Observation device

Abstract

To achieve both high tact and accurate observation of an object.SOLUTION: An observation device 100 includes: a transmitted light collection lens 43; a light detection unit 44; a second vertical movement mechanism 7B that moves the transmitted light collection lens 43; a GUI 10; an aberration correction unit 46 that performs aberration correction of transmitted light I1; and a control unit 9 for controlling the aberration correction unit 46. The aberration correction unit 46 is configured to be able to switch a correction amount of aberration correction. According to an input received at the GUI 10, the control unit 9 switches the amount of correction of first section aberration correction that is aberration correction in a case where a first section of a transmitted light incident surface side in an object 20 is imaged by the light detection unit 44, second section aberration correction that is aberration correction in a case where a second section of an inside in the object 20 is imaged by the light detection unit 44, and third section aberration correction that is aberration correction in a case where a third section on the opposite surface side of the transmitted light incident surface in the object 20 is imaged by the light detection unit 44.SELECTED DRAWING: Figure 14

Description

Technical Field

[0001] The present invention relates to an observation device.

Background Art

[0002] Observation devices that observe an object using transmitted light that is transmissive to the object are known. As this type of technology, for example, Patent Document 1 describes observing a modified region formed inside a semiconductor substrate, processing damage formed in a functional element layer, etc. with an infrared camera provided in a laser processing device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the observation device as described above, in order to realize accurate observation of an object, aberration correction for correcting spherical aberration etc. of the transmitted light may be performed. In this case, if the correction amount of the aberration correction is fixed, although the tact (working efficiency) is high, there is a risk that the aberration cannot be sufficiently corrected. On the other hand, it is also conceivable to optimize the correction amount of the aberration correction by the user turning the correction ring provided on the condenser lens each time of observation. However, in this case, for example, when the depth position to be observed in the object changes, the appropriate correction amount also changes, so there is a risk that the tact decreases due to adjustment of the correction amount.

[0005] Therefore, an object of the present invention is to provide an observation device capable of achieving both high tact and accurate observation of an object.

Means for Solving the Problems

[0006] The observation device according to the present invention is a device that observes an object using transmitted light that is transmissive to the object, and includes a condenser lens that condenses the transmitted light toward the object, an imaging unit that receives the transmitted light reflected by the object and images the object, a moving unit that relatively moves the condenser lens with respect to the object, an input unit that receives an input from a user, an aberration correction unit that corrects the aberration of the transmitted light, and at least a control unit that controls the aberration correction unit. The aberration correction unit is configured to be able to switch the correction amount of the aberration correction, and the control unit performs the first section aberration correction, which is the aberration correction by the aberration correction unit when imaging the first section on the transmitted light incident surface side of the object with the imaging unit, and the second section aberration correction, which is the aberration correction by the aberration correction unit when imaging the second section inside the object with the imaging unit, and the third section aberration correction, which is the aberration correction by the aberration correction unit when imaging the third section on the opposite surface side of the transmitted light incident surface of the object with the imaging unit, and switches at least any one of the correction amounts according to the input received by the input unit.

[0007] In this observation device, the section to be observed in the object is divided into the first to third sections (that is, the transmitted light incident surface side, the inside, and the opposite surface side of the transmitted light incident surface of the object), and when observing these first to third sections, aberration correction can be performed with the correction amount switched according to the user's input for each of them. Thereby, the correction amount can be switched so as to be optimized according to the user's input, and it is possible to suppress the frequency of the switching and maintain a high tact. That is, it is possible to achieve both a high tact and accurate observation of the object.

[0008] In the observation device according to the present invention, the aberration correction unit is configured to be able to switch the correction amount of the aberration correction at least among a first correction amount, a second correction amount, and a third correction amount, and the control unit may switch the correction amounts of the first section aberration correction, the second section aberration correction, and the third section aberration correction among the first correction amount, the second correction amount, and the third correction amount according to the input received by the input unit. In this case, it is possible to easily realize the switching of the correction amounts of the first section aberration correction, the second section aberration correction, and the third section aberration correction.

[0009] In the observation apparatus according to the present invention, the condenser lens has a first condenser lens, a second condenser lens, and a third condenser lens, and the aberration correction unit includes a first aberration correction unit provided in the first condenser lens for realizing aberration correction with a first correction amount, a second aberration correction unit provided in the second condenser lens for realizing aberration correction with a second correction amount, and a third aberration correction unit provided in the third condenser lens for realizing aberration correction with a third correction amount. The first condenser lens, the second condenser lens, and the third condenser lens are attached, and a revolver that is movable so that any one of the first condenser lens, the second condenser lens, and the third condenser lens is disposed on the optical axis of the transmitted light and any one of the first condenser lens, the second condenser lens, and the third condenser lens disposed on the optical axis of the transmitted light is switched may be included. In this case, by switching the condenser lens on the optical axis of the transmitted light by the revolver among the first to third condenser lenses, it is possible to switch each correction amount of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section among the first to third correction amounts.

[0010] In the observation apparatus according to the present invention, the first correction amount may be smaller than the second correction amount, and the second correction amount may be smaller than the third correction amount. By using the first to third correction amounts having such a magnitude relationship, it is possible to optimize the correction amount.

[0011] In the observation apparatus according to the present invention, the aberration correction for the first section may be aberration correction for inspecting the presence or absence of cracks exposed on the transmitted light incident surface of the object, and the aberration correction for the third section may be aberration correction for inspecting the presence or absence of cracks exposed on the opposite surface of the transmitted light incident surface of the object. In this case, it is possible to accurately inspect the presence or absence of cracks exposed on the transmitted light incident surface of the object and the presence or absence of cracks exposed on the opposite surface of the transmitted light incident surface of the object. Further, in the observation apparatus according to the present invention, the aberration correction for the second section may be aberration correction for inspecting a modified region formed inside the object. In this case, it is possible to accurately inspect the modified region formed inside the object.

[0012] In the observation apparatus according to the present invention, the control unit acquires information regarding the position of a detection target based on the movement amount of the condenser lens by the moving unit and a correction coefficient, and may switch the correction coefficient according to the switching of the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section. In this case, it becomes possible to accurately acquire the depth position of the detection target (for example, a modified region or the like) in the object.

[0013] In the observation apparatus according to the present invention, the input unit receives an input regarding the content of an inspection to be performed on the object, and the control unit may switch the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the input regarding the content of the inspection received by the input unit. In this case, it becomes possible to optimize the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the input regarding the content of the inspection from the user.

[0014] In the observation apparatus according to the present invention, the input unit receives an input regarding the type of processing conditions for laser processing to be performed on the object, and the control unit may switch the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the input regarding the type of processing conditions received by the input unit. In this case, it becomes possible to optimize the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the input regarding the type of processing conditions from the user.

[0015] In the observation apparatus according to the present invention, the input unit receives an input regarding the thickness of the object, and the control unit may switch the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the input regarding the thickness of the object received by the input unit. In this case, it becomes possible to optimize the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the input regarding the thickness of the object from the user.

[0016] In the observation device according to the present invention, the input unit receives an input regarding whether the input mode is the simple input mode or the detailed input mode, and when receiving an input regarding the detailed input mode as the input mode, may receive an input of correction amounts for aberration correction for the first section, aberration correction for the second section, and aberration correction for the third section. In this case, the user can input the correction amounts for aberration correction for the first section, aberration correction for the second section, and aberration correction for the third section by inputting the detailed input mode as the input mode.

[0017] In the observation device according to the present invention, the second-section side of the first section and the first-section side of the second section overlap each other in the first overlapping section, the third-section side of the second section and the second-section side of the third section overlap each other in the second overlapping section, and the control unit performs a process of imaging the first overlapping section by the imaging unit while performing aberration correction for the first section by the aberration correction unit, an imaging process of imaging the first overlapping section by the imaging unit while performing aberration correction for the second section by the aberration correction unit, a process of imaging the second overlapping section by the imaging unit while performing aberration correction for the second section by the aberration correction unit, and an imaging process of imaging the second overlapping section by the imaging unit while performing aberration correction for the third section by the aberration correction unit. In this case, more accurate observation is possible in the first and second overlapping sections of the object. Also, in some cases, accurate observation may be possible only with aberration correction for the first and third sections according to the input content such as the thickness of the object.

Advantages of the Invention

[0018] According to the present invention, it is possible to provide an observation device capable of achieving both high tact and accurate observation of an object.

Brief Description of the Drawings

[0019]

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DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments will be described in detail with reference to the drawings. In the description of each figure, the same or corresponding parts may be denoted by the same reference numerals, and redundant descriptions may be omitted. Each figure may show an orthogonal coordinate system defined by the X-axis, Y-axis, and Z-axis. As an example, the X direction and the Y direction are the first horizontal direction and the second horizontal direction that intersect (are orthogonal) to each other, and the Z direction is the vertical direction that intersects (is orthogonal) to the X direction and the Y direction.

[0021] As shown in FIG. 1, the laser processing apparatus 1 according to the embodiment includes a stage 2, a laser processing head 3, alignment cameras 5 and 6, an observation unit 4, a first vertical movement mechanism 7A, a second vertical movement mechanism 7B, a first horizontal movement mechanism 8A, a second horizontal movement mechanism 8B, a control unit 9, and a GUI (Graphical User Interface) 10. The laser processing apparatus 1 is an apparatus that forms a modified region 12 (see FIG. 4) on the object 20 by irradiating the object 20 with a laser beam L.

[0022] As shown in FIGS. 2 and 3, the object 20 is, for example, a wafer. The object 20 includes a semiconductor substrate 21 and a functional element layer 22. The semiconductor substrate 21 has a front surface 21a and a back surface 21b. The semiconductor substrate 21 is, for example, a silicon substrate. The functional element layer 22 is formed on the front surface 21a of the semiconductor substrate 21. The functional element layer 22 includes a plurality of functional elements 22a arranged two-dimensionally along the front surface 21a. The functional elements 22a are, for example, light receiving elements such as photodiodes, light emitting elements such as laser diodes, circuit elements such as memories, etc. The functional elements 22a may be three-dimensionally configured with a plurality of layers stacked. Note that the object 20 may or may not have the functional element layer 22 and may be a bare wafer. A notch 21c indicating the crystal orientation is provided on the semiconductor substrate 21, but an orientation flat may be provided instead of the notch 21c.

[0023] The object 20 is cut for each functional element 22a along each of the plurality of lines 15. The plurality of lines 15 pass between each of the plurality of functional elements 22a when viewed from the thickness direction of the object 20. More specifically, the line 15 passes through the center (center in the width direction) of the street region 23 when viewed from the thickness direction of the object 20. The street region 23 extends through between adjacent functional elements 22a in the functional element layer 22. In the present embodiment, the plurality of functional elements 22a are arranged in a matrix along the surface 21a, and the plurality of lines 15 are set in a grid pattern. Note that the line 15 is a virtual line, but may be an actually drawn line.

[0024] As shown in FIG. 1, the object 20 is placed on the stage 2. The stage 2 supports the object 20, for example, by adsorbing the object 20. The stage 2 is movable along the X direction by the first horizontal movement mechanism 8A. The stage 2 is movable along the Y direction by the second horizontal movement mechanism 8B. The stage 2 is configured to be rotatable about a rotation axis along the Z direction. The stage 2 has a known rotation drive device (not shown) such as a motor, and is rotationally driven about the rotation axis by the driving force thereof. The rotation of the stage 2 is controlled by the control unit 9.

