Spiral scanning apparatus including multiple measurement sensors and wafer inspection method using same

Abstract

The present invention relates to a spiral scanning apparatus including multiple measurement sensors and a wafer inspection method using same. More specifically, the present invention relates to a technology for rapidly and uniformly inspecting the surface or interior of a wafer by using a spiral scanning apparatus including a plurality of measurement sensors, wherein the rotational speed of a chuck stage and the movement of the plurality of measurement sensors may be controlled, and a wafer measurement area may be separated to enable the plurality of measurement sensors to measure respective areas. Contamination and defects on the surface or in the interior of the wafer may be efficiently detected by outputting measured data as images and synthesizing the images. According to embodiments of the present invention, the spiral scanning apparatus including the multiple measurement sensors may comprise a chuck stage (100), a plurality of measurement sensors (110), and a control unit (120).

Description

A spiral scan device including multiple measurement sensors and a wafer inspection method using the same

[0001] The present invention relates to a spiral scan device including multiple measurement sensors and a wafer inspection method using the same. More specifically, the present invention relates to a technology for rapidly and uniformly inspecting the surface or interior of a wafer using a spiral scan device including multiple measurement sensors. The technology comprises controlling the rotational speed of a chuck stage and the movement of multiple measurement sensors, separating wafer measurement areas so that each area can be measured by multiple measurement sensors. By outputting the measured data as an image and synthesizing them, contamination and defects on the surface or interior of the wafer can be efficiently detected.

[0002] The performance, reliability, and functionality of semiconductors are primarily determined by the uniformity and cleanliness of the semiconductor materials and surfaces. These factors are controlled through highly precise processes, and this requires optimization of the systems and processes used to process and manipulate semiconductor materials. The ability to precisely measure and analyze surface and material properties is crucial in this process. Billions of dollars and countless man-hours have been invested in developing and optimizing semiconductor processes, with the core goal of achieving uniform and clean materials and surfaces across the entire wafer.

[0003] During semiconductor manufacturing, it is essential to continuously monitor and control the cleanliness and uniformity of the wafer surface. To achieve this, a scanning probe sensor is used to measure the surface or interior of a rotating wafer while moving at a set interval from the center of the wafer, thereby detecting changes such as height and work function changes on the wafer surface or interior. Depending on the defect being detected, scanning probe sensors can be capacitive sensors, non-vibrational contact potential difference sensors, underwater ultrasonic sensors, laser sensors, or confocal sensors. These sensors can scan the wafer surface or interior and generate high-resolution images of the scan results. These images play a crucial role in assessing wafer quality. These scanning probe sensors can collect data at extremely high speeds without damaging or contaminating the wafer surface or interior, making them an advantageous technology for real-time process control.

[0004] However, conventional radial scanning technology has several significant issues. Conventional methods involve rotating the sensor around the center of the wafer while scanning radially. While this method can scan the entire wafer surface or interior, it can be problematic due to the use of a single sensor. A single sensor is unable to quickly and accurately measure the wafer surface or interior. Because the sensor sequentially measures only specific points on the wafer, real-time monitoring of the wafer surface or interior takes significant time, delaying the inspection process and incurring significant costs and time in the semiconductor manufacturing process, ultimately reducing production efficiency and yield. These issues can negatively impact the quality and reliability of semiconductor devices, and can be particularly detrimental in today's high-tech environment, which demands highly precise semiconductor devices.

[0005] Meanwhile, a technology related to a system and device for inspecting the surface of a wafer using a sensor is disclosed in Korean Patent No. 10-0929768 (announced on November 25, 2009).

[0006]

[0007] The present invention has been made to solve the above problems, and its purpose is to provide a spiral scanning device including multiple measurement sensors for inspecting the cleanliness of the surface of a semiconductor wafer or the uniformity of its interior.

[0008] In addition, the purpose is to provide a spiral scan device including multiple measurement sensors with optimized measurement positions so that multiple measurement sensors installed on the wafer surface can quickly and uniformly measure regardless of size.

[0009] In addition, by using multiple measurement sensors, the scanning speed can be significantly improved, and the rotation speed of the chuck that holds the wafer and the movement speed of the measurement sensor can be optimized to detect defects or contamination on the surface or inside of the wafer more accurately and quickly, thereby providing a spiral scan device including multiple measurement sensors that enables faster and more efficient wafer inspection than the existing method.

[0010]

[0011] According to an embodiment of the present invention, a spiral scan device including multiple measurement sensors includes a chuck stage that loads a wafer, a rotatable chuck stage, a plurality of measurement sensors positioned at positions spaced apart from an upper surface of the chuck stage, and a control unit that controls the rotation speed of the chuck stage, movement of the measurement sensors, and acquires and processes signals output from the measurement sensors.

[0012] It is preferable that the above plurality of measurement sensors are underwater ultrasonic transducers or have different resolutions.

