JP6618432B2 - Surface shape measuring apparatus and method - Google Patents

Description

  The present invention relates to a surface shape measuring apparatus and method for suitably measuring the surface shape of an object to be measured, for example, the surface shape of a plate-like body such as a semiconductor wafer.

  In recent years, integrated circuits have been integrated. A process rule, which is a process condition for manufacturing this integrated circuit on a semiconductor wafer, is usually defined by a minimum processing dimension in the line width or interval of the gate wiring. If this process rule is halved, theoretically, four times as many transistors and wirings can be arranged in the same area, so the area is ¼ with the same number of transistors. As a result, not only the number of dies that can be manufactured from a single semiconductor wafer is quadrupled, but also the yield is usually improved, so that more dies can be manufactured. In order to simultaneously manufacture such a large number of elements on a single semiconductor wafer, the semiconductor wafer needs to be flat. Therefore, a shape measuring apparatus that measures the surface shape of the semiconductor wafer with high accuracy is desired. . In particular, in recent years, an uneven shape called nanotopography has attracted attention. This nanotopography is a minute uneven shape with a relatively short period, excluding a relatively long period shape such as bending or warping of a semiconductor wafer from the surface shape, and has a period of about 0.2 mm to 20 mm, for example. The concavo-convex shape is about 10 nm to several tens of nm (see, for example, Patent Document 2 and Patent Document 3).

  An apparatus for measuring such a surface shape is disclosed in Patent Document 1, for example. The interferometer system for measuring the shape of a large-diameter wafer disclosed in this Patent Document 1 is for placing an opaque plate having a corresponding first parallel reference surface and a second parallel reference surface polished between them. A first spaced reference plate and a second spaced reference plate that form a cavity, wherein the first and second surfaces of the polished opaque plate are disposed when the polished opaque plate is disposed within the cavity; A first spaced reference plate and a second spaced reference plate that are no more than about 2.5 millimeters from the corresponding first reference surface and the second reference surface of the first reference plate and the second reference plate; A first interferometer device and a second interferometer device disposed on opposite sides of the cavity to produce a distribution map of the opposing first and second surfaces of the opaque plate, and the first interferometer Equipment A light emitter optically coupled to the second interferometer device and set to generate light of a plurality of wavelengths, and an optical amplification modulation set to stabilize the output of the light generated by the light emitter A light source, a first interferogram detector, a second interferogram detector, and outputs of the first interferogram detector and the second interferogram detector for measuring a change in thickness of the plate. And at least one computer coupled together.

JP 2013-122454 A JP 2007-61968 A JP 2009-27095 A

  By the way, in order to reduce the cost of an integrated circuit, semiconductor wafers have been increased in diameter in order to manufacture more dies from one semiconductor wafer. In recent years, semiconductor wafers with a diameter of 300 mm have begun to spread, and semiconductor wafers with a diameter of 450 mm have also been developed.

  For such an object having a relatively large diameter, as in the interferometer system disclosed in Patent Document 1, when trying to cover the entire surface with one optical measurement system, such as the diameter and the optical path length, The size of the optical measurement system becomes large, and the surface shape measuring device including such a support structure for the optical measurement system becomes large. As a result, it becomes difficult to adjust the optical measurement system manually, or it is difficult to secure rigidity in the optical interferometer in the optical measurement system, and it is easy to receive disturbance vibration from the installation environment. In other words, a large space is required.

  The present invention has been made in view of the above circumstances, and its purpose is to measure the surface shape of an object to be measured that is larger than a single measurement range, and to achieve a surface that can be measured with higher accuracy while being more compact. To provide a shape measuring device and a surface shape measuring method.

  As a result of various studies, the present inventor has found that the above object is achieved by the present invention described below. That is, the surface shape measuring apparatus according to one aspect of the present invention includes an optical measurement system that generates measurement data related to the shape of an object to be measured using an optical interferometer, the object to be measured, and the object to be measured. A plurality of different surfaces of the object to be measured by relatively moving the object to be measured and the optical measurement system by the holding and moving part that moves relative to the optical measurement system. A shape calculation unit that obtains a surface shape of the entire surface of the object to be measured based on a plurality of measurement data generated by the optical measurement system at a position, and the shape calculation unit includes each of the plurality of measurement data A filter that performs a filtering process to remove a second period component having a longer period than the first period component so as to extract a predetermined first period component based on the measurement data A processing section, a plurality of filter processing result of the filter processing unit corresponding to the plurality of measurement data, characterized in that it comprises a connection processing unit for connecting between the surface location adjacent to each other. Preferably, in the above-described surface shape measuring apparatus, the holding and moving unit holds the object to be measured that is larger than one measurement range of the optical measuring system (the holding moving unit is one of the optical measuring system). Configured to hold the object to be measured that is larger than the measurement range of times). Preferably, in the above-described surface shape measurement apparatus, the measurement data is an interference fringe image, and the shape calculation unit obtains a phase image by phase recovery calculation using the measurement data for each of the plurality of measurement data. A phase image calculation unit; and the filter processing unit extracts the first periodic component from the phase image for each of the plurality of phase images by the phase image calculation unit corresponding to the plurality of measurement data. The filter processing for removing the second period component is performed. Preferably, in the above-described surface shape measuring apparatus, the first periodic component is a component corresponding to a periodic component of nanotopography. Preferably, in the above-described surface shape measuring apparatus, the filter processing unit is a high-pass filter or a band-pass filter.

  Such a surface shape measuring apparatus is configured to move one surface of the object to be measured and a plurality of different surface positions on the object to be measured by relatively moving the object to be measured and the optical measurement system by the holding and moving unit. Since the measurement is performed by the optical measurement system, the surface shape of the object to be measured larger than the single measurement range can be measured without increasing the size of the optical measurement system, and the surface shape measurement apparatus can be further downsized. . In the case where the filtering process is performed after connecting the plurality of measurement data between the adjacent surface positions, the height between the measurement data adjacent to each other at the connection boundary portion at the time of the connection. It is necessary to adjust the direction (offset adjustment) and the surface inclination. For this reason, in a relatively large object to be measured, an error due to insufficient adjustment increases as the distance from the connection start point increases due to the long boundary portion and the two adjustments. However, since the surface shape measuring apparatus removes the second periodic component that is the main cause of the error by performing a filtering process before connecting the plurality of measurement data, it corresponds to the plurality of measurement data. A plurality of filter processing results by the filter processing unit can be connected with higher accuracy. Therefore, the surface shape measuring apparatus can measure the surface shape of an object to be measured that is larger than a single measurement range, and can measure with higher accuracy while further downsizing.

  According to another aspect, in the above-described surface shape measurement apparatus, when the filter processing unit performs the filter processing on the measurement data at the end of the measurement range, the data that is insufficient for the filter size of the filter processing A complementing unit that supplements (insufficient data with respect to the measurement data) with measurement data (complementary data) in a measurement range (adjacent measurement range) of a surface position adjacent to the measurement range (measurement range) of the measurement data, and the complementing unit And a filter unit that performs the filtering process on the measurement data after complementation by.

