Device and method for detecting wafer particle pollution

Abstract

The embodiment of the invention provides a device and a method for detecting wafer particle pollution. The device comprises a detection chamber; the rotatable vacuum chuck is positioned in the detection chamber and is used for bearing and driving the wafer to rotate; the mechanical moving assembly comprises a fixed arm and a guide rail coupled with the first end of the fixed arm, the second end of the fixed arm is coupled to the inner side wall of the detection cavity, the guide rail is parallel to the plane where the vacuum suction cup is located, and the projection of the guide rail on the vacuum suction cup at least covers the radius of the wafer; the particle scanning device is movably arranged on the guide rail and scans and transmits the surface information of the wafer from the upper part of the vacuum chuck in a scanning state; and the processing module is coupled with the particle scanning device and is used for controlling the particle scanning device to move along the mechanical moving assembly, acquiring the surface information and determining whether the wafer has particle pollution or not according to the surface information. By adopting the technical scheme, the problem of detecting particle pollution on the surface of the wafer can be solved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of semiconductor manufacturing technology, and in particular to a device and method for detecting wafer particle contamination. Background Art

[0002] If particles are generated during semiconductor wafer processing, they can lead to reduced wafer yield, device failure, and even batch scrapping. If particle contamination occurs in the photoresistor, developer, or exposure machine, it's often difficult to pinpoint the source of the contamination.

[0003] Therefore, how to provide a technical solution to solve the problem of detecting particle contamination on the wafer surface has become a technical problem that needs to be solved urgently. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a device and method for detecting particle contamination on a wafer, which can effectively detect the problem of particle contamination on the wafer surface.

[0005] To solve the above technical problems, an embodiment of the present invention provides a device for detecting particle contamination of wafers, comprising: a detection chamber; a rotatable vacuum suction cup, located in the detection chamber, for carrying and driving the wafer to rotate; a mechanical moving component, comprising a fixed arm and a guide rail coupled to the first end of the fixed arm, the second end of the fixed arm is coupled to the inner wall of the detection chamber, the guide rail is parallel to the plane where the vacuum suction cup is located, and the projection of the guide rail on the vacuum suction cup covers at least the radius of the wafer; a particle scanning device, movably placed on the guide rail, which scans and transmits surface information of the wafer from above the vacuum suction cup in a scanning state; a processing module, coupled to the particle scanning device, for controlling the particle scanning device to move along the mechanical moving component and obtain the surface information, and determining whether the wafer has particle contamination based on the surface information.

[0006] Optionally, the mechanical moving component also includes: a height adjustment member axially connected to the first end of the fixed arm, and the height adjustment member moves or is fixed relative to the first end of the fixed arm in a direction perpendicular to the plane where the vacuum suction cup is located; wherein the first end of the height adjustment member is connected to the guide rail, and the guide rail is arranged above the plane where the vacuum suction cup is located.

[0007] Optionally, the mechanical moving component also includes: a rotating shaft, through which the second end of the fixed arm is connected to the inner wall of the detection chamber; the rotating shaft includes a fixing part, a connecting part and a control part; the first end of the fixing part is connected to the inner wall of the detection chamber; the connecting part passes through part or all of the second end of the fixing part, and is axially connected to the second end of the fixing part and can rotate and move at the second end of the fixing part, and is fixedly connected to the second end of the fixed arm; the first end of the control part is connected to the inner wall of the detection chamber, and the second end of the control part is meshed with the connecting part, for controlling the rotation of the connecting part to adjust the position of the fixed arm.

[0008] Optionally, a slider is provided on the guide rail for fixing the particle scanning device.

[0009] Optionally, the particle scanning device is selected from: a white light interferometer, a scanning electron microscope, an atomic force microscope, and an optical microscope.

[0010] Optionally, one of the inner walls of the detection chamber has an inwardly recessed storage cavity; in a non-scanning state, the storage cavity is used to accommodate the particle scanning device.

[0011] Optionally, it also includes: a motor coupled to the vacuum suction cup, the motor also coupled to the processing module, for receiving a control signal to accurately control the rotation speed, angle and direction of the vacuum suction cup; wherein the motor is also used to drive the vacuum suction cup to rise and fall.

[0012] Accordingly, the present invention also provides a method for detecting wafer particle contamination, an apparatus for detecting wafer particle contamination, the apparatus comprising a detection chamber, a rotatable vacuum suction cup, a mechanical moving component, a particle scanning device and a processing module; the method comprising: in response to a received wafer placement signal, by raising and lowering the vacuum suction cup, adsorbing and fixing the wafer to a first preset position in the detection chamber, the first preset position being the position of the wafer after the vacuum suction cup receives the wafer and descends to the wafer detection state; by controlling the mechanical moving component, moving the particle scanning device to a second preset position, the second preset position being set above the vacuum suction cup, and the first preset position being set to a second preset position. The projections of the second preset positions are located at the edge of the wafer; the vacuum suction cup is rotated to set the positioning groove of the wafer as the initial position of the wafer directly below the particle scanning device; when the wafer is rotating, the particle scanning device is moved by controlling the mechanical moving component, so that the particle scanning device scans the wafer surface circle by circle starting from the initial position of the wafer to obtain wafer surface information; based on the wafer surface information and the preset particle accuracy threshold, it is judged whether particle contamination occurs; by controlling the mechanical moving component, the particle scanning device is moved to a third preset position, and the third preset position is away from the projection of the wafer in the lifting direction of the vacuum suction cup.

