Device and method for measuring amount of positional displacement of bonded substrate, and semiconductor manufacturing device

Abstract

The present invention is an apparatus and method for measuring the amount of positional displacement of a bonded substrate in which two sets of disk-shaped first and second substrates having different diameters are laminated in the thickness direction, the apparatus and method for measuring the amount of positional displacement of a bonded substrate in which measurement light is projected from the thickness direction to the bonded substrate, the transmission intensity distribution of the measurement light in the diameter direction is measured, and the positional shift amount is calculated on the basis of the measurement result, the measurement light being light having a wavelength capable of penetrating through a substrate having a larger diameter from among the first substrate and the second substrate. A semiconductor manufacturing apparatus of the present invention uses such a device for measuring the amount of positional displacement of a bonded substrate.

Description

Technical Field

[0001] The present invention relates to a device and method for measuring the position offset of two sets of substrates that are stacked and bonded in the thickness direction, and a semiconductor manufacturing apparatus using the device for measuring the position offset of the bonded substrates. Background Technology

[0002] In recent years, for example, laminated substrates have been known to be formed by stacking and bonding multiple substrates in the thickness direction to achieve multiple functions. Examples include laminated substrates of silicon (Si) substrates and quartz substrates (glass substrates), laminated substrates of silicon carbide (SiC) substrates and silicon substrates, and laminated substrates of sapphire substrates and silicon substrates. Such laminated substrates require bonding each substrate to a desired position. Therefore, in order to determine whether each substrate has been bonded to the desired position, it is necessary to measure the positional offset of the bonding. As a technique for measuring this positional offset, for example, there is a laminated substrate positional offset detection device disclosed in Patent Document 1.

[0003] The position offset detection device for a bonding substrate disclosed in Patent Document 1 is a device for detecting the offset between two sets of substrates that are stacked in a circular plate shape. It includes: an outermost edge measuring unit (e.g., a contour measuring unit 3) for detecting the overall contour shape of the two sets of substrates; a distal position measuring unit (e.g., an edge shape measuring unit 4) for measuring the relative concavity and convexity of the outer periphery of the bonding substrate at multiple points in the circumferential direction and measuring the relative distal position relationship of the outer periphery between the two sets of substrates; and a calculation unit for detecting the contour shape data of any one set of substrates based on the detection result of the outermost edge measuring unit, and for the other set of substrates, using the contour shape data of one set of substrates as a reference, calculating the contour shape data based on the relative distal position relationship between the two sets of substrates measured by the distal position measuring unit, comparing the contour shape data between the two sets of substrates, and calculating the offset between the two sets of substrates.

[0004] However, in bonded substrates, there are cases where a first substrate with a relatively large diameter and a second substrate with a relatively small diameter are bonded together. For example, when measuring the positional offset of a bonded substrate with a first substrate and a second substrate of significantly different sizes, such as a 4-inch SiC substrate and an 8-inch Si substrate, the bonded substrate positional offset detection device disclosed in Patent Document 1 requires increasing the size of the distal position measurement unit (e.g., the edge shape measurement unit 4) according to the bonded substrate being measured, so as to be able to photograph the ends of both the first and second substrates, resulting in an overall increase in the size of the device. Moreover, the distal position measurement unit needs to calculate the radius difference between the two substrates through image processing at each measurement point in the circumferential direction, thus increasing the amount of information processing required to calculate the positional offset.

[0005] Existing technical documents

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Publication No. 5373707 Summary of the Invention

[0008] The present invention was made in view of the above circumstances, and its object is to provide a substrate position offset measuring device and a substrate position offset measuring method that can suppress the overall size of the device and the increase in information processing volume, as well as a semiconductor manufacturing apparatus using the substrate position offset measuring device.

[0009] The present invention relates to a device and method for measuring the position offset of a laminated substrate. This device and method measure the position offset of a laminated substrate formed by stacking two sets of first and second substrates (both circular plates with different diameters) in the thickness direction. Measurement light is projected onto the laminated substrate from the thickness direction, and the transmission intensity distribution of the measurement light in the diameter direction is measured. Based on the measurement result, the position offset is determined. The measurement light is light with a wavelength capable of penetrating the substrate with the larger diameter of the first and second substrates. This device for measuring the position offset of a laminated substrate is used in a semiconductor manufacturing apparatus according to the present invention.

[0010] The above-mentioned and other objects, features and advantages of the present invention will become clear from the following detailed description and drawings. Attached Figure Description

[0011] Figure 1 This is a block diagram illustrating the structure of the substrate offset measuring device in the embodiment.

[0012] Figure 2This is a schematic perspective view illustrating the measuring unit and turntable (an example of a moving device) in the device for measuring the position offset of the bonding substrate.

[0013] Figure 3 This is a diagram illustrating the calculation method for the contour shape data representing the contour shapes of the first substrate and the second substrate.

[0014] Figure 4 This is a diagram illustrating the measurement results obtained around the circumference as an example.

[0015] Figure 5 This indicates that polar coordinates were used to illustrate... Figure 4 The polar coordinates of the measurement results are shown in the graph.

[0016] Figure 6 This is a diagram used to illustrate the calculation method for position offset.