  When performing the filtering process, the measurement data is deficient at the edge, and an error due to the deficiency of the data to be filtered occurs. However, since the surface shape measuring apparatus compensates for the shortage of the measurement data with the measurement data adjacent in the measurement range, it is possible to reduce errors due to the lack of data to be filtered.

  According to another aspect, in the above-described surface shape measuring apparatus, the filter processing unit removes a portion corresponding to the data (complementary data) supplemented by the complementing unit from the filter processing result by the filter unit. It is further characterized by further including a removing unit.

  Since such a surface shape measuring apparatus removes a portion corresponding to the data supplemented by the complementing unit, it is possible to reduce an error associated with the connection (the adjustment) caused by the supplementing.

  Moreover, in another aspect, in the above-described surface shape measuring apparatus, the holding and moving unit includes a holding unit that holds the object to be measured in a vertical position, and the holding unit in a radial direction and a circumferential direction in a horizontal direction. The moving part which moves by these 2 axes is provided.

  Since such a surface shape measuring apparatus holds the object to be measured in a vertical position, it is possible to reduce the bending due to the weight of the object to be measured. And since the said surface shape measuring apparatus moves a holding | maintenance part to the radial direction of a horizontal direction, the said holding | maintenance part can be moved in the direction where a moving load is small, and size reduction of a moving part can be achieved.

  Further, in another aspect, in the above-described surface shape measuring apparatus, the holding moving unit includes a second holding unit that holds the object to be measured horizontally, and the second holding unit in a radial direction and a circumferential direction. And a moving unit that moves in two directions.

  Since such a surface shape measuring apparatus holds the object to be measured in a horizontal position, the structure of the holding and moving part can be simplified.

  Further, in another aspect, in the above-described surface shape measuring apparatus, the holding moving unit includes a second holding unit that holds the object to be measured horizontally and the second holding unit that is linearly independent. And a second moving unit that moves in two directions.

  Since such a surface shape measuring apparatus holds the object to be measured in a horizontal position, the structure of the holding and moving part can be simplified.

  The surface shape measurement method according to another aspect of the present invention includes an optical measurement step of generating measurement data related to the shape of an object to be measured using an optical interferometer, and a plurality of different surface positions on the object to be measured. And a shape calculation step for obtaining a surface shape of the entire one surface of the object to be measured based on a plurality of measurement data generated by the optical measurement step, wherein the shape calculation step is performed for each of the plurality of measurement data. A filtering process for performing a filtering process to remove a second period component having a longer period than the first period component so as to extract a predetermined first period component based on the measurement data; and the plurality of measurements A connection processing step of connecting a plurality of filter processing results by the filter processing step corresponding to data between adjacent surface positions. To.

  In such a surface shape measuring method, since one surface of the object to be measured is measured by the optical measurement process at a plurality of different surface positions in the object to be measured, the measurement system used in the optical measurement process is enlarged. In addition, the surface shape of the object to be measured larger than the one measurement range can be measured, and the apparatus can be further downsized. The surface shape measurement method removes the second periodic component that is the main cause of the error by performing a filter process before connecting the plurality of measurement data, and therefore corresponds to the plurality of measurement data. A plurality of filter processing results by the filter processing can be connected with higher accuracy. Therefore, the surface shape measuring method can measure the surface shape of an object to be measured that is larger than a single measurement range, and can measure with higher accuracy while further downsizing.

  The surface shape measuring apparatus and the surface shape measuring method according to the present invention can measure the surface shape of an object to be measured that is larger than a single measurement range, and can measure with higher accuracy while reducing the size.

It is a figure which shows the structure of the surface shape measuring apparatus in embodiment. It is a front view for demonstrating a holding body and a holding piece in the holding | maintenance moving part of the 1st aspect used for the said surface shape measuring apparatus. FIG. 6 is an enlarged side view of the periphery of the holding piece for explaining a holding state of the object to be measured by the holding piece in the holding movement unit of the first aspect. It is a figure for demonstrating the holding | maintenance moving part of the 2nd aspect used for the said surface shape measuring apparatus. It is a figure for demonstrating the relationship between a to-be-measured object and a measurement range in each holding | maintenance moving part of the said 1st and 2nd aspect. It is a figure for demonstrating the holding | maintenance moving part of the 3rd aspect used for the said surface shape measuring apparatus. It is a figure for demonstrating the relationship between a to-be-measured object and a measurement range in the holding | maintenance moving part of the said 3rd aspect. It is a flowchart which shows operation | movement of the said surface shape measuring apparatus. It is a figure for demonstrating the filter process in the edge part of a measurement range in the said surface shape measuring apparatus. In the said surface shape measuring apparatus, it is a figure for demonstrating the relationship between the edge part of a measurement range, and the filter size of a filter process. It is a figure for demonstrating the filter process in the said surface shape measuring apparatus. It is a figure for demonstrating size reduction in the said surface shape measuring apparatus. It is a figure for demonstrating the high precision in the said surface shape measuring apparatus.

  Hereinafter, an embodiment according to the present invention will be described with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted suitably. In this specification, when referring generically, it shows with the reference symbol which abbreviate | omitted the suffix, and when referring to an individual structure, it shows with the reference symbol which attached the suffix.

  The surface shape measuring apparatus in the present embodiment is an apparatus that can suitably measure the surface shape of an object to be measured, particularly a so-called nanotopography. The object to be measured is, for example, a plate-like body such as a semiconductor wafer, and preferably has a surface having an area larger than one measurement range of the surface shape measuring apparatus. Such a surface shape measuring apparatus in the present embodiment includes an optical measurement system that generates measurement data relating to the shape of the object to be measured using an optical interferometer, the object to be measured, the object to be measured, and the optical A holding movement unit that moves relative to the measurement system, and a relative movement between the object to be measured and the optical measurement system by the holding movement unit, so that a plurality of different surface positions in the measurement object can be obtained. A shape calculation unit that obtains a surface shape of the entire surface of the object to be measured based on a plurality of measurement data generated by the optical measurement system. Then, the shape calculation unit, for each of the plurality of measurement data, a second period component having a longer period than the first period component is extracted based on the measurement data. A filter processing unit that performs a filtering process to be removed, and a connection processing unit that connects a plurality of filter processing results by the filter processing unit corresponding to the plurality of measurement data between adjacent surface positions. More specific description will be given below.

  FIG. 1 is a diagram illustrating a configuration of a surface shape measuring apparatus according to an embodiment. FIG. 2 is a front view for explaining a holding body and a holding piece in the holding moving unit of the first aspect used in the surface shape measuring apparatus. FIG. 3 is an enlarged side view of the periphery of the holding piece for explaining a holding state of the object to be measured by the holding piece in the holding moving unit of the first aspect. FIG. 4 is a view for explaining a holding and moving unit of the second aspect used in the surface shape measuring apparatus. FIG. 5 is a diagram for explaining the relationship between the object to be measured and the measurement range in each of the holding and moving units of the first and second aspects. FIG. 6 is a diagram for explaining a holding and moving unit of the third aspect used in the surface shape measuring apparatus. FIG. 7 is a diagram for explaining the relationship between the object to be measured and the measurement range in the holding and moving unit of the third aspect.

