to claim 1, characterized in that, The processor (500) stores a pre-calibrated correspondence between the measured value of the light spot and the gap value, and the processor (500) obtains the actual gap value based on the actual measured value and the correspondence.

3. The gap measuring device according to claim 2, characterized in that, The incident light emitted by the photometric component (300) is one, the actual measured value is the actual pixel coordinate value of the light spot, and the correspondence is the correspondence between the pixel coordinate value of the light spot and the gap value.

4. The gap measuring device according to claim 2, characterized in that, The incident light emitted by the photometric component (300) consists of two incident lights forming an angle between them. There are two light spots. The actual measured value is the actual pixel distance between the two light spots. The correspondence is the correspondence between the pixel distance value and the gap value of the light spots.

5. The gap measuring device according to claim 1, characterized in that, The material of the workpiece (200) is a material that allows light to pass through.

6. The gap measuring device according to claim 1, characterized in that, The optical deflection device (320) is a refracting prism or an electro-optic deflector.

7. The gap measuring device according to claim 1, characterized in that, The optical measurement component (300) also includes: A light source (310) is used to emit incident light in the direction of the focusing ring (100); A photodetector (330) is used to receive the intensity information of the reflected light or the light spot returned from the focusing ring (100); The light deflection device (320) is disposed between the light source (310) and the focusing ring (100) and is located in the optical path of the incident light.

8. The gap measuring device according to claim 7, characterized in that, The optical measurement assembly (300) further includes: a beam splitter, disposed between the light source (310) and the light deflection device (320), for splitting the incident light into two beams separated at a set angle, and forming two light spots on the focusing ring (100); or, There are two light sources (310) that are spaced apart. Each light source (310) emits incident light at a set angle and forms two light spots on the focusing ring (100).

9. The gap measuring device according to claim 7, characterized in that, The light source (310) includes: A light source; or, A light source and an optical fiber connected to the light source, the optical fiber being used at least to transmit the incident light outwards; or... A light source, an optical fiber connected to the light source, and a lens connected to the optical fiber, wherein the optical fiber and the lens are at least used to transmit the incident light outward.

10. The gap measuring device according to claim 7, characterized in that, The acquisition component (400) includes: A microcontroller (410) is connected to the light source (310) and the photodetector (330) and is used to control the operation of the light source (310) and the photodetector (330) and to obtain the actual measurement value based on the light intensity information of the light spot; The transmission module (420) is used to transmit the actual measurement value to the processor (500) via wireless or wired communication.

11. The gap measuring device according to any one of claims 1-10, characterized in that, At least one of the optical measurement component (300) and the acquisition component (400) is fixed to the upper surface of the workpiece (200); or, At least one of the photometry component (300) and the acquisition component (400) is fixed within a groove in the workpiece (200); or, At least one of the optical measurement component (300) and the acquisition component (400) is attached and fixed to the outside of the workpiece (200).

12. The gap measuring device according to any one of claims 1-10, characterized in that, The processor (500) is fixed on the workpiece (200) and connected to the acquisition component (400); or, the processor (500) is a host computer and is connected to the acquisition component (400) via wireless communication.

13. A gap measurement method, characterized in that, The gap measuring device as described in any one of claims 1-12 comprises: The optical measurement component (300) is controlled to emit incident light in the direction of the focusing ring (100). The incident light is deflected by the optical deflection device (320) and enters the interior of the workpiece (200) and is projected onto the focusing ring (100) to form a light spot. The acquisition component (400) acquires the actual measured value of the light spot; The processor (500) obtains the actual gap value in the horizontal direction between the edge of the workpiece (200) and the focusing ring (100) based on the actual measurement value.

14. The gap measurement method according to claim 13, characterized in that, The incident light emitted by the optical measurement component (300) is one, and the acquisition component (400) obtains the actual pixel coordinate value of the light spot based on the light intensity information of the light spot; The processor (500) obtains the actual gap value between the edge of the workpiece (200) and the focusing ring (100) in the horizontal direction based on the correspondence between the actual pixel coordinate value, the pixel coordinate value of the light spot and the gap value.

15. The gap measurement method according to claim 13, characterized in that, The incident light emitted by the optical measurement component (300) consists of two incident lights forming an angle between them, and there are two light spots. The acquisition component (400) obtains the actual pixel coordinates of the two light spots based on the light intensity information of the two light spots, and then obtains the actual pixel distance between the two light spots. The processor (500) obtains the actual gap value between the edge of the workpiece (200) and the focusing ring (100) in the horizontal direction based on the correspondence between the actual pixel distance value, the pixel distance value of the light spot and the gap value.

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