Wafer measurement device and semiconductor manufacturing system including the same

Abstract

To provide a wafer measurement device which can be added to an existing semiconductor manufacturing system in a clean room in order to suppress a content volume in the clean room.SOLUTION: A wafer measurement device 10 comprises: a light source 11; an imaging device 20; and a control device 12 that calculates a film thickness or the like provided to a wafer W from spectral characteristic data of measurement light obtained from the imaging device 20. The control device 12 acquires length data of one obtained by being reflected by the wafer W among thickness calculation liner measurement light used when calculating the film thickness or the like toward a liner direction, and calculates a coordinate position in an operation direction of the wafer of the thickness calculation liner measurement light on the basis of the length data. This construction enables provision of a wafer measurement device having a construction simpler than a conventional one, therefore, the wafer measurement device can be added to an existing semiconductor manufacturing system without enlarging a clean room.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a wafer measuring device and a semiconductor manufacturing system equipped with the same. More specifically, the present invention relates to a wafer measuring device that measures the thickness of a film provided on a wafer or the thickness of the wafer itself from spectroscopic characteristic data of measurement light, and a semiconductor manufacturing system equipped with the same. [Background technology]

[0002] Many semiconductor manufacturing systems are arranged in clean rooms. To maintain the clean room at a specified clean condition (e.g., class 100 or class 10), a large running cost is incurred, so it is desirable to arrange the necessary manufacturing equipment in the clean room in an efficient manner and to make the internal volume as small as possible. Patent Document 1 discloses a semiconductor wafer thickness distribution measurement system that constitutes part of a semiconductor manufacturing system. As shown in FIG. 2 of this document, for example, a semiconductor wafer is transported from a loading section by a robot to a measurement section by a multi-joint robot, and the semiconductor wafer after measurement is transported again by another robot to a storage section or polishing section.

[0003] As shown in Patent Document 1, the thickness of a semiconductor wafer is an item of inspection, and as shown in Patent Document 2, the thickness of a film formed on the semiconductor wafer is an item of inspection. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-112316 A [Patent Document 2] JP 2020-165867 A Summary of the Invention [Problem to be solved by the invention]

[0005] As mentioned above, it is desirable to minimize the internal volume of the clean room in which semiconductor manufacturing equipment is installed. However, when introducing new inspection equipment, it is necessary to consider the installation of a transport device such as a robot, which poses the problem that the internal volume of the clean room is inevitably large. Furthermore, when it is desired to increase the number of measuring devices depending on the type or grade of semiconductors being manufactured, there is a problem that it becomes difficult to install the measuring devices in an existing clean room, if a transport device is also included. In addition, when installing an inspection device within a manufacturing device, the cost increases and the wiring layout becomes more complicated as the number of sensors for measuring the speed or position of a probe or the like of the inspection device and the wiring therefor increases.

[0006] In view of the above circumstances, an object of the present invention is to provide a wafer measurement device that can be added to an existing semiconductor manufacturing system in a clean room in order to reduce the internal volume of the clean room, and that can minimize the amount of equipment to be installed inside the semiconductor manufacturing system, and a semiconductor manufacturing system equipped with the same. [Means for solving the problem]

[0007] The wafer measuring device of the first invention comprises a light source which irradiates a line-shaped measurement light onto a wafer, an imaging device which receives the line-shaped measurement light reflected by the wafer, and a control device which calculates the thickness of a film provided on the wafer or the thickness of the wafer itself from the spectral characteristic data of the line-shaped measurement light obtained from the imaging device, wherein the control device acquires length data in a line-shaped direction of the thickness-calculation line-shaped measurement light reflected by the wafer, which is used when calculating the thickness of the film or the thickness of the wafer itself, and calculates the coordinate position of the thickness-calculation line-shaped measurement light in the moving direction of the wafer based on the length data. The wafer measuring device of the second invention is characterized in that, in the first invention, when the control device calculates the coordinate position of the linear measurement light for thickness calculation in the moving direction of the wafer based on the length data, the control device sets the pixel located at the center of the length data in the linear direction as the center point of the linear direction, acquires the linear direction center point for each linear measurement light for thickness calculation, calculates a center line of the wafer parallel to the moving direction of the wafer based on these linear direction center points, sets the longer of the lengths from the center line to the end of the length data as the calculated length when the length data was acquired, and calculates the coordinate position of the linear measurement light for thickness calculation in the moving direction of the wafer based on the calculated length. The wafer measuring device of the third invention is characterized in that, in the first invention, the control device extracts defects based on the thickness of the film or the thickness of the wafer itself, and calculates the size of the defects based on information of the coordinate position of the wafer in the moving direction. The wafer measuring device of the fourth invention is the same as that of the first invention, and is characterized in that it includes a display device that displays the thickness of the film or the thickness of the wafer itself calculated by the control device, and the display device represents the thickness of the film or the thickness of the wafer itself in a two-dimensional map. A semiconductor manufacturing system according to a fifth aspect of the present invention comprises a semiconductor processing apparatus and a transport robot for transferring wafers to and from the semiconductor processing apparatus, and further comprises the wafer measuring apparatus according to claim 1 for measuring a thickness of a film provided on the wafer or a thickness of the wafer itself while the wafer is being transported by the transport robot. Effect of the Invention