  The surface shape measuring apparatus M according to the embodiment includes, for example, an optical measurement system 1, a holding and moving unit 7, and a control calculation unit 2 having a shape calculation unit 22, as shown in FIG. Then, the storage unit 3, the input unit 4, the output unit 5, and the interface unit (IF unit) 6 are further provided.

  The input unit 4 is connected to the control calculation unit 2 and measures, for example, various commands such as a command for instructing the start of shape measurement of the device under test SP, and the shape such as input of an identifier in the device under test SP, for example. A device that inputs various data necessary for the above to the surface shape measuring apparatus M, such as a plurality of input switches, a keyboard, a mouse, and the like assigned with predetermined functions. The output unit 5 is connected to the control calculation unit 2, and in accordance with control of the control calculation unit 2, commands and data input from the input unit 4 and the shape of the object SP to be measured measured by the surface shape measuring device M are displayed. An output device, for example, a display device such as a CRT display, an LCD (liquid crystal display) and an organic EL display, or a printing device such as a printer.

  A touch panel may be configured from the input unit 4 and the output unit 5. In the case of configuring this touch panel, the input unit 4 is a position input device that detects and inputs an operation position such as a resistive film method or a capacitance method, and the output unit 5 is a display device. In this touch panel, a position input device is provided on the display surface of the display device, one or more input content candidates that can be input to the display device are displayed, and the user touches the display position where the input content to be input is displayed. Then, the position is detected by the position input device, and the display content displayed at the detected position is input to the shape measuring device M as the operation input content of the user. In such a touch panel, since the user can easily understand the input operation intuitively, the surface shape measuring device M that is easy for the user to handle is provided.

  The IF unit 6 is a circuit that is connected to the control calculation unit 2 and inputs / outputs data to / from an external device according to the control of the control calculation unit 2. For example, an interface circuit of RS-232C that is a serial communication method , An interface circuit using the Bluetooth (registered trademark) standard, an interface circuit performing infrared communication such as an IrDA (Infrared Data Association) standard, and an interface circuit using the USB (Universal Serial Bus) standard.

  The optical measurement system 1 is an apparatus that is connected to the control calculation unit 2 and generates measurement data relating to the shape of the object SP to be measured using an optical interferometer according to the control of the control calculation unit 2. The optical interferometer has a plurality of optical elements (for example, total reflection mirrors) that form two first and second optical paths between the incident position of the measurement light and the interference position when measurement light having a predetermined wavelength is incident on the optical interferometer. , Half mirror, lens, etc.). By arranging the object SP to be measured in one of the first and second optical paths in the optical interferometer, the first optical distance of the first optical path and the second optical distance of the second optical path There is a difference between Due to this difference, the first light propagated through the first optical path and the second light propagated through the second optical path in the first and second lights distributed from the measurement light interfere with each other at the interference position, so-called Interference fringes are generated. As such an optical interferometer, for example, various optical interferometers such as a Michelson interferometer, a Twiman Green interferometer, and a Fizeau interferometer can be used. And the said measurement data are produced | generated as the example by imaging the said interference fringe by this optical interferometer with the camera provided with a two-dimensional image sensor etc., for example.

  The holding and moving unit 7 is a device that is connected to the control calculation unit 2, holds the device under test SP according to the control of the control calculation unit 2, and relatively moves the device under test SP and the optical measurement system 1. The holding / moving unit 7 holds an object SP to be measured that is larger than one measurement range SA of the optical measurement system 1. In other words, the holding and moving unit 7 is configured to hold an object SP to be measured that is larger than one measurement range SA of the optical measurement system 1. The holding / moving unit 7 holds, for example, the object SP to be measured, and moves the optical measurement system 1 with respect to the object SP to be fixedly held, so that the object SP and the optical measurement system are moved. 1 may be configured to move relative to each other. For example, the object SP and the optical measurement system 1 are moved relatively by moving the object SP and the optical measurement system 1 respectively. It may be configured as follows. In the present embodiment, the optical measurement system 1 is fixedly held by a support member (not shown), and the object SP is moved relative to the optical measurement system 1 that is fixedly held. The optical measuring system 1 is configured to move relatively. As such a holding and moving unit 7 in the present embodiment, for example, any one of the holding and moving units 7 of the first to third modes is preferably used.

  The holding movement unit 7 of the first aspect includes a holding unit (first holding unit) that holds the object SP to be measured in a vertical position, and the holding unit in a radial direction (r direction) and a circumferential direction (θ direction). ) Of two moving axes (rθ axis). The holding and moving part 7 of this first aspect will be described in more detail below. Since the surface shape measuring apparatus M using the holding / moving unit 7 of the first aspect holds the object SP in a vertical position, it is possible to reduce bending due to the weight of the object SP. And since such a surface shape measuring apparatus M moves the said holding | maintenance part to the radial direction of a horizontal direction, the said holding | maintenance part can be moved in the direction where a moving load is small, and size reduction of the said moving part and by extension, surface shape measurement The apparatus M can be reduced in size.

  For example, as shown in FIG. 4, the holding movement unit 7 of the second mode includes a second holding unit that holds the object SP to be measured horizontally, and the second holding unit in a radial direction (r direction) and a circumferential direction. And a moving unit that moves in two directions (θ direction). FIG. 4A shows that the object SP (second holding unit) and the optical measurement system 1 are relative to each other so that the center position of the measurement range SA in the optical measurement system 1 and the center position of the object SP are coincident with each other. FIG. 4A shows the state of the measured object SP (the second holding unit) so that the measurement range SA in the optical measurement system 1 is located at one end of the measured object SP. The state after relatively moving the optical measurement system 1 is shown. For example, the holding and moving unit 7 of the second aspect includes a stage that moves in one direction, a turntable that is provided on the stage and rotates, and the second holding unit that is provided on the turntable. . The second holding unit is configured in the same manner as the holding unit (the first holding unit) in the holding movement unit 7 of the first mode. For example, as shown in FIG. 5, such a holding and moving unit 7 of the second aspect first moves the second holding unit appropriately in the radial direction and the circumferential direction by the moving unit. The surface shape measuring apparatus M performs measurement by causing the center position of the measurement range SA and the center position of the object SP to be measured to coincide with each other. Next, the holding movement unit 7 according to the second mode performs the second holding with respect to the optical measurement system 1 at a predetermined position in the radial direction that can be measured without gaps in the radial direction by considering the size of the measurement range SA and the like. The part is moved by the moving part. At a predetermined position in the radial direction, the holding and moving unit 7 of the second aspect can measure each of the plurality of measurement ranges SA arranged in the circumferential direction, which can be measured without gaps in the circumferential direction by considering the size of the measurement range SA and the like. The second holding unit is moved in the circumferential direction by the moving unit so as to be positioned at each of a plurality of corresponding surface positions, and the surface shape measuring apparatus M performs measurement at each of the plurality of surface positions. Then, such radial movement and circumferential movement and measurement are repeated up to the end of the object SP to be measured. As a result, measurement data is generated by the optical measurement system 1 over the entire surface of the object SP. Since such a surface shape measuring apparatus M holds the object SP to be measured horizontally, the structure of the holding movement unit 7 of the second aspect can be simplified.

