Method and apparatus, system, and computer program product for three-dimensional measurement of a wafer surface

Abstract

The present invention provides a method, an apparatus, a system, and a computer program product for three-dimensional measurement of a wafer surface. The method for three-dimensional measurement of the wafer surface includes: measurement data acquisition: acquiring a surface image and multi-dimensional measurement data of the wafer; measurement data fitting: fitting the acquired surface image and multi-dimensional measurement data of the wafer to obtain the surface 3D data of the wafer; feature data extraction: extracting required feature data from the surface 3D data of the wafer according to the measurement requirements of feature items; feature data classification: setting range criteria or determination conditions for feature items and classifying the feature data; measurement result display: intuitively displaying the feature data according to the results of the classification processing. The method and apparatus for three-dimensional measurement of the wafer surface provided by the present invention can obtain rich and accurate multi-dimensional data of the wafer surface and can intuitively obtain the measurement results.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and particularly to a method, device, system, and computer program product for three-dimensional measurement of the surface of a semiconductor wafer in a semiconductor measurement device. Background Art

[0002] With the rapid development of semiconductor technology, the integrated circuit manufacturing process and process have become more complex. To ensure the yield and quality of integrated circuit production, the measurement of semiconductor wafers during the integrated circuit manufacturing process has become more important. Generally, the measurement of the wafer surface is two-dimensional, which can no longer meet all current requirements. Moreover, the measurement results are either data output or directly output as qualified or unqualified, making it difficult to intuitively understand the overall measurement situation of the wafer.

[0003] There is a need for a measurement method that can measure wafers more accurately, obtain more abundant information, and can more intuitively reflect the measurement results. Summary of the Invention

[0004] The purpose of the present invention is to provide a measurement method and system that can perform high-precision and multi-dimensional measurement more comprehensively and obtain the measurement results more intuitively.

[0005] To solve the above technical problems, the present invention proposes a method for three-dimensional measurement of the surface of a semiconductor wafer, including:

[0006] Measurement data acquisition: acquiring the surface image and multi-dimensional measurement data of the wafer;

[0007] Measurement data fitting: fitting the acquired surface image and multi-dimensional measurement data of the wafer to obtain the surface 3D data of the wafer;

[0008] Feature data extraction: extracting the required feature data from the surface 3D data of the wafer according to the measurement requirements of the feature items;

[0009] Feature data classification: setting the range standard or determination condition of the feature items, and classifying and processing the feature data;

[0010] Measurement result display: intuitively displaying the feature data classified according to the classification result of the classification process.

[0011] Preferably, the measurement result display includes:

[0012] Color matching: associating feature information in different ranges or under different conditions with different colors to display the classification situation of the feature information through color information.

[0013] Preferably, the measured data is fitted to obtain the 3D data of the surface of the complete wafer, and the 3D data of the surface of the complete wafer includes: the surface image data of the complete wafer, the height of the wafer substrate plane, and the three-dimensional dimensions of the surface topography of the complete wafer.

[0014] Preferably, the step of extracting the feature data includes: extracting the 3D data of the chip surface from the 3D data of the surface of the wafer, and the chip surface includes microbumps, which are suitable for forming electrical connection structures on the microbumps in subsequent processes.

[0015] Preferably, the feature data extraction includes:

[0016] Obtaining the coordinate points of the microbumps in the 3D data of the surface of the wafer;

[0017] A height measurement and analysis step, analyzing the height of the microbumps according to the 3D data of the surface of the wafer to obtain the height value of each microbump.

[0018] Preferably, the feature data classification includes: classifying the range of the height values of the microbumps into: a range less than the minimum value range, a range greater than the maximum value range, and a qualified range between the minimum value and the maximum value.

[0019] Preferably, the measurement result display includes: corresponding to different colors according to the range where the height value of each microbump is located, so as to display different colors corresponding to the height value at the position of the microbump.

[0020] Preferably, the step of obtaining the coordinate points of the microbumps in the 3D data of the surface of the wafer includes: initial wafer positioning, chip positioning, and microbump positioning.

[0021] Preferably, the step of initial wafer positioning includes:

[0022] According to the gap between the position of the positioning notch in the measured surface feature image of the wafer and the positioning mark in the image display system, adjusting the position and orientation of the surface feature image of the wafer to coincide the positioning notch and the positioning mark.

[0023] Preferably, the step of chip positioning includes:

[0024] Dividing all chip regions according to the edges of the minimum periodic patterns in the measured surface feature image of the wafer, and correspondingly obtaining the position information of each chip region.

[0025] Preferably, the step of microbump positioning includes:

[0026] Identifying and marking the microbump regions in each chip region, and correspondingly obtaining the coordinate information of each microbump region in each chip region.

[0027] Preferably, the step of marking and identifying the micro-bump regions in each chip region includes:

[0028] Automatically marking according to the image of the micro-bump contour similar to that in the surface feature image of the measured wafer, and / or manually marking the image of the micro-bumps in the surface feature image of the measured wafer.

[0029] Preferably, the measurement result display further includes: image magnification / shrinkage, performing fixed-point magnification / shrinkage based on the surface image data of the entire wafer to view the image data of the local region and the three-dimensional dimensions of the local wafer surface topography.

[0030] On the other hand, the present invention also provides a device for three-dimensional measurement of the wafer surface, including:

[0031] A measurement data acquisition unit, adapted to acquire the surface image and multi-dimensional measurement data of the wafer;

[0032] A measurement data fitting unit, adapted to fit the acquired surface image and multi-dimensional measurement data of the wafer to obtain the 3D data of the wafer surface;

[0033] A feature data extraction unit, adapted to extract the required feature data from the 3D data of the wafer surface according to the measurement requirements of the feature items;

[0034] A feature data classification unit, adapted to set the range criteria or determination conditions of the feature items and classify the feature data;

[0035] A measurement result display unit, adapted to visually display the feature data by category.