[0017] Figure 7 This is a flowchart illustrating the operation of the device for measuring the position offset of the bonding substrate. Detailed Implementation

[0018] Hereinafter, one or more embodiments of the present invention will be described with reference to the accompanying drawings. However, the scope of the invention is not limited to the disclosed embodiments. Furthermore, structures marked with the same symbols in the various figures represent the same structures, and their descriptions are appropriately omitted. In this specification, reference numerals with suffixes are used when referring to general terms, and reference numerals with suffixes are used when indicating individual structures.

[0019] The substrate offset measuring device in this embodiment measures the position offset of a bonding substrate Ob, which is formed by stacking two sets of first substrates Ob1 and second substrates Ob2, which are circular plates of different sizes, in the thickness direction. Furthermore, as described above, one or both of the two sets of substrates may be multilayer substrates; therefore, they are referred to as "two sets" rather than "two pieces." The circular plates include not only complete circles but also circles that, for example, have notches such as orientation flats or positioning grooves as needed for the application of the substrate; in short, as long as the overall shape is circular, it is acceptable. The substrate offset measuring device includes a measuring unit and a position offset calculation unit. The measuring unit projects measuring light onto the bonding substrate from the thickness direction and measures the transmission intensity distribution of the measuring light in the diameter direction. The position offset calculation unit calculates the position offset based on the measurement results obtained by the measuring unit. Moreover, the measuring light is light with a wavelength capable of penetrating the larger diameter substrate of the first and second substrates. The following describes in more detail the position offset measuring device for the bonding substrate and the method for measuring the position offset of the bonding substrate mounted on the position offset measuring device for the bonding substrate.

[0020] Figure 1 This is a block diagram illustrating the structure of the substrate offset measuring device in the embodiment. Figure 2 This is a schematic perspective view illustrating the measuring unit and turntable (an example of a moving device) in the device for measuring the position offset of the bonding substrate. Figure 3 This is a diagram illustrating the calculation method for the contour shape data representing the contour shapes of the first substrate and the second substrate. Figure 3 A is a side view used to illustrate the relationship between the lengths of the various parts. Figure 3 B is a graph showing the transmission intensity distribution relative to the diameter direction, as an example of the measurement results. Figure 3 The horizontal axis of B represents the positions along the diameter direction. Figure 3 The vertical axis of B represents the transmission intensity (measured value). Figure 4 This is a diagram illustrating the measurement results obtained around the circumference as an example. Figure 4 The horizontal axis represents the positions along the circumference. Figure 4 The vertical axis represents the measured value (transmission intensity). Figure 5 This indicates that polar coordinates were used to illustrate... Figure 4 The polar coordinates of the measurement results are shown in the graph. Figure 5 The X and Y axes are distances measured from the center of rotation of the turntable. Figure 4 The measurement results shown are assigned to the X-axis with the measurement starting point at 0 [°] and plotted in a counterclockwise rotation. Figure 6This is a diagram used to illustrate the calculation method for position offset.

[0021] The substrate position offset measuring device D in the embodiment is, for example, such as Figure 1 and Figure 2 As shown, it includes a measurement unit 1, a control processing unit 2, a turntable 3, an input unit 4, an output unit 5, an interface unit (IF unit) 6, and a storage unit 7.

[0022] Input unit 4 is a device connected to control processing unit 2 that inputs various commands, such as commands indicating the start of measurement, and various data necessary for activating the position offset measuring device D of the bonding substrate, such as threshold Th for determining the end, to the position offset measuring device D of the bonding substrate. Input unit 4 can be, for example, a keyboard, a mouse, or multiple input switches assigned specific functions. Output unit 5 is a device connected to control processing unit 2 that, under the control of control processing unit 2, outputs commands or data input from input unit 4, as well as calculation results. Output unit 5 can be, for example, a display device such as a CRT (Cathode Ray Tube) monitor, an LCD (Liquid Crystal Display) monitor, or an organic EL (Electroluminescence) monitor, or a printing device such as a printer.

[0023] Furthermore, the input unit 4 and the output unit 5 can also be constructed using a touchscreen. In the case of this touchscreen, the input unit 4 is a position input device that detects the operation position and inputs data, such as a resistive or capacitive input device, and the output unit 5 is a display device. This touchscreen has a position input device mounted on the display surface of the display device, and displays one or more candidate input contents on the display device. If the user touches the display position where the desired input content is displayed, the position input device detects that position, and the displayed content at the detected position is input to the substrate offset measuring device D as the user's operation input. Using this type of touchscreen, the user can easily and intuitively understand the input operation; therefore, a substrate offset measuring device D that is easy for the user to operate can be provided.

[0024] The IF section 6 is a circuit connected to the control processing unit 2 that, under the control of the control processing unit 2, inputs and outputs data with external devices, for example. This IF section 6 can be, for example, an interface circuit using serial communication (RS-232C), an interface circuit using the Bluetooth (registered trademark) standard, or an interface circuit using the USB (Universal Serial Bus) standard. Alternatively, the IF section 6 can also be, for example, a data communication card or a communication interface circuit conforming to the IEEE 802.11 standard, for transmitting and receiving communication signals with external devices.