[0008] According to the first invention, the length data in the line direction of the thickness calculation line-shaped measurement light used when calculating a predetermined thickness is obtained, and the coordinate position of the thickness data in the moving direction of the wafer is calculated based on this length data, so that the thickness of the film provided on the wafer can be measured without using a measuring device for identifying the coordinate position in the moving direction of the wafer. Therefore, a wafer measuring device having a simpler configuration than the conventional one can be provided, and the wafer measuring device can be added to an existing semiconductor manufacturing system without enlarging the clean room. In addition, since there is no need to use a wafer transport device controlled with high precision, and the equipment installed inside the semiconductor manufacturing system can be minimized, the device can be provided at low cost. According to the second invention, by determining a center line parallel to the wafer movement direction using a specified method and thereby identifying the coordinate position of the wafer movement direction of the linear measurement light for thickness calculation, even if a notch or orientation flat is present on the wafer, the coordinate position of the linear measurement light for thickness calculation can be identified without inputting such information. According to the third aspect of the present invention, the defect is extracted by a predetermined method and its size is calculated, so that the user of the device can easily recognize the size of the defect. According to the fourth aspect of the present invention, the display device displays the thickness as a two-dimensional map, allowing the user of the device to easily grasp the thickness distribution. According to the fifth invention, by having a wafer measuring device that measures the film thickness etc. of the wafer while it is being transported by the transport robot, it is no longer necessary to secure a large space for the device alone, and a space-saving, simple and low-cost semiconductor manufacturing system can be provided. [Brief description of the drawings]

[0009] [Figure 1] 5A to 5C are explanatory diagrams of a coordinate position calculation method in a first wafer movement direction in the wafer measuring apparatus according to the embodiment of the present invention. [Diagram 2] 1 is a cross-sectional view in a plan view of a semiconductor manufacturing system including a wafer measuring apparatus according to an embodiment of the present invention. [Diagram 3] 1 is a plan view of a wafer measuring apparatus according to an embodiment of the present invention. [Figure 4] FIG. 4 is a front view of the wafer measuring apparatus of FIG. [Diagram 5] FIG. 4 is a perspective view of the wafer measuring apparatus of FIG. [Figure 6] 4 is an explanatory diagram of an imaging device constituting the wafer measuring apparatus of FIG. 3. [Figure 7] FIG. 4 is a control block diagram of the wafer measuring device of FIG. 3. [Figure 8] 4 is an explanatory diagram of a display screen of a display device of the wafer measuring device of FIG. 3. [Figure 9] 11 is an explanatory diagram of a coordinate position calculation method in a second wafer movement direction in the wafer measuring apparatus according to the embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Next, an embodiment of the present invention will be described with reference to the drawings. However, the embodiment shown below is an example of a wafer measuring device and a semiconductor manufacturing system for embodying the technical idea of ​​the present invention, and the present invention does not specify the wafer measuring device and the semiconductor manufacturing system as described below. The size or positional relationship of the members shown in each drawing may be exaggerated to clarify the description. Furthermore, the terms "vertical" and "parallel" in this specification do not necessarily mean strictly vertical or parallel, but mean vertical or parallel to the extent that the function of the part where these terms are used can be fully fulfilled, that is, "substantially vertical" and "substantially parallel". In addition, the wafer is provided with a notch or an orientation flat, but in the specification, when there is no need to distinguish between them, the wafer is indicated with the symbol W, and when there is a need to distinguish between them, the notched wafer is indicated with the symbol W1 and the orientation flat wafer is indicated with the symbol W2.

