Pattern inspection device and pattern inspection method

Abstract

To provide a pattern inspection device and a pattern inspection method capable of detecting defects in internal circuit patterns of a three-dimensionally-converted circuit.SOLUTION: A pattern inspection device according to one aspect of the present invention comprises a light source unit, a detection unit, and an inspection unit. The light source unit emits light having a wavelength band of 1.2 μm to 5.0 μm toward an inspection target including a plurality of stacked Si substrates. The detection unit detects transmitted Bragg-diffraction light generated by transmitted light through the inspection target, or reflected Bragg-diffraction light generated by internal reflection light in the inspection target from the light beams emitted from the light source unit. The inspection unit performs a circuit-pattern inspection on the basis of a plurality of detection results of the detection unit obtained during a process of performing wavelength sweeping by changing the wavelength of the light emitted from the light source unit within the range of the wavelength band.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a pattern inspection device and a pattern inspection method. [Background technology]

[0002] In recent years, miniaturization for the purpose of increasing the integration density of integrated circuits has reached its physical limit, leading to the stacking of circuits, i.e., 3D. Conventional planar circuits have made it possible to perform non-destructive inspection of all products actually used for defect detection. For example, Patent Document 1 discloses a method of detecting defects in a circuit pattern based on the diffraction image obtained by irradiating the circuit pattern with light on the order of nanometers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2013-68551 Summary of the Invention [Problem to be solved by the invention]

[0004] However, there is a problem in that defects in the internal circuit patterns of 3D circuits cannot be detected. Therefore, it is desirable to provide a pattern inspection device and a pattern inspection method that can detect defects in the internal circuit patterns of 3D circuits. [Means for solving the problem]

[0005] A pattern inspection device according to one aspect of the present invention includes a light source unit, a detection unit, and an inspection unit. The light source unit emits light in a wavelength band of 1.2 μm or more and 5.0 μm or less toward an object under inspection, which includes multiple stacked Si substrates. The detection unit detects, from the light emitted from the light source unit, transmitted Bragg diffracted light generated by the light transmitted through the object under inspection, or reflected Bragg diffracted light generated by light internally reflected within the object under inspection. The inspection unit performs circuit pattern inspection based on multiple detection results obtained by the detection unit in the process of sweeping the wavelength of the light emitted from the light source unit by changing it within the wavelength band.

[0006] A pattern inspection method according to one aspect of the present invention includes the following three steps. (1) A step of emitting light in a wavelength band of 1.2 μm or more and 5.0 μm or less toward an object to be inspected, including a plurality of stacked Si substrates, and sweeping the wavelength of the light emitted toward the object to be inspected by changing the wavelength within the range of the wavelength band. (2) Detecting the transmitted Bragg diffracted light generated by the light transmitted through the object under test, or the reflected Bragg diffracted light generated by the light internally reflected by the object under test, among the light emitted toward the object under test. (3) A process for inspecting circuit patterns based on multiple detection results obtained during the wavelength sweep process.

[0007] In a pattern inspection device and a pattern inspection method according to one aspect of the present invention, light in a wavelength band of 1.2 μm or more and 5.0 μm or less that is emitted toward an object under inspection is detected, and transmitted light or reflected light from the object under inspection is detected. This makes it possible to perform pattern inspection based on the detection results obtained by the detection. [Effects of the Invention]