[0013] Optionally, the device for detecting wafer particle contamination includes: a motor and a vacuum pump; the step of sucking and fixing the wafer at a first preset position by raising and lowering the vacuum suction cup includes: driving the vacuum suction cup to rise to a position for receiving the wafer by a motor; sucking and fixing the wafer by turning on the vacuum pump; and driving the vacuum suction cup to descend to the first preset position by a motor.

[0014] Optionally, the step of determining whether particle contamination occurs based on a preset particle precision by acquiring all the information on the wafer surface also includes: determining whether the information on the wafer surface has been scanned completely based on the acquired information on the wafer surface; if complete, determining whether particle contamination occurs based on the preset particle precision; otherwise, rescanning the information on the wafer surface.

[0015] Optionally, the particle accuracy threshold is greater than or equal to 20 nanometers.

[0016] Compared with the prior art, the technical solution of the embodiment of the present invention has the following advantages:

[0017] An embodiment of the present invention provides a device for detecting wafer particle contamination. By setting up a separate detection chamber, the wafer can be detected without affecting the progress of other processes. The detection chamber has a vacuum suction cup for carrying and driving the wafer to rotate, and also has a mechanical moving component for controlling the position of a particle scanning device to drive the particle scanning device to scan the wafer. It can also drive the particle scanning device away from the top of the wafer to avoid collisions during the wafer placement process. The particle scanning device scans and transmits the surface information of the wafer above the wafer, and obtains the surface information through a processing module. Based on the surface information, it is determined whether the wafer has particle contamination. Therefore, it can effectively deal with the problem of detecting particle contamination on the wafer surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the invention of this specification, the following briefly introduces the drawings required for use in the embodiments of the invention of this specification or the description of the prior art. Obviously, the drawings described below are only some embodiments of this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0019] Figure 1 A cross-sectional schematic diagram of a device for detecting wafer particle contamination according to an embodiment of the present invention is shown;

[0020] Figure 2 shows a cross-sectional schematic diagram of a rotating shaft in an embodiment of the present invention;

[0021] Figure 3A schematic flow chart of a method for detecting wafer particle contamination according to an embodiment of the present invention is shown;

[0022] Figure 4 A schematic diagram showing preset positions of a device for detecting wafer particle contamination in an embodiment of the present invention is shown.

[0023] Description of reference numerals:

[0024] Wafer W, slider moving direction A1, height adjustment member moving direction A2;

[0025] Detection chamber 100, storage chamber 110;

[0026] Vacuum suction cup 200, lifting structure 210;

[0027] Mechanical moving assembly, fixed arm 310, first end 310a of the fixed arm, second end 310b of the fixed arm, guide rail 320, slider 321, height adjustment member 330, first end 330a of the height adjustment member, second end 330b of the height adjustment member, rotating shaft 340, fixing portion 341, first end 341a of the fixing portion, second end 341b of the fixing portion, connecting portion 342, control portion 343, first end 343a of the control portion, second end 343b of the control portion;

[0028] Particle scanning device 400;

[0029] Motor 500;

[0030] A first preset position 610 , a second preset position 620 , and a third preset position 630 . DETAILED DESCRIPTION

[0031] The technical solutions of the present invention are described in detail below in conjunction with specific embodiments and the accompanying drawings. The embodiments described herein are specific embodiments of the present invention and are used to illustrate the concept of the present invention. These descriptions are all illustrative and exemplary and should not be construed as limiting the embodiments of the present invention and the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can also adopt obvious other technical solutions based on the contents disclosed in the claims of this application and the specification thereof, including technical solutions that adopt any obvious replacements and modifications to the embodiments described herein.

[0032] It should be noted that the drawings in this embodiment are schematic diagrams to assist in illustrating the concept of the present invention and schematically illustrate the shapes of the various components and their interrelationships. It should be understood that in order to clearly illustrate the structure of the various components of the present invention, the drawings are not drawn to the same scale, and the same reference numerals are used to represent the same parts in the drawings.

[0033] As mentioned in the background, particles generated during semiconductor wafer processing can lead to reduced wafer yield, device failure, and even batch scrapping. If particle contamination originates in the coater, developer, or exposure machine, it's often difficult to pinpoint the source.

[0034] In order to solve the above technical problems, an embodiment of the present invention provides a device for detecting wafer particle contamination. By setting up a separate detection chamber, the wafer can be detected without affecting the progress of other processes. The detection chamber is provided with a vacuum suction cup for carrying and driving the wafer to rotate, and also has a mechanical moving component for controlling the position of the particle scanning device to drive the particle scanning device to scan the wafer, and can also drive the particle scanning device away from above the wafer to avoid collision during the process of taking and placing the wafer. The particle scanning device scans and transmits the surface information of the wafer above the wafer, and obtains the surface information through the processing module. According to the surface information, it is determined whether the wafer has particle contamination. Therefore, the problem of detecting particle contamination on the wafer surface can be effectively handled.