[0011] (Semiconductor Manufacturing System 30) FIG. 2 shows a planar cross-sectional view of a semiconductor manufacturing system 30 equipped with a wafer measuring device according to an embodiment of the present invention. The semiconductor manufacturing system 30 is equipped with a horizontal articulated transfer robot 32. The semiconductor manufacturing system 30 includes the transfer robot 32, a transfer chamber 34 having the transfer robot 32 located substantially at the center, and a plurality of processing chambers 31 and a carrier chamber 33 connected to the transfer chamber 34. Here, the processing chamber 31 is a semiconductor processing device, which may be a semiconductor manufacturing device that performs some processing on the wafer W, or a measuring device that measures the properties of the wafer W after processing. In the semiconductor manufacturing system 30, the transfer robot 32 takes in and out the wafers W one by one, and performs processing (processing or measurement).

[0012] As shown in FIG. 2, the transfer chamber 34 has a hexagonal shape when viewed from above, and the transfer robot 32 is disposed in the center. The processing chambers 31 or the carrier chambers 33 are connected to each side of the hexagon around the transfer chamber 34. In the processing chamber 31, a predetermined process is performed on the wafer W, and in the carrier chamber 33, the wafer W is loaded on a carrier. The wafer W is transferred from another system to the semiconductor manufacturing system 30 while being loaded on the carrier, or is transferred from the semiconductor manufacturing system 30 to another system. A gate valve is provided at each connection port of the transfer chamber 34, the processing chamber 31, and the carrier chamber 33, and the gate valve allows the transfer chamber 34, the processing chamber 31, and the carrier chamber 33 to be kept airtight with each other.

[0013] In the above-described semiconductor manufacturing system 30, a part of the wafer measuring device 10 according to this embodiment is provided in the transfer chamber 34. For example, the light source 11 and the imaging device 20 may be disposed in the transfer chamber 34. Also, the light source 11 and the imaging device 20 may be disposed in a processing chamber 31 dedicated to measurement or in a carrier chamber 33.

[0014] The above-mentioned configuration of the semiconductor manufacturing system 30 is an example, and is not limited to the above. For example, the shape of the transfer chamber 34 may be a polygon other than a hexagon (e.g., a triangle, a square, a pentagon, an octagon, etc.) or a circle. In this case, the number, shape, or arrangement of the processing chambers 31 or the carrier chambers 33 is appropriately changed according to the shape of the transfer chamber 34.

[0015] (Configuration of wafer measuring device 10) Fig. 3 shows a plan view of a wafer measuring apparatus 10 according to an embodiment of the present invention, Fig. 4 shows a side view thereof, and Fig. 5 shows a perspective view thereof. For ease of understanding, Figs. 3 and 4 show only the main components of the wafer measuring apparatus 10. The wafer measuring apparatus 10 according to the present invention is a measuring apparatus that can measure the thickness of a film provided on the wafer W or the thickness of the wafer W itself from the spectral characteristic data of a line-shaped measurement light reflected by the wafer W. Measuring apparatuses that measure the thickness of a film provided on the wafer W from this spectral characteristic data include a white light interference method, a spectral interference method, and a confocal method.

[0016] The object to be measured by the wafer measuring device 10 according to this embodiment is a wafer W. A "wafer" is a thin circular plate made of semiconductor crystals that is the material for IC chips (semiconductor integrated circuits). This wafer W has a notch on its periphery or a straight line called an orientation flat to align the orientation of the wafer W during processing.

[0017] In this embodiment, as shown in Figures 3 and 4, the notched wafer W1 is moved by the transfer robot 32 in the direction indicated by the arrow, that is, from bottom to top on the paper surface of Figure 3 in Figure 3, and from right to left on the paper surface of Figure 4 in Figure 4. In Figure 3, the direction perpendicular to the direction indicated by the arrow is the linear direction of the linear measurement light. The notched wafer W1 moves as indicated by the arrow in the portion where the thickness is measured by the wafer measuring device 10. That is, in this embodiment, the thickness of a film or the like provided on the notched wafer W1 is measured in accordance with the movement of the notched wafer W1, which is the object to be measured, in the direction perpendicular to the linear direction of the light source 11.

[0018] The wafer measuring apparatus 10 according to this embodiment has an apparatus main body. The apparatus main body includes a light source 11 that irradiates a line-shaped measuring light, and an imaging device 20 that receives the line-shaped measuring light reflected by the notched wafer W1. The light source 11 that irradiates the line-shaped measuring light has a line-shaped direction in the left-right direction in FIG. 3 and in the depth direction in FIG. 4.