[0008] According to a pattern inspection device and a pattern inspection method according to one aspect of the present invention, light in a wavelength band of 1.2 μm or more and 5.0 μm or less is emitted toward an object under inspection, and the transmitted light or the reflected light from the object under inspection is detected, so that pattern inspection can be performed based on the detection results obtained by the detection, thereby making it possible to detect defects in internal circuit patterns in 3D circuits. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating an example of an object to be inspected in the pattern inspection device of the present invention. [Figure 2] 1 is a diagram illustrating an example of a schematic configuration of a pattern inspection device according to a first embodiment of the present invention. [Figure 3] FIG. 1 is a diagram illustrating an example of transmission characteristics of a Si substrate. [Figure 4] FIG. 3 is a diagram illustrating an example of an inspection procedure in the pattern inspection device of FIG. [Figure 5] FIG. 10 is a diagram illustrating an example of a schematic configuration of a pattern inspection device according to a second embodiment of the present invention. [Figure 6] FIG. 6 is a diagram illustrating an example of an inspection procedure in the pattern inspection device of FIG. 5. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a detailed description of an embodiment of the present invention will be given with reference to the drawings. The following description is a specific example of the present invention, and the present invention is not limited to the following embodiment. Furthermore, the present invention is not limited to the arrangement, dimensions, and dimensional ratios of the components shown in the drawings.

[0011] <1. Test subject> FIG. 1 shows an example of the cross-sectional structure of an object under inspection 10, which is an example of an object to be inspected by the pattern inspection device of the present invention. The object under inspection 10 is a 3D (three dimensions) chip in which multiple LSI (Large-Scale Integration) chips 12 are stacked on an intermediate substrate 11. The number of layers of the LSI chip 12 is not limited to the five layers shown in FIG. 1 and may be, for example, approximately 100 layers. Resin filling layers 17 are provided between the multiple stacked LSI chips 12 to fill the gaps between the chips. The resin filling layers 17 are made of a resin material such as polyimide.

[0012] Each LSI chip 12 is an integrated circuit formed on a Si substrate. In each LSI chip 12, the integrated circuit on the Si substrate includes, for example, a large number of CMOS (Complementary Metal Oxide Semiconductors) and a large number of wiring patterns.

[0013] Each LSI chip 12 has signal through vias 13 and power supply through vias 15 formed therein that penetrate the Si substrate. The stacked LSI chips 12 are electrically connected by the signal through vias 13 and signal bumps 14 provided between the chips. Various signals are input from the outside to the integrated circuit of each LSI chip 12 via the signal through vias 13 and signal bumps 14. Various signals are output from the integrated circuit of each LSI chip 12 to the outside via the signal through vias 13 and signal bumps 14. The stacked LSI chips 12 are electrically connected by power supply through vias 15 and power supply bridges 16 provided between the chips. The power supply bridges 16 are formed, for example, by electroless plating. Various power supply voltages are supplied from the outside to the integrated circuit of each LSI chip 12 via the power supply through vias 15 and power supply bridges 16.

[0014] Intermediate substrate 11 has a wiring layer for transmitting various signals and supplying various power supply voltages to the stacked LSI chips 12, and a resin layer for supporting the wiring layer. The wiring layer may include passive components such as resistors. One or more interface units 18 are connected to intermediate substrate 11. Interface units 18 are electrically connected to the wiring layer of intermediate substrate 11, and supply various signals and power supply voltages from the outside to intermediate substrate 11, and output various signals from intermediate substrate 11 to the outside.

[0015] With conventional pattern inspection devices, when the inspection target is a 3D chip as described above, it is difficult to detect defects in the internal circuit pattern that are not visible on the chip surface. Therefore, the inventors of the present application propose a pattern inspection device that can detect defects in the internal circuit pattern that are not visible on the chip surface.

[0016] 2. First Embodiment [composition] Next, a pattern inspection device 100 according to a first embodiment of the present invention will be described. Fig. 2 shows an example of a schematic configuration of the pattern inspection device 100. The pattern inspection device 100 is a device that non-destructively inspects defects in an object 10 under inspection. As shown in Fig. 2, the pattern inspection device 100 includes, for example, a support table 110 that supports the object 10 under inspection, and a light source unit 120 that emits (irradiates) light La toward the object 10 under inspection on the support table 110.

[0017] The support table 110, for example, adsorbs the test object 10 and fixes it to the upper surface of the support table 110. The support table 110 may further include, for example, a mechanism for displacing the upper surface of the support table 110 in two axial directions within a plane parallel to the upper surface of the support table 110. The support table 110 may also further include, for example, a mechanism for rotating the upper surface of the support table 110 in an azimuth direction within a plane parallel to the upper surface of the support table 110.

