JP2014092489A - Inspection device and inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inspection device and inspection method by which the amount of error of the mounting position of an inspection target that is mounted on a stage can be obtained in a short time.SOLUTION: For example, a plurality of distance measuring sensors (measuring instruments) LSENw1 to LSENw3, LSENn1, and LSENn2 are arranged at positions that are opposed to a side surface of a semiconductor wafer WF mounted on a stage and are different from each other. Each of the distance measuring sensors (measuring instruments) irradiates the side surface of the WF with an electromagnetic wave and detects a reflection wave therefrom, thereby measuring each of the distances from the corresponding side surfaces. According to measurement results from LSENw1 to LSENw3, the amount of eccentricity error of the mounting position of the WF is calculated, and according to measurement results from LSENn1 and LSENn2 targeting a notch NC for measurement, the amount of rotation error of the mounting position of the WF is calculated.

Description

  The present invention relates to an inspection apparatus and an inspection method, for example, a surface inspection apparatus and a surface inspection method for examining foreign matter / defect distribution information existing on the surface of a semiconductor wafer using a laser beam.

  For example, Patent Document 1 discloses a positioning device that detects an error amount in a rotation direction of a mounting position when the semiconductor wafer is mounted on a turntable and corrects the error amount. The positioning device includes a light source on one of the front side and the back side of the semiconductor wafer and a light receiving element on the other side in the vertical direction of the outer periphery of the semiconductor wafer mounted on the turntable. Then, the positioning device observes the light amount of the light receiving element while rotating the semiconductor wafer, detects the position of the orientation flat or notch from the amount of change, detects the amount of error in the rotation direction, and cancels this amount of error. Rotate the turntable so that.

JP-A-4-204313

  For example, in each manufacturing process of a semiconductor device, an inspection for obtaining the size and position information distribution of foreign matters and defects on the surface of a semiconductor wafer is required. A surface inspection apparatus is used in such inspection. In the surface inspection apparatus, it is important to detect the eccentricity error amount and the rotation error amount of the semiconductor wafer mounted on the turntable in order to accurately obtain the position information of the foreign matter / defect on the semiconductor wafer. For example, in each plane of the turntable and the semiconductor wafer, when the center point is the origin and the x axis and the y axis are defined orthogonally from the origin, the semiconductor wafer is ideally based on the turntable. Are mounted on the turntable so that the origins coincide and the x-axis (or y-axis) forms a predetermined angle (for example, 0 °). In this case, the eccentricity error amount means the error amount between the origin of the turntable and the origin of the semiconductor wafer, and the rotation error amount means the x-axis (or y-axis) of the turntable and the x-axis (or the semiconductor wafer). It means an error amount (that is, an error amount in the rotation direction) from an ideal state (for example, 0 °) of an angle formed by the y-axis.

  Under such circumstances, for example, Patent Document 1 discloses a technique for detecting a rotation error amount. However, in this technique, it is necessary to rotate the semiconductor wafer once through the turntable in order to detect the rotation error amount. In order to rotate the semiconductor wafer once, for example, a time of about 2 to 3 seconds is required. As described above, in this technique, it takes time to acquire the error amount related to the mounting position of the semiconductor wafer mounted on the stage (for example, the turntable), and as a result, the throughput of the surface inspection apparatus may be reduced. .

  The present invention has been made in view of the above, and one of its purposes is an inspection capable of acquiring in a short time an error amount related to the mounting position of an object to be inspected mounted on a stage. It is to provide an apparatus and an inspection method. The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of a typical embodiment will be briefly described as follows.

  The inspection apparatus according to the present embodiment includes a stage on which the inspection object is mounted so that the back surface of the inspection object contacts, and a plurality of measuring devices that measure the mounting position of the inspection object on the stage. And an information processing unit that performs processing using the measurement results of the plurality of measuring instruments. The object to be inspected is mounted at a predetermined target position on the stage. The plurality of measuring instruments are arranged at positions that are opposite to the side surface of the object to be inspected mounted on the stage and at different positions, irradiate electromagnetic waves toward the side surface of the object to be inspected, and detect the reflected waves. Thus, the distance from the side surface of the object to be inspected is measured. The information processing unit recognizes the mounting position of the object to be inspected on the stage based on the measurement results from the plurality of measuring instruments, and calculates an error amount from the target position of the mounting position.