[0019] In this embodiment, the light source 11 that irradiates the linear measurement light is preferably an LED. By using an LED as the light source 11, it is easy to increase the size of the light source 11, increase the amount of light, and reduce the manufacturing cost. However, the light source 11 is not limited to this. For example, a fluorescent lamp, a halogen light source, or a metal halide lamp may be used as long as it irradiates a linear measurement light. In addition, when the light source 11 is a halogen light source, it is suitable for thickness measurement because the wavelength of the measurement light emitted is wide and the intensity of each wavelength is relatively uniform compared to other light sources. In addition, it is preferable to use a cylindrical lens or a rod lens at the tip of the light source 11. This is because the amount of light received by the imaging device 20 is increased. In addition, it is preferable to irradiate uniform light by installing a plate material with light diffusing properties such as a diffuser or a diffusion plate between the light source 11 and the notched wafer W1. This is because the irradiated light becomes uniform, making it possible to obtain stable measurement results. 3, the dashed lines drawn from light source 11 toward imaging device 20 depict the measurement light emitted from light source 11 that is received by imaging device 20 when notched wafer W1 has a sufficient size, and the measurement light actually emitted from light source 11 extends beyond these dashed lines. Note that the measurement light irradiated from light source 11 is preferably visible light.

[0020] FIG. 6 shows a configuration diagram of the imaging device 20 according to this embodiment. FIG. 6 is a cross-sectional view of the imaging device 20 seen from the side. In FIG. 6, the measurement light is indicated by a dashed line. The imaging device 20 receives the measurement light irradiated from the light source 11 by reflecting it off the notched wafer W1. The light is received by dispersing the measurement light. As shown in FIG. 6, the imaging device 20 includes a first lens 21 that collects the measurement light that has passed through the object to be measured, a slit 22 that cuts out unnecessary parts of the collected measurement light to improve the spectroscopic accuracy, a second lens 23 that corrects the measurement light that has passed through the slit 22 to a direction suitable for being incident on a grating element 24, a grating element 24 that disperses the measurement light into wavelengths, a third lens 25 that collects the measurement light after dispersion on a two-dimensional sensor 26, and a two-dimensional sensor 26 that receives the dispersed measurement light, all of which are included in a housing 27.

[0021] The two-dimensional sensor 26 has a configuration having a predetermined length in the left-right direction and the depth direction on the paper surface of FIG. 6, and in this embodiment, a CMOS is used as an element. However, the element is not limited to a CMOS. For example, a CCD, InGaAs, InSb, MCT, QWIP, etc. can also be used. When a CCD or a CMOS is used as an element of the two-dimensional sensor 26, cooling of the two-dimensional sensor 26 is not required, and it is possible to reduce the manufacturing cost of the wafer measuring device 10. In particular, when a CMOS is used, it is possible to perform ROI (Region Of Interest) in both the left-right and depth directions, and it is possible to speed up imaging by narrowing down the sensor area to a necessary one.

[0022] The first lens 21, second lens 23, and third lens 25 used in the imaging device 20 can be any lens capable of focusing and manipulating the measurement light. Instead of these lenses, curved mirrors can be used. The use of curved mirrors increases the freedom of design and allows the imaging device 20 to be made more compact.

[0023] In this embodiment, the grating element 24 is of a transmissive type. When the grating element 24 is of a transmissive type, the imaging device 20 can accommodate a wide range of wavelengths and has a simple structure. However, the present invention is not limited to this, and a reflective grating element can also be used. Examples of the reflective grating element include a blazed diffraction grating and a holographic diffraction grating. The use of a reflective grating element increases the freedom of design and enables the imaging device 20 to be made more compact.

[0024] In this embodiment, the housing 27 of the imaging device 20 is made of aluminum. By making the housing 27 out of aluminum, good heat dissipation and workability can be obtained. In addition, it is possible to reduce costs. However, the material is not limited to this, and resin, stainless steel, etc. can also be used.

[0025] FIG. 7 shows a control block diagram of the wafer measuring apparatus 10 according to this embodiment. The wafer measuring apparatus 10 according to this embodiment has a control device 12. This control device 12 is composed of a CPU and the like. The control device 12 is electrically connected to the light source 11, the imaging device 20, the display device 13, the data storage device 14, and the input device 15. The control device 12 can calculate the thickness of the object to be measured by analyzing the spectroscopic characteristic data of the measurement light measured by the two-dimensional sensor 26 of the imaging device 20. In addition, the control device 12 is preferably provided with an output unit (not shown) for outputting information such as film thickness data, average film thickness value, maximum film thickness value, minimum film thickness value, size, shape, and position of the film thickness abnormality portion to a device other than the wafer measuring apparatus 10.