[0013] In addition, the chuck stage is configured to have a rotation shaft connected to the center of the bottom surface thereof and rotated by a separate motor, and is characterized in that it includes a vacuum suction device connected to the rotation shaft to fix the loaded wafer.

[0014] In addition, the plurality of measurement sensors include a first measurement sensor and a second measurement sensor, the wafer includes a first measurement area including a center of the wafer and a second measurement area outside the first measurement area, the first measurement sensor measures a surface or the inside of the wafer in the first measurement area, the second measurement sensor measures a surface or the inside of the wafer in the second measurement area, and a path along which the first measurement sensor moves is from point 1a to point 1b, point 1a is a boundary between the first measurement area and the second measurement area, point 1b is a center of the wafer, and a path along which the second measurement sensor moves is from point 2a to point 2b, point 2a is a boundary between the first measurement area and the second measurement area, and point 2b is an outer periphery of the wafer.

[0015] In addition, the 1a point and the 2a point are arranged symmetrically in opposite directions from the center of the wafer, and the distance between the 1a point and the 1b point and the distance between the 2a point and the 2b point are the same.

[0016] In addition, the plurality of measurement sensors include a first measurement sensor, a second measurement sensor, and a third measurement sensor, and the wafer includes a first measurement area at the center of the wafer, a second measurement area at the periphery of the wafer, and a third measurement area located between the first measurement area and the second measurement area, and the first measurement sensor measures the surface or the inside of the wafer in the first measurement area, the second measurement sensor measures the surface or the inside of the wafer in the second measurement area, and the third measurement sensor measures the surface or the inside of the wafer in the third measurement area.

[0017] In addition, the path along which the first measurement sensor moves is from the point 1c to the point 1d, the point 1c being the center of the wafer, the point 1d being the boundary between the first measurement area and the third measurement area, the path along which the second measurement sensor moves is from the point 2c to the point 2d, the point 2c being the boundary between the second measurement area and the third measurement area, the point 2d being the outer edge of the wafer, and the path along which the third measurement sensor moves is from the point 3a to the point 3b, the point 3a being the boundary between the second measurement area and the third measurement area, and the point 3b being the boundary between the first measurement area and the third measurement area.

[0018] It is characterized in that the distance between the point 1c and the point 1d, the distance between the point 2c and the point 2d, and the distance between the point 3a and the point 3b are the same.

[0019] In addition, the plurality of measurement sensors are characterized in that they are arranged in a straight line in the Y-axis direction or are arranged spaced apart from each other based on the Y-axis, and when the first to third measurement sensors are arranged spaced apart from each other, the 1c point of the first measurement sensor is the center of the wafer, the 2c point of the second measurement sensor and the 3a point of the third measurement sensor are located to the left or right based on the Y-axis, the 2c point of the second measurement sensor is located in the second quadrant based on the XY axis, and the 3a point of the third measurement sensor is located in the third quadrant based on the XY axis.

[0020] On the other hand, when the first to third measurement sensors are arranged in a straight line in the X-axis direction of the wafer, the path along which the first measurement sensor moves is from point 1e to point 1f, the point 1e being the center of the wafer, the point 1f being the boundary between the first measurement area and the third measurement area, the path along which the second measurement sensor moves is from point 2e to point 2f, the point 2e being the boundary between the second measurement area and the third measurement area, the point 2f being the outer edge of the wafer, and the path along which the third measurement sensor moves is from point 3c to point 3d, the point 3c being the boundary between the first measurement area and the third measurement area, and the point 3d being the boundary between the second measurement area and the third measurement area.

[0021] In addition, the distance between the 1e point and the 1f point, the distance between the 2e point and the 2f point, and the distance between the 3c point and the 3d point are the same, and the distance between the 1e point and the 3c point is narrower than the distance between the 1e point and the 2e point.

[0022] In addition, the plurality of measurement sensors having the plurality of resolutions include at least one of: transducers having different vibration frequencies; probes having different tip sizes and focal lengths; or image detection devices having different resolutions; wherein the vibration frequencies of the transducers have different values ​​within a range of 50 to 150 MHz, and the probe tip sizes and focal lengths have different values ​​within a range of 50 to 150 μm.

[0023] In addition, the plurality of measurement sensors having the plurality of resolutions include a first measurement sensor, a second measurement sensor, and a third measurement sensor, and the plurality of measurement sensors are arranged symmetrically in opposite directions from the center of the wafer, arranged in a straight line in the X-axis or Y-axis direction, or arranged spaced apart from each other, and the plurality of measurement sensors having the plurality of resolutions are characterized in that the arranged positions are measurement start points and measure the same distance from the measurement start point.