[0036] Preferably, the measurement result display unit includes:

[0037] A color matching unit, adapted to associate feature information in different ranges or under different conditions with different colors to display the classification of the feature information through color information.

[0038] Preferably, the measurement data fitting unit obtains the 3D data of the entire wafer surface, and the 3D data of the entire wafer surface includes: the surface image data of the entire wafer, the height of the wafer substrate plane, and the three-dimensional dimensions of the entire wafer surface topography.

[0039] Preferably, the feature data extraction unit is adapted to extract the 3D data of the micro-bumps on the chip surface from the 3D data of the wafer surface, and the micro-bumps are the micro-bumps in the Die on the wafer surface and are adapted to form an electrical connection structure on the micro-bumps in a subsequent process.

[0040] Preferably, the feature data extraction unit includes:

[0041] A positioning unit, adapted to obtain the coordinate points of the microbumps in the 3D data of the surface of the wafer;

[0042] A height measurement and analysis module, adapted to analyze the height of the microbumps according to the 3D data of the surface of the wafer to obtain the height value of each microbump.

[0043] Preferably, the feature data classification unit includes: a range classifier for the height values of the microbumps, and the range classifier for the height values of the microtiles includes: a first storage unit for values less than the lowest value range, a second storage unit for values greater than the highest value range, and a third storage unit for the qualified range between the lowest value and the highest value.

[0044] Preferably, the measurement result display unit includes: corresponding to different colors according to the range where the height value of each microbump is located, so as to display different colors corresponding to the height values at the positions of the microbumps.

[0045] Preferably, the positioning unit includes: a wafer preliminary positioning module, a chip positioning module, and a microbump positioning module.

[0046] Preferably, the wafer preliminary positioning module is adapted to adjust the position and orientation of the surface feature image of the wafer according to the gap between the position of the positioning notch in the surface feature image of the measured wafer and the positioning mark in the image display unit, so as to coincide the positioning notch and the positioning mark.

[0047] Preferably, the chip positioning module is adapted to divide all chip regions according to the edges of the smallest periodic patterns in the surface feature image of the measured wafer, and correspondingly obtain the coordinate information of each chip region.

[0048] Preferably, the microbump module is adapted to identify and mark the microbump regions in each chip region, and correspondingly obtain the coordinate information of each microbump region in each chip region.

[0049] Preferably, the microbump module includes an automatic marking unit and / or a manual marking unit. The automatic marking unit is adapted to automatically mark the images of the microbump contours similar to those in the surface feature image of the measured wafer, and / or the manual marking unit is adapted to manually mark the images of the microbumps in the surface feature image of the measured wafer.

[0050] Preferably, the measurement result display unit further includes an image zooming unit, adapted to perform fixed-point zooming based on the complete surface image data of the wafer to view the image data of the local area and the three-dimensional dimensions of the local wafer surface topography.

[0051] Preferably, the measurement data acquisition unit includes three 3D imaging cameras and one coaxial camera.

[0052] In another aspect, the present invention also provides a system for three-dimensional measurement of a wafer surface, comprising:

[0053] A processor,

[0054] A memory for storing computer programs or instructions, which when executed by the processor implement the steps of the method as described above to perform defect detection on an object.

[0055] In another aspect, the present invention also provides a computer program product, which is stored on a computer-readable storage medium and includes computer programs or instructions that, when executed by the processor, implement the steps of the method as described above.

[0056] Compared with the prior art, the method and device for three-dimensional measurement of a wafer surface provided by the present invention have the following beneficial effects:

[0057] By collecting the surface image and multi-dimensional measurement data of the wafer, rich and accurate multi-dimensional data of the wafer surface are obtained. Then, through fitting, the required characteristic data can be specifically extracted. Finally, through classifying and classifying the display of the required characteristic data, the measurement result can be intuitively obtained.

[0058] Furthermore, in the embodiments of the technical solution provided by the present invention, by analyzing the surface characteristic data of the chip, the height profile information of the microbumps on the chip surface is extracted;

[0059] Furthermore, in the embodiments of the technical solution provided by the present invention, by setting a qualified / unqualified threshold standard range for the height profile information of the microbumps, different classified microbumps are associated with different colors, and finally a distribution map of microbumps rendered in different colors is presented, which can intuitively determine the area of defective dies on the wafer surface.

[0060] Furthermore, in the embodiments of the technical solution provided by the present invention, it is also suitable for performing fixed-point image magnification / shrinking based on the surface image data of the complete wafer to view the image data of a local area and the three-dimensional dimensions of the local wafer surface topography. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is a flowchart of a method for three-dimensional measurement of a wafer surface provided in an embodiment of the present invention.

[0062] Figure 2 It is a schematic diagram of an acquisition camera provided in an embodiment of the present invention.

[0063] Figure 3 Schematic diagram of the direction and path for scanning the surface of the measurement wafer provided in the embodiment of the present invention.

[0064] Figure 4 Schematic flowchart of feature data extraction provided in the embodiment of the present invention.

[0065] Figure 5 Schematic flowchart of obtaining the coordinate points of the micro-bumps provided in the embodiment of the present invention.

[0066] Figure 6 Schematic diagram of measuring the surface image of the wafer provided in the embodiment of the present invention.

[0067] Figures 7 to 9 Schematic diagram of the image of the micro-bumps in the chip on the wafer surface provided in the embodiment of the present invention.