[0026] In this embodiment, the display device 13 is a liquid crystal display, and is capable of displaying the thickness data of the object to be measured two-dimensionally or three-dimensionally in response to a signal from the control device 12. However, the display device 13 is not limited to a liquid crystal display. For example, an organic EL display is also applicable.

[0027] In this embodiment, the data storage device 14 is a hard disk, and is capable of storing compressed data of the thickness data of the object to be measured calculated by the control device 12. However, the data storage device 14 is not limited to a hard disk. For example, a Blu-ray disc drive, an SSD (Solid State Drive), etc. are applicable.

[0028] In this embodiment, the input device 15 is a touch panel, and the user of the wafer measuring device 10 issues commands through the input device 15, which causes the control device 12 to control the light source 11, the imaging device 20, and the operating device. However, the input device 15 is not limited to a touch panel. For example, a keyboard and a mouse are applicable.

[0029] (Coordinate position calculation method in first wafer movement direction of wafer measuring apparatus 10) FIG. 1 is an explanatory diagram of a coordinate position calculation method in a first wafer movement direction in a wafer measuring apparatus 10 according to this embodiment. FIG. 1 shows a state in which a line-shaped measurement light from a light source 11 is irradiated onto the surface of a notched wafer W1, and a line-shaped measurement light L for thickness calculation of the line-shaped measurement light is present. In FIG. 1, the notched wafer W1 moves in the Y direction (the up-down direction in FIG. 1), and the line-shaped measurement light becomes a line in the X direction (the left-right direction in FIG. 1) perpendicular to the moving direction. In addition, coordinate axes Cx and Cy passing through the center of this notched wafer W1 are defined.

[0030] The control device 12 calculates the thickness of the film provided on the notched wafer W1 from the spectral characteristic data of the line-shaped measurement light obtained from the imaging device 20. Here, the wafer measuring device 10 according to the present embodiment may not have a detector for directly detecting the position of the calculated thickness in the coordinates of the movement direction of the notched wafer W1. For this reason, there is a problem that it is not possible to know exactly the position of the calculated thickness in the coordinates of the movement direction of the notched wafer W1. For example, the control device 12 calculates the spectral characteristic data from the imaging device 20 at predetermined time intervals. Since the notched wafer W1 is transported by the horizontal articulated transport robot 32, the horizontal movement speed of the notched wafer W1 is not constant. In such a case, there is a problem that the outer periphery of the notched wafer W1, which is a circle, is displayed in a distorted shape.

[0031] In the wafer measuring device 10 of this embodiment, the control device 12 acquires length data l2 in the line direction of the thickness calculation line-shaped measuring light L (l1 in FIG. 1 indicates the entire length) used in calculating the thickness of the film provided on the notched wafer W1, which is reflected by the notched wafer W1, and calculates the coordinate position of the thickness calculation line-shaped measuring light in the movement direction of the notched wafer W1 based on the length data l2. Here, the length data l2 can be acquired as the length data l2, for example, as an area (pixel) where the amount of light is greater than a specific value. However, the acquisition of the length data l2 is not limited to this. For example, in order not to pick up ambient light, the amount of light can be evaluated left and right from the center of the field of view of the imaging device 20, and the area (pixel) where the amount of light is smaller than a specific value can be acquired as the length data l2. In addition, it is also possible to perform numerical processing such as median on these data, remove noise, and then obtain the length data l2. Furthermore, subpixel processing or interpolation processing can be performed to improve accuracy. This length data l2 etc. can be displayed in pixels and length units (nm, μm, mm etc.). It is also possible to input information on the field of view of the imaging device 20 (e.g. 400 mm) to the wafer measuring device 10 in order to convert it into a length unit.