[0024] Next, a wafer inspection method using a spiral scan device including multiple measurement sensors includes the steps of loading a wafer onto a chuck stage, fixing the loaded wafer onto the chuck stage, positioning a plurality of measurement sensors, which are underwater ultrasonic transducers or have different resolutions, at a position spaced apart from the chuck stage; and scanning a surface or the inside of the wafer by moving each of the plurality of measurement sensors along its own movement path while rotating the chuck stage.

[0025] In addition, the method further includes a step of controlling the rotation speed of the chuck stage and movement of a plurality of measurement sensors, a step of obtaining signals output from the plurality of measurement sensors and synthesizing a scanning image of the wafer surface or interior, and a step of detecting a change in height or a change in work function pattern of the wafer surface or interior through the synthesized image.

[0026] In addition, the plurality of measurement sensors include two or more sensors, and the wafer includes a first measurement area including a center of the wafer, a second measurement area including an outer edge of the wafer, and a third measurement area located between the first measurement area and the second measurement area, and the first measurement sensor measures a surface or the inside of the wafer in the first measurement area, the second measurement sensor measures a surface or the inside of the wafer in the second measurement area, and the third measurement sensor measures a surface or the inside of the wafer in the third measurement area.

[0027] In addition, the plurality of measurement sensors are arranged in a straight line in the Y-axis direction of the wafer, or are arranged spaced apart from each other based on the Y-axis, or are arranged in a straight line in the X-axis direction of the wafer, and any one of the plurality of measurement sensors is arranged at the center of the wafer, or the point where the measurement ends is the center of the wafer, and in the step of scanning the surface or the inside of the wafer and the step of synthesizing the image, when the chuck stage is scanned outside the wafer surface, the chuck stage measurement signal is detected and the generated chuck stage scanning image is excluded and synthesized. In addition, the plurality of measurement sensors are characterized in that the arranged positions are measurement start points and measure the same distance from the measurement start point.

[0028]

[0029] The present invention can shorten the process time by quickly scanning the surface or interior of a wafer by having multiple measurement sensors arranged on the surface of the wafer and performing measurements simultaneously, and can precisely inspect the contamination status of the entire wafer by synthesizing the surface or interior images obtained through each measurement sensor.

[0030] Furthermore, by positioning multiple measurement sensors at regular intervals, interference due to sensor size is minimized, and all sensors perform measurements on the wafer surface or internally, enabling rapid and uniform measurements. This improves semiconductor productivity and yield, and enables early detection of surface or internal contamination, reducing defect rates.

[0031]

[0032] FIG. 1 is a drawing for explaining a spiral scan device including multiple measurement sensors according to one embodiment of the present invention.

[0033] FIG. 2 is a drawing for explaining the arrangement of two measurement sensors and a measurement area according to one embodiment of the present invention.

[0034] FIG. 3 is a drawing for explaining the arrangement of three measurement sensors and a measurement area to which another embodiment of the present invention is applied.

[0035] FIG. 4 is a drawing for explaining the arrangement of three measurement sensors and a measurement area to which another embodiment of the present invention is applied.

[0036] FIG. 5 is a drawing for explaining a measurement sensor and a measurement area arranged in the X-axis direction to which another embodiment of the present invention is applied.

[0037] FIG. 6 is a flowchart of a wafer inspection method using a spiral scan device including multiple measurement sensors according to one embodiment of the present invention.

[0038]

[0039] The present invention is susceptible to various modifications and may take various forms. Therefore, embodiments (or examples) are described in detail herein. However, this is not intended to limit the present invention to a specific disclosed form, and it should be understood that the present invention encompasses all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0040] The terminology used in this specification is only used to describe specific implementations (modes, aspects) (or examples) and is not intended to limit the present invention. The singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, it should be understood that terms such as ~comprises~ or ~consists of~ specify that a feature, number, step, operation, component, part or combination thereof described in the specification is present, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0041] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0042] The terms "first", "second", etc. described in this specification are only used to distinguish between different components, and are not limited to the manufacturing order, and their names may not be consistent in the detailed description of the invention and the claims.

[0043] FIG. 1 is a drawing for explaining a spiral scan device including multiple measurement sensors according to one embodiment of the present invention.

[0044] Referring to FIG. 1, a spiral scan device including multiple measurement sensors may include a chuck stage (100) that loads a wafer and can rotate, a plurality of measurement sensors (110) positioned at positions spaced apart from the upper surface of the chuck stage (100), a control unit (120) that controls the rotation speed of the chuck stage (100) and the movement of the measurement sensors (110) and obtains and processes signals output from the sensors. In addition, the device may further include a rotation shaft (130) connected to the center of the bottom surface of the chuck stage (100), a separate motor (140), and a vacuum suction device (150). The rotation shaft (130) may be rotated by the motor (140), and a wafer loaded on the chuck stage (100) may be fixed through the vacuum suction device (150) connected to the rotation shaft (130).