[0025] The measuring unit 1 is a device connected to the control processing unit 2. Under the control of the control processing unit 2, it projects a predetermined measuring light onto the bonding substrate Ob from the thickness direction t, and measures the transmission intensity distribution of the measuring light along the diameter direction r of the bonding substrate Ob. The measuring unit 1 projects measuring light linearly onto the bonding substrate Ob from the thickness direction t along the diameter direction r, and measures the transmission intensity distribution of the measuring light. The measuring unit 1 measures the transmission intensity distribution of the measuring light at multiple different measuring locations along the circumferential direction θ of the bonding substrate Ob.

[0026] For example, such a measuring section 1 Figure 2 As shown, the assembly includes a light-projecting section 11 that projects measurement light linearly onto the bonding substrate Ob from the thickness direction t along the diameter direction r; a light-receiving section 12 that receives the measurement light projected from the light-projecting section 11 via the bonding substrate Ob; and a holding section 13 that holds the light-projecting section 11 and the light-receiving section 12 opposite to each other at predetermined intervals. The light-projecting section 11, the holding section 13, and the light-receiving section 12 are approximately "コ"-shaped in side view (the shape obtained by removing the "-" in the center of the letter E). Therefore, the light-receiving section 12 is arranged opposite to the light-projecting section 11. The light-projecting unit 11 is configured, for example, with a collimating lens to convert light radiated from a light source into parallel light. This parallel light is then converted into slit light along the diameter direction r by passing through the slit hole of a plate-like member with a rectangular slit hole that has an elongated direction. This slit light is then projected onto the bonding substrate Ob as the measurement light. The light-receiving unit 12 is configured with a line sensor or area image sensor, etc., that is wider than the slit hole. In this type of measurement unit 1, which includes the light-projecting unit 11 and the light-receiving unit 12, the bonding substrate Ob is arranged opposite to the measurement unit 1 such that the diameter direction r is along the aforementioned direction. Alternatively, the light-projecting unit 11 is, for example, a device that uses laser light radiated from a light source as the measurement light, scans the laser along the diameter direction r, and projects the laser onto the bonding substrate Ob. The light-receiving unit 12 is configured with a line sensor or area image sensor, etc., that is wider than the laser light. For this measuring unit 1, which includes a light-emitting part 11 and a light-receiving part 12, a substrate Ob is attached such that the diameter direction r is along the scanning direction and is positioned opposite to the measuring unit 1. The holding part 13 is, for example, a columnar member extending in one direction, and the light-emitting part 11 and the light-receiving part 12 are held by means of the two ends of the columnar member extending in a direction orthogonal to the one direction.

[0027] The turntable 3 is a device connected to the control processing unit 2, which carries the bonding substrate Ob and rotates the bonding substrate Ob along the circumferential direction θ under the control of the control processing unit 2. The turntable 3 is positioned opposite the measuring unit 1 such that the mounted bonding substrate Ob is located between the light-emitting part 11 and the light-receiving part 12 in the measuring unit 1. The turntable 3 rotates the bonding substrate Ob along the circumferential direction θ, thereby causing the bonding substrate Ob to move circumferentially relative to the light-emitting part 11 and the light-receiving part 12 in the measuring unit 1. The turntable 3 is equivalent to an example of a moving mechanism that positions the bonding substrate between the light-emitting part and the light-receiving part, and moves the light-emitting part, the light-receiving part, and the bonding substrate relative to each other along the circumferential direction. Furthermore, in this embodiment, the measuring unit 1 is stationary, and the bonding substrate Ob is moved using the turntable 3; however, the bonding substrate Ob can be stationary while the measuring unit 1 moves relative to the bonding substrate Ob, or both can be moved.

[0028] Furthermore, in this embodiment, the measuring light is light with a wavelength capable of penetrating the larger-diameter substrate of the first substrate Ob1 and the second substrate Ob2 in the bonding substrate Ob. Since it is necessary to be able to measure the transmission intensity of the measuring light passing through the bonding substrate Ob using the measuring unit 1, the transmittance of the bonding substrate Ob for the penetrable wavelength is a value that achieves a significant transmission intensity for the measuring unit 1. That is, the transmittance of the bonding substrate Ob for the penetrable wavelength does not need to be 100% but is a non-zero value. Additionally, while it is possible for the measuring light to penetrate both the first substrate Ob1 and the second substrate Ob2 in the bonding substrate Ob, it is not necessary for it to penetrate both; as mentioned above, it is sufficient to penetrate at least the larger-diameter one of them. Here, the relatively smaller substrate is formed of a material that blocks the measuring light (in other words, the relatively larger substrate is formed of a material that can be penetrated by the measuring light). That is, when the bonding substrate Ob is composed of a second substrate Ob2 with a relatively large diameter and a first substrate Ob1 with a relatively small diameter stacked on the second substrate Ob2 along the thickness direction t, the first substrate Ob1 is formed of a material that blocks the measurement light.