[0068] Figure 10 Schematic diagram of obtaining the height value of the micro-bumps provided in the embodiment of the present invention.

[0069] Figure 11 Schematic diagram of the display situation of the measurement results of the micro-bumps in the chip on the measured wafer surface provided in the embodiment of the present invention.

[0070] Figure 12 Block diagram of the device for three-dimensional measurement of the wafer surface provided in the embodiment of the present invention. Detailed implementation manners

[0071] Many specific details are set forth in the following description in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific implementations disclosed below.

[0072] Secondly, the present invention is described in detail using schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the schematic diagrams are only examples and should not limit the scope of protection of the present invention herein.

[0073] In the embodiments provided by the technical solution of the present invention, the surface of the tested wafer has micro-bumps (bumps) that need to be measured and judged.

[0074] In the embodiments provided by the technical solution of the present invention, during measurement, the EFEM automatic manipulator places the wafer to be tested into the scanning measurement area to perform scanning and measurement of the wafer surface;

[0075] Then, a 3D scanning lens is used to collect the height and diameter of the micro-bumps. The scanning lens is a 3um high-resolution acquisition system that can collect accurate data of the micro-bumps on the wafer in high definition and then save it in the host of the acquisition device;

[0076] Through the advanced algorithms and processing in the measuring device, the surface data of the entire wafer is processed. Specifically, in this embodiment, the characteristic data of the micro-bumps in each die or chip on the wafer is extracted and processed, and then it is judged whether it is qualified: some micro-bump heights meet the process specification requirements, while some are missing, incomplete, or have excessive height, which are considered failures.

[0077] Then, according to the type of qualified or failed micro-bumps, a die or chip map is displayed. The positions of the failed micro-bumps in each die or chip are rendered in color and displayed on the image of the wafer in different colors by outputting a micro-bump distribution map.

[0078] The failure of the micro-bumps will cause the entire die to be unqualified. Then, a re-inspection is required, and each one needs to be magnified to view the details in order to analyze the reason for the die's unqualifiedness. Further, in the embodiment provided by the technical solution of the present invention, it is possible to support zooming in and out of the map image to view the details, and the positions of the failed micro-bumps in each die are displayed in color.

[0079] To make the above objects, features, and advantages of the present application more obvious and understandable, the following will describe the specific embodiments of the present application in detail with reference to the accompanying drawings.

[0080] Refer to Att Figure 1 to Att Figure 5 , in which Figure 1 as shown, in the embodiment provided by the technical solution of the present invention, a flowchart of a method for three-dimensional measurement of the wafer surface is provided, including:

[0081] Step S100: Measurement data acquisition: Collect the surface image and multi-dimensional measurement data of the wafer;

[0082] Step S200: Measurement data fitting: Fit the collected surface image and multi-dimensional measurement data of the wafer to obtain the surface 3D data of the wafer;

[0083] Step S300: Feature data extraction: Extract the required feature data from the surface 3D data of the wafer according to the measurement requirements of the feature items;

[0084] Step S400: Feature data classification: Set the range criteria or determination conditions for feature items, and classify the feature data;

[0085] Step S500: Measurement result display: Intuitively display the feature data classified according to the classification processing result.

[0086] Specifically, in this embodiment, in the step S100 of measurement data acquisition: Acquire the surface image and multi-dimensional measurement data of the wafer; among them, the measurement data acquisition unit includes three 3D image acquisition cameras and one coaxial camera.

[0087] Among them, the acquisition method combines Figure 1 , refer to Figures 2 to 3 shown, Figure 2 Shown in this embodiment is a schematic diagram of the acquisition camera for acquiring the surface image and multi-dimensional data of the measurement wafer. Figure 3 Shown is a schematic diagram of the direction and path of the probe of the acquisition camera scanning on the surface of the measurement wafer in this embodiment.

[0088] Specifically, above the surface of the wafer 660, the measurement data acquisition device includes multiple cameras 81, 82, 83 and an annular light source 60. Among them, at least one camera is located directly above the wafer 660 to acquire the image of the surface of the wafer 660 in the vertical direction. There are also multiple cameras located beside the wafer 660 directly above. In this embodiment, the included angle between the cameras 81, 82, and 83 can be set according to the requirements of the measurement process.

[0089] The probe 40 of the surface acquisition camera scans back and forth point by point (block by block) above the wafer 660 along the law of the F direction to acquire the image of the silicon wafer surface.

[0090] In a preferred embodiment, the images acquired at all points (blocks) can be combined into a complete surface image of the wafer. In other embodiments, at the beginning of the measurement, the test area and its shape are selected on the surface of the wafer 660, and after the test is completed, the images acquired at all points (blocks) can be combined into the area and its shape selected at the beginning of the measurement.

[0091] Further, the measurement data acquisition in this step also includes multi-dimensional measurement data acquisition through a paraxial camera, mainly measuring the surface physical topography of the wafer 660, and performing three-dimensional topography analysis at the micro-nano scale, such as 3D surface topography, 2D depth topography, profiles (depth, width, curvature or angle), surface roughness, etc. Compared with traditional measurement methods, it has higher resolution and the advantages of realizing multi-dimensional simultaneous observation. Further, in one embodiment, the system software processes and analyzes the 3D image of the device surface, and obtains 2D and 3D parameters reflecting the device surface quality, so as to obtain the 3D measurement of the device surface topography.

[0092] Step S200: Measurement data fitting: Fit the surface image and multi-dimensional measurement data of the wafer collected to obtain the 3D data of the surface of the wafer.