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is described clearly and completely below with reference to the accompanying drawings.

[0036] See also Figure 1 , Figure 1 A cross-sectional schematic diagram of a device for detecting wafer particle contamination in an embodiment of the present invention is shown.

[0037] In this embodiment, the device for detecting wafer particle contamination may include: a detection chamber 100, a vacuum suction cup 200, a mechanical moving component, a fixed arm 310, a first end 310a of the fixed arm, a guide rail 320, a second end 310b of the fixed arm, a particle scanning device 400, and a processing module (not shown).

[0038] The detection chamber 100 is disposed inside the machine and independently disposed outside each process chamber. Each process unit can place the wafer in the detection chamber 100 to perform particle contamination detection without affecting the progress of the process.

[0039] In some embodiments, the inspection chamber 100 has an opening for wafers to enter and exit the inspection chamber 100. The opening can accommodate wafers of various sizes, so that the wafers can enter and exit the inspection chamber 100 smoothly.

[0040] In some embodiments, the detection chamber 100 has a top opening and a sealing door matching the top opening. The wafer is placed in the detection chamber 100 and the sealing door is closed to form a closed space.

[0041] In some embodiments, the detection chamber 100 may reuse a portion of the space of a process chamber.

[0042] The vacuum chuck 200 is located in the inspection chamber 100 and is used to carry and drive the wafer to rotate.

[0043] Specifically, the vacuum chuck 200 is coupled to a lifting structure 210. The lifting structure 210 can control the lifting of the vacuum chuck 200 to receive the wafer and suck it down to a predetermined scanning area. In addition, the vacuum chuck 200 can rotate the wafer in the scanning area.

[0044] In some embodiments, the vacuum chuck 200 is disposed on the wafer carrier, combined with the lifting structure 210, and coupled to the motor 500 to provide power to achieve the purpose of receiving the wafer, carrying the wafer, and driving the wafer to rotate.

[0045] The vacuum cup 200 is coupled to a vacuum pump, which can provide negative pressure to the vacuum cup 200 to maintain a vacuum environment.

[0046] The mechanical moving assembly includes a fixed arm 310 and a guide rail 320 coupled to a first end 310 a of the fixed arm. A second end 310 b of the fixed arm is coupled to an inner wall of the detection chamber 100 .

[0047] In other words, the second end 310 b of the fixing arm is directly or indirectly connected to the inner wall of the detection chamber 100 , so as to fix the mechanical moving component to the inner wall of the detection chamber 100 .

[0048] The particle scanning device 400 is movably mounted on the guide rail 320 and, in a scanning state, scans and transmits surface information of the wafer W from above the vacuum chuck 200 . The guide rail 320 is parallel to the plane of the vacuum chuck 200 , and the projection of the guide rail 320 on the vacuum chuck 200 covers at least the radius of the wafer W.

[0049] Specifically, the particle scanning device 400 is fixed on the guide rail 320 and can move along the guide rail 320 in the A1 direction. The guide rail 320 is parallel to the plane of the vacuum chuck 200, ensuring that the movement trajectory of the particle scanning device 400 fixed on the guide rail 320 is parallel to the plane of the vacuum chuck 200. This ensures that the distance between the particle scanning device 400 and the plane of the vacuum chuck 200 is fixed, facilitating the scanning and transmission of surface information of the wafer W from above the vacuum chuck 200 in the scanning state.

[0050] In addition, the projection of the guide rail 320 on the vacuum suction cup 200 covers at least the radius of the wafer W, that is, the length of the guide rail 320 is greater than the radius of the wafer W, so that the particle scanning device 400 cooperates with the rotatable vacuum suction cup 200 that fixes the wafer, and its scanning range can completely cover the wafer W.

[0051] In some embodiments, a rotation axis is provided at the coupling between the first end 310a of the fixed arm and the guide rail 320. One end of the rotation axis is fixed to the first end 310a of the fixed arm, and the other end is connected to the guide rail 320, allowing the guide rail 320 to rotate about the rotation axis. The particle scanning device 400, fixed to the guide rail 320, scans the wafer W in a circle as the guide rail 320 rotates.

[0052] In some embodiments, the mechanical moving component controls the particle scanning device 400 to move to a position close to one of the inner walls of the inspection chamber 100 , leaving sufficient space for placing and taking wafers.

[0053] In this embodiment, one of the inner walls of the detection chamber 100 has an inwardly recessed storage cavity 110 (shown as a rectangular dotted line portion in the figure). In a non-scanning state, the storage cavity 110 is used to accommodate the particle scanning device 400.

[0054] Specifically, after scanning is completed, that is, in the non-scanning state, the mechanical moving component will control the particle scanning device 400 to move to the storage chamber 110, so that the wafer will not collide with the mechanical moving component and the particle scanning device 400 when being taken in and out.