[0045] The plurality of measurement sensors (110) may include two or more measurement sensors, and are preferably arranged at a certain interval on the wafer surface.

[0046] At this time, it is most preferable that the plurality of measurement sensors (110) be placed apart from the wafer surface so that there is no unmeasurable area on the wafer surface or inside without interference with the measurement depending on the size of the sensor.

[0047] Additionally, the plurality of measurement sensors (110) may be either non-vibration contact potential difference sensors (nvCPD) or underwater ultrasonic transducers, depending on the defect to be detected. Depending on the type of sensor, a sensor probe tip may be added.

[0048] The non-vibration contact potential difference sensor (nvCPD) method is a method that generates a signal as a potential difference voltage that is a combination of a change in the work function of the surface to be measured or a change in the surface height, and the underwater ultrasonic inspection method may include a transducer in which ultrasonic waves generated from a probe penetrate into the inside of a wafer and propagate, and if a defect exists in the path of the ultrasonic waves, the ultrasonic waves are reflected by the defect and return, and a pulse signal is generated corresponding to the distance that the ultrasonic waves propagate by detecting the sound waves.

[0049] At this time, the plurality of measurement sensors (110) may have different resolutions. In the case of an underwater ultrasonic inspection device, the plurality of measurement sensors (110) having multiple resolutions may include a first measurement sensor including a transducer having a first vibration frequency and a second measurement sensor including a transducer having a second vibration frequency. It is preferable that the first vibration frequency and the second vibration frequency are set differently within a frequency range of 50 to 150 MHz. For example, if the first vibration frequency is 50 MHz, the second vibration frequency may be 100 MHz.

[0050] In addition, in the case of the non-vibration contact potential difference sensor (nvCPD) method, the plurality of measurement sensors (110) having multiple resolutions may include a first measurement sensor including a first probe having a first tip size and a first focal length, and a second measurement sensor including a second probe having a second tip size and a second focal length. The first tip size and the first focal length may have values ​​in a range of 50 to 150 μm, and the second tip size and the second focal length may be set to values ​​in a range of 50 to 150 μm. At this time, it is preferable that the first tip size and the first focal length and the second tip size and the second focal length have different values.

[0051] Images with different resolutions can be obtained by varying the probe tip size and focal length, and the tip size and focal length can be set differently depending on the purpose of wafer measurement, surface flatness, potential difference range, etc.

[0052] In addition, when using an image detection device, i.e., a camera, a plurality of measurement sensors (110) having multiple resolutions may include a first measurement sensor including an image detection device having a first resolution and a second measurement sensor including an image detection device having a second resolution. In this case, it is preferable that the first measurement sensor and the second measurement sensor have different resolutions.

[0053] FIG. 2 is a drawing for explaining the arrangement of two measurement sensors and a measurement area according to one embodiment of the present invention.

[0054] As shown in FIG. 2, a plurality of measurement sensors (110) according to one embodiment of the present invention include a first measurement sensor (10) and a second measurement sensor (20), and are preferably arranged on a wafer with a predetermined interval (1H). At this time, D is the diameter of the wafer, and the diameter of the wafer is usually 300 mm. 1H is the distance between the first measurement sensor (10) and the second measurement sensor (20), and is preferably about half the diameter of the wafer. Here, H means the distance between the measurement sensors. In FIG. 2, a first measurement area (12) including the center of the wafer and a second measurement area (22) outside the first measurement area (12) are included.

[0055] The first measurement sensor (10) can measure the surface or interior of the wafer in the first measurement area (12), and the second measurement sensor (20) can measure the surface or interior of the wafer in the second measurement area (22). The path along which the first measurement sensor (10) moves is from point 1a to point 1b, and the path along which the second measurement sensor (20) moves is from point 2a to point 2b.

[0056] First, point 1a is the boundary between the first measurement area (12) and the second measurement area (22), and point 1b is the center of the wafer. Next, point 2a is the boundary between the first measurement area (12) and the second measurement area (22), and point 2b is the outer edge of the wafer. At this time, point 1a and point 2a are located at both edges of the first measurement area (12), and are symmetrical in the opposite direction from the center of the wafer.

[0057] Additionally, the distance between point 1a and point 1b and the distance between point 2a and point 2b may be the same, and the two measurement sensors may measure the wafer surface or interior as they move in a straight line by the same distance.

[0058] As the first measurement sensor (10) and the second measurement sensor (20) move in a straight line in the Y-axis direction, the output signals can be converted into images and synthesized through the control unit (120).

[0059] FIG. 3 is a drawing for explaining the arrangement of three measurement sensors and a measurement area to which another embodiment of the present invention is applied.