  Of the inventions disclosed in the present application, the effects obtained by the representative embodiments will be briefly described. It is possible to obtain an error amount related to the mounting position of the inspection target mounted on the stage in a short time. Become.

It is a top view which shows the schematic structural example in the inspection apparatus by Embodiment 1 of this invention. FIG. 2 is a side view showing a detailed configuration example around the inspection origin of the inspection unit in the inspection apparatus of FIG. 1. FIG. 2 is a top view showing a detailed configuration example around the alignment origin of the inspection unit in the inspection apparatus of FIG. 1. It is sectional drawing which shows an example of arrangement | positioning relationship between each distance measurement sensor (measuring instrument) in FIG. 3, and a semiconductor wafer. It is explanatory drawing which shows an example of the measurement principle of the distance measurement sensor (measurement device) which measures the eccentricity error amount in FIG. It is explanatory drawing which shows an example of the measurement principle of the distance measurement sensor (measurement device) which measures a rotation error amount in FIG. It is a flowchart which shows the main operation examples in the inspection apparatus of FIG. It is explanatory drawing which shows an example of the processing content accompanying calculation of the eccentricity error amount and rotation error amount in FIG. 7, and correction | amendment of a test result. (A) And (b) is explanatory drawing which shows an example of the processing content following FIG. It is explanatory drawing which shows an example of the processing content following FIG. In the inspection apparatus by Embodiment 2 of this invention, it is a perspective view which shows the detailed structural example around the alignment origin of the test | inspection part of FIG.

  In the following embodiment, when it is necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments. However, unless otherwise specified, they are not irrelevant, and one is the other. Some or all of the modifications, details, supplementary explanations, and the like are related. Further, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), especially when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to the specific number, and may be more or less than the specific number.

  Further, in the following embodiments, the constituent elements (including element steps and the like) are not necessarily indispensable unless otherwise specified and apparently essential in principle. Needless to say. Similarly, in the following embodiments, when referring to the shapes, positional relationships, etc. of the components, etc., the shapes are substantially the same unless otherwise specified, or otherwise apparent in principle. And the like are included. The same applies to the above numerical values and ranges.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

(Embodiment 1)
<< Schematic configuration of inspection equipment >>
FIG. 1 is a top view showing a schematic configuration example of the inspection apparatus according to Embodiment 1 of the present invention. The inspection apparatus shown in FIG. 1 is a surface inspection apparatus that inspects the presence or absence of foreign matter / defects on the surface of a semiconductor wafer WF, for example. . The loader unit LD installs a wafer storage container (wafer pod) WFP in which a plurality of semiconductor wafers WF are stored. The transfer unit HDU includes a wafer transfer robot HR having an arm and a pre-alignment unit PAL.

  The wafer transfer robot HR takes out the semiconductor wafer WF from the wafer storage container WFP of the loader unit LD, transfers it to the pre-alignment unit PAL, and mounts it on the PAL. The pre-alignment unit PAL adjusts the position of the WF for the purpose of bringing the eccentricity error amount and rotation error amount of the semiconductor wafer WF described above close to zero. The semiconductor wafer WF whose position is adjusted on the pre-alignment unit PAL is taken out again by the wafer transfer robot HR and transferred to the insertion port of the inspection unit MESU.

  The inspection unit MESU includes a mounting stage STG and a control unit CTLU. As described above, the wafer transfer robot HR transfers the semiconductor wafer WF from the pre-alignment unit PAL to the insertion port of the inspection unit MESU and then mounts it on the wafer holding mechanism HM provided on the mounting stage STG. At this time, the wafer holding mechanism HM moves in advance on the mounting stage STG so that the center thereof is a position that coincides with the alignment origin AP. The wafer transfer robot HR mounts the semiconductor wafer WF, whose position has been adjusted by the pre-alignment unit PAL, on the wafer holding mechanism HM by a predetermined operation.