[0029] This type of measurement light uses light of an appropriate wavelength corresponding to the material of the bonding substrate Ob, which is the object of measurement. For example, if the larger diameter substrate in the first substrate Ob1 and the second substrate Ob2 of the bonding substrate Ob is a SiC substrate, the measurement light is green visible light with a wavelength of 505 nm to 555 nm. A green light-emitting diode (green LED) that emits green light is used in the light-emitting section 11, and a silicon photodiode is used in the light-receiving section 12. Alternatively, if the larger diameter substrate in the first substrate Ob1 and the second substrate Ob2 of the bonding substrate Ob is a Si substrate, the measurement light is infrared light with a wavelength of 3 μm to 16 μm. A quantum cascade laser (QCL) or an interband cascade laser (ICL) that emits infrared laser light is used in the light-emitting section 11, and an MCT (HgCdTe) infrared detector is used in the light-receiving section 12. Alternatively, for example, if the larger of the first substrate Ob1 and the second substrate Ob2 in the bonding substrate Ob is a glass substrate, the measuring light is ultraviolet to infrared light with a wavelength of 200 [nm] to 3000 [nm], and various semiconductor laser elements, such as those emitting lasers with a center wavelength of 375 [nm] to 2000 [nm], are used in the light-emitting section 11, and silicon photodiodes are used in the light-receiving section 12.

[0030] The storage unit 7 is a circuit connected to the control processing unit 2, which stores various prescribed programs and various prescribed data under the control of the control processing unit 2. Among the various prescribed programs, there are, for example, control processing programs that control each part 1, 3 to 7 of the substrate offset measuring device D according to their functions, or position offset calculation programs that calculate the position offset of the substrate based on the measurement results measured by the measuring unit 1. Among the various prescribed data, there are, for example, measurement results from the measuring unit 1 or various calculation results during the calculation, data necessary for executing the various programs. This storage unit 7 may include, for example, a non-volatile storage element, i.e., ROM (Read Only Memory), or a rewritable non-volatile storage element, i.e., EEPROM (Electrically Erasable Programmable Read Only Memory). Furthermore, the storage unit 7 includes RAM (Random Access Memory), which serves as the working memory of the control processing unit 2 and stores data generated during the execution of the specified program. The storage unit 7 may also be configured to include a hard disk device with a large storage capacity.

[0031] The control processing unit 2 is a circuit that controls each part 1, 3 to 7 of the substrate position offset measuring device D according to their functions, and calculates the position offset of the substrate. The control processing unit 2 is configured, for example, with a CPU (Central Processing Unit) and its peripheral circuitry. In the control processing unit 2, by executing the control processing program, a control unit 21 and a position offset calculation unit 22 are functionally configured.

[0032] The control unit 21 controls each part 1, 3 to 7 of the substrate position offset measuring device D according to their functions, and controls the entire substrate position offset measuring device D.

[0033] The position offset calculation unit 22 calculates the position offset of the bonding substrate based on the measurement results measured by the measurement unit 1. More specifically, the position offset calculation unit 22 calculates the respective contour shapes of the first substrate Ob1 and the second substrate Ob2 based on multiple measurement results of multiple different measurement locations along the circumferential direction θ of the bonding substrate Ob, and calculates the offset between the respective contour shapes (e.g., the distance between the respective center positions of the respective contour shapes) as the position offset. More specifically, the position offset calculation unit 22 displays the multiple measurement results of the multiple measurement locations using polar coordinates, calculates the respective contour shapes of the first substrate Ob1 and the second substrate Ob2 by finding the circular shape that best fits the multiple measurement results displayed in polar coordinates, and calculates the distance between the respective center positions of the respective contour shapes as the position offset.

[0034] For example, in one of the plurality of measurement locations, such as Figure 3 As shown in Figure A, after measuring the bonding substrate Ob formed by stacking the first substrate Ob1 and the second substrate Ob2 in the thickness direction t using the measuring unit 1, the following is obtained: Figure 3 B shows curve α, representing the transmission intensity distribution of the measurement light. Here, the first substrate Ob1 and the second substrate Ob2 are formed of a material that allows the measurement light to pass through with a specified transmittance. Figure 3 The horizontal axis of B is defined by its origin at the starting position of the projection of the measurement light onto the substrate Ob1, extending diametrically towards the outer periphery. The curve α representing the transmission intensity distribution of the measurement light has the following characteristics: at the origin O, as... Figure 3As shown in Figure A, because the measuring light penetrates both the first substrate Ob1 and the second substrate Ob2, it reaches a first transmission intensity. From the origin O to approximately the outer periphery S1 of the first substrate Ob1, the first transmission intensity remains approximately constant at all positions in the diametrical direction. Near the outer periphery S1 of the first substrate Ob1, the transmission intensity decreases sharply to approximately 0 and then increases sharply to reach a second transmission intensity. From approximately the outer periphery S1 of the first substrate Ob1 to approximately the outer periphery S2 of the second substrate Ob2, the second transmission intensity remains approximately constant at all positions in the diametrical direction. Near the outer periphery S2 of the second substrate Ob2, the transmission intensity decreases sharply to approximately 0 and then increases sharply to approximately reach the measuring light intensity. Because it only penetrates the second substrate Ob2, the second transmission intensity becomes greater than the first transmission intensity when it penetrates both the first substrate Ob1 and the second substrate Ob2. It is speculated that because the outer peripheral edges of the first substrate Ob1 or the second substrate Ob2 are curved, the measurement light will scatter, making it difficult for the transmitted light to reach the light-receiving part 12. Therefore, a sharp change in curve α occurs near the outer peripheral edge S1 of the first substrate Ob1 or the outer peripheral edge S2 of the second substrate Ob2. Since the curve α of the transmission intensity distribution of the measurement light has this characteristic, for example, the position offset calculation unit 22 can determine two points where the transmission intensity of the measurement light reaches a predetermined threshold Th for determining the end, and determine the center position of the two determined points or the position of the point outside the diameter direction of the two points. Thus, the approximate outer peripheral edge S1 of the first substrate Ob1 or the approximate outer peripheral edge S2 of the second substrate Ob2 can be determined.