[0060] FIG. 3 shows another embodiment of the present invention applied to scan the surface or interior of a wafer using three measurement sensors, which may include a first measurement sensor (10), a second measurement sensor (20), and a third measurement sensor (30). In this case, it is preferable that the measurement sensor include one of a transducer having different vibration frequencies, a probe having different tip sizes and focal lengths, or an image detection device having different resolutions.

[0061] It may include a first measurement area (12) including the center of the wafer, a second measurement area (22) including the periphery of the wafer, and a third measurement area (32) located between the first measurement area (12) and the second measurement area (22).

[0062] As previously explained, the first measurement sensor (10) can measure the surface or interior of the wafer in the first measurement area (12), the second measurement sensor (20) can measure the surface or interior of the wafer in the second measurement area (22), and the third measurement sensor (30) can measure the surface or interior of the wafer in the third measurement area (32).

[0063] The first measurement sensor (10) moves from point 1c to point 1d, the second measurement sensor (20) moves from point 2c to point 2d, and the third measurement sensor (30) moves from point 3a to point 3b.

[0064] First, point 1c is the center of the wafer, point 1d is the boundary between the first measurement area (12) and the third measurement area (32). Next, point 2c is the boundary between the second measurement area (22) and the third measurement area (32), and point 2d is the outer edge of the wafer. Finally, point 3a is the boundary between the second measurement area (22) and the third measurement area (32), and point 3b is the boundary between the first measurement area (12) and the third measurement area (32).

[0065] The first to third measuring sensors (10) to (30) are arranged at equal intervals, and the distance between point 1c and point 1d, the distance between point 2c and point 2d, and the distance between point 3a and point 3b may be equal. At this time, D is the diameter of the wafer, and the diameter of the wafer is usually 300 mm. 2H is the distance between the arranged measuring sensors, and it is preferable that 2H is about 1 / 3 of the entire wafer diameter.

[0066] FIG. 4 is a drawing for explaining the arrangement of three measurement sensors and a measurement area to which another embodiment of the present invention is applied.

[0067] As shown in FIG. 4, in another embodiment, the first measurement sensor (10) to the third measurement sensor (30) may be spaced apart from each other with respect to the Y-axis.

[0068] When the first to third measuring sensors (10) to (30) are spaced apart from each other, the 1c point of the first measuring sensor (10) is the center of the wafer, and the 2c point of the second measuring sensor (20) and the 3a point of the third measuring sensor (30) can be located on the left or right side with respect to the Y axis. It is preferable that the 2c point of the second measuring sensor (20) is located in the second quadrant with respect to the XY axis, and the 3a point of the third measuring sensor (30) is located in the third quadrant with respect to the XY axis, but the 2c point and the 3a point can be located in the 1st and 4th quadrants, which are symmetrical positions with respect to the Y axis.

[0069] Also, referring to FIG. 4, D is the diameter of the wafer, and the diameter of the wafer is usually 300 mm. 3H is the distance between the second measurement sensor (20) and the Y-axis, and 4H is the distance between the third measurement sensor (30) and the Y-axis. 3H is 1 to 2 times 4H, and it is preferable that 3H is about 1 / 5 and 4H is about 1 / 10 of the wafer diameter. In addition, 5H is the straight-line distance between each measurement sensor, and it is preferable that it is 1 / 3 to 1 / 4 of the wafer diameter.

[0070] According to another embodiment, the distance between point 1c and point 1d, the distance between point 2c and point 2d, and the distance between point 3a and point 3b may be the same, and in cases where it is difficult to arrange the measurement sensors in a straight line due to their sizes, the measurement sensors may be arranged spaced apart from each other as in the above embodiment.

[0071] FIG. 5 is a drawing for explaining a measurement sensor and a measurement area arranged in the X-axis direction to which another embodiment of the present invention is applied.

[0072] As shown in Fig. 5, a plurality of measurement sensors (110) can be arranged in a straight line in the X-axis direction.

[0073] It is preferable that the path along which the first measurement sensor (10) moves is from point 1e to point 1f, the path along which the second measurement sensor (20) moves is from point 2e to point 2f, and the path along which the third measurement sensor (30) moves is from point 3c to point 3d.

[0074] First, point 1e is the center of the wafer, point 1f is the boundary between the first and third measurement areas, point 2e is the boundary between the second and third measurement areas, point 2f is the outer edge of the wafer, point 3c is the boundary between the first and third measurement areas, point 3d is the boundary between the second and third measurement areas, point 3d is the boundary between the second and third measurement areas.

[0075] In addition, the distance between the point 1e and the point 1f, the distance between the point 2e and the point 2f, and the distance between the point 3c and the point 3d may be the same, and the distance between the point 1e and the point 3c may be narrower than the distance between the point 1e and the point 2e. Specifically, D is the diameter of the wafer, and the value of 7H is greater than 6H. 6H and 7H are values ​​representing the distance between the third measurement sensor (30) and the second measurement sensor (20) based on the first measurement sensor (10) located at the center of the wafer. 6H is the distance between the third measurement sensor (30) and the first measurement sensor (10), and is preferably 1 / 3 to 1 / 4 of the wafer diameter, and 7H is the distance between the first measurement sensor (10) and the second measurement sensor (20), and is preferably 1 / 2 to 1 / 3 of the wafer diameter.