[0025] As shown in FIGS. 1 and 4, the laser processing head 3 is an irradiation unit that irradiates the object 20 supported by the stage 2 with a laser beam L having transmissivity. The laser processing head 3 condenses the laser beam L inside the object 20. When the laser beam L is condensed inside the object 20 supported by the stage 2, the laser beam L is particularly absorbed in a portion corresponding to the condensing position (at least a part of the condensing region) of the laser beam L, and a modified region 12 is formed inside the object 20.

[0026] The modified region 12 is a region where the density, refractive index, mechanical strength, and other physical properties are different from those of the surrounding unmodified regions. Examples of the modified region 12 include a melting treatment region, a crack region, a dielectric breakdown region, a refractive index change region, and the like. The modified region 12 has the property that cracks are likely to extend from the modified region 12 to the incident side and the opposite side of the laser beam L. Such properties of the modified region 12 are utilized for cutting the object 20.

[0027] The laser processing head 3 has a laser beam condensing lens 33 and an observation camera 35 inside the housing H3. The laser beam L is incident from an external light source 31 into the housing H3 of the laser processing head 3. The light source 31 outputs the laser beam L, for example, by a pulse oscillation method. The laser beam condensing lens 33 condenses the laser beam L onto the object 20 supported on the stage 2. In the laser processing head 3, the laser beam L incident from the light source 31 enters the laser beam condensing lens 33 through the dichroic mirror 32 inside the housing H3, and is condensed onto the object 20 by the laser beam condensing lens 33. The laser beam condensing lens 33 may be a lens unit including a plurality of objective lenses. The housing H3 includes a mounting portion 39 provided on its side surface, and is connected and supported to a first vertical movement mechanism 7A described later through this mounting portion 39.

[0028] The observation camera 35 images the object 20 supported on the stage 2 with visible light V. The observation camera 35 images an image of the object 20 with the visible light V emitted from the visible light source 36. Specifically, the visible light V emitted from the visible light source 36 is reflected by the dichroic mirror 37, passes through the dichroic mirror 32, and then is irradiated onto the object 20 through the laser light condensing lens 33. The visible light V is reflected by the laser light incident surface of the object 20, passes through the laser light condensing lens 33 and the dichroic mirrors 32 and 37, and is received by the observation camera 35 through the lens 38. A reticle (not shown) for imparting scale lines to the visible light V may be provided on the optical path of the visible light V. The observation camera 35 is connected to the control unit 9. The observation camera 35 outputs the captured visible image to the control unit 9. The observation camera 35 is not particularly limited, and various known cameras can be used as long as the required performance is satisfied.

[0029] The alignment cameras 5 and 6 acquire information used for aligning the condensing position of the laser light L on the object 20 (hereinafter, also simply referred to as "alignment"). The alignment cameras 5 and 6 irradiate the object 20 with light and detect the light returning from the object 20 to acquire an image as information used for alignment. The alignment cameras 5 and 6 image the object 20 supported on the stage 2.

[0030] The alignment camera 5 has a light source that outputs light having transparency with respect to the object 20. The light source is constituted by, for example, a halogen lamp and a filter and outputs light in the near-infrared region. The alignment camera 5 has a light detection unit that detects the light reflected by the surface 21a of the object 20. The light detection unit is constituted by, for example, a Si camera or an InGaAs camera and detects light in the near-infrared region.

[0031] For example, the alignment camera 5 irradiates the object 20 with light from the back surface 21b side, which is the laser light incident surface, and images the functional element layer 22 by detecting the light returning from the front surface 21a (functional element layer 22). Also, for example, the alignment camera 5 similarly irradiates the object 20 with light from the back surface 21b side and acquires an image of the region including the modification region 12 by detecting the light returning from the formation position of the modification region 12 in the semiconductor substrate 21. These images are used for alignment. The alignment camera 6 has the same configuration as the alignment camera 5 except that its lens has a lower magnification. The alignment camera 6 is used for alignment in the same manner as the alignment camera 5.

[0032] The alignment cameras 5 and 6 are provided on the laser processing head 3 and move integrally with the laser processing head 3. In the illustrated example, the alignment cameras 5 and 6 are fixed to the attachment portion 39 of the laser processing head 3. The alignment cameras 5 and 6 are connected to the control unit 9. The alignment cameras 5 and 6 output the captured images to the control unit 9. The alignment cameras 5 and 6 are not particularly limited, and various known cameras can be used as long as they satisfy the required performance.

[0033] As shown in FIGS. 1 and 5, the observation unit 4 observes the object 20 using transmitted light that is transmissive to the object 20. The observation unit 4 irradiates the object 20 with transmitted light and observes the inside of the object 20 by detecting the transmitted light returning from the object 20. For example, the observation unit 4 images the modification region 12 formed in the object 20 and the tip of the crack 14 extending from the modification region 12.

[0034] 5, the observation unit 4 includes a light source 41, a mirror 42, a transmitted light condensing lens (condensing lens) 43, and a light detection unit 44 in a housing H4. The housing H4 includes an attachment portion 49 provided on a side thereof, and is connected to and supported by a second vertical movement mechanism 7B (described later) via this attachment portion 49. The observation unit 4 is connected to a control unit 9. The observation unit 4 outputs an image (internal image) captured by the light detection unit 44 to the control unit 9.

[0035] The light source 41 outputs transmitted light I1 having transparency. The light source 41 is composed of, for example, a halogen lamp and a filter, and outputs transmitted light I1 in the near-infrared region. The transmitted light I1 output from the light source 41 is reflected by a mirror 42 and passes through a transmitted light condenser lens 43, and is irradiated onto the object 20 from the back surface 21b side of the semiconductor substrate 21.

[0036] The transmitted light condensing lens 43 is a lens that condenses the transmitted light I1 toward the semiconductor substrate 21 of the object 20. The transmitted light condensing lens 43 passes the transmitted light I1 reflected by the surface 21a of the semiconductor substrate 21. The transmitted light condensing lens 43 has a first condensing lens 43A, a second condensing lens 43B, and a third condensing lens 43C (see FIG. 6). The specifications of the first condensing lens 43A, the second condensing lens 43B, and the third condensing lens 43C may be the same as or different from each other. The outer shapes of the first condensing lens 43A, the second condensing lens 43B, and the third condensing lens 43C are cylindrical with their optical axes as the axial direction.

[0037] The light detection unit 44 detects the transmitted light I1 that has passed through the transmitted light collecting lens 43 and the mirror 42. The light detection unit 44 is configured with, for example, an InGaAs camera. The light detection unit 44 receives the transmitted light I1 in the near-infrared region reflected by the object 20, and captures an image of the object 20. The light detection unit 44 configures an imaging unit.

[0038] The observation unit 4 includes an aberration correction unit 46 that performs aberration correction of transmitted light I1 (hereinafter, also simply referred to as "aberration correction"). The aberration correction unit 46 is configured to be able to switch the correction amount of aberration correction. The aberration correction unit 46 corrects spherical aberration generated in the transmitted light I1. Spherical aberration refers to an aberration in which light rays from a point light source do not converge at the focal point but spread in an optical system including a spherical surface. For example, when light is incident on a lens, light passing near the optical axis of the lens and light passing away from the optical axis may not converge at a single point but spread, which is spherical aberration. The aberration correction unit 46 includes a first aberration correction unit 47A, a second aberration correction unit 47B, a third aberration correction unit 47C, and a revolver 48.

[0039] The first aberration correction unit 47A is provided in the first condenser lens 43A and realizes aberration correction with a first correction amount. The first aberration correction unit 47A has a correction ring 47x. That is, the first condenser lens 43A constitutes a so-called correction ring lens. In the first aberration correction unit 47A, by rotating the correction ring 47x, a part of the lens group constituting the first condenser lens 43A is moved in the optical axis direction, thereby adjusting the first correction amount. The second aberration correction unit 47B is provided in the second condenser lens 43B and realizes aberration correction with a second correction amount. The second aberration correction unit 47B has a correction ring 47y. That is, the second condenser lens 43B constitutes a so-called correction ring lens. In the second aberration correction unit 47B, by rotating the correction ring 47y, a part of the lens group constituting the second condenser lens 43B is moved in the optical axis direction, thereby adjusting the second correction amount.

[0040] The third aberration correction unit 47C is provided in the third condenser lens 43C and realizes aberration correction of the third correction amount. The third aberration correction unit 47C has a correction ring 47z. That is, the third condenser lens 43C constitutes a so-called correction ring lens. The third aberration correction unit 27C moves a part of the lens group constituting the third condenser lens 43C in the optical axis direction by rotating the correction ring 47z, thereby adjusting the third correction amount. The rotation of the correction rings 47x, 47y, and 47z may be realized manually by the user or may be realized by a drive unit (not shown) under the control of the control unit 9. The first aberration correction unit 47A, the second aberration correction unit 47B, and the third aberration correction unit 47C are not particularly limited, and for example, aspherical lenses may be used.

[0041] The revolver 48 includes a fixed part 48a and a rotating part 48b. The fixed part 48a is fixed to the housing H4. The rotating part 48b has a disk shape with the Z direction as the thickness direction, and is rotatably provided with respect to the fixed part 48a about a rotation axis passing through its center. The first condenser lens 43A, the second condenser lens 43B, and the third condenser lens 43C are attached at three positions equidistant in the circumferential direction in the rotating part 48b. The first condenser lens 43A, the second condenser lens 43B, and the third condenser lens 43C are arranged with their optical axes along the Z direction.

[0042] The revolver 48 arranges any one of the first condenser lens 43A, the second condenser lens 43B, and the third condenser lens 43C on the optical axis of the transmitted light I1, and is movable (rotates with respect to the fixed part 48a about the rotation axis) so that any one of the first condenser lens 43A, the second condenser lens 43B, and the third condenser lens 43C arranged on the optical axis of the transmitted light I1 is switched. With the above configuration, the aberration correction unit 46 is configured to be able to switch the correction amount of aberration correction at least among the first correction amount, the second correction amount, and the third correction amount by rotating the rotating part 48b of the revolver 48.

[0043] As shown in FIG. 1, the first vertical movement mechanism 7A is a movement mechanism that moves the laser processing head 3 along the Z direction together with the alignment cameras 5 and 6. The first vertical movement mechanism 7A has a first vertical axis 71 provided on a columnar first base portion 75. The first base portion 75 is fixed to, for example, an installation surface or the like. The first vertical axis 71 extends along the Z direction. An attachment portion 39 of the laser processing head 3 is movably attached to the first vertical axis 71 along the Z direction. Such a first vertical movement mechanism 7A moves the laser processing head 3 in the Z direction along the first vertical axis 71 by the driving force of a driving source (not shown). The first vertical movement mechanism 7A is not particularly limited, and various mechanisms can be used as long as the laser processing head 3 can be moved in the Z direction.

[0044] The second vertical movement mechanism 7B is a movement mechanism that moves the observation unit 4 along the Z direction. The second vertical movement mechanism 7B has a second vertical axis 72 provided on a columnar second base portion 76 fixed to, for example, an installation surface or the like. The second base portion 76 is spaced apart from the first base portion 75 in the X direction. For example, the separation distance of the second base portion 76 from the first base portion 75 is equal to or greater than the width of the laser processing head 3 in the X direction.

[0045] The second vertical axis 72 extends along the Z direction. An attachment portion 49 of the observation unit 4 is movably attached to the second vertical axis 72 along the Z direction. Such a second vertical movement mechanism 7B moves the observation unit 4 in the Z direction along the second vertical axis 72 by the driving force of a driving source (not shown). The second vertical movement mechanism 7B is not particularly limited, and various mechanisms can be used as long as the observation unit 4 can be moved in the Z direction. The second vertical movement mechanism 7B constitutes a moving part that relatively moves the transmitted light condensing lens 43 with respect to the object 20.