[0055] The processing module is coupled to the particle scanning device 400 and is used to control the particle scanning device 400 to move along the mechanical moving component and obtain the surface information, and determine whether the wafer is contaminated by particles based on the surface information.

[0056] In other words, the processing module can realize the coordinated control of the mechanical moving component and the particle scanning device 400, so that the particle scanning device 400 obtains the surface information while moving along the mechanical moving component in the A1 direction, and determines whether the wafer is contaminated with particles based on the surface information.

[0057] In addition, the processing module can be coupled with various components in the detection chamber 100 to control the coordinated operation of various components, thereby obtaining surface information of the wafer.

[0058] It should be noted that the number of relative rotations between the particle scanning device 400 and the wafer is an integer, that is, the particle scanning device 400 can scan a certain circle of the wafer multiple times and then move on the guide rail 320 to improve the accuracy of the scanning data.

[0059] In addition, the processing module can realize human-computer interaction and can manually trigger instructions and modify parameters.

[0060] It should be noted that the processing module is only a division of logical functions, and in actual implementation, it can be fully or partially integrated into a physical entity, or physically separated. In addition, the module can be implemented in the form of a processor calling software.

[0061] In some embodiments, the processing module is integrated into the detection chamber 100 and coupled to each component in the detection chamber 100 to process the wafer surface information obtained from the particle scanning device 400 to determine whether the wafer is contaminated by particles.

[0062] If it is determined that the wafer is contaminated by particles, the processing module may transmit a particle contamination signal to the machine, display detection information and / or trigger an early warning.

[0063] In some embodiments, the processing module is integrated into a machine, and the machine receives wafer surface information transmitted from the detection chamber 100. The processing module can determine whether the wafer is contaminated with particles based on the wafer surface information and compare the preset particle accuracy threshold with the detected wafer surface information, and display or warn.

[0064] In this embodiment, the preset particle accuracy threshold is greater than or equal to 20 nanometers.

[0065] The above-mentioned processing module can be implemented in whole or in part by software, hardware, firmware or any other combination. When implemented using software, the above-mentioned embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer program are loaded or executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer program can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer program can be transmitted from one website, computer, server or data center to another website, computer, server or data center by wired or wireless means.

[0066] The wafer surface information is obtained by scanning by the particle scanning device 400 , and the wafer surface information is one or more of the following: images, videos, parameters, and digital signals.

[0067] In some embodiments, the mechanical movement assembly further includes a height adjustment member 330 .

[0068] The second end 330b of the height adjustment member is axially connected to the first end 310a of the fixed arm, and the height adjustment member 330 moves or is fixed relative to the first end 310a of the fixed arm in a direction perpendicular to the plane where the vacuum suction cup 200 is located. Figure 1 As shown in the direction A2, the direction A2 is perpendicular to the plane where the vacuum suction cup 200 is located.

[0069] Specifically, the height adjustment member 330 is a structure that realizes axial relative movement through a precise shaft connection structure. The height adjustment member 330 can precisely adjust its relative position with the first end 310a of the fixed arm through the rotation of the shaft and the internal gear structure.

[0070] In addition, the first end 330 a of the height adjustment member is fixedly connected to the guide rail 320 , and the guide rail 320 is disposed above the plane where the vacuum suction cup 200 is located.

[0071] In other words, the height adjustment member 330 can adjust the distance between the particle scanning device 400 and the plane where the vacuum chuck 200 is located by adjusting its relative position to the first end 310a of the fixed arm. This arrangement can adjust the distance so that the particle scanning device 400 is in the optimal position for scanning signals.

[0072] In some embodiments, the second end 330b of the height adjustment member is fixedly connected to the first end 310a of the fixed arm, and the first end 330a of the height adjustment member is pivotally connected to the guide rail 320. With this arrangement, the height adjustment member 330 can adjust its relative position to the guide rail 320, thereby adjusting the distance between the particle scanning device 400 and the plane where the vacuum suction cup 200 is located, so that the particle scanning device 400 is in an optimal position for scanning signals.

[0073] See also Figure 2 , Figure 2 A cross-sectional schematic diagram of a rotating shaft in an embodiment of the present invention is shown.

[0074] The mechanical movement assembly further includes a rotating shaft 340, through which the second end 310b of the fixed arm is connected to the inner wall of the detection chamber 100. The rotating shaft 340 is coupled to the motor 500 to obtain power to drive the fixed arm 310. The rotating shaft 340 includes a fixing portion 341, a connecting portion 342, and a control portion 343.

[0075] In some embodiments, the rotating shaft 340 is disposed in the storage cavity 110 and connected to one of the inner walls of the storage cavity 110 .

[0076] Specifically, the first end 341a of the fixing portion is connected to the inner wall of the storage chamber 110 for fixing the rotating shaft 340 to the inner wall of the chamber.