  For example, as shown in FIG. 6, the holding movement unit 7 of the third aspect includes a second holding unit that holds the object SP to be measured horizontally and the second holding unit in two linearly independent two axes. And a second moving part that moves at the same time. FIG. 6A shows that the object SP (second holding unit) and the optical measurement system 1 are relative to each other so that the center position of the measurement range SA in the optical measurement system 1 and the center position of the object SP are coincident with each other. FIG. 4A shows the state of the measured object SP (the second holding unit) so that the measurement range SA in the optical measurement system 1 is located at one end of the measured object SP. The state after relatively moving the optical measurement system 1 is shown. For example, the holding movement unit 7 of the third aspect includes an XY stage that moves independently in each of the X direction and the Y direction orthogonal to each other, and the second holding unit provided on the XY stage. For example, as shown in FIG. 7, the holding movement unit 7 of the third aspect first moves the second holding unit appropriately in the X direction and the Y direction by the second movement unit, so that the optical measurement system The measurement range SA of 1 is moved to a certain end of the object SP to be measured, the second holding unit is moved by the second moving unit with respect to the optical measurement system 1, and the surface shape measuring apparatus M performs the measurement. Do. Next, the holding and moving unit 7 of the third aspect can perform a plurality of measurements in the X direction (or Y direction) that can be measured without gaps in the X direction (or Y direction) by considering the size of the measurement range SA and the like. The second holding unit is moved in the X direction by the second moving unit so as to be positioned at each of the plurality of surface positions corresponding to each of the ranges SA, and the surface shape measuring apparatus M performs measurement at each of the plurality of surface positions. . Next, the holding movement unit 7 of the third aspect is in a predetermined position in the Y direction (or X direction) that can be measured without gaps in the Y direction (or X direction) by considering the size of the measurement range SA, etc. The second holding unit is moved by the second moving unit with respect to the optical measurement system 1, and the surface shape measuring apparatus M performs the measurement. Next, at a predetermined position in the Y direction (or X direction), the holding and moving unit 7 of the third aspect performs measurement without gaps in the X direction (or Y direction) by considering the size of the measurement range SA and the like. The second holding unit is moved in the X direction by the second moving unit so as to be positioned at each of the plurality of surface positions corresponding to each of the plurality of measurement ranges SA arranged in the X direction (or Y direction). The apparatus M performs measurement at each of the plurality of surface positions. Then, such movement in the Y direction (or X direction) and movement and measurement in the X direction (or Y direction) are repeated until the other end of the object SP to be measured. As a result, measurement data is generated by the optical measurement system 1 over the entire surface of the object SP. Preferably, the holding and moving unit 7 of the third aspect is configured such that the center position of the measurement range SA and the center position of the object SP to be measured can coincide with each other in the optical measurement system 1. Since such a surface shape measuring apparatus M holds the object SP to be measured horizontally, the structure of the holding and moving part 7 of the third aspect can be simplified.

  As described above, the holding and moving unit 7 may be any one of the second and third modes, but is configured in the first mode in the present embodiment. More specifically, as shown in FIGS. 1 to 3, the holding and moving unit 7 of the first aspect includes a stage 71, an inclined standing mechanism 72, a turntable 73, and an adjustment mechanism 74 (74-1 to 74-). 3), a holding body 75, and holding pieces 76 (76-1 to 76-3).

  The stage 71 is a device that is provided on the support base 8, is connected to the control calculation unit 2, and moves in one direction perpendicular to the paper surface in the example shown in FIG.

  The inclined standing mechanism 72 is provided on the stage 71 and, as will be described later, the object SP to be measured held by the holding body 75 via the holding piece 76 is placed horizontally, as shown by a two-dot chain line in FIG. This is an apparatus for changing the posture of the holding body 75 from a standby posture to a measurement posture shown by a solid line in FIG. Preferably, in the measurement posture, the holding body 75 is erected by the inclined erection mechanism 72 while being inclined by a predetermined angle θ from the vertical direction. In order to stabilize the object SP to be measured by its own weight, the predetermined angle (tilt angle from the vertical direction) θ is preferably larger. However, if the predetermined angle θ is increased, bending deformation due to its own weight is likely to occur. It occurs in the measurement object SP and exceeds the allowable measurement range of the optical measurement system 1 defined in the specification. For this reason, the predetermined angle θ is set according to the measurement allowable range of the optical measurement system 1. For example, the predetermined angle θ is any value in the range of 1 degree to 10 degrees. More preferably, the predetermined angle θ is any value within a range of 2 degrees to 5 degrees. In one example, when the interferometer of the optical measurement system 1 is a Fizeau interferometer, the measurement surface angle allowed as the performance of the Fizeau interferometer is 0.5 mrad or less and the object SP to be measured is a 450 mm semiconductor wafer. In some cases, the predetermined angle θ is set to about 3 degrees.

  Such an inclined standing mechanism 72 includes, for example, an inclined standing mechanism main body that is a plate-like member, and a pair of first members fixedly connected to one side surface of the inclined standing mechanism main body at one end thereof. 1 and a second arm member, an arm shaft which is a columnar member fixedly connected to each other end of each of the first and second arm members at both ends thereof, and connected to the control calculation unit 2 for control And a power unit including, for example, an electric motor connected to the arm shaft via a speed reducer, which rotates the arm shaft according to the control of the calculation unit 2. In the tilted standing mechanism 72 having such a configuration, the arm shaft is driven to rotate by the power unit, thereby holding from the standby posture shown by a two-dot chain line in FIG. 1 to the measurement posture shown by a solid line in FIG. The posture of the body 75 is changed.

  The turntable 73 is a device that is provided in the inclined standing mechanism 72 (provided on the inclined standing mechanism main body in the example shown in FIG. 1) and rotates in the circumferential direction under the control of the control calculation unit 2.

  The adjustment mechanism 74 is a device that adjusts the inclination of the holding body 75 with respect to the turntable 73. In the present embodiment, the adjustment mechanism 74 includes three first to third adjustment mechanisms 74-1 to 74-3 so as to support the holding body 75 at three points with respect to the turntable 73. These first to third adjustment mechanisms 74-1 to 74-3 are disposed on the surface of the turntable 73 at appropriate positions for supporting the holding body 75 at three points. In one example, a triangle is formed when the arrangement positions of the first to third adjustment mechanisms 74-1 to 74-3 are connected. The first to third adjustment mechanisms 74-1 to 74-3 are columnar members, and two of the first to third adjustment mechanisms 74-1 to 74-3, for example, the first and second ones. The adjustment mechanisms 74-1 and 74-2 are configured such that their lengths are expanded and contracted, and the remaining one, in this example, the third adjustment mechanism 74-3 is configured such that its length is fixed. The More specifically, the first and second adjustment mechanisms 74-1 and 74-2 extend and retract their lengths by moving the rods in and out of the main body by a drive motor such as a servo motor or a stepping motor, for example. For example, a linear actuator or the like. The tips of the rods of the first and second adjustment mechanisms 74-1 and 74-2 are connected to the holding body 75 and support the holding body 75. The third adjusting mechanism 74-3 is a columnar member whose tip is a ball head, and supports the holding body 75 at the tip of the ball head. Such first to third adjusting mechanisms 74-1 to 73-3 adjust the lengths of the first and second adjusting mechanisms 74-1 and 74-2, so that the holding body 75 for the turntable 73 is maintained. Can be adjusted around two axes so as to be substantially parallel to the measurement surface of the optical measurement system 1.