[0032] In FIG. 1, the notched wafer W1 is an exact circle except for the notch portion. The diameter or radius of the notched wafer W1 is input in advance by the user of the wafer measuring device 10 from the input device 15 and is stored in the data storage device 14. Here, the control device 12 can obtain length data l2 of the length in the line direction of the thickness-calculating linear measuring light L that is actually reflected by the notched wafer W1. This allows the control device 12 to calculate the coordinate position (for example, the value of y1 in FIG. 1) of the thickness-calculating linear measuring light L in the wafer movement direction from the radius of the notched wafer W1 and half the value of the length data l2 according to Pythagoras' theorem. Note that there are two corresponding points with the coordinate axis Cy as the axis of symmetry for the calculated coordinate position, and the control device 12 can specify one of the two coordinate positions by comparing the length data l2 before and after the calculated coordinate position. Furthermore, since the notch portion is not exactly circular, for example, a user of the wafer measuring apparatus 10 according to this embodiment can store the shape of the notch portion from the input device 15 in the data storage device 14 and compare it with that data to calculate the coordinate position of the linear measurement light L for thickness calculation in the moving direction of the wafer, or calculate the coordinate position in a manner similar to that of the orientation flat described below.

[0033] The method of calculating the coordinate position of the thickness-calculating linear measuring light L in the wafer movement direction is not limited to the above method. For example, the length of the notched wafer W1 at a position parallel to the coordinate axis Cy and spaced apart by y1, i.e., the length of the notched wafer W1 in the linear direction, is uniquely determined, and this may be used to identify the coordinate position in the Y direction of the notched wafer W1 that is equal to the length data l2. In addition, the control device 12 acquires length data l2 of the length of the reflection in the linear direction of the notched wafer W1 that is actually reflected by the notched wafer W1, but when the movement of the notched wafer W1 is slow, the value of the length data l2 acquired by the control device 12 may be the same several times. In such a case, the control device 12 may correct the length data l2 based on the length data l2 acquired at timings before and after the timing of acquiring the length data l2 that has the same value, and use the corrected length data l2 to identify the coordinate position in the Y direction.

[0034] By acquiring length data l2 in the linear direction of the thickness-calculating linear measurement light L used when calculating a predetermined thickness, and calculating the coordinate position of the thickness data in the moving direction of the wafer W based on this length data l2, it is possible to measure the thickness, etc. of a film provided on the wafer W without using a measuring device for identifying the coordinate position in the moving direction of the wafer W. Therefore, it is possible to provide a wafer measuring device 10 with a simpler configuration than conventional devices, and thus the wafer measuring device 10 can be added to an existing system without enlarging the clean room.

[0035] 8 shows an explanatory diagram of the display screen 13a in the display device 13 of the wafer measuring device 10 of this embodiment. The display screen 13a is composed of a plurality of screens. The first screen 13b is a screen for displaying, for example, the number of the wafer W being measured, the second screen 13c is a screen for displaying the distribution of the thickness of the film provided on the wafer W, the third screen 13d is a screen for displaying the film thickness anomalies and defects in the measured film thickness distribution of the wafer W, the fourth screen 13e is a screen for displaying the film thickness at the position where the horizontal line shown on the second screen 13c exists, and the fifth screen 13f is a screen for displaying the film thickness at the position where the vertical line shown on the second screen 13c exists.

[0036] In the second screen 13c, the thickness of the film provided on the wafer W is displayed in different colors on the shape of the wafer W, which is a so-called two-dimensional map. The control device 12 calculates the coordinate position of the thickness calculation line-shaped measurement light L in the wafer movement direction, and displays the thickness of the film provided on the wafer W at the position corresponding to this coordinate position in different colors. The display method is not limited to different colors, and also includes monochrome display, specific color shading display, and three-dimensional display, and a method of displaying numerical values ​​on each measured point is also possible. In the wafer measuring device 10 according to this embodiment, when thickness data is displayed at each measured point, the thickness display points are sparse where the speed of the wafer W is fast, and the thickness display points are dense where the speed of the wafer W is slow. In the two-dimensional map of the second screen 13c, the control device 12 of this embodiment may output thickness data at equal intervals by interpolating or averaging the thickness data in the movement direction of the wafer W.

[0037] As described above, the two-dimensional map is a map in which the thickness data is corrected to fit the shape of the notched wafer W1. By displaying the thickness as a two-dimensional map on the display device 13, the user of the device can easily grasp the thickness distribution.