  Therefore, if there is no error in the position adjustment in the pre-alignment unit PAL and there is no error in the operation of HR, the eccentricity error amount and rotation with respect to the mounting stage STG of the semiconductor wafer WF mounted on the wafer holding mechanism HM. The amount of error is zero. However, in reality, there is a certain amount of error. For example, there may be an eccentricity error amount of about several tens of μm and a rotation error amount of about 0.5 °. Therefore, the alignment origin AP measures the eccentricity error amount and the rotation error amount. Although details will be described later, the measurement method at this time is the main feature of the present embodiment.

  The semiconductor wafer WF in which the eccentricity error amount and the rotation error amount are measured at the alignment origin AP is mounted in a predetermined direction toward the inspection origin MP using the transport mechanism on the mounting stage STG while being mounted on the wafer holding mechanism HM. (Here, the x-axis direction is assumed). Thereafter, the inspection unit MESU inspects the entire surface of the WF while appropriately rotating the semiconductor wafer WF from the inspection origin MP and moving it appropriately in the x-axis direction to detect foreign matter / defects existing on the surface of the WF. To do. The semiconductor wafer WF subjected to the surface inspection is transported toward the transport unit HDU by using a transport mechanism on the mounting stage STG, is taken out by the wafer transport robot HR, and is stored in the wafer storage container WFP.

  The control unit CTLU includes an information processing unit IPU, a stage control unit SCTLU, and an inspection control unit MCTLU. The stage controller SCTLU controls the movement and rotation of the semiconductor wafer WF on the mounting stage STG. The inspection control unit MCTLU controls the measurement mechanism when measuring the error at the alignment origin AP and controls the inspection mechanism when inspecting the surface of the semiconductor wafer WF at the inspection origin MP. The information processing unit IPU performs a predetermined process in response to the measurement result from the measurement mechanism and the inspection result from the inspection mechanism. The control unit CTLU is connected to a terminal TM such as a personal computer via a communication line. The terminal TM, for example, gives an inspection instruction to the control unit CTLU, or obtains an inspection result from the CTLU and displays it.

  As described above, in the surface inspection apparatus, since the eccentricity error amount and the rotation error amount at the alignment origin AP and the surface inspection at the inspection origin MP are performed, in order to improve the throughput of the surface inspection apparatus, In addition to the inspection time of inspection, it is required to shorten the measurement time of the eccentricity error amount and the rotation error amount. Therefore, it is beneficial to use the measurement method of the present embodiment described later. In the present embodiment, a surface inspection apparatus using the semiconductor wafer WF as an object to be inspected will be described as an example. However, the present invention is not necessarily limited to this, and various inspection apparatuses that require accurate coordinate specification. Is applicable. For example, the present invention can be similarly applied to an inspection apparatus that uses a glass substrate of a liquid crystal panel, a solar battery panel, or the like as an object to be inspected.

<Details of surface inspection mechanism>
FIG. 2 is a side view showing a detailed configuration example around the inspection origin MP of the inspection unit in the inspection apparatus of FIG. The inspection unit shown in FIG. 2 includes a mounting stage STG, an X stage XSTG serving as a transport mechanism on the STG, a rotation stage θSTG serving as a wafer rotation mechanism on the STG, a wafer holding mechanism HM, and a laser beam irradiation unit LSOT. A plurality of scattered light detection units LSDT and a control unit CTLU are provided. As described in FIG. 1, the X stage XSTG has a mechanism that moves in the x-axis direction on the mounting stage STG. The rotary stage θSTG is installed on the X stage XSTG and has a mechanism that rotates on the xy plane with the z axis as an axis. Wafer holding mechanism HM is installed on rotary stage θSTG, mounts WF so that the back surface of semiconductor wafer WF contacts, and holds the WF. The stage control unit SCTLU in the control unit CTLU appropriately controls the operations of the X stage XSTG and the rotation stage θSTG based on predetermined program processing or the like.