[0077] The connecting portion 342 passes through part or all of the second end 341b of the fixing portion, is axially connected to the second end 341b of the fixing portion, can rotate and move on the second end 341b of the fixing portion, and is fixedly connected to the second end 310b of the fixing arm.

[0078] In other words, there are two second ends 341b of the fixing part, one end of the connecting part 342 is clamped to the second end 341b of one of the fixing parts, and the other end is passed through the second end 341b of the other fixing part, and the connecting part 342 can rotate in the second end 341b of the fixing part, thereby driving the fixing arm 310 to move.

[0079] The first end 343 a of the control portion is connected to the inner wall of the detection chamber 100 , and the second end 343 b of the control portion is engaged with the connecting portion 342 for controlling the rotation of the connecting portion 342 to adjust the position of the fixed arm 310 .

[0080] Specifically, the control part 343 is coupled to the motor to obtain power, and the first end 343a of the control part realizes power transmission through the gear surface contact with the connecting part 342 passing through the second end 341b of the fixing part to control the rotation of the connecting part 342 to adjust the position of the fixing arm 310.

[0081] Continue to refer to Figure 1 The guide rail 320 is provided with a slider 321 for fixing the particle scanning device 400 .

[0082] In some embodiments, the guide rail 320 is preferably made of high-strength aluminum alloy or stainless steel, which has high rigidity and wear resistance to ensure that the accuracy is maintained during long-term use.

[0083] In addition, the surface of the guide rail 320 may be coated with a lubricating coating to reduce friction resistance when the slider 321 moves.

[0084] In some embodiments, the slider 321 is disposed on the guide rail 320 to fix the particle scanning device 400. The slider 321 is preferably a slider or a moving platform, and a slider 321 is provided at the bottom thereof to cooperate with the guide rail 320 to ensure smooth movement.

[0085] In some embodiments, a mounting bracket is provided on the slider 321 for fixing the particle scanning device 400 and directing the particle scanning device 400 toward the wafer W. The mounting bracket can be adjusted in angle and height to accommodate wafers W of different sizes and types.

[0086] In some embodiments, a limiter may be further provided on the guide rail 320 to limit the moving range of the slider 321 to prevent overtravel.

[0087] In some embodiments, a motor 500 is used to drive the slider 321 to move along the guide rail 320 .

[0088] Specifically, the motor 500 is preferably a stepper motor or a servo motor, which has high precision and high response speed, and can achieve precise control of the particle scanning device 400.

[0089] In some embodiments, the motor 500 is connected to the slider 321 via a coupling to convert rotational motion into linear motion.

[0090] In addition, the motor 500 may be equipped with a reducer to improve torque and motion smoothness.

[0091] In some embodiments, the guide rail 320 further has a position sensor for monitoring the position of the particle scanning device 400 on the guide rail 320 .

[0092] In some embodiments, the position sensor is preferably a photoelectric encoder or a Hall sensor, which is installed at both ends of the guide rail 320 .

[0093] In some embodiments, the position sensor detects the position of the slider 321 in real time and feeds the position information back to a control unit (not shown).

[0094] In some embodiments, the control unit is coupled to the position sensor and the motor 500 , and is configured to control the position of the particle scanning device 400 on the guide rail 320 according to position information transmitted by the position sensor.

[0095] Specifically, the control unit is preferably a microcontroller (MCU) or a programmable logic controller (PLC) with a built-in control algorithm, which can adjust the position of the particle scanning device 400 on the guide rail 320 in real time.

[0096] It is particularly noted that when the processing module is integrated into the detection chamber 100 , the control unit is integrated with the processing module.

[0097] The particle scanning device 400 is selected from: a white light interferometer, a scanning electron microscope, an atomic force microscope, and an optical microscope.

[0098] The white-light interferometer is a device used to analyze the interference fringes formed after light is reflected from two different surfaces. Its basic principle is to form a reference light path and a detection light path using different optical elements. The interference principle is used to measure the difference in optical path lengths, thereby determining relevant physical quantities. Any change in the optical path difference between two coherent light beams will very sensitively cause the interference fringes to shift. The change in the optical path length of a coherent light beam is caused by changes in the geometric path length or refractive index of the medium it traverses. Therefore, the shift in the interference fringes can be used to measure small changes in geometric length or refractive index, thereby measuring other related physical quantities. Measurement accuracy is determined by the accuracy of the optical path difference. For every fringe spacing that the interference fringes shift, the optical path difference changes by one wavelength. Therefore, the white-light interferometer measures the optical path difference in units of light wavelength, achieving a high degree of measurement accuracy unmatched by other measurement methods.

[0099] Scanning electron microscopy, with its exceptional resolution and imaging capabilities, has become a core tool for particle defect detection. By scanning the sample surface with an electron beam and collecting the reflected or scattered electrons to form a high-definition image, it reveals detailed information about tiny particles and surface structures, providing researchers with data on the morphology, size, and distribution of defects.

[0100] Atomic force microscopy (AFM) uses the interaction forces between atoms to create images, mapping precise three-dimensional surface topography by detecting the minute force changes between the tip and the sample surface. AFM has exceptional precision and sensitivity in detecting and analyzing nanoscale particle defects, enabling it to identify subtle defects that may be missed by scanning electron microscopy.