[0018] The light source unit 120 includes a laser capable of emitting light La and a control circuit for controlling the laser emission. The control circuit controls the laser emission based on the control unit 160 (described later). The laser is capable of emitting collimated light in a wavelength band of 1.2 μm to 5.0 μm (mid-infrared region) as the light La. The laser is, for example, a Tm:YAG laser capable of emitting light La with a wavelength of 2.0 μm (constant wavelength). Note that the laser is not limited to a Tm:YAG laser. The light source unit 120 may be, for example, a light-emitting element, such as a semiconductor laser, capable of emitting light La with a wavelength of 2.0 μm, instead of the laser. The mid-infrared region corresponds to a portion of the light transmission region of a Si substrate, as shown in FIG. 3, for example. Therefore, the light La is light that can pass through a Si substrate or an inspection object 10 including a Si substrate.

[0019] When light La is incident on the inspected object 10, a portion of the incident light La is reflected by the inspected object 10 and becomes reflected light Lb, which enters the light detection unit 130 described below, and a portion of the incident light La passes through the inspected object 10 and becomes transmitted light Lc, which enters the light detection unit 140 described below. Here, the inspected object 10 can be optically treated as a volume Bragg element. At this time, the reflected light Lb is a diffraction image (reflected Bragg diffracted light) caused by internally reflected light in the inspected object 10, and the diffraction intensity of the reflected light Lb is strong in a specific direction. The transmitted light Lc is a volume diffraction image (transmitted Bragg diffracted light) caused by light transmitted through the inspected object 10, and the intensity of the transmitted light Lc is also strong in a specific direction.

[0020] The pattern inspection apparatus 100 further includes, for example, light detection units 130 and 140 as shown in FIG.

[0021] The light detection unit 130 is disposed on the optical path of the reflected light Lb. The light detection unit 130 detects the reflected light Lb based on the control unit 160, which will be described later. The light detection unit 130 generates image data Ib based on the detection result (detection result D1), and outputs it to the inspection unit 150, which will be described later. Note that the light detection unit 130 may output the detection result D1 to the inspection unit 150.

[0022] The light detection unit 140 is disposed on the optical path of the transmitted light Lc. The light detection unit 140 detects the transmitted light Lc based on the control unit 160, which will be described later. The light detection unit 140 generates image data Ic based on the detection result (detection result D2), and outputs it to the inspection unit 150, which will be described later. Note that the light detection unit 140 may output the detection result D2 to the inspection unit 150.

[0023] The light detection units 130, 140 are configured to include, for example, an image sensor capable of detecting light in the mid-infrared region. In such an image sensor, for example, an InGaAs element sensitive to a wavelength band from the visible region to a wavelength of 1.7 μm is provided for each pixel. However, the element provided for each pixel is not limited to an InGaAs element.

[0024] 2, the pattern inspection device 100 further includes a moving unit 121 that changes the position of the light source unit 120, a moving unit 131 that changes the position of the light detection unit 130, and a moving unit 141 that changes the position of the light detection unit 140. The moving unit 121 sets the position of the light source unit 120 so that the light La emitted from the light source unit 120 is incident obliquely on the surface of the inspection object 10. The moving unit 121 changes the position of the light source unit 120 based on a control unit 160 described later, thereby changing the angle of incidence of the light La emitted from the light source unit 120 with respect to the inspection object 10. The moving unit 131 changes the position of the light detection unit 130 based on the control unit 160 described later, thereby maintaining the light detection unit 130 (the light receiving surface of the image sensor) on the optical path of the reflected light Lb.

[0025] The pattern inspection device 100 further includes, for example, an inspection unit 150, a control unit 160, and a display unit 170, as shown in FIG.