  The mounting stage STG, the X stage XSTG, the rotation stage θSTG, and the wafer holding mechanism HM can be regarded as one stage on which the semiconductor wafer WF is mounted as a whole. In this case, the stage moves the mounted semiconductor wafer WF to predetermined (x, y) coordinates (alignment origin AP, inspection origin MP, etc. in FIG. 1) as can be seen from FIG. And a mechanism for rotating on the xy plane.

  The laser beam irradiation unit LSOT irradiates a laser beam toward the surface of the semiconductor wafer WF mounted on the wafer holding mechanism HM. Each scattered light detection unit LSDT observes scattered light generated by laser light irradiation. The inspection control unit MCTLU in the control unit CTLU appropriately controls the operations of the laser beam irradiation unit LSOT and the scattered light detection unit LSDT based on a predetermined program process or the like. The information processing unit IPU in the control unit CTLU includes (x, y) coordinates of the semiconductor wafer WF obtained through the stage control unit SCTLU, rotational coordinates (θ) on the xy plane, and scattered light detection units at the respective coordinates. Based on the observation result by LSDT, the presence or absence of a foreign substance or a defect existing on the surface of the WF is detected, and the coordinates and size of the foreign substance or the defect are calculated. Thus, the laser beam irradiation unit LSOT, the scattered light detection unit LSDT, and the control unit CTLU function as a foreign matter / defect detection unit. Of course, the number and location of the laser light irradiation unit LSOT and the scattered light detection unit LSDT are not limited to those shown in FIG. 2 and can be changed as appropriate.

<Details of wafer loading position measurement mechanism>
FIG. 3 is a top view showing a detailed configuration example around the alignment origin AP of the inspection unit in the inspection apparatus of FIG. 1. In FIG. 3, the semiconductor wafer WF includes a notch NC formed to represent a coordinate reference point. The notch NC is obtained by processing a part of the outer periphery of the semiconductor wafer WF into a fan shape, and has two sides extending inward from the outer periphery of the WF. Then, the semiconductor wafer WF is mounted on the mounting stage STG (FIG. 1) with the alignment origin AP as the target position of the center point and the position where the notch NC is the y-axis target as the NC target position.

  The inspection unit shown in FIG. 3 includes a plurality of distance measurement sensors (measurement devices) LSENw1 to LSENw3, LSENn1, and LSENn2 arranged on the outer periphery of the semiconductor wafer WF as a measurement target. The distance measurement sensors LSENw1 to LSENw3 are arranged, for example, in predetermined angular increments (here, 120 ° increments) in the rotation direction (circumferential direction) of the semiconductor wafer, and are arranged so that the distances to the alignment origin AP are equal. Is done. LSENw1 is arranged on the side facing the notch NC across the semiconductor wafer WF on the y-axis, and LSENw2 and LSENw3 are arranged in order counterclockwise from there at 120 ° intervals. LSENw1 to LSENw3 measure the distance from the alignment origin AP at the center point of WF by measuring the distance to the outer periphery of the semiconductor wafer WF (or the amount of displacement from the reference distance) Lw1 to Lw3, respectively. ) Is detected.

  The distance measurement sensors LSENn1 and LSENn2 are provided with two sides in the notch NC included in the semiconductor wafer WF as measurement targets, and an NC rotation error amount based on the y axis (that is, an error amount in the WF rotation direction (circulation direction)). ) Is detected. LSENn1 measures the distance to one side of the notch NC (or the displacement from the reference distance) Ln1, and LSENn2 determines the distance to the other one of the two sides of the NC (or the reference distance). Displacement amount) Ln2. The displacement amount from the reference distance is a displacement amount based on the distance obtained when the semiconductor wafer WF is mounted on the coordinate axis (xy plane) centered on the alignment origin AP without error. Is equivalent to distance.