[0038] The control device 12 detects defects in the following flow and displays the defects on the third screen 13d. First, the control device 12 performs 1) so-called spatial filter processing. This spatial filter processing performs smoothing, subtraction, and sharpening on the thickness data. This thickness data is thickness data in which the coordinate position in the movement direction of the wafer W of the line-shaped measurement light for thickness calculation is specified. Next, the control device 12 performs 2) extraction of defect candidates. The control device 12 judges whether the thickness data after the spatial filter processing is a defect candidate based on a thickness threshold value as a reference value. For example, thickness data below or above the threshold value is regarded as a defect candidate. Next, the control device 12 performs 3) defect judgment. Specifically, the control device 12 judges whether a part corresponding to the multiple pixels that are regarded as defect candidates corresponds to a defect from a shape formed by the multiple pixels. To explain in more detail, the control device 12 judges whether the multiple pixels correspond to a defect from a shape formed by the multiple pixels based on a circumscribed width, a circumscribed length, an area of ​​thickness data thicker than the threshold value, an area of ​​thickness data thinner than the threshold value, a total area of ​​these, a maximum value and a minimum value of the thickness data, and the like. At this time, the control device 12 calculates the size of the defect based on the information on the coordinate position in the movement direction of the notched wafer W1. For example, in this defect determination, the control device 12 (a) can calculate the size of the defect by specifying the length of one pixel of the imaging device 20 for the coordinate in the X direction by the method described in paragraph 0031 above, and calculating the length of the coordinate in the Y direction from the difference value between the first coordinate Y1 that constitutes the defect and the next coordinate Y2. Also, (b) when the defect is composed of two or more pixels, the control device 12 can determine the length of the longest distance between two points that constitute the defect as the size of the defect. Note that when the defect is composed of two or more pixels, it is also possible to calculate the width, length, diagonal length, etc. of the circumscribed rectangle as the size of the defect. It is also possible to set a predetermined reference and calculate the size of the defect from the length from the reference. In this case, the reference can be an axis parallel to the X direction or Y direction, and can also be set from the notch or orientation flat of the wafer.In addition, it is possible to set a reference point and calculate the size of the defect from the coordinate and length from the reference point and the distribution direction of the defect. 4) The defect is shown on a two-dimensional map. Since the coordinate position of the defect in the moving direction of the wafer W of the thickness calculation line-shaped measurement light is specified for the thickness data, the size of the defect can represent the actual size of the defect.

[0039] By extracting the defect using a predetermined method and calculating its size, the user of the device can easily recognize the size of the defect.

[0040] (Coordinate position calculation method in second wafer movement direction of wafer measuring apparatus 10) 9 shows an explanatory diagram of a coordinate position calculation method in the second wafer movement direction in the wafer measuring apparatus 10 according to this embodiment. FIG. 9 shows a state in which a line-shaped measurement light from a light source 11 is irradiated onto the surface of a wafer W2 with an orientation flat, and a line-shaped measurement light L for thickness calculation of the line-shaped measurement light is present. In FIG. 9, the wafer W2 with an orientation flat moves in the Y direction (the up-down direction in FIG. 9), and the line-shaped measurement light becomes a line in the X direction (the left-right direction in FIG. 9) perpendicular to the moving direction. In addition, coordinate axes Cx and Cy passing through the center of the wafer W2 with an orientation flat are defined.

[0041] In FIG. 9, the wafer W2 with an orientation flat is an exact circle except for the orientation flat. The diameter or radius of the wafer W2 with an orientation flat is input in advance by the user of the wafer measuring device 10 from the input device 15 and stored in the data storage device 14. Here, the control device 12 can obtain length data l2 of the length in the line direction of the line-shaped measurement light L for thickness calculation that is actually reflected by the wafer. In the above description, the user of the wafer measuring device 10 inputs the diameter or radius of the wafer W2 with an orientation flat from the input device 15 in advance, but this is not limiting. For example, it is also possible to calculate the size of the wafer W2 from the maximum value of the length data l2 in the line direction of the line-shaped measurement light L that is actually reflected by the wafer W2 with an orientation flat.