[0076] The embodiments and drawings of the present invention described so far are exemplary of the present invention, and a plurality of measurement sensors (110) of a spiral scan device including a multi-measurement sensor according to the present invention move linearly in the Y-axis direction, and the wafer is rotated by the chuck stage (100), so that the entire wafer surface or interior can be scanned.

[0077] At this time, it is preferable that the position where the measurement sensor (110) is placed is placed on the wafer surface so that the measurement is not obstructed depending on the size of the measurement sensor (110) and there is no unmeasurable area on the wafer surface or inside. The distance that the measurement sensor (110) moves in a straight line in one direction may vary for each measurement sensor, and if the measurement sensor (110) measures beyond the wafer surface, the corresponding scanning image may be excluded and synthesized.

[0078]

[0079] Hereinafter, a wafer inspection method using a spiral scan device including multiple measurement sensors according to one embodiment of the present invention will be described.

[0080] FIG. 6 is a flowchart of a wafer inspection method using a spiral scan device including multiple measurement sensors according to one embodiment of the present invention.

[0081] Referring to FIG. 6, the wafer inspection method may include a step of loading a wafer onto a chuck stage (100) (S100), a step of fixing the loaded wafer onto the chuck stage (100) (S110), a step of positioning a plurality of measurement sensors (110) that are underwater ultrasonic transducers or have different resolutions at a location spaced apart from the chuck stage (100) (S120), and a step of scanning the surface or interior of the wafer by simultaneously moving each of the plurality of measurement sensors (110) along its own movement path while rotating the chuck stage (100) (S130).

[0082] The step (S110) of fixing the loaded wafer to the chuck stage (100) can be vacuum-sucked using a vacuum suction device (150) or fixed through static electricity.

[0083] In addition, it may further include a step (S140) of controlling the rotation speed of the chuck stage (100) and the movement of a plurality of measurement sensors (110), a step (S150) of obtaining signals output from a plurality of measurement sensors (110) and synthesizing a wafer surface or internal scanning image, and a step (S160) of detecting a change in height or a work function pattern of the wafer surface or internal through the synthesized image.

[0084] A plurality of measurement sensors (110) can be moved to measure contamination or defects on the wafer surface or inside, and at this time, each sensor can move in the same direction and distance, and the movement can be controlled at a constant speed. The measured data can be output as an image in real time through the control unit (120), and the output images can be synthesized to represent an image of the entire wafer surface or inside.

[0085] At this time, a spiral scan device including multiple measurement sensors used for wafer inspection may include a plurality of measurement sensors (110) including at least two or more. In addition, wafer inspection may be performed by dividing the inspection into a first measurement area (12) including the center of the wafer, a second measurement area (22) including the periphery of the wafer, and a third measurement area (32) located between the first measurement area (12) and the second measurement area (22).

[0086] It is preferable that the first measurement sensor (10) measures the wafer surface or interior of the first measurement area (12), the second measurement sensor (20) measures the wafer surface or interior of the second measurement area (22), and the third measurement sensor (30) measures the wafer surface or interior of the third measurement area (32).

[0087] In addition, a plurality of measurement sensors (110) for wafer inspection may be arranged in a straight line in the Y-axis direction of the wafer, or may be arranged spaced apart from each other based on the Y-axis, or may be arranged in a straight line in the X-axis direction of the wafer. It is preferable that the position where the measurement sensors are arranged be optimally arranged so that the measurement is not disturbed depending on the size of the measurement sensor, and since the speed and distance of each measurement sensor are constant, a step of searching for the optimal arrangement that can scan the entire wafer surface or interior within the same time may be performed first.

[0088] Through the above steps, the optimal placement coordinates are determined based on the type of sensor and the defects in the wafer to be detected, and the positions at which multiple measurement sensors (110) are placed can serve as the measurement start points. It is preferable to measure at the same distance from the measurement start point, and the measured data can be used to synthesize an image of the entire wafer surface or interior.

[0089]

[0090] As described above, the present invention is not limited to the described embodiments, and it is obvious to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention.

[0091] Accordingly, the embodiments of the present invention are merely illustrative in all respects and should not be construed as limiting, and can be implemented in various modified forms without departing from the technical idea or main characteristics.

[0092] That is, although the detailed description of the present invention described above has been described with reference to preferred embodiments of the present invention, it will be understood that those skilled in the art or having ordinary knowledge in the art can modify and change the present invention in various ways without departing from the spirit and technical scope of the present invention described in the claims to be described later.