  The holding body 75 is a member for holding the DUT SP, and is, for example, a plate-like body having a rectangular shape and a flat surface in a plan view as shown in FIGS. In order to prevent deformation, the holding body 75 is formed of a rigid plate (a plate-like body having a small deformation with respect to force) having a relatively high rigidity. The holding body 75 is made of, for example, a metal material (including an alloy) such as stainless steel and aluminum.

  The holding piece 76 is disposed on the plane of the holding body 75, and is to be measured via the edge of the measurement object SP so that a predetermined distance is provided between one surface of the measurement object SP and the plane of the holding body 75. It is a member that holds the measurement object SP. As a result, the other surface (back surface) facing the one surface (front surface) of the object SP to be measured does not come into contact with the holding body 75, and the other surface of the object SP to be measured can be prevented from being soiled. Preferably, the holding piece 76 holds the measurement object SP so that the one surface of the measurement object SP and the flat surface of the holding body 75 are parallel to each other with the predetermined interval. The holding piece 76 has, for example, a stepped cross section (substantially L-shaped cross section), and the height (thickness) from the plane of the holding body 75 to the stepped portion in the stepped shape corresponds to the predetermined interval. In addition, in the present embodiment, the inner peripheral shape of the step portion in the step shape may be a cylindrical member that is substantially the same as or slightly larger than the outer peripheral shape of the object SP. As shown in FIGS. 1 and 3, the piece 76 includes three members (first to third holding pieces 76-1 to 76-3) having a step-like cross section (substantially L-shaped cross section). Configured. These 1st thru | or 3rd holding pieces 76-1 to 76-3 are the magnitude | sizes of the inner peripheral shape formed in each step part in the said step shape in these 1st thru | or 3rd holding pieces 76-1 to 76-3. Are arranged on the plane of the holding body 75 at a predetermined interval so as to be substantially the same as or slightly larger than the size of the outer peripheral shape of the object SP to be measured. When the device under test SP has, for example, a disk shape that is a general shape of a semiconductor wafer, these first to third holding pieces 76-1 to 76-3 are formed as shown in FIG. The size of the inner peripheral shape formed in each step portion in the step shape in the first to third holding pieces 76-1 to 76-3 is substantially the same as or slightly larger than the size of the outer peripheral shape of the object SP to be measured. They are arranged on the plane of the holding body 75 on the circumference at regular intervals of 120 degrees in the circumferential direction. Each of the first to third holding pieces 76-1 to 76-3 is formed such that the height from the plane of the holding body 75 to the stepped portion in the step shape corresponds to the predetermined interval. . For example, each of the first to third holding pieces 76-1 to 76-3 is substantially L-shaped by bending a plate-like piece having a thickness corresponding to the predetermined interval at about 90 degrees in the middle thereof. It is formed by making it into a shape. In the holding piece 76 having such a configuration, as shown in FIG. 1 to FIG. 3, the object SP to be measured is placed on each step portion in the step shape of the first to third holding pieces 76-1 to 76-3. By being placed, these first to third holding pieces 76-1 to 76-3 cooperate with each other to hold the device under test SP via the edge of the device under test SP.

  The holding movement unit 7 of the first aspect having such a configuration can move the holding body 75 in the radial direction (r direction) by the stage 71 in the measurement posture, and the holding table 75 can be moved by the turntable 73. It can move in the circumferential direction (θ direction). Then, the holding and moving part 7 of the first aspect is similar to the holding and moving part 7 of the second aspect, for example, as shown in FIG. By appropriately moving in the circumferential direction, the center position of the measurement range SA in the optical measurement system 1 and the center position of the object SP to be measured are made to coincide with each other. Measurement of the object SP to be measured held through 76 is performed. Next, the holding movement unit 7 according to the third aspect holds the holding body 75 with respect to the optical measurement system 1 at a predetermined position in the radial direction that can be measured without gaps in the radial direction by considering the size of the measurement range SA and the like. Is moved by the stage 71. At a predetermined position in the radial direction, the holding movement unit 7 of the third aspect can measure each of the plurality of measurement ranges SA arranged in the circumferential direction that can be measured without gaps in the circumferential direction by taking into consideration the size of the measurement range SA and the like. The holding body 75 is moved in the circumferential direction by the turntable 73 so as to be located at each of a plurality of corresponding surface positions, and the surface shape measuring device M is placed on the holding body 76 on the holding body 75 at each of the plurality of surface positions. The object SP to be measured is measured via the. Then, such radial movement and circumferential movement and measurement are repeated up to the end of the object SP to be measured. As a result, measurement data is generated by the optical measurement system 1 over the entire surface of the object SP.

  The storage unit 3 is a circuit that is connected to the control calculation unit 2 and stores various predetermined programs and various predetermined data under the control of the control calculation unit 2. Examples of the various predetermined programs include a control program for controlling each part of the surface shape measuring apparatus M according to the function of each part, and the optical measurement system 1 at a plurality of different surface positions in the object SP. A control processing program such as a shape calculation program for obtaining the surface shape of the entire one surface of the DUT SP based on the plurality of generated measurement data is included. The shape calculation program includes a phase image calculation program for obtaining a phase image by phase recovery calculation using the measurement data for each of the plurality of measurement data, and a predetermined value based on the measurement data for each of the plurality of measurement data. A filter processing program for performing a filter process for removing a second period component having a longer period than the first period component so as to extract a first period component of the first period component, and a filter processing program corresponding to the plurality of measurement data A connection processing program for connecting a plurality of filter processing results between adjacent surface positions is included. When the filter processing program performs the filter processing on the measurement data at the end of the measurement range SA, the filter processing program measures the data of the surface position adjacent to the measurement range SA of the measurement data by using data that is insufficient for the filter size of the filter processing. Complementary program supplemented with measurement data in range SA, filter program for performing filter processing on measurement data after supplementation by supplementary program, and data supplemented by supplementary program from filter processing result by filter program The removal program etc. which remove the part to perform are included. The various predetermined data include the plurality of measurement data generated by the optical measurement system 1, the surface shape of the object SP to be measured, and an identifier (object to be identified and identified). Data necessary for executing each program such as measured object ID, sample name, serial number, etc.) are included. The storage unit 3 includes, for example, a ROM (Read Only Memory) that is a nonvolatile storage element, an EEPROM (Electrically Erasable Programmable Read Only Memory) that is a rewritable nonvolatile storage element, and the like. The storage unit 3 includes a RAM (Random Access Memory) serving as a working memory of the so-called control calculation unit 2 that stores data generated during the execution of the predetermined program.