  FIG. 4 is a cross-sectional view showing an example of an arrangement relationship between each distance measurement sensor (measuring instrument) and the semiconductor wafer in FIG. As shown in FIG. 4, each distance measurement sensor (measurement device) LSEN (LSENw1 to LSENw3, LSENn1, LSENn2) is arranged at a position facing the side surface of the semiconductor wafer WF, for example, on the xy plane. Each distance measurement sensor (measurement device) LSEN measures the distance L between the side surface by irradiating the electromagnetic wave toward the side surface of the semiconductor wafer WF and detecting the reflected wave from the side surface. Each distance measuring sensor (measuring instrument) LSEN typically measures the amount of displacement from a reference distance using electromagnetic waves such as laser light. Although not particularly limited, for example, if a reflective laser displacement sensor using triangulation is used, the amount of displacement from a reference distance can be measured with an accuracy of 1 μm or less. The thickness H of the semiconductor wafer WF is, for example, 500 μm to 1000 μm. Each distance measuring sensor (measuring instrument) may be any sensor that can measure a distance, and may be an ultrasonic sensor, a contact sensor, or the like depending on circumstances.

  FIG. 5 is an explanatory diagram showing an example of the measurement principle of the distance measurement sensor (measuring instrument) that measures the eccentricity error amount in FIG. As shown in FIG. 5, for example, distance measurement sensors (measurement devices) LSENw1 to LSENw3 are arranged at an equal distance from the alignment origin AP, and the semiconductor wafer is mounted at a position with zero error (reference position REFwf). In this case, the distances measured by LSENw1 to LSENw3 are all the same. When the center point C1 of the semiconductor wafer WF is shifted from the alignment origin AP by (Δx, Δy), for example, as in the example of FIG. 5, using the distance obtained at the reference position REFwf as a reference, a distance measurement sensor (measurement device ) The distance Lw2 measured by LSENw2 increases and the distance Lw1 measured by LSENw1 decreases.

  Thus, if the distances Lw1 to Lw3 are measured by the distance measuring sensors (measurement devices) LSENw1 to LSENw3, a circle passing through all points separated from the LSENw1 to LSENw3 by Lw1 to Lw3 is uniquely determined, and the center of this circle is determined. The eccentricity error amount (Δx, Δy) can be calculated by uniquely determining the point. Since the diameter of the semiconductor wafer WF is determined in advance, in principle, the eccentricity error amount can be calculated if the distances at two different locations from the side surface of the WF are known. Therefore, in some cases, instead of LSENw1 to LSENw3, a configuration in which two distance measuring sensors (measuring instruments) are arranged with two different sides of the semiconductor wafer WF as measurement targets may be used. Further, LSENw1 to LSENw3 may be arranged such that the distance from the alignment origin AP is different. However, in order to further increase the calculation accuracy of the eccentricity error amount, it is desirable to arrange three or more distance measurement sensors (measuring instruments) in equal angular increments, and from the viewpoint of apparatus cost, it is preferable to use three. desirable.

  FIG. 6 is an explanatory diagram showing an example of the measurement principle of the distance measurement sensor (measuring instrument) that measures the rotation error amount in FIG. As shown in FIG. 6, for example, when distance measuring sensors (measurement devices) LSENn1 and LSENn2 are arranged on the y-axis target and the semiconductor wafer is mounted at a position with zero error (reference position REFwf), LSENn1, Both distances measured by LSENn2 are the same. With reference to the distance obtained at the reference position REFwf, distance measurement is performed when the notch NC of the semiconductor wafer WF is shifted by Δθ in the rotation direction (circumferential direction) of the WF with respect to the y-axis as in the example of FIG. The distance Ln1 measured by the sensor (measurement device) LSENn1 is extended, and the distance Ln2 measured by LSENn2 is reduced.

  Since the notch NC is formed in a predetermined size and shape on the outer periphery of the semiconductor wafer WF, the position of the outer periphery of the WF and the distances Ln1 and Ln2 by the distance measurement sensors (measurement devices) LSENn1 and LSENn2 are found. For example, the coordinates of NC are uniquely determined. Since the position of the outer periphery of the semiconductor wafer WF is determined by the measurement of FIG. 5, the NC coordinates can be obtained using the measurement results of the distances Ln1 and Ln2, and the rotation error amount (Δθ) can be calculated. FIG. 6 shows an example in which a rotation error amount (Δθ) occurs when the center point of the semiconductor wafer WF is equal to the alignment origin AP.