[0046] The first horizontal movement mechanism 8A is a movement mechanism that moves the stage 2 along the X direction. The first horizontal movement mechanism 8A has, for example, a first horizontal axis 81 fixed to an installation surface or the like. The first horizontal axis 81 extends along the X direction. The stage 2 is attached to the first horizontal axis 81 via the second horizontal movement mechanism 8B so as to be movable along the X direction. Such a first horizontal movement mechanism 8A moves the stage 2 and the second horizontal movement mechanism 8B along the first horizontal axis 81 in the X direction by the driving force of a driving source (not shown). The first horizontal movement mechanism 8A is not particularly limited, and various mechanisms can be used as long as the stage 2 can be moved in the X direction.

[0047] The second horizontal movement mechanism 8B is a movement mechanism that moves the stage 2 along the Y direction. The second horizontal movement mechanism 8B has, for example, a second horizontal axis 82 provided on the first horizontal movement mechanism 8A. The second horizontal axis 82 extends along the Y direction. The stage 2 is attached to the second horizontal axis 82 so as to be movable along the Y direction. The second horizontal axis 82 is movable along the first horizontal axis 81 together with the stage 2. Such a second horizontal movement mechanism 8B moves the stage 2 along the second horizontal axis 82 in the Y direction by the driving force of a driving source (not shown). The second horizontal movement mechanism 8B is not particularly limited, and various mechanisms can be used as long as the stage 2 can be moved in the Y direction.

[0048] The control unit 9 is configured as a computer device including a processor, a memory, a storage, a communication device, and the like. In the control unit 9, the processor executes software (program) read into the memory or the like, and controls the reading and writing of data in the memory and the storage, as well as communication by the communication device. The control unit 9 controls various operations of the laser processing apparatus 1. The control unit 9 controls the operations of the rotation driving device of the stage 2, the laser processing head 3, the alignment cameras 5 and 6, the observation unit 4, the first vertical movement mechanism 7A, the second vertical movement mechanism 7B, the first horizontal movement mechanism 8A, the second horizontal movement mechanism 8B, and the GUI 10.

[0049] The GUI 10 displays various types of information. The GUI 10 displays the imaging results of the observation unit 4 and the imaging results of the alignment cameras 5 and 6. The GUI 10 includes, for example, a touch panel display. Various settings regarding processing conditions and the like are input to the GUI 10 by operations such as the user's touch. The GUI 10 constitutes an input unit that receives inputs from the user.

[0050] In the laser processing apparatus 1, as an example, the object 20 is irradiated with the laser beam L from the back surface 21b side of the semiconductor substrate 21, and the stage 2 is moved along the line 15, and the condensing position (condensing point) of the laser beam L with respect to the object 20 is relatively moved along the line 15, whereby a plurality of modified spots are formed so as to line up along the line 15. One modified spot is formed by the irradiation of one pulse of the laser beam L. One row of modified regions 12 is a collection of a plurality of modified spots arranged in a row. Adjacent modified spots may be connected to each other or separated from each other depending on the relative movement speed of the condensing position with respect to the object 20 and the repetition frequency of the laser beam L. In the present embodiment, as shown in FIG. 4, two rows of modified regions 12 are formed inside the semiconductor substrate 21 along the line 15. The two rows of modified regions 12 are adjacent to each other in the thickness direction (Z direction) of the object 20. The two rows of modified regions 12 are formed by relatively moving two condensing positions C along the line 15 with respect to the semiconductor substrate 21.

[0051] In the laser processing apparatus 1, as described above, the housing H3 of the laser processing head 3 is supported by the first vertical movement mechanism 7A so as to be movable in the Z direction. As a result, the laser processing head 3 and the alignment cameras 5 and 6 provided on the laser processing head 3 are configured to be movable in the Z direction and immovable in the X and Y directions. In the laser processing apparatus 1, as described above, the housing H4 of the observation unit 4 is supported by the second vertical movement mechanism 7B so as to be movable in the Z direction. As a result, the observation unit 4 is configured to be movable in the Z direction and immovable in the X and Y directions. In the above, the stage 2, the observation unit 4, the second vertical movement mechanism 7B, the control unit 9, the GUI 10, the first horizontal movement mechanism 8A, and the second horizontal movement mechanism 8B constitute the observation device 100.

[0052] Next, an outline of the operation of the laser processing apparatus 1 will be exemplified with reference to the flowchart of FIG. 7. First, after startup, after warming up and calibrating each device, the object 20 is placed on the stage 2 by a robot arm (not shown), and the object 20 is adsorbed on the stage 2 (step S101). Subsequently, alignment is performed (step S102). In step S102, based on the image (for example, the image of the functional element layer 22 of the object 20) acquired by the alignment camera 5 or the alignment camera 6, the control unit 9 controls the operations of the first horizontal movement mechanism 8A and the second horizontal movement mechanism 8B, and moves the stage 2 along the X and Y directions so that the condensing position of the laser beam L matches the alignment position. For example, the alignment position is the processing start position (predetermined position) on the line 15 as viewed from the Z direction. Also, in step S102, the position information of the stage 2 at the time of alignment is acquired as alignment information.

[0053] Subsequently, height setting is performed (step S103). In step S103, the control unit 9 controls the operation of the first vertical movement mechanism 7A based on the visible image (for example, an image of the laser light incident surface of the object 20) acquired by the observation camera 35, and moves the laser processing head 3 (that is, the laser light condensing lens 33) along the Z direction so that the condensing position of the laser light L is located on the laser light incident surface. Subsequently, the control unit 9 controls the operation of the first vertical movement mechanism 7A, and moves the laser processing head 3 along the Z direction so that the condensing position of the laser light L is located at a predetermined depth from the laser light incident surface with reference to the position at the time of height setting. Subsequently, the control unit 9 appropriately controls the ON / OFF of the laser light L from the laser processing head 3, and the operations of the first horizontal movement mechanism 8A, the second horizontal movement mechanism 8B, and the rotation drive device of the stage 2, and moves the stage 2 so that the condensing position of the laser light L moves relatively along the plurality of lines 15. Thereby, a modified region 12 is formed inside the object 20 along the plurality of lines 15 (step S104).

[0054] Subsequently, internal observation of the object 20 is performed. In the internal observation of the object 20, the control unit 9 controls the operations of the rotation drive device of the stage 2, the first horizontal movement mechanism 8A, and the second horizontal movement mechanism 8B, and moves the stage 2 so that the object 20 is located at the start position of the internal observation by the observation unit 4 (step S105). In step S105, based on the alignment information acquired in step S102 above, the position of the object 20 in the X direction, Y direction, and θ direction is controlled so that the optical axis of the transmitted light condensing lens 43 coincides with the alignment position of the object 20 (here, the processing start position on the line 15).

[0055] Subsequently, the observation unit 4 performs internal observation of the object 20 to acquire a plurality of internal images (step S106). In step S106, for example, at at least one location on each line 15, the following internal observation process is executed by the observation unit 4 under the control of the control unit 9. That is, the observation unit 4 is moved along the Z direction by the second vertical movement mechanism 7B, the condensing position of the transmitted light I1 is aligned with a plurality of positions inside the object 20 to image the object 20, and a plurality of internal images are acquired. Information regarding the movement amount of the observation unit 4 is associated with each of the plurality of internal images, and this is acquired as imaging data. Acquisition of such imaging data is repeated by aligning the optical axis of the transmitted light condensing lens 43 at other locations on the same line 15 or another line 15.

[0056] Subsequently, the control unit 9 determines the processing state based on the acquired imaging data (step S107). In step S107, as an example, it is automatically determined (AI determination is performed) which one of the internal images in the plurality of imaging data has a relatively clear image of the crack 14 by image recognition. The control unit 9 calculates the crack position based on the movement amount when the determined internal image was imaged. The crack position can be calculated, for example, by multiplying the movement amount by a predetermined correction coefficient. The correction coefficient will be described later. Also, the control unit 9 estimates the position of the reformed region 12 and the like based on the acquired crack position and the like. Subsequently, the control unit 9 stores the determination result determined in step S107 in an arbitrary storage device. The control unit 9 causes the GUI 10 to display the determination result determined in step S107 (step S8). Thus, the process ends.

[0057] In the observation by the observation unit 4 of the present embodiment, for example, by "direct observation" and "back surface reflection observation", the crack 14 and the modified region 12 can be detected, and information regarding their positions can be obtained. As shown in FIG. 8, the direct observation is the observation when the condensing point of the transmitted light I1 is directly aligned with the crack 14 without passing through the reflection at the front surface 21a while the transmitted light I1 is incident from the back surface 21b (when the focus F is aligned with the crack 14 from the back surface 21b side). The back surface reflection observation is the observation when the condensing point of the transmitted light I1 reflected at the front surface 21a is aligned with the crack 14 while the transmitted light I1 is incident from the back surface 21b (when the focus is aligned from the back surface 21b side to a region on the side opposite to the back surface 21b with respect to the front surface 21a, and the virtual focus symmetric to the focus with respect to the front surface 21a is aligned with the crack 14).

[0058] In the determination of the processing state (AI determination) in the present embodiment, for example, regarding the internal image of the object 20, first, a straight line group is detected. For the detection of the straight line group, an algorithm such as Hough transform or LSD (Line Segment Detector) is used. The Hough transform is a method of detecting all the straight lines passing through a point on the image and detecting the straight lines while weighting the straight lines passing through more feature points. LSD is a method of estimating the region that becomes a line segment by calculating the gradient and angle of the luminance value in the image, and detecting the straight line by approximating the region to a rectangle. The crack 14 is detected from the straight line group by calculating the similarity with the crack line for the straight line group.

[0059] Also, in the determination of the processing state (AI determination) in the present embodiment, for example, regarding the internal image of the object 20, corners (concentration of edges) in the image are detected as key points, and their positions, sizes, and directions are detected to detect feature points. As methods for detecting feature points in this way, Eigen, Harris, Fast, SIFT, SURF, STAR, MSER, ORB, AKAZE, etc. are known. The reformed region (scar) 12 has strong corner features because shapes such as circles and rectangles are arranged at regular intervals. Therefore, by aggregating the feature amounts of the feature points in the image, it becomes possible to detect the reformed region 12 with high accuracy. When comparing the total feature amounts for each image captured with a shift in the depth direction, a mountain-like change indicating the amount of cracks 14 can be confirmed. The peak of the change is estimated as the position of the reformed region 12.

[0060] Next, the processing in the control unit 9 and the input to the GUI 10 of the present embodiment will be specifically described.

[0061] The control unit 9 controls the aberration correction unit 46. The control unit 9 switches at least one of the correction amounts, which is the first-section aberration correction by the aberration correction unit 46 when imaging the first section on the transmitted-light incident surface side of the object 20 with the light detection unit 44, the second-section aberration correction by the aberration correction unit 46 when imaging the second section inside the object 20 with the light detection unit 44, and the third-section aberration correction by the aberration correction unit 46 when imaging the third section on the opposite surface side of the transmitted-light incident surface of the object 20 with the light detection unit 44, according to the input received by the GUI 10.