  The control processing unit 2 controls each part of the surface shape measuring apparatus M according to the function of each part, and obtains the surface shape of the object SP to be measured. By executing the control processing program, the control calculation unit 2 is functionally configured with a control unit 21 and a shape calculation unit 22. The shape calculation unit 22 includes a phase image calculation unit 221 and a filter processing unit 222. The connection processing unit 223 is functionally configured, and the filter processing unit 222 is functionally configured with a complementing unit 2221, a filter unit 2222, and a removal unit 2223.

  The control unit 21 controls each part of the surface shape measuring apparatus M according to the function of each part.

  The shape calculator 22 obtains the surface shape of the entire surface of the object SP based on a plurality of measurement data generated by the optical measurement system 1 at a plurality of surface positions different from each other in the object SP. .

  When obtaining the surface shape of the object SP to be measured, the phase image calculating unit 221 obtains a phase image for each of the plurality of measurement data by a known so-called phase recovery calculation using the measurement data. The measurement data is preferably an interference fringe image, and the phase image represents a surface shape of the measurement object SP including a component having a relatively long period shape due to bending deformation or warpage of the measurement object SP.

  When determining the surface shape of the object SP to be measured, the filter processing unit 222 extracts the first periodic component for each of the plurality of measurement data based on the measurement data. Filter processing for removing the second period component having a longer period than that is performed. Such a filter processing unit 222 is preferably a high-pass filter that filters a component in a frequency band higher than a predetermined cutoff frequency, or a band-pass filter that filters a component in a predetermined frequency band. It is. Preferably, the first periodic component is a component corresponding to a periodic component of nanotopography.

  When the filtering process is performed on the measurement data at the end of the measurement range SA, the complementing unit 2221 has insufficient data for the filter size of the filtering process (insufficient data for the measurement data). Is supplemented with measurement data (complementary data) in the measurement range SA (adjacent measurement range SAb) of the surface position adjacent to the measurement range SA (measurement range SAa) of the measurement data. During the filtering process, the filter unit 2222 performs the filtering process on the measurement data after complementation by the complementing unit 2221. At the time of the filtering process, the removing unit 2223 removes a part corresponding to the data supplemented by the complementing unit 2221 (the supplementary data) from the filter processing result by the filter unit 2222.

  When obtaining the surface shape of the object SP to be measured, the connection processing unit 223 connects a plurality of filter processing results by the filter processing unit 222 corresponding to the plurality of measurement data between adjacent surface positions. is there.

  Such a control calculation part 2, the memory | storage part 3, the input part 4, the output part 5, and the IF part 6 can be comprised by computers, such as a desktop computer and a notebook computer, for example.

  Next, the operation of this embodiment will be described. FIG. 8 is a flowchart showing the operation of the surface shape measuring apparatus. FIG. 9 is a diagram for explaining the filtering process at the end of the measurement range in the surface shape measuring apparatus. FIG. 10 is a diagram for explaining the relationship between the end of the measurement range and the filter size of the filter process in the surface shape measuring apparatus. FIG. 11 is a diagram for explaining filter processing in the surface shape measuring apparatus. FIG. 11A shows before filter processing, and FIG. 11B shows after filter processing. 11A and 11B, the horizontal axis indicates the surface position along a certain radial direction in the object SP to be measured, and the vertical axis indicates the data value. FIG. 12 is a diagram for explaining downsizing in the surface shape measuring apparatus. FIG. 12A shows the case of this embodiment, and FIG. 12B shows the case of a comparative example. FIG. 13 is a diagram for explaining high accuracy in the surface shape measuring apparatus.

  In the surface shape measuring apparatus M having such a configuration, first, when a power switch (not shown) is turned on, the surface shape measuring apparatus M is activated, and necessary parts are initialized by the control calculation unit 2 and controlled. The calculation unit 2 is functionally configured with a control unit 21 and a shape calculation unit 22 by executing a control processing program. The shape computing unit 22 is functionally configured with a phase image computing unit 221, a filter processing unit 222, and a connection processing unit 223, and the filter processing unit 222 functionally includes a complementing unit 2221 and a filter unit 2222. And the removal part 2223 is comprised.

  When the measurement of the measurement object SP is started, the surface shape measuring apparatus M is in a standby posture, and a user such as an operator places the measurement object SP on the holding movement unit 7 in the standby posture. When the measurement start is instructed, the surface shape measuring apparatus M moves the holding and moving unit 7 from the standby posture to the measuring posture by the control unit 21 of the control calculation unit 2, and moves the object SP to be measured to the optical measuring system 1. The object SP is adjusted by the adjustment mechanism 74 so as to be substantially parallel to the measurement surface of the optical measurement system 1. Whether or not the measurement object SP is substantially parallel to the measurement surface of the optical measurement system 1 is determined by placing the first to third distance sensors in the vicinity of the first to third adjustment mechanisms 74-1 to 74-3. Further, it may be implemented by each distance to the object SP to be measured detected by the first to third distance sensors, but in the present embodiment, the measurement data generated by the optical measurement system 1 is used. Is done. More specifically, the adjustment mechanism 74 is driven so that the interference fringes of the measurement data are the sparsest state (the state where there is little interference and the number of the interference fringes is the smallest), and the interference fringes of the measurement data are the sparsest. The state is determined to be a state in which the object to be measured SP is substantially parallel to the measurement surface of the optical measurement system 1.

  When such preparation for measurement is completed, in FIG. 8, first, the surface shape measuring device M is controlled by the control unit 21 of the control calculation unit 2 by the stage 71 and the turntable 73 as described above with reference to FIG. 5. By moving the holding body 75 in the radial direction and the circumferential direction, the center position of the measurement range SA in the optical measurement system 1 and the center position of the object SP are measured to coincide with each other. The circumferential movement and measurement are repeatedly executed, whereby a plurality of measurement data at each surface position is generated by the optical measurement system 1 over the entire surface of the object SP to be measured, and each measurement data is stored in the storage unit 3. Store (S1). The measurement data generated by the optical measurement system 1 using an optical interferometer is, for example, interference fringe image data.

  Next, the surface shape measurement apparatus M uses the shape calculation unit 22 of the control calculation unit 2 to extract a predetermined first periodic component for each of the plurality of measurement data based on the measurement data. A filtering process is performed to remove a second period component having a period longer than one period component, and a plurality of filter processing results by the filtering process corresponding to the plurality of measurement data are connected between adjacent surface positions.

  More specifically, in the surface shape measuring apparatus M, the shape calculating unit 22 of the control calculating unit 2 selects one measurement data from the plurality of measurement data, and the phase image calculating unit of the shape calculating unit 22 is selected. By using the selected measurement data (interference fringe image FP) 221, a phase image HP is obtained by a known so-called phase recovery calculation (S 2).