[0035] Furthermore, when the measuring light is light with a wavelength capable of penetrating the larger-diameter substrate among the first substrate Ob1 and the second substrate Ob2 in the bonded substrate Ob, as described above, the first substrate Ob is formed of a material that blocks the measuring light. Figure 3 In B, from the origin 0 to the approximate outer periphery S1 of the first substrate Ob1, the first transmission intensity "0" is approximately constant at each position in the diameter direction.

[0036] If the length from the rotation center of the turntable 3 to the projection start position (coordinate origin 0) is defined as L, then the first length R1 from the rotation center of the turntable 3 to the outer peripheral edge of the first substrate Ob1 is given by the following formula 1, and the second length R2 from the rotation center of the turntable 3 to the outer peripheral edge of the second substrate Ob2 is given by the following formula 2.

[0037] Equation 1: R1 = L + - S1

[0038] Equation 2: R2 = L + S2

[0039] Therefore, by measuring at multiple different measurement locations along the circumferential direction θ on the bonding substrate Ob, multiple R1(θ) and multiple R2(θ) are obtained, where the multiple R1(θ) represent the outline shape of the first substrate Ob1 and the multiple R2(θ) represent the outline shape of the second substrate Ob2. An example is shown in... Figure 4 Furthermore, at the measurement location corresponding to the so-called orientation plane, the length from the outer peripheral end to the rotation center of the turntable 3 becomes shorter. Therefore, at the measurement location near the orientation plane, R1(θ) becomes a smaller (shorter) value than other measurement locations, and the curve of R1(θ) becomes valley-shaped. Similarly, R2(θ) becomes a smaller (shorter) value than other measurement locations, and the curve of R2(θ) also becomes valley-shaped. The first substrate Ob1 has two first and second orientation planes (1st orientation plane and 2nd orientation plane), therefore, its curve R2(θ) forms valleys at two locations. Typically, the extension direction of the orientation plane is orthogonal to the diameter direction of the substrate; therefore, the valley bottom position (valley crest position) corresponds to the position where the extension direction of the orientation plane is orthogonal to the diameter direction of the substrate.

[0040] The interval of the diameter direction θ of the plurality of measurement points is set in advance appropriately, for example, it is set to 0.02 [°] according to the size of the first substrate Ob1 and the second substrate Ob2.

[0041] The turntable 3 rotates using a motor driven by pulse control at equal angular intervals. The number of pulses required for one rotation of the turntable is constant, and the rotation angle of each pulse is constant. Therefore, the control processing unit 2 can identify and measure the rotation angle of the turntable 3 by performing measurements synchronously with the constant pulse intervals.

[0042] The position offset calculation unit 22 displays multiple measurement results of the multiple measurement locations using polar coordinates. Polar coordinates are a coordinate system that uses the distance from the origin and the angle from a direction (reference direction) to represent the position of a point. More specifically, the measurement result R(θ) representing the contour shape is plotted as a point (θ, R(θ)). More specifically, taking one of the multiple measurement locations R(θ) as the starting point θ = 0 [°], the multiple measurement results are arranged in the order of diameter direction θ-θ0, R(0) is plotted as a point (0, R(0)), and rotating counterclockwise from the X-axis, R(θ-θ0) is plotted as a point in the diameter direction θ-θ0 with a distance of R(θ-θ0). Thus, Figure 4 The measurement results R1(θ) and R2(θ) shown are as follows: Figure 5 As shown, this is represented in polar coordinates. Figure 5 In the polar coordinates shown, the X-axis and Y-axis are the lengths measured from the rotation center of turntable 3.

[0043] Next, the position offset calculation unit 22 calculates the contour shape of the first substrate Ob1 by finding the circle shape that best fits the multiple measurement results R1(θ) shown in polar coordinates as described above, and calculates the contour shape of the second substrate Ob2 by finding the circle shape that best fits the multiple measurement results R2(θ) shown in polar coordinates. For example, the fitting is performed by the least squares method. More specifically, the points (xi, yi) on the circumference of the circle with center (a, b) and radius c are represented by the following equation 3. a, b, and c are calculated by using the least squares method (the minimum value problem of the square error of the equation 3) of the measurement results (θ-θ0, R(θ-θ0)) displayed in polar coordinates. Thus, the contour shapes of the first substrate Ob1 and the second substrate Ob2 are calculated.

[0044] Equation 3: (xi-a) 2 +(yi-b) 2 =c 2

[0045] Furthermore, when determining the best-fitting circular shape, the measurement results near the orientation plane (i.e., the measurement results that form the valley) are not on the circumference, so it is preferable to exclude these measurement results.

[0046] Next, the position offset calculation unit 22 calculates the distance between the center positions in the contour shapes of the first substrate Ob1 and the second substrate Ob2, which have been calculated as described above, as the position offset. For example, when the center position of the first substrate Ob1 is (a1, b1) and the center position of the second substrate Ob2 is (a2, b2), the distance between the center positions (the position offset) PD is calculated by the following formula 4.