[0026] The inspection unit 150 performs a pattern inspection of the object under inspection 10 based on the detection result D1 obtained from the light detection unit 130 and the detection result D2 obtained from the light detection unit 140. Specifically, the inspection unit 150 performs a pattern inspection of the object under inspection 10 using image data Ib and image data Ic. The inspection unit 150 performs the pattern inspection based on a plurality of detection results D1, D2 (test data) obtained while the angle of incidence of light La on the object under inspection 10 is changed by the moving unit 121. Specifically, the inspection unit 150 performs the pattern inspection based on a plurality of image data Ib, Ic (test data) obtained while the angle of incidence of light La on the object under inspection 10 is changed by the moving unit 121. In other words, the test data includes a plurality of detection results D1, D2 or a plurality of image data Ib, Ic having different angles of incidence.

[0027] In addition, when the inspection unit 150 acquires detection results D1 and D2 from the light detection units 130 and 140, it may generate image data Ib based on the detection result D1 acquired from the light detection unit 130, and may also generate image data Ic based on the detection result D2 acquired from the light detection unit 140.

[0028] The inspection unit 150 has, as master data, a plurality of detection results D1, D2 or a plurality of image data Ib, Ic obtained from the inspection object 10 without defects. The master data includes a plurality of detection results D1, D2 or a plurality of image data Ib, Ic obtained at different angles of incidence. The inspection unit 150 compares the master data and test data having a common angle of incidence to determine whether or not there is a singularity (an element that may indicate the presence of a defect) in the inspection object 10 from which the test data was obtained. One example of a comparison method is to calculate the difference between the master data and the test data. As a result, if the inspection unit 150 determines that there is no singularity, it generates information indicating that there is no singularity and outputs the information to the control unit 160. On the other hand, if the inspection unit 150 determines that there is a singularity, it generates information indicating the singularity and outputs the information to the control unit 160.

[0029] The inspection unit 150 may determine whether or not there is a singular point on the inspection object 10 by, for example, comparing the detection results D1 and D2 or the image data Ib and Ic that have a common angle of incidence. Examples of the comparison method include taking the difference between the detection result D1 and the detection result D2, or the difference between the image data Ib and the image data Ic. In this case, no master data is required for the determination.

[0030] The inspection unit 150 may have a learning model trained using, as training data, the detection results D1, D2 or image data Ib, Ic obtained from an object 10 under inspection without defects, or multiple detection results D1, D2 or multiple image data Ib, Ic obtained from multiple objects 10 under inspection with defects in different locations or types. In this case, the inspection unit 150 inputs test data into the learning model, causing the learning model to determine whether or not there is a singularity in the object 10 under inspection from which the test data was obtained. The inspection unit 150 outputs the determination result by the learning model to the control unit 160.

[0031] The inspection unit 150 may have a learning model that has been trained using, as teaching data, the difference between the detection result D1 and the detection result D2 obtained from a defect-free inspected object 10 or the difference between the detection result D1 and the detection result D2 obtained from a plurality of inspected objects 10 having defects in different locations or types. In this case, the inspection unit 150 inputs the difference between the detection result D1 and the detection result D2 obtained from a test inspected object 10 into the learning model, thereby causing the learning model to determine whether or not a singularity exists in the test inspected object 10. The inspection unit 150 outputs the determination result obtained by the learning model to the control unit 160.

[0032] The inspection unit 150 may have a learning model that has been trained using, as training data, the difference between image data Ib and image data Ic obtained from an object 10 under inspection that has no defects, or the difference between image data Ib and image data Ic obtained from a plurality of objects 10 under inspection that have defects in different locations or types. In this case, the inspection unit 150 inputs the difference between image data Ib and image data Ic obtained from a test object 10 to the learning model, thereby causing the learning model to determine whether or not there is a singularity in the test object 10 under inspection. The inspection unit 150 outputs the determination result made by the learning model to the control unit 160.