Claims

1. Wafer loading and rotatable chuck stage; A plurality of measurement sensors arranged at a position spaced apart from the upper surface of the chuck stage; and A control unit that controls the rotation speed of the chuck stage, the movement of the measurement sensors, and obtains and processes signals output from the sensors; Including, A spiral scan device comprising multiple measurement sensors, wherein the plurality of measurement sensors are underwater ultrasonic transducers.

2. Wafer loading and rotatable chuck stage; A plurality of measurement sensors having a plurality of resolutions and arranged at a position spaced apart from the upper surface of the chuck stage; and A control unit that controls the rotation speed of the chuck stage, movement of the measurement sensors, and acquires and processes signals output from the sensors; A spiral scan device comprising multiple measurement sensors including:

3. In paragraph 1 or 2, A rotation axis is connected to the center of the bottom surface of the above chuck stage and is configured to be rotated by a separate motor, A spiral scan device comprising a multi-measurement sensor characterized in that it fixes the loaded wafer, including a vacuum suction device connected to the rotation axis.

4. In paragraph 1, The above plurality of measurement sensors include a first measurement sensor and a second measurement sensor, The wafer includes a first measurement area including the center of the wafer and a second measurement area outside the first measurement area, A spiral scan device including multiple measurement sensors, characterized in that the first measurement sensor measures the surface or the inside of the wafer in the first measurement area, and the second measurement sensor measures the surface or the inside of the wafer in the second measurement area.

5. In paragraph 4, The path along which the first measuring sensor moves is from point 1a to point 1b, A spiral scan device including a multi-measurement sensor, characterized in that the point 1a is a boundary between the first measurement area and the second measurement area, and the point 1b is a center of the wafer.

6. In paragraph 4, The path along which the second measuring sensor moves is from point 2a to point 2b, A spiral scan device including a multi-measurement sensor, characterized in that the second point a is a boundary between the first measurement area and the second measurement area, and the second point b is an outer edge of the wafer.

7. In paragraph 5 or 6, A spiral scan device including a multi-measurement sensor, characterized in that the first point a and the second point b are arranged symmetrically in opposite directions from the center of the wafer.

8. In paragraph 5 or 6, A spiral scan device including a multi-measurement sensor, characterized in that the distance between the point 1a and the point 1b and the distance between the point 2a and the point 2b are the same.

9. In paragraph 1, The above plurality of measurement sensors include a first measurement sensor, a second measurement sensor, and a third measurement sensor, The wafer includes a first measurement area at the center of the wafer, a second measurement area at the periphery of the wafer, and a third measurement area located between the first measurement area and the second measurement area. A spiral scan device including multiple measurement sensors, characterized in that the first measurement sensor measures the surface or interior of the wafer in the first measurement area, the second measurement sensor measures the surface or interior of the wafer in the second measurement area, and the third measurement sensor measures the surface or interior of the wafer in the third measurement area.

10. In paragraph 9, The path along which the first measuring sensor moves is from point 1c to point 1d, A spiral scan device including a multi-measurement sensor, characterized in that the 1c point is the center of the wafer, and the 1d point is the boundary between the first measurement area and the third measurement area.

11. In paragraph 9, The path along which the second measuring sensor moves is from point 2c to point 2d, A spiral scan device including a multi-measurement sensor, characterized in that the 2c point is a boundary between the 2nd measurement area and the 3rd measurement area, and the 2d point is an outer edge of the wafer.

12. In paragraph 9, The path along which the third measuring sensor moves is from point 3a to point 3b, A spiral scan device including a multi-measurement sensor, characterized in that the 3a point is a boundary between the 2nd measurement area and the 3rd measurement area, and the 3b point is a boundary between the 1st measurement area and the 3rd measurement area.

13. In any one of paragraphs 10 to 12, A spiral scanning device including a multi-measurement sensor, characterized in that the distance between the point 1c and the point 1d, the distance between the point 2c and the point 2d, and the distance between the point 3a and the point 3b are the same.

14. In paragraph 4, A spiral scan device including multiple measurement sensors, characterized in that the first measurement sensor and the second measurement sensor are arranged in a straight line in the Y-axis direction.

15. In paragraph 9, A spiral scan device including multiple measurement sensors, characterized in that the first to third measurement sensors are arranged in a straight line or spaced apart from each other in the Y-axis direction.

16. In paragraph 15, When the first to third measuring sensors are spaced apart from each other, The first point c of the first measuring sensor is the center of the wafer, A spiral scan device including multiple measurement sensors, characterized in that the 2c point of the second measurement sensor and the 3a point of the third measurement sensor are located to the left or right with respect to the Y axis.

17. In paragraph 16, A spiral scan device including multiple measuring sensors, characterized in that the 2c point of the second measuring sensor is located in the second quadrant based on the XY axis, and the 3a point of the third measuring sensor is located in the third quadrant based on the XY axis.