[0047] Equation 4: PD = ((a1 - a2) 2 +(b1-b2) 2 ) 1 / 2

[0048] An example of the contour shapes of the first substrate Ob1 and the second substrate Ob2, as determined above, is shown in [the figure]. Figure 6 .exist Figure 6 In this process, the coordinate transformation is performed on the contour shapes of the first substrate Ob1 and the second substrate Ob2, as determined above, by making the center position of the contour shape of the second substrate Ob2 the origin of the coordinate system (x←x-a2, y←y-b2; a=a1-a2, b=b1-b2). Therefore, the distance between the center positions (the position offset) PD becomes (a 2 +b 2 ) 1 / 2 (PD=(a 2 +b 2 )1 / 2 ).

[0049] Next, the control unit 21 outputs the position offset PD of the bonding substrate calculated by the position offset calculation unit 22 from the output unit 5.

[0050] The control processing unit 2, input unit 4, output unit 5, IF unit 6, and storage unit 7 in this type of substrate offset measuring device D can be, for example, composed of a desktop or laptop computer.

[0051] Next, the operation of this embodiment will be explained. Figure 7 This is a flowchart illustrating the operation of the device for measuring the position offset of the bonding substrate.

[0052] The position offset measuring device D of this type of substrate performs the necessary initialization of each part after its power is turned on, and then begins its operation. In the control processing unit 2, the control unit 21 and the position offset calculation unit 22 are functionally configured by executing its control processing program.

[0053] The user (operator) places the bonding substrate Ob, which is to be measured, on the turntable 3. After receiving the input to start the measurement, the bonding substrate position offset measuring device D rotates the turntable 3 through the control unit 21 of the control processing unit 2, and uses the measuring unit 1 to measure at the specified measurement location. Thus, the transmission intensity (S1) is measured at multiple measurement locations along the circumferential direction θ of the bonding substrate Ob.

[0054] Next, the substrate offset measuring device D, through the position offset calculation unit 22 of the control processing unit 2, calculates the respective contour shapes of the first substrate Ob1 and the second substrate Ob2 based on multiple measurement results of multiple measurement locations measured in processing S1 (S2). More specifically, the position offset calculation unit 22 uses Equation 1 above to generate R1(θ) representing the contour shape of the first substrate Ob1, and uses Equation 2 above to generate R2(θ) representing the contour shape of the second substrate Ob2.

[0055] Next, the position offset measuring device D, which is attached to the substrate, uses the position offset calculation unit 22 to display multiple measurement results of the multiple measurement locations using polar coordinates (S3). More specifically, the position offset calculation unit 22 plots the measurement result R(θ) representing the contour shape as a point (θ, R(θ)).

[0056] Next, the position offset measuring device D of the substrate calculates the circle shape that best fits the multiple measurement results R1(θ) and R2(θ) shown in polar coordinates as described above by the position offset calculation unit 22, and thereby calculates the contour shape of the first substrate Ob1 and the second substrate Ob2 (S4).

[0057] Next, the position offset measuring device D of the bonding substrate calculates the distance between the center positions of each contour shape of the first substrate Ob1 and the second substrate Ob2, which has been calculated as described above, as the position offset PD (S5) by the position offset calculation unit 22.

[0058] Then, the substrate position offset measuring device D outputs the position offset PD calculated as described above (S6) from the output unit 5 via the control unit 21 of the control processing unit 2, and the process ends. Alternatively, the substrate position offset measuring device D may output the position offset calculated in process S5 to an external device via the IF unit 6, as needed.

[0059] As explained above, the substrate position offset measuring device D and the substrate position offset measuring method mounted on the substrate position offset measuring device D in the embodiment do not require the distal position measuring unit (edge ​​shape measuring unit 4, as an example) in the substrate position offset detection device disclosed in Patent Document 1. The substrate position offset measuring device uses measuring light with a wavelength capable of penetrating the substrate with the larger diameter of the first and second substrates to measure the transmission intensity distribution of the measuring light in the diameter direction. Therefore, instead of determining the end obtained by combining the first and second substrates as in the outermost edge measuring unit (contour measuring unit 3, as an example) in the substrate position offset detection device disclosed in Patent Document 1, it is possible to determine the end of the first substrate (outer peripheral end) and the end of the second substrate (outer peripheral end). Therefore, the substrate position offset measuring device D and the substrate position offset measuring method described above can suppress the overall enlargement of the device and the increase in information processing volume.

[0060] The above-described substrate position offset measuring device D and substrate position offset measuring method cause the light-emitting part 11 and the light-receiving part 12 and the substrate Ob to move relative to each other along the circumferential direction. Therefore, it is possible to measure the transmission intensity distribution of the measurement light in the diameter direction at multiple measurement locations that are different from each other along the circumferential direction.

[0061] The aforementioned substrate position offset measuring device D and substrate position offset measuring method utilize polar coordinates to display multiple measurement results R(θ) for multiple different measurement locations along the circumferential direction θ, thus simplifying the calculation for determining the contour shape. The aforementioned substrate position offset measuring device D and substrate position offset measuring method determine the best-fitting circular shape as the contour shape, thus enabling more accurate determination of the position offset.