[0093] In this embodiment, in this step, through a 3D modeling algorithm, etc., a surface 3D image is established for the measurement data obtained by non-contact scanning of the device surface in the previous step, and the 3D data of the surface of the wafer is obtained.

[0094] Further, the measurement data fitting obtains the complete 3D data of the surface of the wafer, and the complete 3D data of the surface of the wafer includes: the surface image data of the complete wafer, the height of the wafer substrate plane, and the three-dimensional dimensions of the complete surface topography of the wafer.

[0095] Step S300: Feature data extraction: Extract the required feature data from the 3D data of the surface of the wafer according to the measurement requirements of the feature items.

[0096] Further, in this embodiment, the steps of the feature data extraction include:

[0097] Extract the 3D data of the microbumps on the surface of the chip from the 3D data of the surface of the wafer. The microbumps are the microbumps in the chips (Dies) on the surface of the wafer, and are suitable for forming electrical connection structures on the microbumps in subsequent processes.

[0098] Further, in this embodiment, referring to Figure 4 shown, is the flow schematic diagram of the feature data extraction. Specifically, it includes:

[0099] Step S310: Obtain the coordinate points of the microbumps in the 3D data of the surface of the wafer.

[0100] Step S320: Height measurement analysis step, analyze the height of the microbumps according to the 3D data of the surface of the wafer to obtain the height value of each microbump.

[0101] Further, Figure 5As shown, it is a schematic flowchart of obtaining the coordinate points of the microbumps in the 3D data of the surface of the wafer in an embodiment, which includes:

[0102] Step 311: Initial wafer positioning;

[0103] Step 312: Chip positioning;

[0104] Step 313: Microbump positioning.

[0105] Further, in this embodiment, the steps of performing Step 311: Initial wafer positioning include:

[0106] According to the gap between the position of the positioning notch in the measured surface feature image of the wafer and the positioning mark in the image display system, adjust the position and orientation of the measured surface feature image of the wafer to coincide the positioning notch and the positioning mark.

[0107] In other embodiments, it may also be when there is a difference between the position of the positioning notch in the measured surface feature image of the wafer and the positioning mark in the image display system, adjust the position and orientation of the wafer. Preferably, the adjustment angle and direction are determined according to the difference between the position of the positioning notch of the measured wafer and the positioning mark in the image display system.

[0108] In another embodiment, the initial wafer positioning in Step 311 can also be performed by laser alignment. Specifically, the positioning mark in the image display system corresponds to the position of the positioning laser device. The positioning laser is emitted vertically towards the edge area of the surface of the measured wafer. When the positioning laser passes through the positioning notch of the measured wafer, the energy of the laser detected by the system is the strongest. When the positioning laser hits the edge of the measured wafer, the laser cannot pass through and the system cannot detect the energy of the laser. During the process of the measured wafer rotating one circle, the positioning laser will successively pass through the process of hitting the edge surface of the measured wafer, passing through the positioning notch, and hitting the edge surface of the measured wafer, and the laser energy detected by the system will also experience the process of no energy, weakening, strongest, weakening, and no energy. The detection system records the position where the detected laser energy is the strongest, and then through coordinate conversion, coincides the position of the positioning notch in the measured surface feature image of the wafer and the positioning mark in the image display system.

[0109] After this step, ensure that the measured wafer image is consistent with the positioning coordinates in the image display system, so as to correspond the position on the wafer image with the coordinates in the image display system.

[0110] Further, determine the coordinate origin of the wafer in the measured surface feature image of the wafer and correspond it to the origin coordinates in the image display system.

[0111] Furthermore, through the correspondence between the measured wafer image and the positioning coordinates in the image display system, the three-dimensional dimensions of the measured wafer surface topography are also corresponded with the positioning coordinates in the image display system.

[0112] Furthermore, in this embodiment, step 312: chip positioning is performed. Specifically, the chip positioning includes:

[0113] Figure 6 As shown, it is a schematic diagram of the surface image of the measured wafer provided in this embodiment. Specifically, in this embodiment, all chip (die) regions can be divided according to the edges of the smallest periodic patterns in the surface feature image of the measured wafer, and the coordinate information of each chip region can be obtained correspondingly.

[0114] Specifically, in one embodiment, the method for dividing all chip (die) regions according to the edges of the smallest periodic patterns in the surface feature image of the measured wafer includes:

[0115] Use Fourier transform to find the conjugate coefficients, transform the surface feature image of the measured wafer from the spatial domain to the frequency domain, use two-dimensional sine wave to fit the fluctuation of the gray value, find the image sizes of the periodic patterns in the horizontal and vertical directions, and thus calculate the sizes of the periodic patterns. Among them, the pattern with periodicity is the pre-template image, and the size of the periodic pattern is the size of the chip (Die) on the wafer surface, including the width and length of the chip. Based on the size and edge features of the pre-template image, match each smallest periodic pattern in the surface feature image of the measured wafer to divide all chip (Die) regions.

[0116] Specifically, in this embodiment, obtaining the coordinate information of each chip region includes:

[0117] Establish a coordinate system in the wafer plane with the origin of the wafer in the surface feature image of the measured wafer, and obtain the position coordinates of each Die on the wafer.

[0118] Among them, in one embodiment, the origin of the measured wafer can be determined, for example, by the center of the circle formed by three points on the wafer edge, as Figure 6 shown, define Die(0, 0) as the Die where the wafer origin is located. Establish a rectangular coordinate system in the wafer plane with this origin, so that the positions of all other Dies on the wafer can be indexed and defined.

[0119] In another embodiment, the origin of the measured wafer is defined as the center of the positioning notch (chuck) of the wafer, which is the wafer origin (0, 0) point. Die (0, 0) is defined as the Die where the wafer origin is located. A rectangular coordinate system is established on the wafer plane with this origin, so that the positions of all other Dies on the wafer can be indexed and defined.