[0033] The control unit 160 controls the light source unit 120, the light detection units 130 and 140, and the movement units 121, 131, and 141. The control unit 160 controls the emission and extinction of light by the light source unit 120. The control unit 160 controls the reception of light by the light detection units 130 and 140. The control unit 160 controls the position of the light source unit 120 by the movement unit 121, the position of the light detection unit 130 by the movement unit 131, and the position of the light detection unit 140 by the movement unit 141. The control unit 160 outputs image data including the determination result in the inspection unit 150 to the display unit 170. The display unit 170 displays the image data input from the control unit 160.

[0034] [Operation] Next, an example of inspection of the object under inspection 10 by the pattern inspection apparatus 100 will be described.

[0035] First, the control unit 160 sets the angle of incidence of light La (step S101). The control unit 160 outputs a signal related to position information to the movement unit 121 in order to set the angle of incidence of light La to a predetermined value (starting point) in the sweep range. Then, the movement unit 121 moves the light source unit 120 based on the signal input from the control unit 160 so that the angle of incidence of light La becomes the predetermined value (starting point). Next, the control unit 160 outputs a signal to start light output to the light source unit 120. Then, the light source unit 120 outputs light La based on the signal input from the control unit 160 (step S102).

[0036] Next, the control unit 160 outputs a signal to start light detection to the light detection units 130 and 140. Then, the light detection unit 130 detects the reflected light Lb based on the signal input from the control unit 160 (step S103). The light detection unit 130 generates image data Ib based on the detection result D1 and outputs it to the inspection unit 150 (step S104). The light detection unit 140 detects the transmitted light Lc based on the signal input from the control unit 160 (step S103). The light detection unit 140 generates image data Ic based on the detection result D2 and outputs it to the inspection unit 150 (step S104).

[0037] The control unit 160 determines whether the currently set incident angle is the last incident angle (end point) in the sweep range (step S105). If the currently set incident angle is not the last incident angle (end point) in the sweep range (step S105; N), the control unit 160 changes the incident angle of the light La within the sweep range (step S106). For example, the control unit 160 outputs a signal related to position information to the moving unit 121 in order to set the incident angle of the light La to a value shifted by a predetermined amount toward the end point. Thereafter, steps S103 to S105 are executed.

[0038] On the other hand, if the currently set incident angle corresponds to the last incident angle (end point) in the sweep range (step S105; Y), the control unit 160 ends changing the incident angle of the light La and outputs a signal to the inspection unit 150 to start a comparison, for each incident angle, between the image data Ib and Ic, which are test data, and the image data Ir1 and Ir2, which are master data. Then, the inspection unit 150 performs the above comparison (step S107). The image data Ir1 corresponds to the image data Ib obtained from the inspection object 10 without defects. The image data Ir2 corresponds to the image data Ic obtained from the inspection object 10 without defects.

[0039] The inspection unit 150, for example, calculates the difference between image data Ib and image data Ir1 (hereinafter referred to as "difference α") and calculates the difference between image data Ic and image data Ir2 (hereinafter referred to as "difference β"). The inspection unit 150, for example, determines whether or not there is a singularity in the differences α and β (step S108). As a result, if it is determined that there is a singularity in at least one of the differences α and β (step S108; Y), the inspection unit 150 determines that there is a defect in the object under inspection 10 (step S110). On the other hand, if it is determined that there is no singularity in either the difference α or the difference β (step S108; N), the inspection unit 150 determines that there is no defect in the object under inspection 10 (step S109).

[0040] The control unit 160 generates image data including the determination result by the inspection unit 150 and outputs it to the display unit 170. The display unit 170 displays the image data input from the control unit 160. In this manner, the inspection of the object under inspection 10 by the pattern inspection device 100 is performed.

[0041] [effect] Next, the effects of the pattern inspection device 100 according to this embodiment will be described.

[0042] In recent years, miniaturization for the purpose of increasing the integration density of integrated circuits has reached its physical limit, leading to the stacking of circuits, i.e., 3D circuits. With conventional planar circuits, it was possible to perform non-destructive inspection of all products actually used for defects. For example, Patent Document 1 discloses a method of detecting defects in a circuit pattern based on the diffraction image obtained by irradiating the circuit pattern with light on the order of nanometers. However, with 3D circuits, there was a problem in that defects in the internal circuit pattern could not be detected.