<< Inspection method using inspection equipment >>
FIG. 7 is a flowchart showing a main operation example in the inspection apparatus of FIG. In FIG. 7, the inspection apparatus (surface inspection apparatus) aligns the semiconductor wafer WF using the pre-alignment unit PAL as described in FIG. 1, and then mounts the WF at the target position on the mounting stage STG. (Step S701). Here, as described in FIG. 3, the target position of the center point of the semiconductor wafer WF is the alignment origin AP, and the target position of the notch NC of the WF is the position where NC is the y-axis target. Next, as described in FIGS. 5 and 6, the surface inspection apparatus uses the distance measurement sensors (measurement devices) LSENw <b> 1 to LSENw <b> 3, LSENn <b> 1, LSENn <b> 2 to mount the semiconductor wafer WF (distance to the outer peripheral side surface of WF). The distance to the side surfaces of the two sides of the notch NC is measured (step S702).

  Subsequently, as described in FIGS. 5 and 6, the surface inspection apparatus uses the information processing unit IPU in FIG. 1 to determine the eccentric error amount (Δx, Δy) of the semiconductor wafer WF from the measurement result in step S702. And a rotation error amount (Δθ) is calculated (step S703). Next, the surface inspection apparatus moves the semiconductor wafer WF to the inspection origin MP on the mounting stage STG, and inspects the surface of the WF using the foreign matter / defect detection unit as shown in FIG. 2 (step S704). Thereafter, the surface inspection apparatus uses the information processing unit IPU of FIG. 1 to add the eccentricity error amount (Δx, Δy) and the rotation error amount (Δθ) calculated in step S703 to the inspection result obtained in step S704. Based on the correction, the corrected result is output to the terminal TM shown in FIG. 1 (step S705).

<Details of correction processing for surface inspection results>
8, FIG. 9 (a), FIG. 9 (b), and FIG. 10 are explanatory diagrams showing an example of the processing contents accompanying the calculation of the eccentricity error amount and the rotation error amount and the correction of the inspection result in FIG. . First, as shown in FIG. 8, the information processing unit IPU determines the outer frame coordinates of the semiconductor wafer including the notch NC (based on the distance measurement results by the distance measurement sensors (measurement devices) LSENw1 to LSENw3, LSENn1, and LSENn2). CALwf) can be calculated. From the outer frame coordinates (CALwf) of the semiconductor wafer, the information processing unit IPU, as shown in FIG. 9A, the outer frame coordinates (CAL'wf) of the semiconductor wafer when the rotation error amount is zero, and CAL The coordinates (Δx, Δy) of the center point C1 of the circle formed by 'wf can be calculated. As a result, the information processing unit IPU can calculate the eccentricity error amount (Δx, Δy) from the coordinates (0, 0) of the alignment origin AP.

  Further, as shown in FIG. 9B, the information processing unit IPU has the outer frame coordinates (CAL'wf) of the semiconductor wafer when the rotation error amount shown in FIG. The rotation error amount (Δθ) can be calculated from, for example, the difference in the coordinates of the front end portion where two sides in the notch NC intersect with each other by comparing with the outer frame coordinates (CALwf) of the semiconductor wafer shown. On the other hand, in step S704 in FIG. 7, the foreign matter / defect detection unit described above assumes that there is no error in the mounting position of the semiconductor wafer WF as shown in FIG. 0,0) is constructed), and the coordinates (x1, y1) of the foreign matter / defect in the WF are output.