[0120] Furthermore, 3D data of the chip surface is obtained, where the 3D data of the chip surface includes coordinate positions within the range of each chip (die) area and height profile information related to the coordinate points within the range of each chip (die) area. The height profile information of each Die consists of the position (X, Y) relative to the wafer origin inside the Die and the height Z at this position.

[0121] Furthermore, after identifying the Dies in the measured wafer image, a specific code or label can be assigned to each Die.

[0122] Furthermore, in this embodiment, the step 313: the step of micro-bump positioning includes:

[0123] Identify and mark each micro-bump area, and correspondingly obtain the three-dimensional information of each micro-bump (bump) area.

[0124] Specifically, wafer bumping is to form or install solder balls (also known as bumps, bumps) at preset positions on the wafer before dicing the wafer. Wafer bumping is a key technology for realizing the interconnection between the chip and the PCB or substrate. The material selection, structure, and size design of wafer bumps are affected by various factors, such as package size, cost, and electrical, mechanical, heat dissipation, and other performance requirements. As the space of portable electronic products continues to shrink, the working frequency increases day by day, and the functional requirements become diversified, the number of chip input / output (I / O) signal interfaces has increased significantly, and the precision requirements for the bump and solder ball pitch (Bump Pitch&BallPitch) have become increasingly strict.

[0125] Wafer bumping technology can provide significant performance, form factor, and overall cost advantages in semiconductor packaging. A variety of alloy materials and processes can be used in wafer bumping, including printed bumps, solder balls, or electroplating techniques using eutectic, lead-free, and copper pillar alloys. Current wafer bumps include printed bump (PrintedBump) technology, eutectic electroplating ball drop (BallDrop withEutecticPlating) technology, lead-free alloy (Lead-FreeAlloy), and copper pillar alloy (Copper-PillarAlloy) bump technology.

[0126] Figures 7 to 9As shown, it is a schematic diagram of the image of the microbumps in the Die on the surface of the wafer in this embodiment.

[0127] Among them, Figure 7 It is a schematic diagram of the distribution of microbumps on the chip (die) in the measured wafer image. Combining Figure 6 , referring to Figure 7 , it can be seen from the figure that the surface of the measured wafer 660 is divided into several regions according to the chip (die) area 84, and the microbumps 70 are distributed on the surface of the chip area 84 according to the design rules.

[0128] Figure 8 It is a detailed enlarged view of the microbump area in the two-dimensional image of the surface of the measured wafer. It can be seen from the figure that in the uniform gray background area is the surface of the measured wafer 660, and the microbump 70 areas with an approximately elliptical contour and a bright surface are distributed intermittently therein. In this embodiment, the maximum length and width values of the microbump 70 can also be obtained by selecting a specific microbump 70.

[0129] Figure 9 It is a three-dimensional structure schematic diagram of the microbump 70 on the surface of the measured wafer 660.

[0130] Furthermore, in this embodiment, the steps of marking and identifying the microbump area include:

[0131] Automatically marking, and / or manually marking the image of the microbump in the surface feature image of the measured wafer according to the image of the microbump contour similar to that in the surface feature image of the measured wafer.

[0132] Specifically, in this embodiment, the image of the microbump contour similar to that in the surface feature image of the measured wafer can be automatically marked first, and then the image of the microbump contour similar to that in the surface feature image of the measured wafer can be manually supplemented and marked.

[0133] Extract the position coordinates (x, y) in each microbump contour according to the microbump contour area, and obtain the height value corresponding to the position coordinates (x, y), and comprehensively process to obtain the three-dimensional information data of each microbump. Thus, calculate the height value, volume value, and area value of the microbump according to the three-dimensional information data of the microbump. According to actual needs, the height value in the microbump contour may include: the average height value in the microbump contour, the maximum height value and / or the minimum height value.

[0134] Furthermore, among them, the corresponding code or label of the chip where it is located can be obtained according to the (x, y) coordinate range of the position of the microbump contour area. So as to facilitate the subsequent program to output the code or label of the chip with unqualified microbumps.

[0135] Referring to Figure 10As shown, in this embodiment, it is a schematic diagram of obtaining the height value of a selected micro-bump for the three-dimensional image of the micro-bumps on the surface of the measured wafer. Specifically, the three-dimensional image of the micro-bump corresponds to its relevant three-dimensional information data. In the three-dimensional image of the micro-bumps on the surface of the measured wafer on the left, a single micro-bump 70 selected by the selected square A can obtain a two-dimensional map of the upper surface of this micro-bump 70 in the image above the right. Then, by drawing lines on the two-dimensional map of the micro-bump, a height profile map of the cross-section of the part where the line is drawn on the selected micro-bump 70 can be obtained in the image below the right, and at the same time, the numerical value of the corresponding height profile can also be obtained.

[0136] Perform step S400: Feature data classification: Set the range standard or determination condition of the feature items, and classify and process the feature data;

[0137] Furthermore, in this embodiment, the feature data classification includes: classifying the range of the height value of the micro-bump into: a range less than the minimum value range, a range greater than the maximum value range, and a qualified range between the minimum value and the maximum value. Specifically, according to the requirements of the process specifications, set the range of the height value of the micro-bump. For example, in the first process specification, set the minimum value of the height value of the micro-bump to 15 nm and the maximum value to 45 nm. In the second process specification, set the minimum value of the height value of the micro-bump to 35 nm and the maximum value to 65 nm. In the third process specification, set the minimum value of the height value of the micro-bump to 10 nm and the maximum value to 15 nm, and so on.