[0101] Although optical microscopes lack the resolution of scanning electron microscopes and atomic force microscopes, their simple operation and low cost make them a popular choice for macroscopic defect detection. They can quickly identify larger particle defects, providing preliminary information for subsequent precise analysis.

[0102] In this embodiment, the particle scanning device 400 is preferably a white light interferometer. The information transmitted by the white light interferometer during scanning is the optical path difference between the detection light and the reference light, that is, the surface information or wafer surface information.

[0103] The motor 500 is coupled to the vacuum cup 200 to provide power for the lifting and rotation of the vacuum cup 200 .

[0104] The motor 500 is further coupled to the processing module for receiving a control signal to precisely control the rotation speed, angle, and direction of the vacuum chuck 200 .

[0105] The motor is selected from: a servo motor, a stepper motor, and a direct drive motor.

[0106] The servo motor can control speed and position with high precision, converting voltage signals into torque and speed to drive the controlled object. The rotor speed of a servo motor is controlled by an input signal and responds quickly. It is used as an actuator in automatic control systems and features a small electromechanical time constant and high linearity. It converts the received electrical signal into an angular displacement or angular velocity output on the motor shaft. This servo motor was chosen primarily because it can maintain constant torque at low speeds.

[0107] A stepper motor is an actuator that converts electrical pulses into angular displacement. When a stepper driver receives a pulse signal, it drives the stepper motor to rotate in a set direction and a fixed angle (called the "step angle"). The rotation is performed step by step at a fixed angle. The angular displacement can be controlled by controlling the number of pulses, thereby achieving precise control of rotational positioning.

[0108] Direct-drive motors are novel rotary or linear motors that are directly coupled or connected to a driven load. This eliminates many of the intermediate links in traditional systems, such as belts, chains, wire ropes, and gearboxes, significantly simplifying the structure. This results in a system with advantages such as high efficiency and low power consumption, high speed and precision, high reliability and maintenance-free operation, high rigidity and fast response, no lubrication required, and quiet operation.

[0109] It can be understood that the above describes multiple embodiment schemes provided by this embodiment, and the various optional methods introduced in each embodiment scheme can be combined and cross-referenced with each other without conflict, thereby extending a variety of possible embodiment schemes, which can all be considered as embodiment schemes disclosed and open to the public by the present invention.

[0110] This embodiment also provides a method for detecting wafer particle contamination corresponding to the above-mentioned device for detecting wafer particle contamination, which is described below with reference to Figure 3It should be noted that the content of the method for detecting wafer particle contamination described below can be referenced in correspondence with the content of the device for detecting wafer particle contamination described above.

[0111] See also Figure 3 , Figure 3 A schematic flow chart of a method for detecting wafer particle contamination according to an embodiment of the present invention is shown. Steps S31 to S36 may be performed as follows. Figure 4 To explain, Figure 4 A schematic diagram showing preset positions of a device for detecting wafer particle contamination in an embodiment of the present invention is shown.

[0112] In step S31, in response to the received wafer placement signal, the wafer is adsorbed and fixed at the first preset position 610 in the inspection chamber by raising and lowering the vacuum suction cup 200. The first preset position 610 is the position of the wafer after the vacuum suction cup 200 receives the wafer and descends to the wafer inspection state.

[0113] After the processing module in the inspection chamber 100 receives the wafer placement signal from the machine, the processing module drives the vacuum chuck 200 through the motor.

[0114] The step of sucking and fixing the wafer at the first preset position 610 by lifting and lowering the vacuum chuck 200 includes: driving the vacuum chuck to rise to a position for receiving the wafer by a motor.

[0115] In a specific embodiment, the processing module sends an ascending instruction to the servo motor to drive the vacuum chuck 200 to move in the vertical direction ( Figure 1 The robot (not shown) moves upward (in the direction A2 shown) to a wafer receiving height, which is 2 to 5 mm below the opening of the inspection chamber 100, to ensure that a robot arm (not shown) can stably place the wafer (W).

[0116] In the step of adsorbing and fixing the wafer by turning on the vacuum pump, when the wafer (W) is placed on the surface of the vacuum suction cup 200, the processing module triggers the vacuum control valve to open, so that the vacuum pump establishes negative pressure (-80kPa to -95kPa) within 50 to 100ms, and the wafer is evenly adsorbed by the vacuum suction cup 200.

[0117] In some embodiments, the vacuum adsorption process is monitored in real time by a pressure sensor. If the adsorption force does not reach a set threshold (such as -80 kPa), an alarm is triggered and the process is terminated, and the wafer is repositioned.

[0118] In the step of driving the vacuum suction cup to descend to the first preset position 610 by the motor, after the adsorption is completed, the motor drives the vacuum suction cup 200 to descend to the first preset position 610, which satisfies the following conditions:

[0119] The space above the wafer surface is sufficient for the particle scanning device 400 to complete the scanning.