[0062] The aberration correction for the first section may be an aberration correction for inspecting the presence or absence of a crack 14 exposed on the back surface 21b, which is the transmitted light incident surface of the transmitted light I1 in the object 20. The aberration correction for the first section may be an aberration correction for inspecting the modified region 12 (indentation) on the back surface 21b side of the object 20. The aberration correction for the second section may be an aberration correction for inspecting the modified region 12 formed inside the object 20 (the portion other than the surface 21a side and the back surface 21b side). The aberration correction for the second section may be an aberration correction for inspecting the presence or absence of locations that may appear as unevenness (so-called end face unevenness) on the cut surface after cutting and black streak-like locations (so-called black streaks) inside the object 20. The aberration correction for the third section may be an aberration correction for inspecting the presence or absence of a crack 14 exposed on the surface 21a, which is the surface opposite to the transmitted light incident surface of the object 20. The aberration correction for the third section may be an aberration correction for inspecting the modified region 12 on the surface 21a side of the object 20.

[0063] Regarding the ranges of the first to third sections, they may be set for each thickness of the object 20 and stored in the control unit 9, or may be input or selectable via the GUI 10 as described later. For example, the control unit 9 may previously store a data table in which the correction amounts of the aberration corrections for the first to third sections are separated according to the input content of the GUI 10, and may switch the correction amounts of the aberration corrections for the first to third sections based on the data table and the input actually received via the GUI 10.

[0064] The control unit 9 switches the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section among the first correction amount, the second correction amount, and the third correction amount according to the input received by the GUI 10. Specifically, when the control unit 9 switches the correction amount of the aberration correction to the first correction amount, the control unit 9 rotates the revolver 48 so that the first condenser lens 43A provided with the first aberration correction unit 47A is disposed on the optical axis of the transmitted light I1. When the control unit 9 switches the correction amount of the aberration correction to the second correction amount, the control unit 9 rotates the revolver 48 so that the second condenser lens 43B provided with the second aberration correction unit 47B is disposed on the optical axis of the transmitted light I1. When the control unit 9 switches the correction amount of the aberration correction to the third correction amount, the control unit 9 rotates the revolver 48 so that the third condenser lens 43C provided with the third aberration correction unit 47C is disposed on the optical axis of the transmitted light I1.

[0065] The control unit 9 acquires information regarding the depth position (position in the Z direction) of a detection target (for example, the reformed region 12 or the crack 14) based on the amount of movement of the observation unit 4 (transmitted light condenser lens 43) along the Z direction by the second vertical movement mechanism 7B and a correction coefficient. The control unit 9 switches the correction coefficient according to the switching of the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section. The correction coefficient will be specifically described below.

[0066] The correction coefficient is a predetermined coefficient that is multiplied by the amount of movement of the transmitted light condensing lens 43 in the Z direction. Suppose the observation unit 4 is moved by an amount of movement Fz along the Z direction in order to adjust the position of the condensing point of the transmitted light I1 inside the semiconductor substrate 21. At this time, if there is no semiconductor substrate 21, the amount of movement of the condensing point of the transmitted light I1 is also the amount of movement Fz. However, when the condensing point of the transmitted light I1 is formed inside the semiconductor substrate 21, the amount of movement of the condensing point of the transmitted light I1 becomes the actual amount of movement Hz, which is different from the amount of movement Fz. The actual amount of movement Hz defines the actual imaging position inside the semiconductor substrate 21, that is, the position of the detection target. On the other hand, the information that the control unit 9 can directly obtain is the amount of movement Fz of the observation unit 4 (that is, the amount of movement Fz of the condensing point when there is no semiconductor substrate 21). Therefore, in order for the control unit 9 to obtain the position of the actual detection target inside the semiconductor substrate 21, it is necessary to multiply the amount of movement Fz by some coefficient. The coefficient applied at this time is the correction coefficient.

[0067] The GUI 10 receives an input regarding the content of the inspection to be performed on the object 20. The control unit 9 switches the correction amounts for the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the input regarding the content of the inspection received by the GUI 10. Examples of the content of the inspection include an FC inspection for inspecting that cracks 14 and modified regions 12 are formed from the front surface 21a to the back surface 21b of the object 20, a BHC inspection for inspecting that a crack 14 is exposed on the front surface 21a, which is the opposite surface of the transmitted light incident surface of the object 20, and an ST inspection for inspecting that no crack 14 is exposed on the front surface 21a and the back surface 21b of the object 20.

[0068] The GUI 10 receives an input regarding the type of processing conditions for laser processing to be performed on the object 20. The control unit 9 switches the correction amounts for the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the input regarding the type of processing conditions received by the GUI 10. Examples of the type of processing conditions include the SDBG condition in which the modification region 12 is formed inside the object 20 and the object 20 is polished and thinned, and the FC condition in which the cracks 14 and the modification region 12 are formed across the front surface 21a to the back surface 21b of the object 20. Further, examples of the type of processing conditions include the MEMS condition in which processing is performed under the FC condition so that there are fewer unevennesses on the end face for particle suppression, the memory condition in which processing is performed under the SDBG condition while ensuring device quality such as straightness of the bottom crack and damage suppression, and the device condition set according to the type of device and the quality required by the user.

[0069] The GUI 10 receives an input regarding the thickness of the object 20. The control unit 9 switches the correction amounts for the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the input regarding the thickness of the object 20 received by the GUI 10.

[0070] The GUI 10 receives an input regarding whether the input mode is the simple input mode or the detailed input mode. When the GUI 10 receives an input regarding the detailed input mode as the input mode, the GUI 10 receives an input of the correction amounts for the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section. The control unit 9 switches these correction amounts according to the input of the correction amounts for the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section received by the GUI 10. When the GUI 10 receives an input regarding the detailed input mode as the input mode, the GUI 10 receives an input regarding the ranges of the first section, the second section, and the third section. The control unit 9 switches the first section, the second section, and the third section according to the input regarding the ranges of the first section, the second section, and the third section received by the GUI 10.

[0071] FIG. 9(a) and FIG. 9(b) are diagrams showing examples of data tables regarding the correction amounts for aberration correction for the first section, aberration correction for the second section, and aberration correction for the third section. FIG. 9(a) is a data table used when the inspection content is an FC inspection. FIG. 9(b) is a data table used when the processing condition is an SDBG condition. "-" means that observation is not performed or the correction amount of aberration correction is not particularly limited (any correction amount). "0 mm correction", "0.1 mm correction", "0.2 mm correction", "0.4 mm correction", and "0.8 mm correction" in the figure represent the correction amounts of aberration correction, and the correction amounts increase in this order. "0 mm correction", "0.1 mm correction", "0.2 mm correction", "0.4 mm correction", and "0.8 mm correction" can be realized by appropriately rotating the correction rings 47x, 47y, 47z in the first aberration correction unit 47A, the second aberration correction unit 47B, and the third aberration correction unit 47C. For example, "0.8 mm correction" means a correction amount set so that the spherical aberration is the smallest at a depth position of 0.8 mm inside the object 20. The parentheses in the figure mean that correction may be performed with the correction amount inside the parentheses. These explanations are the same in the following.

[0072] When the control unit 9 receives an input to set the inspection content as an FC inspection in the GUI 10, for example, based on the input regarding the thickness of the object 20 received in the GUI 10, the control unit 9 may switch the correction amounts of the aberration corrections for the first to third sections using the data table shown in FIG. 9(a). Similarly, when the control unit 9 receives an input to set the processing condition as an SDBG condition in the GUI 10, for example, based on the input regarding the thickness of the object 20 received in the GUI 10, the control unit 9 may switch the correction amounts of the aberration corrections for the first to third sections using the data table shown in FIG. 9(b).

[0073] FIG. 10 is a diagram showing an example of the input screen 10a of the GUI 10 when performing an observation for inspecting the object 20. In the example shown in FIG. 10, in the input screen 10a of the GUI 10 by the user, processing is selected as "not yet", and it is input that it is before laser processing. Also, in the input screen 10a of the GUI 10 by the user, the inspection content is "FC inspection", the input mode is "simple input mode", and the thickness of the object 20 is selected and input as "400 μm".

[0074] As a result of the input by the GUI 10, the control unit 9 determines laser processing conditions based on the input using, for example, a preset data table, and displays the determined laser processing conditions on the input screen 10a as "laser processing conditions (draft)". For example, the control unit 9 determines a recipe for the laser processing conditions. The recipe includes the number of passes (the number of columns in the thickness direction of the modified region 12 to be formed), the processing Z position (the position in the Z direction of each column of the modified region 12), and the processing energy (the energy of the laser beam L), etc.

[0075] Also, as a result of the input by the GUI 10, the control unit 9 switches the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section based on the input using, for example, a preset data table. For example, the control unit 9 switches to "0 mm correction" as the correction amount of the aberration correction for the first section, "0.2 mm correction" as the correction amount of the aberration correction for the second section, and "0.4 mm correction" as the correction amount of the aberration correction for the third section. Also, the control unit 9 switches the respective correction coefficients at the time of execution of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the switching of the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section using, for example, a preset data table. For example, the control unit 9 switches to "0 mm correction coefficient" as the correction coefficient at the time of execution of the aberration correction for the first section, "0.2 mm correction coefficient" as the correction coefficient at the time of execution of the aberration correction for the second section, and "0.4 mm correction coefficient" as the correction coefficient at the time of execution of the aberration correction for the third section. Then, the control unit 9 displays the switched correction amounts and correction coefficients on the input screen 10a.

[0076] Also, as a result of the input by the GUI 10, the control unit 9 switches the ranges of the first section, the second section, and the third section based on the input, for example, using a preset data table, and causes the input screen 10a to display the switched first section, second section, and third section. Also, as a result of the input by the GUI 10, the control unit 9 switches the observation order when observing the first section, the second section, and the third section based on the input, for example, using a preset data table, and causes the input screen 10a to display the switched observation order.

[0077] Also, as a result of the input by the GUI 10, the control unit 9 switches the inspection items (judgment items) for aberration correction for the first section, aberration correction for the second section, and aberration correction for the third section based on the input, for example, using a preset data table, and causes the input screen 10a to display the switched inspection items. In the figure, "HC / ST" means the presence or absence of the crack 14 exposed on the light incident surface of the object 20, and "BHC / ST" means the presence or absence of the crack 14 exposed on the opposite surface of the light incident surface of the object 20. In the example shown in FIG. 10, since it is in the simple input mode, the laser processing conditions, the correction amounts for aberration correction for the first to third sections, the ranges of the first to third sections, the observation order, and the inspection items are displayed on the input screen 10a, but the user cannot change or input them.

[0078] FIG. 11 is a diagram showing another example of the input screen 10a of the GUI 10 when performing observation for inspecting the object 20. In the example shown in FIG. 11, on the input screen 10a of the GUI 10 by the user, processing is selected as "completed", and it is input that it is after laser processing. Also, on the input screen 10a of the GUI 10 by the user, the inspection content is "BHC inspection", the input mode is "detailed input mode", and the thickness of the object 20 is selected and input as "775 μm".

[0079] As a result of the input by the GUI 10, the control unit 9 determines laser processing conditions based on the input using, for example, a preset data table, and causes the input screen 10a to display the determined laser processing conditions as "laser processing conditions (completed)". Further, as a result of the input by the GUI 10, the control unit 9 switches the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section based on the input using, for example, a preset data table. For example, the control unit 9 switches the correction amount of the aberration correction for the first section to "arbitrary correction amount", the correction amount of the aberration correction for the second section to "arbitrary correction amount", and the correction amount of the aberration correction for the third section to "0.8 mm correction". Further, in response to the switching of the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section, the control unit 9 switches the respective correction coefficients at the time of execution of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section using, for example, a preset data table. For example, the control unit 9 switches the correction coefficient at the time of execution of the aberration correction for the third section to "0.8 mm correction coefficient". Then, the control unit 9 causes the input screen 10a to display the switched correction amounts and correction coefficients.