[0062] According to this embodiment, a device D for measuring the position offset of a bonding substrate and a method for measuring the position offset of a bonding substrate can be provided, wherein the distance between the center positions of each contour shape of the first substrate Ob1 and the second substrate Ob2 is used as the position offset.

[0063] Furthermore, the substrate offset measuring device D in the above embodiments can be used in suitable semiconductor manufacturing apparatuses. For example, as disclosed in Patent Document 1, the semiconductor manufacturing apparatus is an apparatus for forming semiconductor elements on a substrate Ob, which responds to the position offset measured by the substrate offset measuring device D and corrects the position of the element formed on the substrate Ob, thereby enabling the element to be formed in the correct position taking into account the position offset of the bonding. Alternatively, for example, as disclosed in Japanese Patent Publication No. 2005-005318, the semiconductor apparatus is a bonding apparatus for manufacturing a substrate, which responds to the position offset measured by the substrate offset measuring device D and corrects the bonding position, thereby enabling the manufacture of a better bonding substrate. For example, the bonding apparatus includes a pressing plate that presses two overlapping wafers in a horizontal direction (with the thickness direction as the normal direction within a horizontal plane) for alignment. Before alignment, the bonding apparatus measures the positional offset using a substrate offset measuring device D. Based on the measured offset, the pressing plate is controlled to perform the alignment, thereby manufacturing the bonding substrate. Alternatively, for example, the bonding substrate manufactured by the bonding apparatus can be used as a sample. The substrate offset measuring device D measures the positional offset, and the pressing plate is pre-adjusted based on the measured offset before manufacturing the bonding substrate. Alternatively, for example, as disclosed in Japanese Patent Publication No. 6916877, the semiconductor device is a chemical mechanical polishing (CMP) device for polishing wafers. If the position offset measured by the substrate offset measuring device D is large (if the position offset exceeds a preset threshold), the wafer is excluded from the manufacturing line so that it will not be polished by the CMP device, thereby avoiding problems during manufacturing.

[0064] Although this specification discloses the various techniques described above, the main techniques are summarized as follows.

[0065] One method involves a substrate position offset measuring device that measures the position offset of a laminated substrate formed by stacking two sets of first and second substrates, which are circular plates with different diameters, in the thickness direction. The device includes: a measuring unit that projects measuring light onto the laminated substrate from the thickness direction and measures the transmission intensity distribution of the measuring light in the diameter direction; and a position offset calculation unit that calculates the position offset based on the measurement results obtained by the measuring unit, wherein the measuring light is light of a wavelength capable of penetrating the substrate with the larger diameter of the first and second substrates. Preferably, in the above-described substrate position offset measuring device, the position offset is the distance between the center positions of the first and second substrates. Preferably, in the above-described substrate position offset measuring device, the measuring unit measures the transmission intensity distribution at multiple different measuring locations along the circumferential direction, and the position offset calculation unit calculates the contour shapes of each of the first and second substrates based on the multiple measurement results at the multiple measuring locations, and calculates the offset between the contour shapes as the position offset. Preferably, in the above-described substrate position offset measuring device, the transmittance of the substrate for the wavelength of light that can be transmitted is a value at which the measuring unit achieves a significant transmission intensity. Preferably, in the above-described substrate position offset measuring device, the transmittance of the substrate for the wavelength of light that can be transmitted is a non-zero value.

[0066] This type of substrate offset measurement device eliminates the need for the distal position measurement unit (edge ​​shape measurement unit 4, as an example) in the substrate offset detection device disclosed in Patent Document 1. The aforementioned substrate offset measurement device utilizes measurement light with a wavelength capable of penetrating the larger diameter substrate of the first and second substrates to measure the transmission intensity distribution of the measurement light in the diameter direction. Therefore, instead of determining the end of the first substrate (outer peripheral end) and the end of the second substrate (outer peripheral end) as in the outermost edge measurement unit (contour measurement unit 3, as an example) in the substrate offset detection device disclosed in Patent Document 1, it can determine the end of the first substrate (outer peripheral end) and the end of the second substrate (outer peripheral end). Therefore, the aforementioned substrate offset measurement device can suppress the overall enlargement of the device and the increase in information processing volume.

[0067] Furthermore, in this specification, one or both of the two sets of substrates may be multilayer substrates, therefore, they are referred to as "two sets" rather than "two pieces".

[0068] In another embodiment, in the above-mentioned substrate position offset measuring device, the measuring unit includes: a light-projecting unit that projects measuring light onto the substrate linearly from the thickness direction along the diameter direction, and a light-receiving unit opposite to the light-projecting unit. The position offset measuring device further includes a moving mechanism that positions the substrate between the light-projecting unit and the light-receiving unit, and moves the light-projecting unit, the light-receiving unit, and the substrate relative to each other along the circumferential direction.

[0069] This type of substrate offset measuring device moves the light-emitting part and the light-receiving part relative to the substrate in a circumferential direction. Therefore, it is possible to measure the transmission intensity distribution of the measurement light in the diameter direction at multiple measurement points that are different from each other in the circumferential direction.