[0042] In the case of the wafer W2 with an orientation flat, the length data l2 of the linear measurement light L for thickness calculation is shorter in the orientation flat portion than when there is no orientation flat. Therefore, the control device 12 first obtains the center line of the wafer W2 with an orientation flat (the line indicated as Cy in FIG. 9). The control device 12 determines the pixel located at the center in the linear direction from the length data l2 of the linear measurement light L for thickness calculation as the center point of the linear direction. The control device 12 obtains this center point of the linear direction for each linear measurement light L for thickness calculation over the entire surface of the wafer W2 with an orientation flat. For example, the control device 12 determines the straight line that passes through the most frequent value of all the data of the center points of the linear direction and is perpendicular to the operation direction of the wafer W2 with an orientation flat as the center line of the wafer W2 with an orientation flat. The control device 12 then determines the longer of the lengths from this center line to the end of the length data l2 as the calculated length when the length data l2 is acquired. As a result, the control device 12 calculates the coordinate position (for example, the value of y2 in FIG. 9) of the thickness calculation linear measurement light L in the wafer movement direction from the radius of the orientation flat wafer W2 and the calculated length value by Pythagoras' theorem. The calculated coordinate position corresponds to two points with the coordinate axis Cy as the axis of symmetry, and the control device 12 can specify one of the two coordinate positions by comparing it with the length data l2 before and after it. Although the method of using the most frequent value has been described as a method of determining the center line of the orientation flat wafer W2, the method of determining the center line is not limited to this. For example, it is also possible to use the average value, or an average value limited to a predetermined range (a range in which abnormal data and data of the center point that has shifted in the flat part are removed), or to assume that the linear center point has a specific distribution (such as a Gaussian distribution) and to determine the apex of the line by fitting.

[0043] By determining a center line parallel to the movement direction of the wafer W using a specified method and thereby identifying the coordinate position of the linear measurement light L for thickness calculation in the wafer movement direction, the wafer may have a notch or orientation flat, but even if such a notch or orientation flat is present, the coordinate position of the linear measurement light L for thickness calculation can be identified without inputting such information.

[0044] (others) In the above coordinate position calculation method, the case of calculating the thickness of a film provided on the wafer W has been described, but the present invention is not limited to this. When the light source 11 is a near-infrared ray, the case of calculating the thickness of the wafer W itself is also included in the wafer measuring device 10 according to the present invention.

[0045] Furthermore, while the display screen 13a in the coordinate position calculation method for the first wafer movement direction of the wafer measuring apparatus 10 has been described with reference to FIG. 8, a similar display screen 13a in the coordinate position calculation method for the second wafer movement direction can also be used.

[0046] In addition, in the method of calculating the coordinate position in the wafer movement direction, the notch is arranged at the right edge of the paper in Fig. 1, and the orientation flat is arranged parallel to Cx in Fig. 9, but these positions are not particularly limited. The method of calculating the coordinate position can be carried out without any problem even if these are in any positions. [Explanation of symbols]

[0047] 10 Wafer measuring device 11 Light source 12 Control device 13 Display device 20 Imaging device 30 Semiconductor Manufacturing Systems 32 Transport Robot L Linear measurement light for thickness calculation W wafer l2 Length data

Claims

1. a light source that irradiates a line-shaped measurement light onto the wafer; an imaging device that receives the linear measurement light reflected by the wafer; a control device that calculates a thickness of a film provided on the wafer or a thickness of the wafer itself from the spectral characteristic data of the line-shaped measurement light obtained from the imaging device; The control device includes: Among the line-shaped measurement light for thickness calculation used when calculating the thickness of the film or the thickness of the wafer itself, Acquire length data in a linear direction of the light reflected by the wafer; calculating a coordinate position of the thickness-calculation linear measurement light in a moving direction of the wafer based on the length data; 2. A wafer measuring apparatus comprising:

2. The control device, When calculating a coordinate position of the thickness-calculating linear measuring light in a moving direction of the wafer based on the length data, The control device includes: A pixel located at the center of the length data in the line-shaped direction is set as a line-shaped direction center point, acquiring a center point in the line-shaped direction for each of the thickness-calculating line-shaped measurement beams; Calculating a centerline of the wafer that is parallel to the direction of movement of the wafer based on these linear directional center points; The longer of the lengths from the center line to the end of the length data is set as the calculated length when the length data is obtained, calculating a coordinate position of the thickness-calculation linear measurement light in the wafer movement direction based on the calculated length; 2. The wafer measuring apparatus according to claim 1.

3. The control device includes: Extracting defects based on the thickness of the film or the thickness of the wafer itself; Calculating the size of the defect based on information on the coordinate position of the wafer in the moving direction; 2. The wafer measuring apparatus according to claim 1.

4. a display device that displays the thickness of the film or the thickness of the wafer itself calculated by the control device; The display device displays the thickness of the film or the thickness of the wafer itself in a two-dimensional map.

2. The wafer measuring apparatus according to claim 1.

5. A semiconductor processing apparatus and a transport robot for transferring a wafer to and from the semiconductor processing apparatus, a wafer measuring device according to claim 1, which measures a thickness of a film provided on the wafer or a thickness of the wafer itself while the wafer is being transported by the transport robot; A semiconductor manufacturing system comprising:

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