[0080] Further, as a result of the input by the GUI 10, the control unit 9 switches the ranges of the first section, the second section, and the third section based on the input using, for example, a preset data table, and causes the input screen 10a to display the switched first section, second section, and third section. Further, as a result of the input by the GUI 10, the control unit 9 switches the observation order when observing the first section, the second section, and the third section based on the input using, for example, a preset data table, and causes the input screen 10a to display the switched observation order.

[0081] Also, as a result of the input by the GUI 10, the control unit 9 switches, for example, inspection items for aberration correction for the first section, aberration correction for the second section, and aberration correction for the third section based on the input using a preset data table, and causes the input screen 10a to display the switched inspection items. In the example shown in FIG. 11, since it is the detailed input mode, the user can change or input the laser processing conditions, the correction amounts for aberration correction for the first to third sections, the ranges of the first to third sections, the observation order, and the inspection items on the input screen 10a.

[0082] FIG. 12 is a diagram showing an example of the input screen 10a of the GUI 10 when observing the object 20 for formulating processing conditions (so-called condition setting). In the example shown in FIG. 12, on the input screen 10a of the GUI 10 by the user, processing is selected as "not yet", and it is input that it is before laser processing. Also, on the input screen 10a of the GUI 10 by the user, the processing conditions are "SDBG conditions", the input mode is "simple input mode", and the thickness of the object 20 is selected and input as "775 μm".

[0083] As a result of the input by the GUI 10, the control unit 9 determines the laser processing conditions based on the input using a preset data table, for example, and causes the input screen 10a to display the determined laser processing conditions as "Laser processing conditions (draft)". Also, as a result of the input by the GUI 10, the control unit 9 switches the required quality based on the input using a preset data table, for example, and causes the input screen 10a to display the switched required quality. Examples of the required quality include that the magnitude of the end face unevenness is within 10 μm, the BHC straightness is within 6 μm, and the level of particle suppression is at a predetermined level (or is not a concern), etc. The BHC straightness corresponds to the meandering width when the crack 14 exposed on the opposite surface of the light transmission incident surface in the object 20 meanders.

[0084] Also, as a result of the input by the GUI 10, the control unit 9 switches the correction amounts for aberration correction for the first section, aberration correction for the second section, and aberration correction for the third section based on the input, using, for example, a preset data table. For example, the control unit 9 switches the correction amount for aberration correction for the first section to "arbitrary correction amount", the correction amount for aberration correction for the second section to "arbitrary correction amount", and the correction amount for aberration correction for the third section to "0.8 mm correction". Further, the control unit 9 switches the respective correction coefficients at the time of execution of aberration correction for the first section, aberration correction for the second section, and aberration correction for the third section according to the switching of the correction amounts for aberration correction for the first section, aberration correction for the second section, and aberration correction for the third section, using, for example, a preset data table. For example, the control unit 9 switches the correction coefficient at the time of execution of aberration correction for the third section to "0.8 mm correction coefficient". Then, the control unit 9 causes the input screen 10a to display the switched correction amounts and correction coefficients.

[0085] Also, as a result of the input by the GUI 10, the control unit 9 switches the ranges of the first section, the second section, and the third section based on the input, using, for example, a preset data table, and causes the input screen 10a to display the switched first section, second section, and third section. Also, as a result of the input by the GUI 10, the control unit 9 switches the observation order when observing the first section, the second section, and the third section based on the input, using, for example, a preset data table, and causes the input screen 10a to display the switched observation order.

[0086] Also, as a result of the input by the GUI 10, the control unit 9 switches the inspection items for aberration correction for the first section, aberration correction for the second section, and aberration correction for the third section based on the input, using, for example, a preset data table, and causes the input screen 10a to display the switched inspection items. Note that in the example shown in FIG. 12, since it is in the simple input mode, the laser processing conditions, required quality, correction amounts for aberration correction for the first to third sections, ranges of the first to third sections, observation order, and inspection items are displayed on the input screen 10a, but the user cannot change or input them.

[0087] FIG. 13 is a diagram showing another example of the input screen 10a of the GUI 10 when observing the object 20 for formulating processing conditions. In the example shown in FIG. 13, in the input screen 10a of the GUI 10 by the user, processing is selected as "completed", and it is input that it is after laser processing. Also, in the input screen 10a of the GUI 10 by the user, the processing conditions are "MEMS conditions", the input mode is "detailed input mode", and the thickness of the object 20 is selected and input as "400 μm".

[0088] As a result of the input by the GUI 10, the control unit 9 determines laser processing conditions based on the input using, for example, a preset data table, and causes the input screen 10a to display the determined laser processing conditions as "laser processing conditions (completed)". Also, as a result of the input by the GUI 10, the control unit 9 switches the required quality based on the input using, for example, a preset data table, and causes the input screen 10a to display the switched required quality.

[0089] Also, as a result of the input by the GUI 10, the control unit 9 switches the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section based on the input using, for example, a preset data table. For example, the control unit 9 switches to "0 mm correction" as the correction amount of the aberration correction for the first section, "0.2 mm correction" as the correction amount of the aberration correction for the second section, and "0.4 mm correction" as the correction amount of the aberration correction for the third section. Also, the control unit 9 switches the respective correction coefficients at the time of execution of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section using, for example, a preset data table according to the switching of the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section. For example, the control unit 9 switches to "0 mm correction coefficient" as the correction coefficient at the time of execution of the aberration correction for the first section, "0.2 mm correction coefficient" as the correction coefficient at the time of execution of the aberration correction for the second section, and "0.4 mm correction coefficient" as the correction coefficient at the time of execution of the aberration correction for the third section. Then, the control unit 9 causes the input screen 10a to display the switched correction amounts and correction coefficients.

[0090] Also, as a result of the input by the GUI 10, the control unit 9 switches, for example, the ranges of the first section, the second section, and the third section based on the input using a preset data table, and causes the input screen 10a to display the switched first section, second section, and third section. Also, as a result of the input by the GUI 10, the control unit 9 switches, for example, the observation order when observing the first section, the second section, and the third section based on the input using a preset data table, and causes the input screen 10a to display the switched observation order.

[0091] Also, as a result of the input by the GUI 10, the control unit 9 switches, for example, the inspection items for aberration correction for the first section, aberration correction for the second section, and aberration correction for the third section based on the input using a preset data table, and causes the input screen 10a to display the switched inspection items. In the example shown in FIG. 13, since it is the detailed input mode, the user can change or input the laser processing conditions, required quality, correction amounts for aberration correction for the first to third sections, ranges of the first to third sections, observation order, and inspection items on the input screen 10a. For example, when the user changes the required quality, the inspection items change accordingly, and the correction amounts for aberration correction for the first to third sections also change accordingly.

[0092] Next, the processing when performing the observation for the inspection of the object 20 will be described with reference to the flowchart of FIG. 14 and the schematic cross-sectional view of FIG. 15. In FIG. 15, for convenience of explanation, the cross-section of the object 20 in the case of rear surface reflection observation is shown as a virtual cross-section, and the range of the virtual cross-section is included in the third section (the same applies in FIGS. 19 and 20).

[0093] Assume that an input as shown in FIG. 10, for example, is made by the user on the input screen 10a of the GUI 10. The correction ring 47x of the first aberration correction unit 47A is appropriately rotated, and the first correction amount is set to "0 mm correction". The correction ring 47y of the second aberration correction unit 47B is appropriately rotated, and the second correction amount of the second aberration correction unit 47B is set to "0.2 mm correction". The correction ring 47z of the third aberration correction unit 47C is appropriately rotated, and the third correction amount of the third aberration correction unit 47C is set to "0.4 mm correction". In this case, the control unit 9 executes the following processing.

[0094] First, the revolver 48 is rotated so that the first condenser lens 43A is disposed on the optical axis of the transmitted light I1, and the correction amount of aberration correction by the aberration correction unit 46 is switched to the first correction amount by the first aberration correction unit 47A (step S1). In response to switching the correction amount to the first correction amount, the correction coefficient is switched to the correction coefficient corresponding to the first correction amount (step S2). Subsequently, height setting is performed (step S3). In step S3, for example, the control unit 9 controls the operation of the second vertical movement mechanism 7B, and the observation unit 4 is moved along the Z direction so that the condensing position of the transmitted light I1 is located on the back surface 21b which is the transmitted light incident surface, and the position at that time is set as the reference position.

[0095] Subsequently, the observation unit 4 performs internal observation of the first section of the object 20 and acquires a plurality of internal images (step S4). In step S4, for example, by the second vertical movement mechanism 7B, the observation unit 4 is moved along the Z direction with reference to the reference position at the time of height setting in step S3, the condensing position of the transmitted light I1 is aligned with a plurality of positions in the first section of the object 20 to image the object 20, and a plurality of internal images are acquired. For each of the plurality of internal images, depth position information obtained by multiplying the movement amount of the observation unit 4 in the Z direction by the correction coefficient is associated therewith, and this is acquired as imaging data. The internal observation of the first section here is direct observation.

[0096] Subsequently, the revolver 48 is rotated so that the second light collecting lens 43B is disposed on the optical axis of the transmitted light I1, and the correction amount of aberration correction by the aberration correction unit 46 is switched to the second correction amount by the second aberration correction unit 47B (step S5). In response to switching the correction amount to the second correction amount, the correction coefficient is switched to the correction coefficient corresponding to the second correction amount (step S6). Subsequently, height setting is performed in the same manner as in step S3 (step S7).

[0097] Subsequently, the observation unit 4 performs internal observation of the second section of the object 20 and acquires a plurality of internal images (step S8). In step S4, for example, the observation unit 4 is moved along the Z direction with reference to the reference position at the time of height setting in step S8 by the second vertical movement mechanism 7B, and the object 20 is imaged by aligning the light collecting position of the transmitted light I1 at a plurality of positions in the second section of the object 20, and a plurality of internal images are acquired. For each of the plurality of internal images, depth position information obtained by multiplying the movement amount of the observation unit 4 in the Z direction by the correction coefficient is associated therewith, and this is acquired as imaging data. The internal observation of the second section here is direct observation.

[0098] Subsequently, the revolver 48 is rotated so that the third light collecting lens 43C is disposed on the optical axis of the transmitted light I1, and the correction amount of aberration correction by the aberration correction unit 46 is switched to the third correction amount by the third aberration correction unit 47C (step S9). In response to switching the correction amount to the third correction amount, the correction coefficient is switched to the correction coefficient corresponding to the third correction amount (step S10). Subsequently, height setting is performed (step S11). In step S11, for example, the control unit 9 controls the operation of the second vertical movement mechanism 7B, and the observation unit 4 is moved along the Z direction so that the light collecting position of the transmitted light I1 is located on the back surface 21b, and the position at that time is set as the reference position. Also in step S11, the control unit 9 controls the operation of the second vertical movement mechanism 7B, and the observation unit 4 is moved along the Z direction so that the light collecting position of the transmitted light I1 is located on the front surface 21a, and the position at that time is set as another reference position.

[0099] Subsequently, the observation unit 4 performs an internal observation of the third section of the object 20 to acquire a plurality of internal images (step S12). In step S12, for example, the observation unit 4 is moved along the Z direction with reference to the reference position at the height setting in step S11 by the second vertical movement mechanism 7B, and the object 20 is imaged by aligning the condensing position of the transmitted light I1 at a plurality of positions in the third section of the object 20, thereby acquiring a plurality of internal images. For each of the plurality of internal images, depth position information obtained by multiplying the movement amount of the observation unit 4 in the Z direction by a correction coefficient is associated therewith, and this is acquired as imaging data. The internal observation of the second section here is direct observation and back surface reflection observation.