  Next, the surface shape measuring apparatus M uses the interpolation unit 2221 of the filter processing unit 222 in the shape calculation unit 22 to set the filter size in the filter processing of the next processing S4 to the phase image HP obtained from the selected measurement data. Insufficient data (insufficient data with respect to the measurement data (deficient data in the phase image in the present embodiment)) of the surface position adjacent to the measurement range SA (measurement range SAa) of the measurement data corresponding to the phase image HP. The measurement data (complementary data (in this embodiment, insufficient data in the phase image)) in the measurement range SA (adjacent measurement range SAb) is supplemented (S3).

  For example, as shown in FIG. 10, the filter process of the next process S4 is performed by applying an image filter FS that performs a high-pass filter or a band-pass filter to the phase image HP. When this filtering process is performed, a shortage of the phase image HP (in other words, measurement data used when obtaining the phase image HP) occurs at the end, and an error due to a lack of data to be filtered occurs. For this reason, effective data after filtering cannot be generated from the entire phase image HP, and the data after filtering obtained from the entire phase image HP does not have insufficient data to be filtered. An effective area FDe composed of data after filtering that does not include the error due to the data shortage, and after filtering that includes the error due to the data shortage, the data to be filtered is insufficient around the effective area FDe And an ineffective area FDi consisting of the following data. That is, the effective area FDe is an area that is smaller than the entire phase image HP by the amount of insufficient data to be filtered according to the filter size of the image filter. For this reason, in this embodiment, before the filter process of next process S4 is implemented, the complement process of this process S3 is implemented.

  More specifically, in this embodiment, for example, as shown in FIG. 9, the measurement range SA is a regular hexagonal shape, and in the measurement at each surface position in the processing S <b> 1, the surface positions adjacent to each other are The measurement range SA is set so that part of the measurement range SA overlaps with each other to form an overlapping area SAs. In the calculation of the phase image HP in the process S2, a regular hexagonal phase image having overlapping regions HPs around (at each side) from the measurement data (regular hexagonal interference fringe image) of the regular hexagonal measurement range SA. HP is generated. In the complementing process in the process S3, for such a regular hexagonal phase image HP, data that is insufficient for the filter size of the image filter FS in the filter process in the next process S4 is measured data corresponding to the phase image HP. Is supplemented with measurement data (complementary data (in this embodiment, deficient data in the phase image)) in the measurement range SA (adjacent measurement range SAb) of the surface position adjacent to the measurement range SA (the measurement range SAa). The phase image HPc obtained from the measured data is connected to the phase image HP and added. For example, in the example shown in FIG. 10, the regular hexagonal 0th measurement range SA-0 located in the center of FIG. 10 is adjacent to each side and a part thereof overlaps to form an overlapping region SAs. First to sixth measurement ranges SA-1 to SA-6 are provided. In one example, the 0th measurement range SA-0 and the 0th measurement range SA-0 and the first measurement range SA-1 adjacent to the right side of the paper surface form an overlapping region SAs-01 that overlaps with a predetermined length. ing. Then, the 0th phase image HP-0 obtained from the measurement data (interference fringe image) measured and generated in the 0th measurement range is adjacent to each side for the filtering process of the next process S4. Each phase image HPc is obtained by extracting from the respective measurement data measured and generated in each of the first to sixth measurement ranges SA-1 to SA-6 corresponding to the data that is insufficient for the filter size of the image filter FS. Connected to each side and added. In one example, data that is insufficient for the filter size of the image filter FS (insufficient) is extracted from the adjacent first measurement range SA-1 that overlaps with the overlapping area SAs-01 on the right side of the paper in the zeroth measurement range SA-0. Thus, the phase image HPc-01 is obtained, and the phase image HPc-01 is connected and added to the right side of the page of the 0th phase image HP-0. In this connection, adjustment in the height direction (offset adjustment) and adjustment of surface inclination between data adjacent to each other at the connection boundary portion are performed by a known conventional method. Since the length of the connection boundary portion is at most the length corresponding to the filter size of the image filter FS, it is shorter than the length of the connection boundary portion when the measurement data of the entire measurement range SA is connected. In the connection of the measurement data in the entire measurement range SA, the error due to the insufficient adjustment increases as the distance from the connection start point increases due to the long boundary portion and the two adjustments. In this connection, since there is only one connection, the error does not increase. The overlapping area SAs (HPs) is used as a so-called glue margin at the time of this connection. In the overlapping area SAs (HPs), the data to be connected is weighted so that the weight is reduced toward the side, while the data to be connected is weighted so that the weight is increased toward the side. Each weighted data is weighted and added to obtain data of the overlapping area SAs (HPs). In one example, in the overlapping area SAs-01 (HPs-01), the data of the 0th measurement range SA-0 to be connected is weighted so that the weight is reduced toward the side, while the first measurement range to be connected is connected. The SA-1 data is weighted so as to increase in weight toward the side, and each of the weighted data is weighted and added to form data of the overlapping area SAs-01 (HPs-01).

  In the above description, the measurement range is a regular hexagon. However, the measurement range is not limited to this. For example, a regular triangle such as a regular triangle or a square can be tiled without gaps when the overlapping area SAs is not provided. It may be a polygon.

  After such interpolation processing, the surface shape measuring apparatus M causes the filter unit 2222 of the filter processing unit 222 to apply the image filter FS to the phase image HP after complementing by the complementing unit 2221 to perform filtering processing. Execute (S4). Thus, for example, as shown in FIG. 11A, the component data having a relatively long period shape such as so-called nanotopography is added to the data of the component having a relatively long period shape due to bending deformation or warpage of the object SP. As shown in FIG. 11B, component data having the relatively short cycle shape is extracted from the data on which the data is superimposed. In the filtering process of the process S4, there is no data itself used for complementation at the end of the object SP to be measured (the peripheral part around the outer edge of the object SP), not at the end of the measurement range SA. The filter size of the image filter FS is gradually reduced toward the edge of the object SP, so-called shrink processing, or the data inside the object SP is folded outwards with the edge of the object SP as the axis of symmetry to generate pseudo data. A known conventional method such as a so-called loop interpolation process is used.

  Next, the surface shape measuring apparatus M removes the portion corresponding to the data supplemented by the complementing unit 2221 from the filtering processing result by the filtering unit 2222 by the removing unit 2223 of the filtering unit 222 (S5). In the example illustrated in FIG. 9, in one example, a part corresponding to the phase image HPc-01 supplemented by the complementing unit 2221 is removed from the filter processing result.

  Next, the surface shape measuring apparatus M determines whether or not each of the processes S2 to S5 has been executed for all measurement data by the filter processing unit 222 (S6). As a result of this determination, when each process is not executed for all measurement data (No), the filter processing unit 222 returns the process to the process S2, while on the other hand, for each measurement data, When the process is being executed (Yes), the filter processing unit 222 executes the next process S7.

  In this process S7, the surface shape measuring apparatus M connects the plurality of filter processing results corresponding to the plurality of measurement data between the adjacent surface positions by the connection processing unit 223 of the shape calculating unit 22, and measures the measurement target. The surface shape of the object SP is obtained. In this connection, since the data of the component having the relatively long period shape that is the main cause of the error is removed, it is only necessary to connect without performing the two adjustments, and the information processing of the connection is simplified. The

  And the surface shape measuring apparatus M outputs the surface shape of the to-be-measured object SP calculated | required in this way from the output part 5 by the control part 21 of the control calculating part 2 (S8), and complete | finishes a process. Note that the surface shape measuring apparatus M may output the surface shape of the measurement object SP from the IF unit 6 as necessary.