[0138] Step S500: Measurement result display: Intuitively display the feature data classified according to the classification result.

[0139] Furthermore, in this embodiment, the measurement result display includes: corresponding different colors according to the range where the height value of each micro-bump is located, so as to display different colors corresponding to the height value at the position of the micro-bump.

[0140] Reference Figure 11 As shown, it is a schematic diagram of the measurement result display of the micro-bumps in a partial area of the Die on the surface of the measured wafer in this embodiment.

[0141] Among them, the color block corresponding to P indicates that the micro-bump 70 it represents is qualified, the color block corresponding to F1 indicates that the height of the micro-bump 70 it represents is insufficient, and the color block corresponding to F2 indicates that the height of the micro-bump 70 it represents is too high.

[0142] After comparing the feature data with the set standard, it is obtained that:

[0143] Some micro-bumps have heights that meet the process specification requirements and are displayed associated with the first color P;

[0144] Some micro - bumps have a height value lower than the minimum due to loss or damage, and are associated with the second color F1 for display;

[0145] Alternatively, some micro - bumps have a height value greater than the maximum due to local process problems, and are associated with the third color F2 for display;

[0146] Among them, the micro - bumps displayed in the second color F1 and the third color F2 are unqualified.

[0147] The unqualified micro - bumps will cause the entire chip (die) 84 to be unqualified, and it is necessary to magnify each one to view the details in order to discover detailed information and analyze the cause of unqualified.

[0148] Furthermore, in this embodiment, it further includes steps of image magnification / reduction, which is suitable for performing fixed - point magnification / reduction based on the surface image data of the complete wafer to view the image data of a local area and the three - dimensional dimensions of the local wafer surface topography.

[0149] Figure 12 The block diagram of a device 1400 for three - dimensional measurement of the wafer surface according to an embodiment of the present disclosure is shown. For example, Figure 1 The three - dimensional measurement method of the wafer surface shown can be implemented by the device 1400.

[0150] Specifically, the present invention also provides a device for three - dimensional measurement of the wafer surface, including:

[0151] A measurement data acquisition unit 1401, which is suitable for acquiring the surface image and multi - dimensional measurement data of the wafer;

[0152] A measurement data fitting unit 1402, which is suitable for fitting the acquired surface image and multi - dimensional measurement data of the wafer to obtain the surface 3D data of the wafer;

[0153] A feature data extraction unit 1403, which is suitable for extracting the required feature data from the surface 3D data of the wafer according to the measurement requirements of feature items;

[0154] A feature data classification unit 1404, which is suitable for setting the range criteria or determination conditions of feature items and classifying the feature data;

[0155] A measurement result display unit 1405, which is suitable for visually displaying the feature data by category.

[0156] Preferably, the measurement result display unit includes:

[0157] A color matching unit, which is suitable for associating feature information in different ranges or under different conditions with different colors to display the classification of the feature information through color information.

[0158] Preferably, the measurement data fitting unit obtains the 3D data of the surface of the complete wafer, and the 3D data of the surface of the complete wafer includes: the surface image data of the complete wafer, the height of the wafer substrate plane, and the three-dimensional dimensions of the surface topography of the complete wafer.

[0159] Preferably, the feature data extraction unit is adapted to extract the 3D data of the microbumps on the surface of the chip from the 3D data of the surface of the wafer, and the microbumps are the microbumps in the Dies on the surface of the wafer, and are adapted to form an electrical connection structure on the microbumps in subsequent processes.

[0160] Preferably, the feature data extraction unit includes:

[0161] a positioning unit adapted to obtain the coordinate points of the microbumps in the 3D data of the surface of the wafer;

[0162] a height measurement and analysis module adapted to analyze the height of the microbumps according to the 3D data of the surface of the wafer to obtain the height value of each microbump.

[0163] Preferably, the feature data classification unit includes: a range classifier for the height values of the microbumps, and the range classifier for the height values of the microbumps includes: a first storage unit for values less than the lowest value range, a second storage unit for values greater than the highest value range, and a third storage unit for the qualified range between the lowest value and the highest value.

[0164] Preferably, the measurement result display unit includes: corresponding different colors to the ranges where the height values of each microbump are located, so as to display different colors corresponding to the height values at the positions of the microbumps.

[0165] Preferably, the positioning unit includes: a wafer initial positioning module, a chip positioning module, and a microbump positioning module.

[0166] Preferably, the wafer initial positioning module is adapted to adjust the position and orientation of the surface feature image of the wafer according to the gap between the position of the positioning notch in the measured surface feature image of the wafer and the positioning mark in the image display unit, so as to coincide the positioning notch and the positioning mark.

[0167] Preferably, the chip positioning module is adapted to divide all chip regions according to the edges of the minimum periodic patterns in the measured surface feature image of the wafer, and correspondingly obtain the coordinate information or coding / label information of each chip region.

[0168] Preferably, the microbump module is adapted to identify and mark the coordinate information of each microbump region.

[0169] Preferably, the micro bump module includes an automatic marking unit and / or a manual marking unit. The automatic marking unit is adapted to automatically mark the images of the profiles of the micro bumps similar to those in the surface feature image of the measured wafer, and / or the manual marking unit is adapted to manually mark the images of the micro bumps in the surface feature image of the measured wafer.

[0170] Preferably, the measurement result display unit further includes an image zooming unit, which is adapted to perform fixed-point zooming in or out based on the surface image data of the complete wafer to view the image data of a local area and the three-dimensional dimensions of the local wafer surface topography.

[0171] Preferably, the measurement data acquisition unit includes three 3D image acquisition cameras and one coaxial camera.