[0100] Based on the results of the above observations, the internal state of the first section is determined by the above-described AI determination based on the imaging data acquired in step S4, and the presence or absence of HC and the state of the indentation are inspected from the determination result. Based on the imaging data acquired in step S8, the internal state of the second section is determined by the above-described AI determination, and the state of the indentation is inspected from the determination result. Based on the imaging data acquired in step S12, the internal state of the third section is determined by the above-described AI determination, and the presence or absence of BHC and the state of the indentation are inspected from the determination result.

[0101] Next, the processing when performing observations for formulating processing conditions will be described with reference to the flowcharts of FIGS. 16, 17, and 18 and the schematic cross-sectional views of FIGS. 19 and 20.

[0102] Assume that the user makes an input on the input screen 10a of the GUI 10, which is the same as the input shown in FIG. 10, for example. Here, regarding the observation order, assume that "third section", "first section", and "entire section (first to third sections)" are input in this order on the input screen 10a. The correction ring 47x of the first aberration correction unit 47A is appropriately rotated so that the first correction amount is set to "0 mm correction". The correction ring 47y of the second aberration correction unit 47B is appropriately rotated so that the second correction amount of the second aberration correction unit 47B is set to "0.2 mm correction". The correction ring 47z of the third aberration correction unit 47C is appropriately rotated so that the third correction amount of the third aberration correction unit 47C is set to "0.4 mm correction". In this case, the control unit 9 executes the following processing.

[0103] First, as shown in FIG. 19(a), in the third section of the object 20 on the stage 2, based on the set processing conditions, the laser processing head 3 performs the above-described laser processing to form the modified region 12 and the crack 14 (step S21). The control unit 9 controls the stage 2, the first horizontal movement mechanism 8A, and the second horizontal movement mechanism 8B to move the stage 2 to a position where the internal observation of the object 20 by the observation unit 4 is possible (hereinafter also referred to as the "observation system") (step S22).

[0104] Subsequently, the revolver 48 is rotated so that the third condenser lens 43C is disposed on the optical axis of the transmitted light I1, and the correction amount of the aberration correction by the aberration correction unit 46 is switched to the third correction amount by the third aberration correction unit 47C (step S23). In response to switching the correction amount to the third correction amount, the correction coefficient is switched to the correction coefficient corresponding to the third correction amount (step S24).

[0105] Subsequently, a height setting is performed (step S25). In step S25, for example, the control unit 9 controls the operation of the second vertical movement mechanism 7B to move the observation unit 4 along the Z direction so that the condensing position of the transmitted light I1 is located on the back surface 21b, and sets the position at that time as the reference position. Also in step S25, the control unit 9 controls the operation of the second vertical movement mechanism 7B to move the observation unit 4 along the Z direction so that the condensing position of the transmitted light I1 is located on the front surface 21a, and sets the position at that time as another reference position.

[0106] Subsequently, the observation unit 4 performs an internal observation of the third section of the object 20 and acquires a plurality of internal images (step S26). In step S26, for example, by the second vertical movement mechanism 7B, the observation unit 4 is moved along the Z direction with reference to the reference position at the time of height setting in step S25, and the object 20 is imaged by aligning the condensing position of the transmitted light I1 with a plurality of positions in the third section of the object 20, thereby acquiring a plurality of internal images. For each of the plurality of internal images, depth position information obtained by multiplying the moving amount of the observation unit 4 in the Z direction by a correction coefficient is associated therewith, and this is acquired as imaging data. The internal observation of the third section here is direct observation and back surface reflection observation.

[0107] Subsequently, the control unit 9 determines the internal state of the third section based on the imaging data acquired in step S26 (step S27). For example, in step S27, by the above-described AI determination, an internal image in which the images of the inspection targets (the reformed region 12 and the crack 14) in the third section are relatively clear is determined, and the depth position of the inspection target is calculated by multiplying the movement amount of the observation unit 4 at that time by a correction coefficient. Based on the internal image and the depth position of the inspection target in the third section, it is determined whether the required quality (refer to FIG. 10) according to the input from the user by the GUI 10 is satisfied. If the required quality is not satisfied, it is determined that the internal state of the third section is not normal (NO in step S28), the set processing conditions are changed, and the process returns to step S21. On the other hand, if the required quality is satisfied, it is determined that the internal state of the third section is normal (YES in step S28), and the control unit 9 controls the stage 2, the first horizontal movement mechanism 8A, and the second horizontal movement mechanism 8B to move the stage 2 to a position where laser processing of the object 20 by the laser processing head 3 is possible (hereinafter, also referred to as the "laser processing system") (step S29).

[0108] Subsequently, as shown in FIG. 19(b), in the first section of the object 20 on the stage 2, based on the set processing conditions, the above-described laser processing is performed by the laser processing head 3 to form the reformed region 12 and the crack 14 (step S30). The control unit 9 controls the stage 2, the first horizontal movement mechanism 8A, and the second horizontal movement mechanism 8B to move the stage 2 to the observation system (step S31). The revolver 48 is rotated so that the first condenser lens 43A is disposed on the optical axis of the transmitted light I1, and the correction amount of the aberration correction by the aberration correction unit 46 is switched to the first correction amount by the first aberration correction unit 47A (step S32). In response to switching the correction amount to the first correction amount, the correction coefficient is switched to the correction coefficient corresponding to the first correction amount (step S33).

[0109] Subsequently, a height setting is performed (step S34). For example, in step S34, the control unit 9 controls the operation of the second vertical movement mechanism 7B to move the observation unit 4 along the Z direction so that the condensing position of the transmitted light I1 is located on the back surface 21b, and sets the position at that time as the reference position. Subsequently, the observation unit 4 performs an internal observation of the first section of the object 20 and acquires a plurality of internal images (step S35). For example, in step S35, the second vertical movement mechanism 7B moves the observation unit 4 along the Z direction with reference to the reference position at the time of height setting in step S34, aligns the condensing position of the transmitted light I1 with a plurality of positions in the first section of the object 20 to image the object 20, and acquires a plurality of internal images. For each of the plurality of internal images, depth position information obtained by multiplying the movement amount of the observation unit 4 in the Z direction by a correction coefficient is associated therewith, and this is acquired as imaging data. The internal observation of the first section here is a direct observation.

[0110] Subsequently, the control unit 9 determines the internal state of the first section based on the imaging data acquired in step S35 (step S36). For example, in step S36, by the above-described AI determination, an internal image in which the image of the inspection target in the first section is relatively clear is determined, and the depth position of the inspection target is calculated by multiplying the movement amount of the observation unit 4 at that time by a correction coefficient. Based on the internal image and the depth position of the inspection target in the first section, it is determined whether or not the required quality (see FIG. 10) according to the input from the user by the GUI 10 is satisfied. If the required quality is not satisfied, it is determined that the internal state of the first section is not normal (NO in step S37), the set processing conditions are changed, and the process returns to step S29. On the other hand, if the required quality is satisfied, it is determined that the internal state of the first section is normal (YES in step S37), and the control unit 9 controls the stage 2, the first horizontal movement mechanism 8A, and the second horizontal movement mechanism 8B to move the stage 2 to the laser processing system (step S38).

[0111] Subsequently, as shown in FIG. 20, in all the sections (first to third sections) of the object 20 on the stage 2, based on the set processing conditions, the above-described laser processing is performed by the laser processing head 3 to form the modified region 12 and the crack 14 (step S39). The control unit 9 controls the stage 2, the first horizontal movement mechanism 8A, and the second horizontal movement mechanism 8B to move the stage 2 to the observation system (step S40). The revolver 48 is rotated so that the first condenser lens 43A is disposed on the optical axis of the transmitted light I1, and the correction amount of the aberration correction by the aberration correction unit 46 is switched to the first correction amount by the first aberration correction unit 47A (step S41). In response to switching the correction amount to the first correction amount, the correction coefficient is switched to the correction coefficient corresponding to the first correction amount (step S42). Height setting is performed in the same manner as in step S34 (step S43). The first section of the object 20 is internally observed by the observation unit 4 in the same manner as in step S35, and a plurality of internal images are acquired (step S44).

[0112] Subsequently, the revolver 48 is rotated so that the second condenser lens 43B is disposed on the optical axis of the transmitted light I1, and the correction amount of the aberration correction by the aberration correction unit 46 is switched to the second correction amount by the second aberration correction unit 47B (step S45). In response to switching the correction amount to the second correction amount, the correction coefficient is switched to the correction coefficient corresponding to the first correction amount (step S46). Height setting is performed in the same manner as in step S34 (step S47). The second section of the object 20 is internally observed by the observation unit 4, and a plurality of internal images are acquired (step S48). For example, in step S48, the observation unit 4 is moved along the Z direction with reference to the reference position at the time of height setting in step S47 by the second vertical movement mechanism 7B, and the object 20 is imaged by aligning the condensing position of the transmitted light I1 at a plurality of positions in the second section of the object 20, and a plurality of internal images are acquired. Depth position information obtained by multiplying the movement amount of the observation unit 4 in the Z direction by the correction coefficient is associated with each of the plurality of internal images, and this is acquired as imaging data. The internal observation of the second section here is direct observation.

[0113] Subsequently, the revolver 48 is rotated so that the third condenser lens 43C is disposed on the optical axis of the transmitted light I1, and the correction amount of aberration correction by the aberration correction unit 46 is switched to the third correction amount by the third aberration correction unit 47C (step S49). In response to switching the correction amount to the third correction amount, the correction coefficient is switched to the correction coefficient corresponding to the third correction amount (step S50). A height setting is performed in the same manner as in step S25 (step S51). Observation of the inside of the third section of the object 20 is performed by the observation unit 4 in the same manner as in step S26, and a plurality of internal images are acquired (step S52).

[0114] Then, based on the imaging data acquired in steps S44, S48, and S52, the control unit 9 determines the internal state of the entire section (step S53). For example, in step S53, by the above-described AI determination, an internal image in which the images of the inspection targets (the reformed region 12 and the crack 14) of the entire section are relatively clear is determined, and the depth position of the inspection target is calculated by multiplying the movement amount of the observation unit 4 at that time by the correction coefficient. Based on the internal image and the depth position of the inspection target of the entire section, it is determined whether or not the required quality (see FIG. 10) according to the input from the user by the GUI 10 is satisfied. If the required quality is not satisfied, it is determined that the internal state of the entire section is not normal (NO in step S54), the set processing conditions are changed, and the process returns to step S39. On the other hand, if the required quality is satisfied, it is determined that the internal state of the entire section is normal (YES in step S54), and the process ends.

[0115] As described above, in the observation apparatus 100, the section to be observed in the object 20 is divided into three first to third sections with high importance (that is, the transmitted light incident surface side, the inside, and the opposite side of the transmitted light incident surface of the object 20). When observing these first to third sections, aberration correction can be performed with a correction amount switched according to the user's input for each of them. As a result, the correction amount can be switched so as to be optimized according to the user's input, and the switching frequency can be suppressed and a high tact can be maintained as compared with the case where the correction amount is optimized each time of observation. That is, it is possible to achieve both a high tact and an accurate observation of the object 20.