  In the above description, one measurement data is selected, and a phase image HP is obtained for the selected one measurement data. In the complementing process, the complementary measurement data is extracted to obtain a complementary phase image HPc. However, a plurality of phase images HP corresponding to each of the plurality of measurement data may be obtained, and in the interpolation process, a complementary phase image HPc corresponding to the complementary measurement data may be extracted and supplemented. Alternatively, one measurement data may be selected, supplemented measurement data may be extracted and supplemented for the selected one measurement data, and the phase image HP may be obtained from the complemented measurement data. Alternatively, one measurement data is selected, and a phase image HP is obtained for each selected measurement data and each measurement data adjacent to the one measurement data in the measurement range SA (surface position). In the interpolation process, a complementary phase image HPc corresponding to the complementary measurement data may be extracted and supplemented.

  As described above, the surface shape measuring device M and the surface shape measuring method mounted on the surface shape measuring device M according to the present embodiment are measured by the holding and moving unit 7 and the optical measurement as shown in FIGS. 5 and 12A, for example. Since one surface of the object SP is measured by the optical measuring system 1 at a plurality of different surface positions in the object SP by moving relative to the system 1, as shown in FIG. In order to measure a large object SP at a time, the optical measuring system 1A is not enlarged, and the object SP (for example, a diameter, for example, having a diameter of 100 mm or a diameter of 150 mm) larger than the single measurement range SA is measured. 300 mm, diameter 450 mm, etc.) can be measured, and the surface shape measuring apparatus M can be further downsized. Then, as in the flow shown by the broken lines in FIG. 13, if the filtering process is performed after the plurality of measurement data are connected between the adjacent surface positions, the connection boundary is determined at the time of the connection. It is necessary to adjust the height direction (offset adjustment) and the surface inclination between the measurement data adjacent to each other in the part. In particular, a measurement apparatus that can measure a plurality of measurement items related to shapes such as warpage, thickness distribution, roll-off, and the like is often processed in such a flow. For this reason, in a relatively large object SP to be measured, an error due to insufficient adjustment increases as the distance from the connection start point increases due to a long boundary portion (for example, 300 mm or more for a large semiconductor wafer) and two adjustments. . This is due to deformation of the measured object SP at each measurement time due to its own weight deflection, movement of the measured object SP, atmospheric pressure difference, vibration, etc., which is on the order of several to several tens of micrometers, and the desired shape, particularly nano It is an order of magnitude larger than the topography shape. However, the surface shape measuring apparatus M and the surface shape measuring method are mainly responsible for the error by performing a filtering process before connecting the plurality of measurement data, as in the flow indicated by a one-dot chain line in FIG. Since a certain second period component is removed, a plurality of filter processing results by the filter processing unit 222 corresponding to the plurality of measurement data can be connected with higher accuracy. Therefore, the surface shape measuring apparatus and the surface shape measuring method can measure the surface shape of the object SP to be measured which is larger than one measurement range SA, and can be measured with higher accuracy (for example, on the order of nanometers) while further downsizing. it can. In particular, the surface shape measuring apparatus and the surface shape measuring method can suitably measure nanotopography by setting the first periodic component to a component corresponding to the periodic component of nanotopography.

  In the surface shape measuring apparatus M and the surface shape measuring method, the shortage of the measurement data in the filtering process is compensated by the measurement data adjacent in the measurement range SA, so that the error due to the lack of data to be filtered can be reduced.

  Since the surface shape measuring apparatus M and the surface shape measuring method remove the portion corresponding to the data supplemented by the complementing unit 2221, it is possible to reduce an error associated with the connection (the adjustment) caused by the compensation.

  In order to express the present invention, the present invention has been properly and fully described through the embodiments with reference to the drawings. However, those skilled in the art can easily change and / or improve the above-described embodiments. It should be recognized that this is possible. Therefore, unless the modifications or improvements implemented by those skilled in the art are at a level that departs from the scope of the claims recited in the claims, the modifications or improvements are not covered by the claims. To be construed as inclusive.

M surface shape measuring apparatus 1 optical measurement system 2 control calculation unit 7 holding movement unit 22 shape calculation unit 221 phase image calculation unit 222 filter processing unit 223 connection processing unit 2221 complementing unit 2222 filter unit 2223 removal unit

Claims (7)

An optical measurement system that generates measurement data relating to the shape of the object to be measured using an optical interferometer;
A holding and moving unit for holding the object to be measured and relatively moving the object to be measured and the optical measurement system;
Based on a plurality of measurement data generated by the optical measurement system at a plurality of different surface positions in the measurement object by relatively moving the measurement object and the optical measurement system by the holding and moving unit. And a shape calculating unit for obtaining the surface shape of the entire surface of the one to be measured,
The shape calculating unit removes a second cycle component having a longer period than the first cycle component so as to extract a predetermined first cycle component based on the measurement data for each of the plurality of measurement data. A surface comprising: a filter processing unit that performs filter processing; and a connection processing unit that connects a plurality of filter processing results by the filter processing unit corresponding to the plurality of measurement data between adjacent surface positions. Shape measuring device. The filtering process unit, if the relative the measurement data at the end of the measurement range to filter the data missing in the filter size of the filter, the measuring range of the surface position adjacent to the measurement range of the measurement data The surface shape measuring device according to claim 1, further comprising: a complementing unit that supplements with the measurement data in the step; and a filter unit that performs the filtering process on the measurement data after complementing by the complementing unit. The surface shape measuring device according to claim 2, wherein the filter processing unit further includes a removing unit that removes a part corresponding to the data supplemented by the complementing unit from the filtering result of the filtering unit. . The holding movement unit includes a holding unit that holds the object to be measured in a vertical position, and a moving unit that moves the holding unit along two axes in a radial direction and a circumferential direction. The surface shape measuring apparatus according to any one of claims 1 to 3. The holding and moving unit includes a second holding unit that holds the object to be measured horizontally, and a moving unit that moves the second holding unit in two radial and circumferential axes. The surface shape measuring apparatus of any one of Claim 1 thru | or 3. The holding and moving unit includes a second holding unit that holds the object to be measured horizontally, and a second moving unit that moves the second holding unit along two axes in two linearly independent directions. The surface shape measuring device according to any one of claims 1 to 3. An optical measurement process for generating measurement data relating to the shape of the object to be measured using an optical interferometer;
Based on a plurality of measurement data generated by the optical measurement step at a plurality of different surface positions in the object to be measured, and a shape calculation step for obtaining a surface shape of one entire surface of the object to be measured,
The shape calculation step removes a second period component having a longer period than the first period component so as to extract a predetermined first period component based on the measurement data for each of the plurality of measurement data. A surface processing method comprising: a filter processing step for performing filter processing; and a connection processing step for connecting a plurality of filter processing results obtained by the filter processing step corresponding to the plurality of measurement data between adjacent surface positions. Shape measurement method.

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