[0172] For the sake of clarity, certain optional modules of the device 1400 are not shown in Figure 12 However, it should be understood that the various features described above with reference to Figures 1 to 11 equally apply to the device 1400. Moreover, the various modules of the device 1400 can be hardware modules or software modules. For example, in some embodiments, the device 1400 can be implemented partially or entirely using software and / or firmware, such as being implemented as a computer program product included in a computer-readable medium. Alternatively or additionally, the device 1400 can be implemented partially or entirely based on hardware, such as being implemented as an integrated circuit (IC), an application-specific integrated circuit (ASIC), a system-on-chip (SOC), a field-programmable gate array (FPGA), etc. The scope of the present disclosure is not limited in this regard.

[0173] On the other hand, the present invention also provides a system for three-dimensional measurement of the surface of a wafer, including:

[0174] a processor,

[0175] a memory storing computer programs or instructions, which, when executed by the processor, implement the steps of the method described above to perform defect detection on an object.

[0176] On the other hand, the present invention also provides a computer program product, which is stored on a computer-readable storage medium and includes computer programs or instructions, which, when executed by the processor, implement the steps of the method described above.

[0177] Embodiments of the present disclosure can be implemented by a computer program product. The computer program product is tangibly stored on a non-transitory computer-readable medium and includes machine-executable instructions. The machine-executable instructions, when executed, cause the machine to execute any step of the method according to the embodiments of the present disclosure.

[0178] The above embodiments are only used to illustrate the technical concept and features of the present invention, and the purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it accordingly. However, it is not used to limit the protection scope of the present invention.

[0179] Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention by using the methods and technical content disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes, and decorations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention all belong to the protection scope of the technical solution of the present invention.

Claims

1. A method for three-dimensional measurement of a wafer surface, characterized in that, Including: Measurement data acquisition: Collect the surface image and multi-dimensional measurement data of the wafer through a measurement data acquisition device. Among them, the measurement data acquisition device includes an annular light source, three 3D image acquisition cameras, and one coaxial camera. The annular light source and the one coaxial camera are located above the wafer to be collected, and the three 3D image acquisition cameras are located on the side directly above the wafer to be collected. The angle between each 3D image acquisition camera is set according to the requirements of the measurement process; the surface image of the wafer is collected by the coaxial camera, and the multi-dimensional measurement data is collected by the three 3D image acquisition cameras; Measurement data fitting: Fit the collected surface image and multi-dimensional measurement data of the wafer to obtain the surface 3D data of the wafer; Feature data extraction: Extract the required feature data from the surface 3D data of the wafer according to the measurement requirements of the feature items, including: extracting the 3D data of the chip surface from the surface 3D data of the wafer, and the chip surface includes microbumps, which are suitable for forming electrical connection structures on the microbumps in subsequent processes; Feature data classification: Set the range standard or determination condition of the feature items, and classify the feature data; Measurement result display: Intuitively display the feature data classified according to the result of the classification process.

2. The method for three-dimensional measurement of the wafer surface according to claim 1, wherein, The measurement result display includes: Color matching: Associate feature information in different ranges or under different conditions with different colors to display the classification of the feature information through color information.

3. The method for three-dimensional measurement of the wafer surface according to claim 1, wherein The measurement data fitting obtains the surface 3D data of the complete wafer, and the surface 3D data of the complete wafer includes: the surface image data of the complete wafer, the height of the wafer substrate plane, and the three-dimensional dimensions of the complete surface topography of the wafer.

4. The method for three-dimensional measurement of the wafer surface according to claim 1, wherein The steps of the feature data extraction include: Obtain the coordinate points of the microbumps in the surface 3D data of the wafer; Height measurement and analysis step, analyze the height of the microbumps according to the surface 3D data of the wafer to obtain the height value of each microbump.

5. The method for three-dimensional measurement of the wafer surface according to claim 4, characterized in that, The feature data classification includes: classifying the range of the height values of the microbumps into: a range less than the minimum value range, a range greater than the maximum value range, and a qualified range between the minimum value and the maximum value.

6. The method for three-dimensional measurement of the wafer surface according to claim 4, wherein, The measurement result display includes: corresponding to different colors according to the range where the height value of each microbump is located, so as to display different colors corresponding to the height value at the position of the microbump.

7. The method for three-dimensional measurement of the wafer surface according to claim 4, wherein The steps of obtaining the coordinate points of the microbumps in the surface 3D data of the wafer include: initial wafer positioning, chip positioning, and microbump positioning.

8. The method for three-dimensional measurement of the wafer surface according to claim 7, wherein, The steps of the initial wafer positioning include: According to the gap between the position of the positioning notch in the surface feature image of the wafer and the positioning mark in the image display system, adjust the position and orientation of the surface feature image of the wafer to coincide the positioning notch and the positioning mark.

9. The method for three-dimensional measurement of the wafer surface according to claim 7, characterized in that, The steps of the chip positioning include: Divide all chip areas according to the edges of the smallest periodic patterns in the surface feature image of the measured wafer, and correspondingly obtain the position information of each chip area.

10. The method for three-dimensional measurement of the wafer surface according to claim 7, wherein, The steps of the microbump positioning include: Identify and mark each micro-bump region, and correspondingly obtain the coordinate information of each micro-bump region.

11. The method for three-dimensional measurement of the wafer surface according to claim 10, characterized in that, The step of identifying and marking each micro-bump region includes: Automatically marking according to the micro-bump contour image similar in the surface feature image of the wafer, and / or manually marking the image of the micro-bump in the surface feature image of the wafer.