[0043] On the other hand, in this embodiment, of the light La in the wavelength band of 1.2 μm or more and 5.0 μm or less that is emitted toward the object under test 10, the transmitted light Lc through the object under test 10 or the reflected light Lb from the object under test 10 is detected. This makes it possible to perform pattern inspection based on the detection results obtained by the detection. This also makes it possible to detect defects in the internal circuit pattern of a 3D circuit.

[0044] Furthermore, in this embodiment, pattern inspection is performed based on the multiple detection results D1, D2 or image data Ib, Ic obtained by the light detection units 130, 140 as the incident angle changes, which makes it possible to detect defects in the internal circuit pattern of a 3D circuit.

[0045] In this embodiment, the inspection unit 150 may perform pattern inspection based on the detection result D1 or the detection result D2. In this embodiment, the inspection unit 150 may perform pattern inspection based on the image data Ib or the image data Ic. Even in this case, defects in the internal circuit pattern of the 3D circuit can be detected.

[0046] 3. Second Embodiment [composition] Next, a pattern inspection device 200 according to a second embodiment of the present invention will be described. FIG. 5 shows an example of a schematic configuration of the pattern inspection device 200. The pattern inspection device 200 is a device that non-destructively inspects defects in an object to be inspected 10. As shown in FIG. 5, the pattern inspection device 200 corresponds to the above-mentioned pattern inspection device 100, with the movement units 121, 131, and 141 omitted and with a light source unit 180 instead of the light source unit 120. In the following, the same reference numerals will be used to designate components that are common to the first embodiment, and descriptions of the components that are common to the first embodiment will be omitted as appropriate.

[0047] The light source unit 180 includes a laser capable of emitting light Ld and a control circuit that controls the laser emission. The laser is disposed so that the light Ld emitted from the laser is obliquely incident on the surface of the inspection object 10. The control circuit controls the laser emission based on the control unit 160. The laser is capable of emitting collimated light in a wavelength band of 1.2 μm to 5.0 μm (mid-infrared region) as the light Ld. The laser is, for example, a GaSb-based semiconductor laser capable of emitting light Ld of any wavelength within a wavelength range of 1.9 μm to 2.5 μm. The laser is not limited to a semiconductor laser and may also be a solid-state laser. The laser may be, for example, a Cr:ZnSe laser capable of emitting light Ld of any wavelength within a wavelength range of 2.2 μm to 2.9 μm. The laser is not limited to a Cr:ZnSe laser. The light source unit 180 may have, for example, a light emitting element capable of emitting light Ld of any wavelength within a wavelength range of 2.2 μm or more and 2.9 μm or less, instead of the laser. The mid-infrared region is included in the light transmission region of a Si substrate, for example, as shown in FIG. 3. Therefore, the light Ld is light that can pass through a Si substrate or an inspection object 10 including a Si substrate.

[0048] When light Ld is incident on the inspected object 10, part of the incident light Ld is reflected by the inspected object 10 and becomes reflected light Lb, which enters the light detection unit 130, and part of the incident light La passes through the inspected object 10 and becomes transmitted light Lc, which enters the light detection unit 140. Here, the inspected object 10 can be optically treated as a volume Bragg element. At this time, the reflected light Lb is diffracted light (Bragg reflected light) from inside the inspected object 10, and the diffraction intensity of the reflected light Lb is strong in a specific direction. Similarly, the intensity of the transmitted light Lc is also strong in a specific direction.