[0120] The distance between the edge of the wafer and the side wall of the inspection chamber 100 is ≥10 mm to avoid collision.

[0121] During the descent, the acceleration is controlled at 0.1-0.5 m / s 2 , to avoid displacement of the wafer on the surface of the vacuum chuck 200 due to inertia.

[0122] In step S32 , the particle scanning device 400 is moved to a second preset position 620 by controlling the mechanical moving component. The second preset position 620 is set above the vacuum chuck 200 , and the projection of the second preset position 620 is located at the edge of the wafer.

[0123] Specifically, the spatial coordinates of the second preset position 620 are pre-stored in the memory of the processing module. In the height direction, the distance between the particle scanning device 400 and the surface of the wafer W is adjusted by the height adjustment member 330 to ensure the focusing accuracy of the particle scanning device 400. In the horizontal direction, the projection center of the particle scanning device 400 is located 2 to 5 mm inside the edge of the wafer (e.g. Figure 4 as shown) to completely cover the edge detection area.

[0124] After reaching the second preset position 620 , the system verifies the deviation between the actual coordinates and the preset coordinates (needed to be ≤±1 μm), and triggers automatic compensation if the deviation exceeds the tolerance.

[0125] In step S33, the vacuum chuck is rotated to set the positioning groove of the wafer as the initial position of the wafer directly below the particle scanning device.

[0126] The motor 500 drives the vacuum suction cup 200 to rotate at a low speed (5 to 10 rpm), and at the same time scans the edge surface information of the wafer through the particle scanning device 400, and identifies the edge positioning groove features of the wafer (such as a V-shaped notch or a flat edge) through an image processing algorithm, so as to set the positioning groove of the wafer as the initial position of the wafer directly below the particle scanning device 400.

[0127] In step S34 , while the wafer is rotating, the particle scanning device is moved by controlling the mechanical moving component so that the particle scanning device scans the wafer surface circle by circle starting from the initial position of the wafer to obtain wafer surface information.

[0128] In other words, the processing module coordinates the rotational movement of the vacuum suction cup 200 and the linear movement of the mechanical moving component, so that the particle scanning device 400 starts from the initial position of the wafer (positioning groove alignment position) and covers the entire surface of the wafer (W) circle by circle with a spiral scanning trajectory, thereby obtaining surface morphology and particle contamination information in real time.

[0129] The vacuum chuck 200 is driven by the motor 500 and rotates at a constant angular velocity ω (1-30 rpm) with a speed fluctuation of ≤±0.1%. The guide rail 320 of the mechanical motion assembly adjusts the radial position of the slider 321 in real time along a spiral trajectory. The processing module's algorithm synchronizes the rotational linear motion of the vacuum chuck 200 and the mechanical motion assembly, enabling the particle scanning device 400 to perform a spiral scan, ensuring 100% coverage of all locations on the wafer surface without missing any detections.

[0130] In step S35 , whether particle contamination occurs is determined based on the wafer surface information and a preset particle accuracy threshold.

[0131] Specifically, the processing module performs data integrity verification, and determines whether the wafer surface information is scanned completely based on the wafer surface information obtained by scanning and in combination with the wafer size.

[0132] If complete, the processing module performs particle contamination determination and determines whether particle contamination occurs based on a preset particle precision threshold that is greater than or equal to 20 nanometers.

[0133] Otherwise, rescan the information on the wafer surface.

[0134] In step S36 , the particle scanning device is moved to a third preset position 630 by controlling the mechanical moving component. The third preset position 630 is away from the projection of the wafer in the lifting direction of the vacuum chuck 200 .

[0135] In the lifting direction of the vacuum chuck 200 , the projection of the third preset position 630 is completely out of the occupied area of the wafer W, thereby avoiding collision during wafer transportation.

[0136] In some embodiments, the processing module calculates an interference-free path from the current scanning position to the third preset position 630 based on the three-dimensional model of the detection chamber 100, and moves the particle scanning device 400 to a safe standby area in the detection chamber 100 by controlling the mechanical moving component.

[0137] In some embodiments, the third preset position 630 is located in the storage cavity 110 .

[0138] It can be understood that the above describes multiple embodiments of the method for detecting the angle of the wafer positioning groove. The various optional methods introduced in each embodiment can be combined and cross-referenced with each other without conflict, thereby extending a variety of possible embodiments, which can all be considered as embodiments disclosed and open to the public by the present invention.

[0139] It should be understood that the term "and / or" as used herein simply describes an association between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " as used herein indicates that the related objects are in an "or" relationship.

[0140] The term "plurality" used in the embodiments of the present application refers to two or more.

[0141] The first, second, etc. descriptions appearing in the embodiments of this application are only for illustration and distinction of the description objects. There is no order, nor does it indicate any special limitation on the number of devices in the embodiments of this application, and cannot constitute any limitation on the embodiments of this application.

[0142] It should be noted that the serial numbers of the steps in this embodiment do not limit the execution order of the steps.