[0116] In the observation device 100, the aberration correction unit 46 is configured to be able to switch at least the correction amount of aberration correction between a first correction amount, a second correction amount, and a third correction amount. The control unit 9 switches the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section among the first correction amount, the second correction amount, and the third correction amount according to the input received by the GUI 10. In this case, it is possible to easily realize the switching of the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section.

[0117] In the observation device 100, the transmitted light condenser lens 43 includes a first condenser lens 43A, a second condenser lens 43B, and a third condenser lens 43C. The aberration correction unit 46 includes a first aberration correction unit 47A provided in the first condenser lens 43A, a second aberration correction unit 47B provided in the second condenser lens 43B, a third aberration correction unit 47C provided in the third condenser lens 43C, and a revolver 48. In this case, by switching the transmitted light condenser lens 43 on the optical axis of the transmitted light I1 by the revolver 48 between the first to third condenser lenses 43A to 43C, it is possible to switch the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section among the first to third correction amounts.

[0118] In the observation device 100, the first correction amount is smaller than the second correction amount, and the second correction amount is smaller than the third correction amount. By using the first to third correction amounts having such a magnitude relationship, it is possible to optimize the correction amount.

[0119] In the observation device 100, the aberration correction for the first section may be an aberration correction for inspecting the presence or absence of the crack 14 exposed on the transmission light incident surface of the object 20. The aberration correction for the second section may be an aberration correction for inspecting the modified region 12 formed inside the object 20. The aberration correction for the third section may be an aberration correction for inspecting the presence or absence of the crack 14 exposed on the surface 21a which is the opposite surface of the transmission light incident surface in the object 20. In this case, it becomes possible to accurately inspect the presence or absence of HC of the object 20, the modified region 12 formed inside the object 20, and the presence or absence of BHC of the object 20.

[0120] Incidentally, when the observation unit 4 is moved by the movement amount Fz along the Z direction in order to adjust the position of the condensing point of the transmitted light I1 inside the object 20, the movement amount Fz may vary. As a cause thereof, the observation position shift due to the defocusing of the transmitted light condensing lens 43 can be considered. Further, as a cause of the variation in the movement amount Fz, the shift before and after the operation of the so-called correction ring lens can be considered. That is, when the transmitted light condensing lens 43 has the correction rings 47x, 47y, 47z, the operation amount of the correction rings 47x, 47y, 47z with respect to the change amount of the correction amount of the aberration correction may not be constant. As a result, the observation position may shift before and after the operation of the correction rings 47x, 47y, 47z. Further, the mechanical error of the transmitted light condensing lens 43 of the observation unit 4 or its detachment, etc. also contribute to the variation in the movement amount Fz. When the depth position of the detection target is calculated by multiplying the varying movement amount Fz by a constant correction coefficient, the calculation result also varies. Therefore, in the observation device 100, in order to acquire the accurate depth position of the detection target, the correction coefficient is switched according to the switching of the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section in order to use an appropriate correction coefficient. Thereby, it becomes possible to accurately acquire the depth position of the detection target in the object 20.

[0121] In the observation device 100, the GUI 10 receives an input regarding the inspection content to be performed on the object 20. The control unit 9 switches the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the input regarding the inspection content received by the GUI 10. In this case, it becomes possible to optimize the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the input regarding the inspection content from the user.

[0122] In the observation device 100, the GUI 10 receives an input regarding the type of processing conditions for laser processing to be performed on the object 20. The control unit 9 switches the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the input regarding the type of processing conditions received by the GUI 10. In this case, it becomes possible to optimize the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the input regarding the type of processing conditions from the user.

[0123] In the observation device 100, the GUI 10 receives an input regarding the thickness of the object 20. The control unit 9 switches the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the input regarding the thickness of the object 20 received by the GUI 10. In this case, it becomes possible to optimize the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the input regarding the thickness of the object 20 from the user.

[0124] In the observation device 100, the GUI 10 receives an input regarding whether the input mode is the simple input mode or the detailed input mode, and when receiving an input regarding the detailed input mode as the input mode, receives an input of the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section. In this case, the user can input the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section by inputting the detailed input mode as the input mode.

[0125] FIG. 21 is a table showing the relationship between the correction amount of aberration correction and the determination of multiple types of inspection contents. In the figure, "〇" indicates that it can be accurately determined, "△" indicates that it can be determined, and "×" indicates that it cannot be determined. HC detection means the detection of the crack 14 exposed on the transmitted-light incident surface of the object 20. HC meandering means the meandering of the crack 14 exposed on the transmitted-light incident surface of the object 20. Upper crack detection means the detection of the end of the crack 14 closest to the transmitted-light incident surface inside the object 20. Dent (direct observation) means the detection of the dent (modified region 12) by direct observation. Lower crack detection means the detection of the end of the crack 14 on the opposite side of the transmitted-light incident surface inside the object 20. Dent (rear-surface reflection observation) means the detection of the dent by rear-surface reflection observation.

[0126] In the example shown in the figure, the thickness of the object 20 is set to 400 μm. Here, the range from the transmitted-light incident surface to 0.2 mm in the thickness direction is defined as the first section, the range from the opposite surface of the transmitted-light incident surface to 0.2 mm in the thickness direction is defined as the third section, and the range other than the first and second sections inside the object 20 is defined as the second section. HC detection, HC meandering, and upper crack detection are inspection contents that can be determined by observing the first section. Dent (direct observation), black streak, and end-face unevenness are inspection contents that can be determined by observing the second section. Lower crack detection and bullet mark (rear-surface reflection observation) are inspection contents that can be determined by observing the third section. As shown in FIG. 21, it can be seen that by dividing into the first to third sections instead of fixing the correction amount of aberration correction, accurate determination can be made for many inspection contents.

[0127] In addition, in the present embodiment, the second-section side of the first section and the first-section side of the second section may overlap each other in the first overlapping section, and the third-section side of the second section and the second-section side of the third section may overlap each other in the second overlapping section. In this case, in the first overlapping section, two observations with different correction amounts for aberration correction (observation for performing aberration correction for the first section and observation for performing aberration correction for the second section) are performed, and in the second overlapping section as well, two observations with different correction amounts for aberration correction (observation for performing aberration correction for the second section and observation for performing aberration correction for the third section) may be performed. That is, in this case, the control unit 9 performs a process of imaging the first overlapping section by the light detection unit 44 while performing aberration correction for the first section by the aberration correction unit 46, an imaging process of imaging the first overlapping section by the light detection unit 44 while performing aberration correction for the second section by the aberration correction unit 46, a process of imaging the second overlapping section by the light detection unit 44 while performing aberration correction for the second section by the aberration correction unit 46, and an imaging process of imaging the second overlapping section by the light detection unit 44 while performing aberration correction for the third section by the aberration correction unit 46. Thereby, more accurate observation becomes possible in the first and second overlapping sections of the object 20. Also, depending on the input content such as the thickness of the object 20, accurate observation (determination) may be possible with only aberration correction for the first and third sections.

[0128] One aspect of the present invention is not limited to the above embodiment and can be arbitrarily modified.

[0129] FIG. 22 is a perspective view showing the observation unit 104 according to the first modification. The observation unit 104 shown in FIG. 22 is different from the observation unit 4 (see FIG. 5) in that its light detection unit 44 is also used as the light detection unit of the alignment camera 5. The observation unit 104 has a revolver 148, and at four positions equally spaced in the circumferential direction at the rotating part 148b of the revolver 148, a first condenser lens 43A, a second condenser lens 43B, a third condenser lens 43C, and an alignment lens 5D are attached. The revolver 148 arranges any one of the first condenser lens 43A, the second condenser lens 43B, the third condenser lens 43C, and the alignment lens 5D on the optical axis of the transmitted light I1, and is movable (rotates with respect to the fixed part 148a around the rotation axis) so that any one of these arranged on the optical axis of the transmitted light I1 is switched.

[0130] The first condenser lens 43A, the second condenser lens 43B, and the third condenser lens 43C are so-called correction ring lenses with a magnification of, for example, 50 times, and are arranged on the optical axis of the transmitted light I1 by driving the revolver 148 when the light detection unit 44 is used for internal observation. The alignment lens 5D is a lens with a magnification of, for example, 10 times (or 20 times), and is arranged on the optical axis of the transmitted light I1 by driving the revolver 148 when the light detection unit 44 is used for high-magnification alignment. In such a modification, the light detection unit 44 is shared for internal observation and high-magnification alignment, and there is an effect that the cost can be suppressed.

[0131] FIG. 23 is a perspective view showing the observation unit 204 according to the second modification. The observation unit 204 shown in FIG. 23, similar to the above-described observation unit 104 (see FIG. 22), has its light detection unit 44 used also as the light detection unit of the alignment camera 5. The observation unit 204 has a linear stage 248. At four equally spaced positions in the X direction or the Y direction on the linear stage 248, a first condenser lens 43A, a second condenser lens 43B, a third condenser lens 43C, and an alignment lens 5D are attached. The linear stage 248 arranges any one of the first condenser lens 43A, the second condenser lens 43B, the third condenser lens 43C, and the alignment lens 5D on the optical axis of the transmitted light I1, and moves linearly (in the X direction or the Y direction) so that any one of them arranged on the optical axis of the transmitted light I1 is switched.

[0132] When the light detection unit 44 is used for internal observation, the first condenser lens 43A, the second condenser lens 43B, and the third condenser lens 43C are arranged on the optical axis of the transmitted light I1 by driving the linear stage 248. When the light detection unit 44 is used for high-magnification alignment, the alignment lens 5D is arranged on the optical axis of the transmitted light I1 by driving the linear stage 248. Even in such a modification, the light detection unit 44 is made common for internal observation and high-magnification alignment, and there is an effect that the cost can be suppressed.

[0133] FIG. 24 is a schematic view showing the configuration of the observation unit 304 according to the third modification. The observation unit 304 shown in FIG. 24, similar to the above-described observation unit 104 (see FIG. 22), has its light detection unit 44 used also as the light detection unit of the alignment camera 5. Further, the optical path of the observation unit 304 is switched by shutters 301A and 301B. The shutters 301A and 301B are, for example, electric mechanical shutters, and are connected to the control unit 9 (see FIG. 1) and their opening and closing are controlled.

[0134] In the observation unit 304, when performing internal observation, the shutter 301A is closed and the shutter 301B is opened by the control unit 9. In this case, the transmitted light I1 passes through the reticle RT, is reflected by the half mirror 302, passes through the transmitted light condenser lens 43, and is irradiated onto the object 20 (see FIG. 5). The transmitted light I1 reflected by the object 20 passes through the transmitted light condenser lens 43 and the half mirror 302, passes through the shutter 301B, is reflected by the total reflection mirror 303, is reflected by the half mirror 314, and then is received by the light detection unit 44. On the other hand, in the observation unit 304, when performing alignment, the shutter 301B is closed and the shutter 301A is opened by the control unit 9. In this case, the transmitted light I1 is reflected by the half mirror 305, passes through the alignment lens 5D, and is irradiated onto the object 20. The transmitted light I1 reflected by the object 20 passes through the alignment lens 5D and the shutter 301A, passes through the half mirror 314, and then is received by the light detection unit 44.

[0135] The transmitted light condenser lens 43 is, for example, a so-called correction ring lens with a magnification of 50 times. The correction amount of aberration correction of the transmitted light condenser lens 43 is switched by rotating its correction ring by the drive unit 310. Note that the transmitted light condenser lens 43 has first to third condenser lenses 43A to 43C as shown in FIG. 22 or FIG. 23, and any one of them may be arranged on the optical axis of the transmitted light I1 by driving the revolver 148 or the linear stage 248. In the illustrated example, the light source of the transmitted light I1 is separated so that the reticle RT for internal observation does not appear in the alignment image.