18. In paragraph 9, A spiral scan device including multiple measurement sensors, characterized in that the first to third measurement sensors are arranged in a straight line in the X-axis direction of the wafer.

19. In paragraph 18, The path along which the first measurement sensor moves is from point 1e to point 1f, A spiral scan device including a multi-measurement sensor, characterized in that the 1e point is the center of the wafer, and the 1f point is the boundary between the first measurement area and the third measurement area.

20. In paragraph 18, The path along which the second measuring sensor moves is from point 2e to point 2f, A spiral scan device including a multi-measurement sensor, characterized in that the second e point is a boundary between the second measurement area and the third measurement area, and the second f point is an outer edge of the wafer.

21. In paragraph 18, The path along which the third measuring sensor moves is from point 3c to point 3d. A spiral scan device including a multi-measurement sensor, characterized in that the 3c point is a boundary between the first measurement area and the third measurement area, and the 3d point is a boundary between the second measurement area and the third measurement area.

22. In any one of paragraphs 19 to 21, The distance between the 1e point and the 1f point, the distance between the 2e point and the 2f point, and the distance between the 3c point and the 3d point are the same, A spiral scanning device including a multi-measurement sensor, characterized in that the distance between the point 1e and the point 3c is narrower than the distance between the point 1e and the point 2e.

23. In paragraph 2, The plurality of measurement sensors having the above plurality of resolutions are: Transducers with different vibration frequencies; Probes with different tip sizes and focal lengths; or Image detection devices having different resolutions; A spiral scan device comprising a multi-measurement sensor characterized by including at least one of:

24. In paragraph 23, The vibration frequency of the above transducer has different values ​​within the range of 50 to 150 MHz, A spiral scan device including a multi-measurement sensor, characterized in that the probe tip size and focal length have different values ​​within a range of 50 to 150 μm.

25. In paragraph 2, A spiral scan device including multiple measurement sensors, characterized in that the plurality of measurement sensors having the plurality of resolutions include a first measurement sensor, a second measurement sensor, and a third measurement sensor.

26. In paragraph 2, A spiral scan device including multiple measurement sensors, characterized in that the plurality of measurement sensors are arranged symmetrically in opposite directions from the center of the wafer, arranged in a straight line in the X-axis or Y-axis direction, or arranged spaced apart from each other.

27. In paragraph 2, A spiral scan device including multiple measurement sensors, wherein the plurality of measurement sensors having the plurality of resolutions are arranged at a measurement start point and measure the same distance from the measurement start point.

28. Step of loading the wafer onto the chuck stage; A step of fixing the loaded wafer to the chuck stage; A step of positioning a plurality of underwater ultrasonic transducers or measuring sensors having different resolutions at a position spaced apart from the chuck stage; and A step of scanning the surface or interior of the wafer by rotating the chuck stage and moving each of the plurality of measurement sensors along its own movement path; A wafer inspection method using a spiral scan device including a multi-measurement sensor characterized by including:

29. In paragraph 28, A step of controlling the rotation speed of the chuck stage and the movement of a plurality of measurement sensors; A step of acquiring signals output from the plurality of measurement sensors and synthesizing a scanning image of the wafer surface or interior; and A step of detecting a change in height or work function pattern on the surface or inside of the wafer through the synthesized image; A wafer inspection method using a spiral scan device including a multi-measurement sensor characterized by further including:

30. In paragraph 28, The above plurality of measurement sensors include two or more measurement sensors, The wafer includes a first measurement area including the center of the wafer and a second measurement area including the periphery of the wafer, and a third measurement area between the first measurement area and the second measurement area. A wafer inspection method using a spiral scan device including multiple measurement sensors, characterized in that the first measurement sensor measures the surface or the inside of the wafer in the first measurement area, the second measurement sensor measures the surface or the inside of the wafer in the second measurement area, and the third measurement sensor measures the surface or the inside of the wafer in the third measurement area.

31. In paragraph 28 or 29, The above plurality of measurement sensors are arranged in a straight line in the Y-axis direction of the wafer, or are arranged spaced apart from each other based on the Y-axis, or are arranged in a straight line in the X-axis direction of the wafer, Any one of the plurality of measurement sensors is positioned at the center of the wafer, or the point at which the measurement ends is the center of the wafer, A wafer inspection method using a spiral scan device including a multi-measurement sensor, characterized in that when scanning the chuck stage outside the wafer surface in the step of scanning the wafer surface or the inside and the step of synthesizing the image, the chuck stage scanning image generated by detecting the chuck stage measurement signal is excluded and synthesized.

32. In paragraph 31, A wafer inspection method using a spiral scan device including multiple measurement sensors, wherein the plurality of measurement sensors are arranged at a measurement start point and measure the same distance from the measurement start point.

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