  However, since the semiconductor wafer WF actually has an eccentricity error amount (Δx, Δy) and a rotation error amount (Δθ), the actual coordinates of the foreign matter / defect in the WF are different from (x1, y1). Therefore, as shown in FIG. 10, the information processing unit IPU sets a point obtained by adding an eccentricity error amount (Δx, Δy) to the alignment origin AP as an origin C ′, and the C ′ as coordinates (0, 0). An x′y ′ coordinate axis is constructed, and this x′y ′ coordinate axis is set as an actual coordinate axis in the semiconductor wafer WF. The x ′ axis intersects the x axis at an angle of rotation error amount (Δθ), and the y ′ axis also intersects the y axis at an angle of rotation error amount (Δθ). Then, the information processing unit IPU corrects (converts) the foreign matter / defect coordinates (x1, y1) on the xy coordinate axis described above to the actual foreign matter / defect coordinates (x2, y2) on the x'y 'coordinate axis. Then, the coordinates (x2, y2) after the correction (conversion) are output to the terminal TM or the like. Specifically, (x2, y2) can be calculated by converting (x1 + Δx, y1 + Δy) by a so-called rotation matrix determined by a trigonometric function of Δθ.

  As described above, by using the inspection apparatus according to the first embodiment, for example, an object to be inspected (for example, a semiconductor wafer) mounted on the mounting stage STG without rotating the semiconductor wafer WF as disclosed in Patent Document 1. It is possible to acquire an error amount related to the mounting position of (WF). As a result, the amount of error can be acquired in a short time, which makes it possible to improve the throughput of an inspection apparatus represented by a surface inspection apparatus, for example.

(Embodiment 2)
<< Details of wafer mounting position measurement mechanism (variation) >>
FIG. 11 is a perspective view showing a detailed configuration example around the alignment origin AP of the inspection unit in FIG. 1 in the inspection apparatus according to the second embodiment of the present invention. The inspection unit illustrated in FIG. 11 includes optical cameras CM1 to CM4 instead of the distance measurement sensors (measurement devices) LSENw1 to LSENw3, LSENn1, and LSENn2 in FIG. Each of CM1 to CM4 is arranged in the z-axis direction (the WF rotation axis direction) at the position of the outer periphery of the semiconductor wafer WF in 90 ° increments, and partially images the outer periphery of the WF in 90 ° increments. Of these, the CM 4 images the notch NC.

  In this case, for example, the information processing unit IPU in FIG. 1 detects the outer periphery from the imaging results of the optical cameras CM1 to CM3, and the detected outer peripheral coordinates and the predetermined reference outer peripheral coordinates (that is, The eccentricity error amount is calculated based on the difference from the outer peripheral coordinates of the ridge obtained when the semiconductor wafer WF is at the reference position REFwf in FIG. Further, the information processing unit IPU in FIG. 1 detects the shape of the notch NC from the imaging result of the optical camera CM4, and the coordinates of the detected NC and the coordinates of the NC serving as a predetermined reference (that is, FIG. The rotational error amount is calculated based on the difference from the NC coordinates of the heel obtained in the case of 5 REFwf and the above-described eccentric error amount.

  By using such a configuration example, as in the case of the first embodiment, it is possible to acquire an error amount related to the mounting position of the object to be inspected (for example, the semiconductor wafer WF) in a short time. It is possible to improve the throughput of the inspection apparatus represented by However, in order to obtain high measurement accuracy at a low cost, the configuration example using the distance measurement sensor (measurement device) as in the first embodiment is preferable.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. . Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  For example, FIG. 1 shows a configuration example in which the alignment origin AP and the inspection origin MP are individually provided on the mounting stage STG. However, in some cases, the alignment origin AP and the inspection origin MP are unified into one origin. It is also possible. That is, when the semiconductor wafer WF is placed at the one origin and the surface inspection is performed, it is possible to detect the eccentricity error amount and the rotation error amount in a short time immediately before or after the surface inspection. is there.