[0136] Even in such a modification, the light detection unit 44 can be shared for internal observation and high-magnification alignment, which has the effect of suppressing costs. In addition, in order to use the observation unit for alignment purposes, the accuracy in the X direction, Y direction, and θ direction is important compared to internal observation. Therefore, the optical path for alignment requires a configuration that ensures accuracy in the X direction, Y direction, and θ direction. The observation unit 304 can realize a configuration that ensures accuracy in the X direction, Y direction, and θ direction.

[0137] FIG. 25 is a schematic diagram showing the configuration of the observation unit 404 according to the fourth modification example. The observation unit 404 shown in FIG. 25 is the same as the above-described observation unit 304 (see FIG. 24) in that its light detection unit 44 is also used as the light detection unit of the alignment camera 5. Further, in the observation unit 404, its optical path is switched by the movement of the total reflection mirror 401. The total reflection mirror 401 is connected to the control unit 9 (see FIG. 1), and its movement is controlled.

[0138] In the observation unit 404, when performing internal observation, the total reflection mirror 401 is moved by the control unit 9 and disposed on the optical path of the transmitted light I1. In this case, the transmitted light I1 passes through the reticle RT, is reflected by the half mirror 402, passes through the transmitted light condenser lens 43, and is irradiated onto the object 20 (see FIG. 5). The transmitted light I1 reflected by the object 20 passes through the transmitted light condenser lens 43 and the half mirror 402, is reflected by the total reflection mirror 403, is reflected by the total reflection mirror 401, and then is received by the light detection unit 44. On the other hand, in the observation unit 404, when performing alignment, the total reflection mirror 401 is moved by the control unit 9 to a position away from the optical path of the transmitted light I1. In this case, the transmitted light I1 is reflected by the half mirror 405, passes through the alignment lens 5D, and is irradiated onto the object 20. The transmitted light I1 reflected by the object 20 passes through the alignment lens 5D and the half mirror 405, and then is received by the light detection unit 44.

[0139] Even in such a modification example, the light detection unit 44 can be shared for internal observation and high-magnification alignment, and there is an effect that the cost can be suppressed. Further, in the observation unit 404, a configuration that ensures the accuracy in the X direction, Y direction, and θ direction can be realized.

[0140] In the above-described embodiment, the configuration of the laser processing apparatus 1 is not limited. For example, it may be a laser processing apparatus 101 shown in FIG. 26. The difference between the laser processing apparatus 101 and the laser processing apparatus 1 (see FIG. 1) according to the above-described embodiment is that it includes a first vertical movement mechanism 107A instead of the first vertical movement mechanism 7A (see FIG. 1), and a second vertical movement mechanism 107B instead of the second vertical movement mechanism 7B (see FIG. 1).

[0141] The first vertical movement mechanism 107A is a mechanism that moves the laser processing head 3 along the Z direction together with the alignment cameras 5 and 6. The first vertical movement mechanism 107A has a first vertical axis 171 provided on one side in the X direction of the columnar first base portion 175. The first base portion 175 is fixed to, for example, an installation surface or the like. The first vertical axis 171 extends along the Z direction. An attachment portion 39 of the laser processing head 3 is movably attached to the first vertical axis 171 along the Z direction. Such a first vertical movement mechanism 107A moves the laser processing head 3 in the Z direction along the first vertical axis 171 by the driving force of a driving source (not shown). The first vertical movement mechanism 107A is not particularly limited, and various mechanisms can be used as long as the laser processing head 3 can be moved in the Z direction.

[0142] The second vertical movement mechanism 107B is a mechanism (moving part) that moves the observation unit 4 along the Z direction. The second vertical movement mechanism 107B has a second vertical axis 172 provided on the other side in the X direction in the first base part 175. That is, the first vertical axis 171 and the second vertical axis 172 are both provided in the first base part 175 and are arranged to face each other via the first base part 175. The second vertical axis 172 extends along the Z direction. An attachment part 49 of the observation unit 4 is movably attached to the second vertical axis 172 along the Z direction. Such a second vertical movement mechanism 107B moves the observation unit 4 in the Z direction along the second vertical axis 172 by the driving force of a driving source (not shown). The second vertical movement mechanism 107B is not particularly limited, and various mechanisms can be used as long as the observation unit 4 can be moved in the Z direction. In the laser processing apparatus 101, an apparatus configuration can be realized in which the base part provided with the first vertical axis 171 and the second vertical axis 172 is shared as the first base part 175.

[0143] In the above embodiment, the alignment cameras 5 and 6 may be movable along the Z direction on an axis different from that of the laser processing head 3 and the observation unit 4. In the above embodiment, the second vertical movement mechanisms 7B and 107B that move the entire observation unit 4 in the Z direction are used as the moving part. Instead, an actuator or the like that moves the transmitted light condenser lens 43 in the Z direction may be used as the moving part.

[0144] In the above-described embodiment, the input from the user by the GUI 10 only needs to include at least any one of the above-described inputs. Further, the input from the user by the GUI 10 is not limited to the above-described inputs, and may include inputs related to information on other objects 20 and inputs related to other inspection contents. For example, as information on the object 20 input from the user, information on the material of the object 20 may be included. Also, for example, as inspection contents input from the user, information related to the state inspection of the laser processing apparatus 1, 101, information related to the non-defective product inspection (yield inspection), and information related to the required quality inspection may be included. In the above-described embodiment, observations may be made without rotating the correction rings 47x, 47y, 47z of the first to third condenser lenses 43A, 43B, 43C from the time of setting (that is, keeping them constant). In this case, since the correction coefficient does not shift by rotating the correction rings 47x, 47y, 47z and there is no need to re-derive the correction coefficient, the tact can be increased.

[0145] In the above-described embodiment, as the aberration correction unit 46, a spatial light modulator disposed on the optical path of the transmitted light I1 may be used. In the above-described embodiment, the observation apparatus 100 is applied to the laser processing apparatus 1, but it may be applied to other processing apparatuses. Each configuration in the above-described embodiment and modification example is not limited to the above-described materials and shapes, and various materials and shapes can be applied. Further, each configuration in the above-described embodiment and modification example can be arbitrarily applied to each configuration in other embodiments or modification examples.

Explanation of Reference Numerals

[0146] 1,101…Laser processing apparatus, 2…Stage, 4,104,204,304,404…Observation unit, 5,6…Alignment cameras, 7B,107B…Second vertical movement mechanism (moving part), 8A…First horizontal movement mechanism, 8B…Second horizontal movement mechanism, 9…Control unit, 10…GUI (input unit), 12…Modification area, 14…Crack, 20…Object, 21a…Surface (opposite surface), 21b…Back surface (transmitted light incident surface), 43…Transmitted light condenser lens (condenser lens), 43A…First condenser lens, 43B…Second condenser lens, 43C…Third condenser lens, 44…Light detection unit (imaging unit), 46…Aberration correction unit, 47A…First aberration correction unit, 47B…Second aberration correction unit, 47C…Third aberration correction unit, 48…Revolver, 100…Observation device, I1…Transmitted light.

Claims

1. An apparatus for observing an object using transmitted light that is transmissive to the object, comprising: a condenser lens that condenses the transmitted light toward the object; an imaging unit that receives the transmitted light reflected by the object and images the object; a moving unit that relatively moves the condenser lens with respect to the object; an input unit that receives an input from a user; an aberration correction unit that corrects the aberration of the transmitted light; a control unit that controls at least the aberration correction unit, wherein the aberration correction unit is configured to be able to switch the correction amount of aberration correction, and the control unit switches at least any one of the correction amount of the first-section aberration correction by the aberration correction unit when imaging the first section on the transmitted-light incident surface side of the object by the imaging unit, the correction amount of the second-section aberration correction by the aberration correction unit when imaging the second section inside the object by the imaging unit, and the correction amount of the third-section aberration correction by the aberration correction unit when imaging the third section on the opposite surface side of the transmitted-light incident surface of the object by the imaging unit, according to the input received by the input unit. An observation apparatus.

2. The aberration correction unit is configured to be able to switch the correction amount of aberration correction at least among a first correction amount, a second correction amount, and a third correction amount, and the control unit switches the correction amounts of the first-section aberration correction, the second-section aberration correction, and the third-section aberration correction among the first correction amount, the second correction amount, and the third correction amount according to the input received by the input unit. The observation apparatus according to claim 1.

3. The condenser lens has a first condenser lens, a second condenser lens, and a third condenser lens, and the aberration correction unit a first aberration correction unit provided in the first condenser lens and realizing aberration correction of the first correction amount; a second aberration correction unit provided in the second condenser lens and realizing aberration correction of the second correction amount; a third aberration correction unit provided in the third condenser lens and realizing aberration correction of the third correction amount; a turret to which the first condenser lens, the second condenser lens, and the third condenser lens are attached, and which moves such that any one of the first condenser lens, the second condenser lens, and the third condenser lens is arranged on the optical axis of the transmitted light and any one of the first condenser lens, the second condenser lens, and the third condenser lens arranged on the optical axis of the transmitted light is switched. The observation apparatus according to claim 2.

4. The first correction amount is smaller than the second correction amount, The second correction amount is smaller than the third correction amount. The observation apparatus according to claim 2 or 3.

5. The aberration correction for the first section is an aberration correction for inspecting the presence or absence of cracks exposed on the light transmission incident surface of the object, The aberration correction for the third section is an aberration correction for inspecting the presence or absence of cracks exposed on the opposite surface of the light transmission incident surface of the object. The observation apparatus according to any one of claims 1 to 3.

6. The aberration correction for the second section is an aberration correction for inspecting a modified region formed inside the object. The observation apparatus according to claim 5.

7. The control unit, Based on the moving amount of the condenser lens by the moving unit and the correction coefficient, obtains information regarding the position of the detection target, Switches the correction coefficient according to the switching of the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section. The observation apparatus according to any one of claims 1 to 6.

8. The input unit receives an input regarding the content of the inspection to be performed on the object, The control unit, Switches the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the input regarding the content of the inspection received by the input unit. The observation apparatus according to any one of claims 1 to 7.

9. The input unit receives an input regarding the type of processing conditions for laser processing to be performed on the object, The control unit, Switches the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the input regarding the type of processing conditions received by the input unit. The observation apparatus according to any one of claims 1 to 8.

10. The input unit receives an input regarding the thickness of the object, The control unit switches the correction amounts of the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section according to the input regarding the thickness of the object received by the input unit. The observation apparatus according to any one of claims 1 to 9.

11. The input unit, Receives an input regarding whether the input mode is the simple input mode or the detailed input mode, and When receiving an input related to the detailed input mode as the input mode, the observation device according to any one of claims 1 to 10 receives inputs of correction amounts for the aberration correction for the first section, the aberration correction for the second section, and the aberration correction for the third section.

12. The side of the first section on the second section side and the side of the second section on the first section side overlap each other in a first overlapping section. The side of the second section on the third section side and the side of the third section on the second section side overlap each other in a second overlapping section. The control unit a process of imaging the first overlapping section by the imaging unit while performing the aberration correction for the first section by the aberration correction unit; an imaging process of imaging the first overlapping section by the imaging unit while performing the aberration correction for the second section by the aberration correction unit; a process of imaging the second overlapping section by the imaging unit while performing the aberration correction for the second section by the aberration correction unit; an imaging process of imaging the second overlapping section by the imaging unit while performing the aberration correction for the third section by the aberration correction unit, and executes the observation device according to any one of claims 1 to 11.

Images