[0143] Although the embodiments of the present invention are disclosed above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A device for detecting wafer particle contamination, characterized in that: include: Detection chamber; A rotatable vacuum chuck is located in the inspection chamber and is used to carry and drive the wafer to rotate; A mechanical moving assembly includes a fixed arm and a guide rail coupled to a first end of the fixed arm, a second end of the fixed arm coupled to an inner wall of the inspection chamber, the guide rail being parallel to a plane where the vacuum chuck is located, and a projection of the guide rail on the vacuum chuck covers at least a radius of the wafer; a particle scanning device, movably placed on the guide rail, and in a scanning state, scanning and transmitting surface information of the wafer from above the vacuum chuck; A processing module is coupled to the particle scanning device, and is used to control the particle scanning device to move along the mechanical moving component and obtain the surface information, and determine whether the wafer is contaminated by particles based on the surface information.

2. The device for detecting wafer particle contamination according to claim 1, characterized in that: The mechanical movement assembly further comprises: a height adjustment member axially connected to the second end of the fixed arm, wherein the height adjustment member is movable or fixed relative to the second end of the fixed arm in a direction perpendicular to the plane where the vacuum suction cup is located; Wherein, the first end of the height adjustment member is connected to the guide rail, and the guide rail is arranged above the plane where the vacuum suction cup is located.

3. The device for detecting wafer particle contamination according to claim 2, characterized in that: The mechanical moving assembly further includes: a rotating shaft, through which the second end of the fixed arm is connected to the inner wall of the detection chamber; The rotating shaft includes a fixing portion, a connecting portion and a control portion; The first end of the fixing portion is connected to the inner wall of the detection chamber; The connecting portion passes through part or all of the second end of the fixing portion, is axially connected to the second end of the fixing portion and is capable of rotating and moving at the second end of the fixing portion, and is fixedly connected to the second end of the fixing arm; The first end of the control part is connected to the inner wall of the detection chamber, and the second end of the control part is engaged with the connecting part for controlling the rotation of the connecting part to adjust the position of the fixed arm.

4. The device for detecting wafer particle contamination according to claim 1, wherein: The guide rail is provided with a slider for fixing the particle scanning device.

5. The device for detecting wafer particle contamination according to claim 1, wherein: The particle scanning device is selected from: a white light interferometer, a scanning electron microscope, an atomic force microscope, and an optical microscope.

6. The device for detecting wafer particle contamination according to claim 1, characterized in that: One of the inner walls of the detection chamber has an inwardly recessed storage cavity; In a non-scanning state, the storage cavity is used to accommodate the particle scanning device.

7. The device for detecting wafer particle contamination according to claim 1, characterized in that: Also includes: a motor coupled to the vacuum chuck, the motor also coupled to the processing module, for receiving a control signal to precisely control the rotation speed, angle, and direction of the vacuum chuck; Wherein, the motor is also used to drive the vacuum suction cup to rise and fall.

8. A method for detecting wafer particle contamination, characterized in that: An apparatus for detecting wafer particle contamination, the apparatus comprising a detection chamber, a rotatable vacuum chuck, a mechanical moving component, a particle scanning device, and a processing module; The method comprises: In response to the received wafer placement signal, the wafer is fixed in a first preset position in the inspection chamber by raising and lowering the vacuum suction cup, wherein the first preset position is the position of the wafer after the vacuum suction cup receives the wafer and descends to the wafer inspection state; By controlling the mechanical moving component, the particle scanning device is moved to a second preset position, wherein the second preset position is set above the vacuum chuck, and the projection of the second preset position is located at the edge of the wafer; Rotating the vacuum chuck to position the wafer's positioning groove directly below the particle scanning device as the wafer's initial position; When the wafer is rotating, the particle scanning device is moved by controlling the mechanical moving component so that the particle scanning device scans the wafer surface circle by circle starting from the initial position of the wafer to obtain wafer surface information; Determining whether particle contamination occurs based on the wafer surface information and a preset particle accuracy threshold; The particle scanning device is moved to a third preset position by controlling the mechanical moving component, wherein the third preset position is away from a projection of the wafer in the lifting direction of the vacuum chuck.

9. The method for detecting wafer particle contamination according to claim 8, wherein: The device for detecting wafer particle contamination includes: a motor and a vacuum pump; The step of sucking and fixing the wafer at the first preset position by lifting and lowering the vacuum suction cup includes: The vacuum chuck is driven by a motor to rise to a position to receive the wafer; By turning on the vacuum pump, the wafer is adsorbed and fixed; The vacuum suction cup is driven by a motor to descend to a first preset position.

10. The method for detecting wafer particle contamination according to claim 8, wherein: The step of determining whether particle contamination occurs based on the obtained information about the wafer surface and a preset particle accuracy further includes: By obtaining the information of the wafer surface, it is determined whether the information of the wafer surface is scanned completely; If it is complete, it is determined whether particle contamination occurs based on the preset particle accuracy; Otherwise, rescan the information on the wafer surface.

11. The method for detecting wafer particle contamination according to claim 8, wherein: The particle accuracy threshold is greater than or equal to 20 nanometers.

Images