[0049] The inspection unit 150 performs a pattern inspection of the object under inspection 10 based on the detection result D1 obtained from the light detection unit 130 and the detection result D2 obtained from the light detection unit 140. Specifically, the inspection unit 150 performs a pattern inspection of the object under inspection 10 using image data Ib and image data Ic. The inspection unit 150 performs the pattern inspection based on a plurality of detection results D1, D2 (test data) obtained while the wavelength of the light Ld is changing. Specifically, the inspection unit 150 performs the pattern inspection based on a plurality of image data Ib, Ic (test data) obtained while the wavelength of the light Ld is changing. In other words, the test data includes a plurality of detection results D1, D2 or a plurality of image data Ib, Ic obtained while the wavelength of the light Ld is changing.

[0050] The inspection unit 150 has, as master data, a plurality of detection results D1, D2 or a plurality of image data Ib, Ic obtained from a defect-free inspection object 10. The master data includes a plurality of detection results D1, D2 or a plurality of image data Ib, Ic obtained using light Ld with different wavelengths. The inspection unit 150 compares the master data and test data, which use the same wavelength of light Ld, to determine whether or not there is a singularity (an element that may indicate the presence of a defect) in the inspection object 10 from which the test data was obtained. One example of a comparison method is to calculate the difference between the master data and the test data. As a result, if the inspection unit 150 determines that there is no singularity, it generates information indicating that there is no singularity and outputs the information to the control unit 160. On the other hand, if the inspection unit 150 determines that there is a singularity, it generates information indicating the singularity and outputs the information to the control unit 160.

[0051] The inspection unit 150 may determine whether or not there is a singular point on the inspection object 10 by, for example, comparing the detection results D1 and D2 or the image data Ib and Ic, which have the same wavelength of light Ld. Examples of the comparison method include taking the difference between the detection result D1 and the detection result D2, or the difference between the image data Ib and the image data Ic. In this case, no master data is required for the determination.

[0052] The control unit 160 controls the light source unit 180 and the light detection units 130 and 140. The control unit 160 controls the light emission / quenching and emission wavelength of the light source unit 180. The control unit 160 controls the light reception of the light detection units 130 and 140. The control unit 160 outputs image data including the determination result in the inspection unit 150 to the display unit 170. The display unit 170 displays the image data input from the control unit 160.

[0053] [Operation] Next, an example of inspection of the object under inspection 10 by the pattern inspection apparatus 200 will be described.

[0054] First, the control unit 160 sets the wavelength of the light Ld (step S201). The control unit 160 outputs a signal related to the wavelength to the light source unit 180 in order to set the wavelength of the light Ld to a predetermined value (starting point) in the sweep range. Then, the light source unit 180 outputs the light La at the wavelength of the predetermined value (starting point) based on the signal input from the control unit 160 (step S102).

[0055] Next, the control unit 160 outputs a signal to start light detection to the light detection units 130 and 140. Then, the light detection unit 130 detects the reflected light Lb based on the signal input from the control unit 160 (step S203). The light detection unit 130 generates image data Ib based on the detection result D1 and outputs it to the inspection unit 150 (step S204). The light detection unit 140 detects the transmitted light Lc based on the signal input from the control unit 160 (step S203). The light detection unit 140 generates image data Ic based on the detection result D2 and outputs it to the inspection unit 150 (step S204).

[0056] The control unit 160 determines whether the currently set wavelength of the light Ld is the last wavelength (end point) in the sweep range (step S205). If the currently set wavelength of the light Ld is not the last wavelength (end point) in the sweep range (step S205; N), the control unit 160 changes the wavelength of the light Ld within the sweep range (step S206). For example, the control unit 160 outputs a signal related to the wavelength to the light source unit 180 in order to set the wavelength of the light Ld to a value shifted by a predetermined amount toward the end point. Thereafter, steps S203 to S205 are executed.

[0057] On the other hand, if the currently set wavelength of light Ld corresponds to the last wavelength (end point) in the sweep range (step S205; Y), the control unit 160 ends changing the wavelength of light Ld and outputs a signal to the inspection unit 150 to start a comparison, for each wavelength, between the image data Ib and Ic, which are test data, and the image data Ir3 and Ir4, which are master data. Then, the inspection unit 150 performs the above comparison (step S207). The image data Ir3 corresponds to the image data Ib obtained from the inspection object 10 without defects. The image data Ir4 corresponds to the image data Ic obtained from the inspection object 10 without defects.