[0070] In another embodiment, in these aforementioned substrate position offset measuring devices, the position offset calculation unit calculates the respective contour shapes of the first substrate and the second substrate based on the measurement results measured by the measuring unit, and calculates the distance between the center positions of the respective contour shapes as the position offset.

[0071] Therefore, a device for measuring the position offset of a bonding substrate can be provided, which determines the distance between the center positions of each contour shape of the first substrate and the second substrate as the position offset.

[0072] In another embodiment, in these aforementioned substrate position offset measuring devices, the measuring unit measures the transmission intensity distribution at multiple different measuring locations along the circumferential direction, the position offset calculation unit displays multiple measurement results at the multiple measuring locations using polar coordinates, calculates the contour shape of each of the first substrate and the second substrate by finding the circle shape that best fits the multiple measurement results displayed by the polar coordinates, and calculates the distance between the center positions of each contour shape as the position offset.

[0073] This substrate offset measuring device uses polar coordinates to display multiple measurement results at several different measurement locations along the circumferential direction, thus simplifying the calculation of the contour shape. The substrate offset measuring device determines the best-fitting circular shape as the contour shape, thereby enabling more accurate determination of the offset.

[0074] Another method involves measuring the positional offset of a bonding substrate by stacking two sets of first and second substrates of different diameters in the thickness direction. The method includes: a measurement step of projecting measurement light onto the bonding substrate from the thickness direction and measuring the transmission intensity distribution of the measurement light in the diameter direction; and a positional offset calculation step of calculating the positional offset based on the measurement result obtained in the measurement step, wherein the measurement light is light of a wavelength capable of penetrating the substrate with the larger diameter of the first and second substrates.

[0075] This method for measuring the position offset of the bonding substrate can produce the same effect as the aforementioned device for measuring the position offset of the bonding substrate, while suppressing the overall enlargement of the device and the increase in information processing volume.

[0076] Another aspect of the present invention relates to a semiconductor manufacturing apparatus that includes any of the above-described substrate position offset measuring devices.

[0077] Therefore, a semiconductor manufacturing apparatus is provided that uses the position offset measuring device of the bonding substrate.

[0078] This application is based on Japanese Patent Application No. 2023-40047, filed on March 14, 2023, the contents of which are included in this application.

[0079] To exemplify the invention, it has been adequately and sufficiently described above with reference to the accompanying drawings and embodiments. However, it should be understood that those skilled in the art can readily make changes and / or modifications to the above embodiments. Therefore, any changes or modifications made by those skilled in the art that do not depart from the scope of the claims are to be construed as being included within the scope of the relevant claims.

[0080] Industrial availability

[0081] According to the present invention, an apparatus and method for measuring the position offset of two sets of substrates that are stacked and bonded in the thickness direction are provided, as well as a semiconductor manufacturing apparatus using the apparatus for measuring the position offset of the bonded substrates.

Claims

1. A device for measuring the positional offset of a bonding substrate, comprising measuring the positional offset of a bonding substrate formed by stacking two sets of first and second substrates of different diameters in the thickness direction, characterized in that... include: The measuring unit projects measuring light onto the bonding substrate from the thickness direction and measures the transmission intensity distribution of the measuring light in the diameter direction; as well as The position offset calculation unit calculates the position offset based on the measurement result obtained by the measurement unit, wherein... The measuring light is light of a wavelength capable of penetrating the larger diameter substrate of the first and second substrates.

2. The device for measuring the position offset of the bonding substrate according to claim 1, characterized in that, The measuring unit includes: a light-projecting unit that projects measuring light linearly onto the bonding substrate from the thickness direction along the diameter direction, and a light-receiving unit opposite to the light-projecting unit. The position offset measuring device further includes a moving mechanism, which positions the bonding substrate between the light-emitting part and the light-receiving part, and moves the light-emitting part, the light-receiving part, and the bonding substrate relative to each other along the circumferential direction.

3. The device for measuring the position offset of the bonding substrate according to claim 1, characterized in that, The position offset calculation unit calculates the contour shape of each of the first substrate and the second substrate based on the measurement results measured by the measurement unit, and calculates the distance between the center positions of each contour shape as the position offset.

4. The device for measuring the position offset of the bonding substrate according to claim 1, characterized in that, The measuring unit measures the transmission intensity distribution at multiple different measuring points along the circumferential direction. The position offset calculation unit uses polar coordinates to display multiple measurement results of the multiple measurement locations. By finding the circle shape that best fits the multiple measurement results displayed by the polar coordinates, it calculates the contour shapes of the first substrate and the second substrate respectively, and calculates the distance between the center positions of the contour shapes as the position offset.

5. A method for measuring the positional offset of a bonding substrate, comprising measuring the positional offset of a bonding substrate formed by stacking two sets of first and second substrates of different diameters in the thickness direction, characterized in that... include: The measurement step involves projecting measurement light onto the bonding substrate from the thickness direction and measuring the transmission intensity distribution of the measurement light in the diameter direction. The position offset calculation step calculates the position offset based on the measurement results obtained in the measurement step, wherein... The measuring light is light of a wavelength capable of penetrating the larger diameter substrate of the first and second substrates.

6. A semiconductor manufacturing apparatus, characterized in that, Includes a device for measuring the position offset of the bonding substrate according to any one of claims 1 to 4.

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