AP alignment origin C center point CM optical camera CTLU control unit HDU transport unit (handling unit)
HM Wafer holding mechanism HR Wafer transfer robot IPU Information processing unit L Distance LD Loader unit LSDT Scattered light detection unit LSEN Distance measurement sensor (measuring instrument)
LSOT laser beam irradiation unit MCTLU inspection control unit MESU inspection unit MP inspection origin NC notch PAL pre-alignment unit REFwf reference position SCTLU stage control unit STG mounting stage TM terminal WF semiconductor wafer WFP wafer storage container (wafer pod)
XSTG X stage θSTG Rotation stage

Claims (10)

A stage on which the inspection object is mounted so that the back surface of the inspection object contacts;
A plurality of measuring instruments for measuring the mounting position of the inspection object on the stage;
An information processing unit that performs processing using measurement results of the plurality of measuring instruments,
The inspection object is mounted at a predetermined target position on the stage,
The plurality of measuring instruments are arranged at positions different from and different from the side surfaces of the object to be inspected mounted on the stage, irradiate electromagnetic waves toward the side surfaces of the object to be inspected, and By detecting a reflected wave from the side surface of the inspection object, each distance between the inspection object side surface is measured,
The information processing unit recognizes a mounting position of the inspection object on the stage based on measurement results from the plurality of measuring instruments, and calculates an error amount of the mounting position from the target position. Inspection device. The inspection apparatus according to claim 1,
The inspection object is a semiconductor wafer,
When the semiconductor wafer is viewed from the surface, the plurality of measuring instruments are arranged at predetermined angular intervals in the rotation direction of the semiconductor wafer at positions outside the outer periphery of the semiconductor wafer. Inspection device including a vessel. The inspection apparatus according to claim 2,
The plurality of measuring devices further include fourth and fifth measuring devices provided with two sides in a notch included in the semiconductor wafer as measurement targets,
The fourth measuring instrument is disposed at a position facing a side surface of one side of the two sides, and measures a distance between the side surface of the one side,
The fifth measuring instrument is an inspection apparatus that is disposed at a position facing a side surface of the other side of the two sides and measures a distance between the side surface of the other side. The inspection apparatus according to claim 3, wherein
The information processing unit calculates an error amount of the center coordinates of the semiconductor wafer based on the measurement results of the first to third measuring instruments, and determines the rotation direction of the semiconductor wafer based on the measurement results of the fourth and fifth measuring instruments. Inspection device that calculates the amount of error. The inspection apparatus according to claim 4, further comprising:
Irradiating a laser beam toward the surface of the semiconductor wafer mounted on the stage, and observing scattered light from the surface of the semiconductor wafer to detect the presence or absence of foreign matter or defects present on the surface of the semiconductor wafer Provided with a foreign matter detection unit that detects the coordinates of foreign matter or defects,
The said information processing part correct | amends the coordinate of the said foreign material or a defect from the said foreign material detection part based on the calculated error amount, and outputs the coordinate after the said correction | amendment. A first step of mounting the object to be inspected on a stage so that the back surface of the object to be inspected contacts;
A second step of measuring a mounting position of the inspection object on the stage;
A third step of performing processing using the measurement result in the second step,
In the first step, the inspection object is mounted at a predetermined target position on the stage,
In the second step, an electromagnetic wave is irradiated toward a side surface of the inspection object mounted on the stage, and a reflected wave from the side surface of the inspection object is detected, whereby the inspection object The distance between each side of the object is measured,
In the third step, an inspection in which the mounting position of the inspection object on the stage is recognized based on the measurement result in the second step, and an error amount of the mounting position from the target position is calculated. Method. The inspection method according to claim 6,
The inspection object is a semiconductor wafer,
In the second step, the electromagnetic wave is irradiated to three or more different side surfaces of the semiconductor wafer. The inspection method according to claim 7,
The second step is an inspection method in which electromagnetic waves are further irradiated to the side surfaces of two sides in a notch provided in the semiconductor wafer. The inspection method according to claim 8, wherein
In the third step, the error amount of the center coordinate of the semiconductor wafer and the error amount of the rotation direction of the semiconductor wafer are calculated. The inspection method according to claim 9, further comprising:
The surface of the semiconductor wafer mounted on the stage is irradiated with laser light, and the presence or absence of foreign matters or defects present on the surface of the semiconductor wafer by observing scattered light from the surface of the semiconductor wafer Comprising a fourth step in which the coordinates of the foreign object or defect are detected;
In the third step, the coordinates of the foreign matter or defect detected in the fourth step are corrected based on the error amount calculated in the third step, and the corrected coordinates are output.

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