[0058] The inspection unit 150, for example, calculates the difference between image data Ib and image data Ir3 (hereinafter referred to as "difference α") and calculates the difference between image data Ic and image data Ir4 (hereinafter referred to as "difference β"). The inspection unit 150, for example, determines whether or not there is a singularity in the differences α and β (step S208). As a result, if it is determined that there is a singularity in at least one of the differences α and β (step S208; Y), the inspection unit 150 determines that there is a defect in the object under inspection 10 (step S210). On the other hand, if it is determined that there is no singularity in either the difference α or the difference β (step S208; N), the inspection unit 150 determines that there is no defect in the object under inspection 10 (step S209).

[0059] The control unit 160 generates image data including the determination result by the inspection unit 150 and outputs it to the display unit 170. The display unit 170 displays the image data input from the control unit 160. In this manner, the inspection of the object under inspection 10 by the pattern inspection device 100 is performed.

[0060] [effect] Next, the effects of the pattern inspection device 200 according to this embodiment will be described.

[0061] In this embodiment, light Ld in the wavelength band of 1.2 μm or more and 5.0 μm or less is emitted toward the object under test 10, and light Lc transmitted through the object under test 10 or light Lb reflected by the object under test 10 is detected. This makes it possible to perform pattern inspection based on the detection results obtained by the detection. This also makes it possible to detect defects in the internal circuit pattern of a 3D circuit.

[0062] Furthermore, in this embodiment, pattern inspection is performed based on the multiple detection results D1, D2 or image data Ib, Ic obtained by the light detection units 130, 140 during the process of changing the wavelength of light Ld. This makes it possible to detect defects in the internal circuit pattern of a 3D circuit. [Explanation of symbols]

[0063] 10...object to be inspected, 11...intermediate substrate, 12...LSI chip, 13...signal through via, 14...signal bump, 15...power supply through via, 16...power supply bridge, 17...resin filling layer, 18...interface section, 100, 200...pattern inspection device, 110...support stand, 120, 180...light source section, 121, 131, 141...moving section, 130, 140...light detection section, 150...inspection section, 160...control section, 170...display section, D1, D2...detection results, Ib, Ic, Ir1, Ir2, Ir3, Ir4...image data, La...light, Lb...reflected light, Lc...transmitted light.

Claims

1. a light source unit that emits light in a wavelength band of 1.2 μm or more and 5.0 μm or less toward an object to be inspected including a plurality of stacked Si substrates; a detection unit that detects, from the light emitted from the light source unit, transmitted Bragg diffracted light generated by light transmitted through the object under test or reflected Bragg diffracted light generated by light internally reflected by the object under test; an inspection unit that performs a circuit pattern inspection based on a plurality of detection results obtained by the detection unit in the process of changing the wavelength of the light emitted from the light source unit within the range of the wavelength band and sweeping the wavelength; Equipped with Circuit pattern inspection device.

2. The inspection unit performs the circuit pattern inspection based on a comparison result between the plurality of detection results and a plurality of master data for each sweep wavelength.

2. The circuit pattern inspection device according to claim 1.

3. emitting light in a wavelength band of 1.2 μm or more and 5.0 μm or less toward an object to be inspected, the object including a plurality of stacked Si substrates, and sweeping the wavelength of the light emitted toward the object to be inspected by changing the wavelength within the range of the wavelength band; Detecting transmitted Bragg diffracted light generated by light transmitted through the object under test or reflected Bragg diffracted light generated by light internally reflected at the object under test from the light emitted toward the object under test; performing a circuit pattern inspection based on a plurality of detection results obtained during the wavelength sweeping process; Contains Circuit pattern inspection method.

4. The circuit pattern inspection is carried out based on a comparison result between the plurality of detection results and a plurality of master data for each sweep wavelength. Contains 4. The circuit pattern inspection method according to claim 3.

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