12. The method for three-dimensional measurement of the wafer surface according to claim 3, wherein The measurement result display further includes: image zooming, suitable for performing fixed-point zooming based on the surface image data of the complete wafer to view the image data of the local area and the three-dimensional dimensions of the local wafer surface topography.

13. A device for three-dimensional measurement of the surface of a wafer, characterized in that, It includes: A measurement data acquisition unit, suitable for acquiring the surface image and multi-dimensional measurement data of the wafer through a measurement data acquisition device. Among them, the measurement data acquisition device includes an annular light source, three 3D imaging cameras, and one coaxial camera. The annular light source and the one coaxial camera are located above the wafer to be acquired, and the three 3D imaging cameras are located beside the wafer to be acquired directly above. And the included angle between each 3D imaging camera is set according to the requirements of the measurement process; the surface image of the wafer is acquired by the coaxial camera, and the multi-dimensional measurement data is acquired by the three 3D imaging cameras; A measurement data fitting unit, suitable for fitting the acquired surface image and multi-dimensional measurement data of the wafer to obtain the surface 3D data of the wafer, including: extracting the 3D data of the chip surface from the surface 3D data of the wafer. The chip surface includes micro-bumps, suitable for forming an electrical connection structure on the micro-bumps in subsequent processes; A feature data extraction unit, suitable for extracting the required feature data from the surface 3D data of the wafer according to the measurement requirements of the feature items; A feature data classification unit, suitable for setting the range standard or determination condition of the feature items and classifying the feature data; A measurement result display unit, suitable for visually displaying the feature data by category.

14. The device for three-dimensional measurement of the wafer surface according to claim 13, wherein, The measurement result display unit includes: A color matching unit, suitable for associating feature information in different ranges or under different conditions with different colors to display the classification of the feature information through color information.

15. The device for three-dimensional measurement of the wafer surface according to claim 13, characterized in that, The measurement data fitting unit obtains the complete surface 3D data of the wafer. The complete surface 3D data of the wafer includes: the surface image data of the complete wafer, the height of the wafer substrate plane, and the three-dimensional dimensions of the complete wafer surface topography.

16. The device for three-dimensional measurement of the wafer surface according to claim 13, wherein, The feature data extraction unit is suitable for extracting the 3D data of the chip surface from the surface 3D data of the wafer. The chip surface includes micro-bumps, suitable for forming an electrical connection structure on the micro-bumps in subsequent processes.

17. The device for three-dimensional measurement of the wafer surface according to claim 16, wherein, The feature data extraction unit includes: A positioning unit, suitable for obtaining the coordinate points of the micro-bumps in the surface 3D data of the wafer; A height measurement and analysis module, suitable for analyzing the height of the micro-bumps according to the surface 3D data of the wafer to obtain the height value of each micro-bump.

18. The device for three-dimensional measurement of the wafer surface according to claim 17, wherein, The feature data classification unit includes: a classifier for the range of the height values of the microbumps, and the classifier for the range of the height values of the microbumps includes: a first storage unit for values less than the lowest value range, a second storage unit for values greater than the highest value range, and a third storage unit for the qualified range between the lowest value and the highest value.

19. The device for three-dimensional measurement of the wafer surface according to claim 17, wherein The measurement result display unit includes: corresponding to different colors according to the range where the height value of each microbump is located, so as to display different colors corresponding to the height values at the positions of the microbumps.

20. The device for three-dimensional measurement of a wafer surface according to claim 17, characterized in that, The positioning unit includes: a wafer preliminary positioning module, a chip positioning module, and a microbump positioning module.

21. The device for three-dimensional measurement of the wafer surface according to claim 20, wherein, The wafer preliminary positioning module is adapted to adjust the position and orientation of the surface feature image of the wafer according to the gap between the position of the positioning notch in the surface feature image of the wafer and the positioning mark in the image display unit, so as to coincide the positioning notch and the positioning mark.

22. The device for three-dimensional measurement of the wafer surface according to claim 20, wherein, The chip positioning module is adapted to divide all chip regions according to the edges of the smallest periodic patterns in the surface feature image of the wafer, and correspondingly obtain the coordinate information of each chip region.

23. The device for three-dimensional measurement of the wafer surface according to claim 22, wherein, The microbump module is adapted to identify and mark each microbump region, and correspondingly obtain the coordinate information of each microbump region in each chip region.

24. The device for three-dimensional measurement of the wafer surface according to claim 22, characterized in that, The microbump module includes an automatic marking unit and / or a manual marking unit. The automatic marking unit is adapted to automatically mark the images of the microbump contours similar to those in the surface feature image of the wafer, and / or the manual marking unit is adapted to manually mark the images of the microbumps in the surface feature image of the wafer.

25. The device for three-dimensional measurement of the wafer surface according to claim 24, wherein, The measurement result display unit further includes an image zooming unit, which is adapted to perform fixed-point zooming based on the complete surface image data of the wafer, so as to view the image data of the local area and the three-dimensional dimensions of the local wafer surface topography.

26. The device for three-dimensional measurement of the wafer surface according to claim 13, wherein, The measurement data acquisition unit includes three 3D imaging cameras and one coaxial camera.

27. A system for three-dimensional measurement of a wafer surface, characterized in that, Including: a processor, a memory for storing computer programs or instructions, and the computer programs or instructions, when executed by the processor, implement the steps of the method according to any one of claims 1 to 12 to perform defect detection on an object.

28. A computer program product, characterized in that, The computer program product is stored on a computer-readable storage medium and includes computer programs or instructions, and the computer programs or instructions, when executed by the processor, implement the steps of the method according to any one of claims 1 to 12.

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